regmap: rework ->max_register handling

When regmap consists of single register, 'regmap' subsystem is unable to
understand whether ->max_register is set or not, because in both cases it
is equal to zero. It leads to that the logic based on value of
->max_register doesn't work. For example using of REGCACHE_FLAT fails.

This patch introduces an extra parameter to regmap config, indicating
that zero value in ->max_register is authentic.

Signed-off-by: Jan Dakinevich <jan.dakinevich@salutedevices.com>
Link: https://lore.kernel.org/r/20240126200836.1829995-1-jan.dakinevich@salutedevices.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: fix regmap_noinc_write() description

Change "Write data from" -> "Write data to".

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231121230900.3754785-1-hugo@hugovil.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: prevent noinc writes from clobbering cache

Currently, noinc writes are cached as if they were standard incrementing
writes, overwriting unrelated register values in the cache. Instead, we
want to cache the last value written to the register, as is done in the
accelerated noinc handler (regmap_noinc_readwrite).

Fixes: cdf6b11daa77 ("regmap: Add regmap_noinc_write API")
Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com>
Link: https://lore.kernel.org/r/20231101142926.2722603-2-ben.wolsieffer@hefring.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: fix NULL deref on lookup

Not all regmaps have a name so make sure to check for that to avoid
dereferencing a NULL pointer when dev_get_regmap() is used to lookup a
named regmap.

Fixes: e84861fec32d ("regmap: dev_get_regmap_match(): fix string comparison")
Cc: stable@vger.kernel.org # 5.8
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20231006082104.16707-1-johan+linaro@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Remove dynamic allocation warnings for rbtree and maple

Thanks to Dan and Guenter's very prompt updates of the rbtree and maple
caches to support GPF_ATOMIC allocations and since the update shook out
a bunch of users at least some of whom have been suitably careful about
ensuring that the cache is prepoulated so there are no dynamic
allocations after init let's revert the warnings.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230721-regmap-enable-kmalloc-v1-1-f78287e794d3@kernel.org

regmap: Reject fast_io regmap configurations with RBTREE and MAPLE caches

REGCACHE_RBTREE and REGCACHE_MAPLE dynamically allocate memory for regmap
operations. This is incompatible with spinlock based locking which is used
for fast_io operations. Reject affected configurations.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230720032848.1306349-2-linux@roeck-us.net
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Revert "add 64-bit mode support" and Co.

With unsigned int type we never ever can pass 64-bit value.
Remove never properly worked code.

Note, there are no users in kernel for this size of register
offsets or data.

This reverts commit afcc00b91f1865f6d0bbdb687dd642ce8a3c3c9e.

Also revert other 64-bit code excerpts in the regmap implementation
that had been induced by the false impression made by the above
mentioned change that there is a support of that data size.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230622183613.58762-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Drop initial version of maximum transfer length fixes

When problems were noticed with the register address not being taken
into account when limiting raw transfers with I2C devices we fixed this
in the core. Unfortunately it has subsequently been realised that a lot
of buses were relying on the prior behaviour, partly due to unclear
documentation not making it obvious what was intended in the core. This
is all more involved to fix than is sensible for a fix commit so let's
just drop the original fixes, a separate commit will fix the originally
observed problem in an I2C specific way

Fixes: 3981514180c9 ("regmap: Account for register length when chunking")
Fixes: c8e796895e23 ("regmap: spi-avmm: Fix regmap_bus max_raw_write")
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Xu Yilun <yilun.xu@intel.com>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230712-regmap-max-transfer-v1-1-80e2aed22e83@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Drop early readability check

We have some drivers that have a use case for cached write only
registers, doing read/modify/writes on read only registers in order to
work more easily with bitfields. Go back to trying the cache before we
check if we can read from the device.

Fixes: eab5abdeb79f0 ("regmap: Check for register readability before checking cache during read")
Reported-by: Konrad Dybcio <konradybcio@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230615-regmap-drop-early-readability-v1-1-8135094362de@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Check for register readability before checking cache during read

Ensure that we don't return a spurious cache hit for unreadable registers
(eg, with the flat cache which doesn't understand sparseness) by checking
for readability before we do a cache lookup.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230613-b4-regmap-check-readability-before-cache-v1-1-b144c0b01ed9@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add debugfs file for forcing field writes

`_regmap_update_bits()` checks if the current register value differs
from the new value, and only writes to the register if they differ. When
testing hardware drivers, it might be desirable to always force a
register write, for example when writing to a `regmap_field`. This
enables and simplifies testing and verification of the hardware
interaction. For example, when using a hardware mock/simulation model,
one can then more easily verify that the driver makes the correct
expected register writes during certain events.

Add a bool variable `force_write_field` and a corresponding debugfs
entry to enable this. Since this feature could interfere with driver
operation, guard it with a macro.

Signed-off-by: Waqar Hameed <waqar.hameed@axis.com>
Link: https://lore.kernel.org/r/pnd1qifa7sj.fsf@axis.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add missing cache_only checks

The current behaviour around cache_only is slightly inconsistent,
most paths will only check cache_only if cache_bypass is false,
and will return -EBUSY if a read attempts to go to the hardware
whilst cache_only is true. However, a couple of paths will not check
cache_only at all. The most notable of these being regmap_raw_read
which will check cache_only in the case it processes the transaction
one register at a time, but not in the case it handles them as a
block. In the typical case a device has been put into cache_only
whilst powered down this can cause physical reads to happen whilst the
device is unavailable.

Add a check in regmap_raw_read and move the check in regmap_noinc_read,
adding a check for cache_bypass, such that all paths are covered and
consistent.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230601101036.1499612-2-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Account for register length when chunking

Currently, when regmap_raw_write() splits the data, it uses the
max_raw_write value defined for the bus. For any bus that includes
the target register address in the max_raw_write value, the chunked
transmission will always exceed the maximum transmission length.
To avoid this problem, subtract the length of the register and the
padding from the maximum transmission.

Signed-off-by: Jim Wylder <jwylder@google.com
Link: https://lore.kernel.org/r/20230517152444.3690870-2-jwylder@google.com
Signed-off-by: Mark Brown <broonie@kernel.org

regmap: allow upshifting register addresses before performing operations

Similar to the existing reg_downshift mechanism, that is used to
translate register addresses on busses that have a smaller address
stride, it's also possible to want to upshift register addresses.

Such a case was encountered when network PHYs and PCS that usually sit
on a MDIO bus (16-bits register with a stride of 1) are integrated
directly as memory-mapped devices. Here, the same register layout
defined in 802.3 is used, but the register now have a larger stride.

Introduce a mechanism to also allow upshifting register addresses.
Re-purpose reg_downshift into a more generic, signed reg_shift, whose
sign indicates the direction of the shift. To avoid confusion, also
introduce macros to explicitly indicate if we want to downshift or
upshift.

For bisectability, change any use of reg_downshift to use reg_shift.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Tested-by: Colin Foster <colin.foster@in-advantage.com>
Link: https://lore.kernel.org/r/20230407152604.105467-1-maxime.chevallier@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Support paging for buses with reg_read()/reg_write()

We don't currently support paging for regmaps where the I/O happens through
bus provided reg_read() and reg_write() operatons, we simply ignore the
range since nothing is wired up properly. Wire things up.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230324-regmap-reg-read-write-page-v1-1-1fbc0dac67ae@kernel.org

regmap: add a helper to translate the register address

Register addresses passed to regmap operations can be offset with
regmap.reg_base and downshifted with regmap.reg_downshift.

Add a helper to apply both these operations and return the translated
address, that we can then use to perform the actual register operation
ont the underlying bus.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://lore.kernel.org/r/20230324093644.464704-2-maxime.chevallier@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: apply reg_base and reg_downshift for single register ops

reg_base and reg_downshift currently don't have any effect if used with
a regmap_bus or regmap_config which only offers single register
operations (ie. reg_read, reg_write and optionally reg_update_bits).

Fix that and take them into account also for regmap_bus with only
reg_read and read_write operations by applying reg_base and
reg_downshift in _regmap_bus_reg_write, _regmap_bus_reg_read.

Also apply reg_base and reg_downshift in _regmap_update_bits, but only
in case the operation is carried out with a reg_update_bits call
defined in either regmap_bus or regmap_config.

Fixes: 0074f3f2b1e43d ("regmap: allow a defined reg_base to be added to every address")
Fixes: 86fc59ef818beb ("regmap: add configurable downshift for addresses")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Tested-by: Colin Foster <colin.foster@in-advantage.com>
Link: https://lore.kernel.org/r/Y9clyVS3tQEHlUhA@makrotopia.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add regmap_might_sleep()

With the dawn of MMIO gpio-regmap users, it is desirable to let
gpio-regmap ask the regmap if it might sleep during an access so
it can pass that information to gpiochip. Add a new regmap_might_sleep()
to query the regmap.

Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20221121150843.1562603-1-michael@walle.cc
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: check right noinc bounds in debug print

We were using the wrong bound in the debug prints: this
needs to be the number of elements, not the number of bytes,
since we're indexing into an element-size typed array.

Fixes: c20cc099b30a ("regmap: Support accelerated noinc operations")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220823135700.265019-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: introduce value tracing for regmap bulk operations

Currently, only one-register io operations support tracepoints with
value logging. For the regmap bulk operations developer can view
hw_start/hw_done tracepoints with starting reg number and registers
count to be reading or writing. This patch injects tracepoints with
dumping registers values in the hex format to regmap bulk reading
and writing.

Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Link: https://lore.kernel.org/r/20220816181451.5628-1-ddrokosov@sberdevices.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Support accelerated noinc operations

Several architectures have accelerated operations for MMIO
operations writing to a single register, such as writesb, writesw,
writesl, writesq, readsb, readsw, readsl and readsq but regmap
currently cannot use them because we have no hooks for providing
an accelerated noinc back-end for MMIO.

Solve this by providing reg_[read/write]_noinc callbacks for
the bus abstraction, so that the regmap-mmio bus can use this.

Currently I do not see a need to support this for custom regmaps
so it is only added to the bus.

Callbacks are passed a void * with the array of values and a
count which is the number of items of the byte chunk size for
the specific register width.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220816204832.265837-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Make use of get_unaligned_be24(), put_unaligned_be24()

Since we have a proper endianness converters for BE 24-bit data use
them. While at it, format the code using switch-cases as it's done
for the rest of the endianness handlers.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220726151213.71712-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Wire up regmap_config provided bulk write in missed functions

There are some functions that were missed by commit d77e74561368 ("regmap:
Add bulk read/write callbacks into regmap_config") when support to define
bulk read/write callbacks in regmap_config was introduced.

The regmap_bulk_write() and regmap_noinc_write() functions weren't changed
to use the added map->write instead of the map->bus->write handler.

Also, the regmap_can_raw_write() was not modified to take map->write into
account. So will only return true if a bus with a .write callback is set.

Fixes: d77e74561368 ("regmap: Add bulk read/write callbacks into regmap_config")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20220616073435.1988219-4-javierm@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Make regmap_noinc_read() return -ENOTSUPP if map->read isn't set

Before adding support to define bulk read/write callbacks in regmap_config
by the commit d77e74561368 ("regmap: Add bulk read/write callbacks into
regmap_config"), the regmap_noinc_read() function returned an errno early
a map->bus->read callback wasn't set.

But that commit dropped the check and now a call to _regmap_raw_read() is
attempted even when bulk read operations are not supported. That function
checks for map->read anyways but there's no point to continue if the read
can't succeed.

Also is a fragile assumption to make so is better to make it fail earlier.

Fixes: d77e74561368 ("regmap: Add bulk read/write callbacks into regmap_config")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20220616073435.1988219-3-javierm@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Re-introduce bulk read support check in regmap_bulk_read()

Support for drivers to define bulk read/write callbacks in regmap_config
was introduced by the commit d77e74561368 ("regmap: Add bulk read/write
callbacks into regmap_config"), but this commit wrongly dropped a check
in regmap_bulk_read() to determine whether bulk reads can be done or not.

Before that commit, it was checked if map->bus was set. Now has to check
if a map->read callback has been set.

Fixes: d77e74561368 ("regmap: Add bulk read/write callbacks into regmap_config")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20220616073435.1988219-2-javierm@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Wire up regmap_config provided bulk write in missed functions

There are some functions that were missed by commit d77e74561368 ("regmap:
Add bulk read/write callbacks into regmap_config") when support to define
bulk read/write callbacks in regmap_config was introduced.

The regmap_bulk_write() and regmap_noinc_write() functions weren't changed
to use the added map->write instead of the map->bus->write handler.

Also, the regmap_can_raw_write() was not modified to take map->write into
account. So will only return true if a bus with a .write callback is set.

Fixes: d77e74561368 ("regmap: Add bulk read/write callbacks into regmap_config")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20220616073435.1988219-4-javierm@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Make regmap_noinc_read() return -ENOTSUPP if map->read isn't set

Before adding support to define bulk read/write callbacks in regmap_config
by the commit d77e74561368 ("regmap: Add bulk read/write callbacks into
regmap_config"), the regmap_noinc_read() function returned an errno early
a map->bus->read callback wasn't set.

But that commit dropped the check and now a call to _regmap_raw_read() is
attempted even when bulk read operations are not supported. That function
checks for map->read anyways but there's no point to continue if the read
can't succeed.

Also is a fragile assumption to make so is better to make it fail earlier.

Fixes: d77e74561368 ("regmap: Add bulk read/write callbacks into regmap_config")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20220616073435.1988219-3-javierm@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Re-introduce bulk read support check in regmap_bulk_read()

Support for drivers to define bulk read/write callbacks in regmap_config
was introduced by the commit d77e74561368 ("regmap: Add bulk read/write
callbacks into regmap_config"), but this commit wrongly dropped a check
in regmap_bulk_read() to determine whether bulk reads can be done or not.

Before that commit, it was checked if map->bus was set. Now has to check
if a map->read callback has been set.

Fixes: d77e74561368 ("regmap: Add bulk read/write callbacks into regmap_config")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20220616073435.1988219-2-javierm@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: permit to set reg_update_bits with bulk implementation

A regmap may still require to set a custom reg_update_bits instead of
relying to the regmap_bus_read/write general function.

Permit to set it in the map if provided by the regmap config.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Link: https://lore.kernel.org/r/20220715201032.19507-1-ansuelsmth@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add WARN_ONCE when invalid mask is provided to regmap_field_init()

In regmap_field_init() when a invalid mask is provided it still
initializes with any warnings.

An example of this is when the LSB is greater than MSB a mask of zero
is produced.

WARN_ONCE() is not ideal for this but requires less changes to core regmap
code.

Cc: Mark Brown <broonie@kernel.org>
Cc: Nishanth Menon <nm@ti.com>
Signed-off-by: Matt Ranostay <mranostay@ti.com>
Link: https://lore.kernel.org/r/20220708013125.313892-1-mranostay@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: provide regmap_field helpers for simple bit operations

We have set/clear/test operations for regmap, but not for regmap_field yet.
So let's introduce regmap_field helpers too.

In many instances regmap_field_update_bits() is used for simple bit setting
and clearing. In these cases the last argument is redundant and we can
hide it with a static inline function.

This adds three new helpers for simple bit operations: set_bits,
clear_bits and test_bits (the last one defined as a regular function).

Signed-off-by: Li Chen <lchen@ambarella.com>
Link: https://lore.kernel.org/r/180eef422c3.deae9cd960729.8518395646822099769@zohomail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Wire up regmap_config provided bulk write in missed functions

There are some functions that were missed by commit d77e74561368 ("regmap:
Add bulk read/write callbacks into regmap_config") when support to define
bulk read/write callbacks in regmap_config was introduced.

The regmap_bulk_write() and regmap_noinc_write() functions weren't changed
to use the added map->write instead of the map->bus->write handler.

Also, the regmap_can_raw_write() was not modified to take map->write into
account. So will only return true if a bus with a .write callback is set.

Fixes: d77e74561368 ("regmap: Add bulk read/write callbacks into regmap_config")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/r/20220616073435.1988219-4-javierm@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Make regmap_noinc_read() return -ENOTSUPP if map->read isn't set

Before adding support to define bulk read/write callbacks in regmap_config
by the commit d77e74561368 ("regmap: Add bulk read/write callbacks into
regmap_config"), the regmap_noinc_read() function returned an errno early
a map->bus->read callback wasn't set.

But that commit dropped the check and now a call to _regmap_raw_read() is
attempted even when bulk read operations are not supported. That function
checks for map->read anyways but there's no point to continue if the read
can't succeed.

Also is a fragile assumption to make so is better to make it fail earlier.

Fixes: d77e74561368 ("regmap: Add bulk read/write callbacks into regmap_config")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/r/20220616073435.1988219-3-javierm@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Re-introduce bulk read support check in regmap_bulk_read()

Support for drivers to define bulk read/write callbacks in regmap_config
was introduced by the commit d77e74561368 ("regmap: Add bulk read/write
callbacks into regmap_config"), but this commit wrongly dropped a check
in regmap_bulk_read() to determine whether bulk reads can be done or not.

Before that commit, it was checked if map->bus was set. Now has to check
if a map->read callback has been set.

Fixes: d77e74561368 ("regmap: Add bulk read/write callbacks into regmap_config")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/r/20220616073435.1988219-2-javierm@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add missing map->bus check

The map->bus can be NULL here, add the missing NULL pointer check.

Fixes: d77e745613680 ("regmap: Add bulk read/write callbacks into regmap_config")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
To: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/20220509003035.225272-1-marex@denx.de
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add bulk read/write callbacks into regmap_config

Currently the regmap_config structure only allows the user to implement
single element register read/write using .reg_read/.reg_write callbacks.
The regmap_bus already implements bulk counterparts of both, and is being
misused as a workaround for the missing bulk read/write callbacks in
regmap_config by a couple of drivers. To stop this misuse, add the bulk
read/write callbacks to regmap_config and call them from the regmap core
code.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
To: dri-devel@lists.freedesktop.org
Link: https://lore.kernel.org/r/20220430025145.640305-1-marex@denx.de
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: allow a defined reg_base to be added to every address

There's an inconsistency that arises when a register set can be accessed
internally via MMIO, or externally via SPI. The VSC7514 chip allows both
modes of operation. When internally accessed, the system utilizes __iomem,
devm_ioremap_resource, and devm_regmap_init_mmio.

For SPI it isn't possible to utilize memory-mapped IO. To properly operate,
the resource base must be added to the register before every operation.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Link: https://lore.kernel.org/r/20220313224524.399947-3-colin.foster@in-advantage.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add configurable downshift for addresses

Add an additional reg_downshift to be applied to register addresses before
any register accesses. An example of a device that uses this is a VSC7514
chip, which require each register address to be downshifted by two if the
access is performed over a SPI bus.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Link: https://lore.kernel.org/r/20220313224524.399947-2-colin.foster@in-advantage.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Call regmap_debugfs_exit() prior to _init()

Since commit cffa4b2122f5 ("regmap: debugfs: Fix a memory leak when
calling regmap_attach_dev"), the following debugfs error is seen
on i.MX boards:

debugfs: Directory 'dummy-iomuxc-gpr@20e0000' with parent 'regmap' already present!

In the attempt to fix the memory leak, the above commit added a NULL check
for map->debugfs_name. For the first debufs entry, map->debugfs_name is NULL
and then the new name is allocated via kasprintf().

For the second debugfs entry, map->debugfs_name() is no longer NULL, so
it will keep using the old entry name and the duplicate name error is seen.

Quoting Mark Brown:

"That means that if the device gets freed we'll end up with the old debugfs
file hanging around pointing at nothing.
...
To be more explicit this means we need a call to regmap_debugfs_exit()
which will clean up all the existing debugfs stuff before we loose
references to it."

Call regmap_debugfs_exit() prior to regmap_debugfs_init() to fix
the problem.

Tested on i.MX6Q and i.MX6SX boards.

Fixes: cffa4b2122f5 ("regmap: debugfs: Fix a memory leak when calling regmap_attach_dev")
Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Fabio Estevam <festevam@denx.de>
Link: https://lore.kernel.org/r/20220107163307.335404-1-festevam@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: allow to define reg_update_bits for no bus configuration

Some device requires a special handling for reg_update_bits and can't use
the normal regmap read write logic. An example is when locking is
handled by the device and rmw operations requires to do atomic operations.
Allow to declare a dedicated function in regmap_config for
reg_update_bits in no bus configuration.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Link: https://lore.kernel.org/r/20211104150040.1260-1-ansuelsmth@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: teach regmap to use raw spinlocks if requested in the config

Some drivers might access regmap in a context where a raw spinlock is
held. An example is drivers/irqchip/irq-ls-extirq.c, which calls
regmap_update_bits() from struct irq_chip :: irq_set_type, which is a
method called by __irq_set_trigger() under the desc->lock raw spin lock.

Since desc->lock is a raw spin lock and the regmap internal lock for
mmio is a plain spinlock (which can become sleepable on RT), this is an
invalid locking scheme and we get a splat stating that this is a
"[ BUG: Invalid wait context ]".

It seems reasonable for regmap to have an option use a raw spinlock too,
so add that in the config such that drivers can request it.

Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20210825205041.927788-2-vladimir.oltean@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: allow const array for {devm_,}regmap_field_bulk_alloc reg_fields

The reg_fields array fed to {devm_}regmap_field_bulk_alloc is currently
not const, which is not correct on semantics (the functions shouldn't
change reg_field contents) and prevents pre-defined const reg_field
array to be used.

As the implementation of this function doesn't change the content of it,
just add const to its prototype.

Signed-off-by: Icenowy Zheng <icenowy@sipeed.com>
Link: https://lore.kernel.org/r/20210802063741.76301-1-icenowy@sipeed.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Prefer unsigned int to bare use of unsigned

Fix checkpatch warnings:
WARNING: Prefer 'unsigned int' to bare use of 'unsigned'

Signed-off-by: Jinchao Wang <wjc@cdjrlc.com>
Link: https://lore.kernel.org/r/20210628171907.63646-1-wjc@cdjrlc.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: fix the offset of register error log

This patch fixes the offset of register error log
by using regmap_get_offset().

Signed-off-by: Jeongtae Park <jeongtae.park@gmail.com>
Link: https://lore.kernel.org/r/20210701142630.44936-1-jeongtae.park@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add support for 7/17 register formating

This patch adds support for 7 bits register, 17 bits value type register
formating. This is used, for example, by the Analog Devices
ADMV1013/ADMV1014.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Signed-off-by: Andrei Drimbarean <andrei.drimbarean@analog.com>
Message-Id: <20210526085223.14896-1-antoniu.miclaus@analog.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap-i2c: Set regmap max raw r/w from quirks

Set regmap raw read/write from i2c quirks max read/write
so regmap_raw_read/write can split the access into chunks

Signed-off-by: Lucas Tanure <tanureal@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20210512135222.223203-1-tanureal@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Fix order of regmap write log

_regmap_write can trigger a _regmap_select_page, which will call
another _regmap_write that will be executed first, but the log shows
the inverse order

Also, keep consistency with _regmap_read which only logs in case of
success

Signed-off-by: Lucas Tanure <tanureal@opensource.cirrus.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20201112150217.459844-1-tanureal@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add support to regmap_field_bulk_alloc/free apis

Usage of regmap_field_alloc becomes much overhead when number of fields
exceed more than 3.
QCOM LPASS driver has extensively converted to use regmap_fields.

Using new bulk api to allocate fields makes it much more cleaner code to read!

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Tested-by: Srinivasa Rao Mandadapu <srivasam@codeaurora.org>
Link: https://lore.kernel.org/r/20200925164856.10315-2-srinivas.kandagatla@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: destroy mutex (if used) in regmap_exit()

While not destroying mutexes doesn't lead to memory leaks, it's still
the correct thing to do for mutex debugging accounting.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20200928120614.23172-1-brgl@bgdev.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: debugfs: Fix more error path regressions

Many error paths in __regmap_init rely on ret being pre-initialised to
-EINVAL, add an extra initialisation in after the new call to
regmap_set_name.

Fixes: 94cc89eb8fa5 ("regmap: debugfs: Fix handling of name string for debugfs init delays")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20200918152212.22200-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: fix page selection for noinc writes

Non-incrementing writes can fail if register + length crosses page
border. However for non-incrementing writes we should not check for page
border crossing. Fix this by passing additional flag to _regmap_raw_write
and passing length to _regmap_select_page basing on the flag.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Fixes: cdf6b11daa77 ("regmap: Add regmap_noinc_write API")
Link: https://lore.kernel.org/r/20200917153405.3139200-2-dmitry.baryshkov@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: fix page selection for noinc reads

Non-incrementing reads can fail if register + length crosses page
border. However for non-incrementing reads we should not check for page
border crossing. Fix this by passing additional flag to _regmap_raw_read
and passing length to _regmap_select_page basing on the flag.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Fixes: 74fe7b551f33 ("regmap: Add regmap_noinc_read API")
Link: https://lore.kernel.org/r/20200917153405.3139200-1-dmitry.baryshkov@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: debugfs: Add back in erroneously removed initialisation of ret

Fixes: 94cc89eb8fa5 ("regmap: debugfs: Fix handling of name string for debugfs init delays")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20200918112002.15216-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: debugfs: Fix handling of name string for debugfs init delays

In regmap_debugfs_init the initialisation of the debugfs is delayed
if the root node isn't ready yet. Most callers of regmap_debugfs_init
pass the name from the regmap_config, which is considered temporary
ie. may be unallocated after the regmap_init call returns. This leads
to a potential use after free, where config->name has been freed by
the time it is used in regmap_debugfs_initcall.

This situation can be seen on Zynq, where the architecture init_irq
callback registers a syscon device, using a local variable for the
regmap_config. As init_irq is very early in the platform bring up the
regmap debugfs root isn't ready yet. Although this doesn't crash it
does result in the debugfs entry not having the correct name.

Regmap already sets map->name from config->name on the regmap_init
path and the fact that a separate field is used to pass the name
to regmap_debugfs_init appears to be an artifact of the debugfs
name being added before the map name. As such this patch updates
regmap_debugfs_init to use map->name, which is already duplicated from
the config avoiding the issue.

This does however leave two lose ends, both regmap_attach_dev and
regmap_reinit_cache can be called after a regmap is registered and
would have had the effect of applying a new name to the debugfs
entries. In both of these cases it was chosen to update the map
name. In the case of regmap_attach_dev there are 3 users that
currently use this function to update the name, thus doing so avoids
changes for those users and it seems reasonable that attaching
a device would want to set the name of the map. In the case of
regmap_reinit_cache the primary use-case appears to be devices that
need some register access to identify the device (for example devices
in the same family) and then update the cache to match the exact
hardware. Whilst no users do currently update the name here, given the
use-case it seemed reasonable the name might want to be updated once
the device is better identified.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20200917120828.12987-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add support for 12/20 register formatting

Devices such as the AD5628 require 32 bits of data divided in 12 bits
for dummy, command and address, and 20 for data and dummy. Eg:

XXXXCCCCAAAADDDDDDDDDDDDDDDDXXXX

Where X is dont care, C is command, A is address and D is data bits.

Which would requierd the following regmap_config:

static const struct regmap_config config_dac = {
.reg_bits = 12,
.val_bits = 20,
.max_register = 0xff,
};

Signed-off-by: Ricardo Ribalda <ribalda@kernel.org>
Link: https://lore.kernel.org/r/20200917114727.1120373-1-ribalda@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add can_sleep configuration option

Regmap can't sleep if spinlock is used for the locking protection.
This patch fixes regression caused by a previous commit that switched
regmap to use fsleep() and this broke Amlogic S922X platform.

This patch adds new configuration option for regmap users, allowing to
specify whether regmap operations can sleep and assuming that sleep is
allowed if mutex is used for the regmap locking protection.

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Fixes: 2b32d2f7ce0a ("regmap: Use flexible sleep")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20200902141843.6591-1-digetx@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Use flexible sleep

The multi-reg write function uses udelay(), which is a busy-loop based
delaying function that is not suitable for a long delays. Hence let's
replace the udelay() with fsleep(), which is flexible sleep function that
selects best delay function based on the delay-time.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20200830185356.5365-3-digetx@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Switch to use fwnode instead of OF one

Make regmap firmware node type agnostic by switching it to use fwnode.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200708161232.17914-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: dev_get_regmap_match(): fix string comparison

This function is used by dev_get_regmap() to retrieve a regmap for the
specified device. If the device has more than one regmap, the name parameter
can be used to specify one.

The code here uses a pointer comparison to check for equal strings. This
however will probably always fail, as the regmap->name is allocated via
kstrdup_const() from the regmap's config->name.

Fix this by using strcmp() instead.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/r/20200703103315.267996-1-mkl@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Fix memory leak from regmap_register_patch

When a register patch is registered the reg_sequence is copied but the
memory allocated is never freed. Add a kfree in regmap_exit to clean it
up.

Fixes: 22f0d90a3482 ("regmap: Support register patch sets")
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20200617152129.19655-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: remove stray space

There are two spaces between arguments in regmap_fields_update_bits_base()
so remove one.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20200615072507.11303-1-brgl@bgdev.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: fix the kerneldoc for regmap_test_bits()

The kerneldoc comment for regmap_test_bits() says that it returns -1 on
regmap_read() failure. This is not true - it will propagate the error
code returned by regmap_read(). Fix it.

Fixes: aa2ff9dbaedd ("regmap: provide helpers for simple bit operations")
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20200607093421.22209-1-brgl@bgdev.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: provide helpers for simple bit operations

In many instances regmap_update_bits() is used for simple bit setting
and clearing. In these cases the last argument is redundant and we can
hide it with a static inline function.

This adds three new helpers for simple bit operations: set_bits,
clear_bits and test_bits (the last one defined as a regular function).

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

regmap: fix alignment issue

The assembly and disassembly of data to be sent to or received from
a device invoke functions regmap_format_XX() and regmap_parse_XX()
that extract or insert data items from or into a buffer, using
assignments. In some cases the functions are called with a buffer
pointer with an odd address. On architectures with strict alignment
requirements this can result in a kernel crash. The assignments
have been replaced by functions that take alignment into account.

Signed-off-by: Jens Thoms Toerring <jt@toerring.de>
Link: https://lore.kernel.org/r/20200531095300.GA27570@toerring.de
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: provide helpers for simple bit operations

In many instances regmap_update_bits() is used for simple bit setting
and clearing. In these cases the last argument is redundant and we can
hide it with a static inline function.

This adds three new helpers for simple bit operations: set_bits,
clear_bits and test_bits (the last one defined as a regular function).

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20200528154503.26304-2-brgl@bgdev.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add bus reg_update_bits() support

Add reg_update_bits() support in case some platforms use a special method
to update bits of registers.

Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Link: https://lore.kernel.org/r/df32fd0529957d1e7e26ba1465723f16cfbe92c8.1586757922.git.baolin.wang7@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: fix writes to non incrementing registers

When checking if a register block is writable we must ensure that the
block does not start with or contain a non incrementing register.

Fixes: 8b9f9d4dc511 ("regmap: verify if register is writeable before writing operations")
Signed-off-by: Ben Whitten <ben.whitten@gmail.com>
Link: https://lore.kernel.org/r/20200118205625.14532-1-ben.whitten@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: fix bulk writes on paged registers

On buses like SlimBus and SoundWire which does not support
gather_writes yet in regmap, A bulk write on paged register
would be silently ignored after programming page.
This is because local variable 'ret' value in regmap_raw_write_impl()
gets reset to 0 once page register is written successfully and the
code below checks for 'ret' value to be -ENOTSUPP before linearising
the write buffer to send to bus->write().

Fix this by resetting the 'ret' value to -ENOTSUPP in cases where
gather_writes() is not supported or single register write is
not possible.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add proper SPDX identifiers on files that did not have them.

There were a few files in the regmap code that did not have SPDX
identifiers on them, so fix that up. At the same time, remove the "free
form" text that specified the license of the file, as that is impossible
for any tool to properly parse.

Also, as Mark loves // comment markers, convert all of the headers to be
the same to make things look consistent :)

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: verify if register is writeable before writing operations

regmap provides a couple of ways to validate the register range used.
a) maxim allowed register, b) writable/readable register tables,
c) callback function that can be provided by the driver to validate
a register. regmap framework should verify if registers
are writeable before every write operation. However this doesn't
seems to happen in every situation.

The method `_regmap_raw_write_impl` is only using the `writeable_reg`
callback to verify if register is writeable, ignoring the other two.
This can lead to undefined behaviour since this allows to write to
registers that could be declared un-writeable by using any other
option.

Change `_regmap_raw_write_impl` to use the `regmap_writeable` method
to verify if registers are writable before the write operation.

Signed-off-by: Nandor Han <nandor.han@vaisala.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: use less #ifdef for LOG_DEVICE

Move the checking of the LOG_DEVICE into a function to reduce the
number of #ifdefs and ensure more of the code gets compiled/checked,
and make it easier to change this for internal debugging purposes
(such as checking >1 device).

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add regmap_noinc_write API

The regmap API had a noinc_read function added for instances where devices
supported returning data from an internal FIFO in a single read.

This commit adds the noinc_write variant to allow writing to a non
incrementing register, this is used in devices such as the sx1301 for
loading firmware.

Signed-off-by: Ben Whitten <ben.whitten@lairdtech.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: split up regmap_config.use_single_rw

Split regmap_config.use_single_rw into use_single_read and
use_single_write. This change enables drivers of devices which only
support bulk operations in one direction to use the regmap_bulk_*()
functions for both directions and have their bulk operation split into
single operations only when necessary.

Update all struct regmap_config instances where use_single_rw==true to
instead set both use_single_read and use_single_write. No attempt was
made to evaluate whether it is possible to set only one of
use_single_read or use_single_write.

Signed-off-by: David Frey <dpfrey@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add regmap_noinc_read API

The regmap API usually assumes that bulk read operations will read a
range of registers but some I2C/SPI devices have certain registers for
which a such a read operation will return data from an internal FIFO
instead. Add an explicit API to support bulk read without range semantics.

Some linux drivers use regmap_bulk_read or regmap_raw_read for such
registers, for example mpu6050 or bmi150 from IIO. This only happens to
work because when caching is disabled a single regmap read op will map
to a single bus read op (as desired). This breaks if caching is enabled and
reg+1 happens to be a cacheable register.

Without regmap support refactoring a driver to enable regmap caching
requires separate I2C and SPI paths. This is exactly what regmap is
supposed to help avoid.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Merge redundant handling in regmap_bulk_write

The handling for the first two cases in regmap_bulk_write is
essentially identical. The first case is just a better implementation of
the second, supporting 8 byte registers and doing the locking manually to
avoid bouncing the lock for each register. Drop some redundant code by
removing the second of these cases and allowing both situations to be
handled by the same code.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Tidy up regmap_raw_write chunking code

Raw writes may need to be split into small chunks if max_raw_write is
set. Tidy up the code implementing this, the new code is slightly
clearer, slightly shorter and slightly more efficient.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Move the handling for max_raw_write into regmap_raw_write

Currently regmap_bulk_write will split a write into chunks before
calling regmap_raw_write if max_raw_write is set. It is more logical
for this handling to be inside regmap_raw_write itself, as this
removes the need to keep re-implementing the chunking code, which
would be the same for all users of regmap_raw_write.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Remove unnecessary printk for failed allocation

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Format data for raw write in regmap_bulk_write

In the case were the bulk transaction is split up into smaller chunks
data is passed directly to regmap_raw_write. However regmap_bulk_write
uses data in host endian and regmap_raw_write expects data in device
endian. As such if the host and device differ in endian the wrong data
will be written to the device. Correct this issue using a similar
approach to the single raw write case below it, duplicate the data
into a new buffer and use parse_inplace to format the data correctly.

Fixes: adaac459759d ("regmap: Introduce max_raw_read/write for regmap_bulk_read/write")
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: use debugfs even when no device

This registers regmaps with debugfs even when they do not have an
associated device. For example, this is common for syscon regmaps.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Use _regmap_read in regmap_bulk_read

Bulk reads may potentially read a lot of registers and regmap_read will
take and release the regmap lock for each register. Avoid bouncing
the lock so frequently by holding the lock locally and calling
_regmap_read instead. This also has the nice side-effect that all the
reads will be done atomically so no other threads can sneak a write in
during the regmap_bulk_read.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Tidy up regmap_raw_read chunking code

Raw reads may need to be split into small chunks if max_raw_read is
set. Tidy up the code implementing this, the new code is slightly
clearer, slightly shorter and slightly more efficient.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Move the handling for max_raw_read into regmap_raw_read

Currently regmap_bulk_read will split a read into chunks before
calling regmap_raw_read if max_raw_read is set. It is more logical for
this handling to be inside regmap_raw_read itself, as this removes the
need to keep re-implementing the chunking code, which would be the
same for all users of regmap_raw_read.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Use helper function for register offset

As a helper function exists for calculating register offsets lets use
that rather than open coding with the reg_stride.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Don't use format_val in regmap_bulk_read

A bulk read can be implemented either through regmap_raw_read, or
by reading each register individually using regmap_read. Both
regmap_read and regmap_bulk_read should return values in native
endian. In the individual case the current implementation calls
format_val to put the data into the output array, which can cause
endian issues. The regmap_read will have already converted the data
into native endian, if the hosts endian differs from the device then
format_val will switch the endian back again.

Rather than using format_val simply use the code that is called if
there is no format_val function. This code supports all cases except
24-bit but there don't appear to be any users of regmap_bulk_read for
24-bit. Additionally, it would have to be a big endian host for the
old code to actually function correctly anyway.

Fixes: 15b8d2c41fe5 ("regmap: Fix regmap_bulk_read in BE mode")
Reported-by: David Rhodes <david.rhodes@cirrus.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Correct comparison in regmap_cached

The cache pointer points to the actual memory used by the cache, as the
comparison here is looking for the type of the cache it should check
against cache_type.

Fixes: 1ea975cf1ef5 ("regmap: Add a function to check if a regmap register is cached")
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Correct offset handling in regmap_volatile_range

The current implementation is broken for regmaps that have a reg_stride,
since it doesn't take the stride into account. Correct this by using the
helper function to calculate the register offset.

Fixes: f01ee60fffa4 ("regmap: implement register striding")
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Fix reversed bounds check in regmap_raw_write()

We're supposed to be checking that "val_len" is not too large but
instead we check if it is smaller than the max.

The only function affected would be regmap_i2c_smbus_i2c_write() in
drivers/base/regmap/regmap-i2c.c. Strangely that function has its own
limit check which returns an error if (count >= I2C_SMBUS_BLOCK_MAX) so
it doesn't look like it has ever been able to do anything except return
an error.

Fixes: c335931ed9d2 ("regmap: Add raw_write/read checks for max_raw_write/read sizes")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

regmap: Allow empty read/write_flag_mask

All zero read and write masks in the regmap config are used to signal no
special mask is needed and the bus defaults are used. In some devices
all zero read/write masks are the special mask and bus defaults should
not be used. To signal this a new variable is added.

For example SPI often sets bit 7 in address to signal to the device a
read is requested. On TI AFE44xx parts with SPI interfaces no bit
needs to be set as registers are either read or write only and the
operation can be determined from the address only. For this case both
masks must be zero to not effect the address.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add one flag to indicate if a hwlock should be used

Since the hwlock id 0 is valid for hardware spinlock core, but now id 0
is treated as one invalid value for regmap. Thus we should add one extra
flag for regmap config to indicate if a hardware spinlock should be used,
then id 0 can be valid for regmap to request.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: use proper part of work_buf for storing val

The map->work_buf is a buffer preallocated in __regmap_init() with size
allowing it to store all 3 parts of a buffer - reg, pad and val. While
reg and val parts are always properly setup before each transaction, the
pad part is left at its default value (zeros). Until it is overwritten,
that is.

_regmap_bus_read(), when calling _regmap_raw_read() uses beginning of
work_buf as a place to store data read. Usually that is fine but if
val_bits > reg_bits && pad_bits > 0, padding area of work_buf() may get
overwritten. Since padding is not zeroed before each transaction,
garbage will be used on next calls.

This patch moves the val pointer used for _regmap_raw_read() to point
to a part of work_buf intended for storing value read.

Signed-off-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: potentially duplicate the name string stored in regmap

Currently we just copy over the pointer passed to regmap_init() in
the regmap config struct. To be on the safe side: duplicate the string
with kstrdup_const() so that if an unaware user passes an address to
a stack-allocated buffer, we won't crash.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Disable debugfs when locking is disabled

The recently added support for disabling the regmap internal locking left
debugfs enabled for devices with the locking disabled. This is a problem
since debugfs allows userspace to do things like initiate reads from the
hardware which will use the scratch buffers protected by the regmap locking
so could cause data corruption.

For safety address this by just disabling debugfs for these devices. That
is overly conservative since some of the debugfs files just read internal
data structures but it's much simpler to implmement and less likely to
lead to problems with tooling that works with debugfs.

Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: rename regmap_lock_unlock_empty() to regmap_lock_unlock_none()

Minor naming convention tweak.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: allow to disable all locking mechanisms

We have a use case in the at24 EEPROM driver (recently converted to
using regmap instead of raw i2c/smbus calls) where we read from/write
to the regmap in a loop, while protecting the entire loop with
a mutex.

Currently this implicitly makes us use two mutexes - one in the driver
and one in regmap. While browsing the code for similar use cases I
noticed a significant number of places where locking *seems* redundant.

Allow users to completely disable any locking mechanisms in regmap
config.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Remove the redundant config to select hwspinlock

The hwspinlock was changed to a bool by commit d048236dfdfe
("hwspinlock: Change hwspinlock to a bool"), so we do not need
the REGMAP_HWSPINLOCK config to select hwspinlock or not.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Fix unused warning

This patch fixes the warning of label 'err_map' defined but not used.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Clean up hwspinlock on regmap exit

We should free any hwspinlocks when we destroy the regmap, do so.

Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Also protect hwspinlock in error handling path

The previous patch to allow the hwspinlock code to be disabled missed
handling the free in the error path, do so using the better IS_ENABLED()
pattern as suggested by Baolin. While we're at it also check that we have
a hardware spinlock before freeing it - the core code reports an error
when freeing an invalid lock.

Suggested-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add a config option for hwspinlock

Unlike other lock types hwspinlocks are optional and can be built
modular so we can't use them unconditionally in regmap so add a config
option that drivers that want to use hwspinlocks with regmap can select
which will ensure that hwspinlock is built in.

Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add hardware spinlock support

On some platforms, when reading or writing some special registers through
regmap, we should acquire one hardware spinlock to synchronize between
the multiple subsystems. Thus this patch adds the hardware spinlock
support for regmap.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Fixup the kernel-doc comments on functions/structures

Most of the kernel-doc comments in regmap don't actually generate
correctly. This patch fixes up a few common issues, corrects some typos
and adds some missing argument descriptions.

The most common issues being using a : after the function name which
causes the short description to not render correctly and not separating
the long and short descriptions of the function. There are quite a few
instances of arguments not being described or given the wrong name as
well.

This patch doesn't fixup functions/structures that are currently missing
descriptions.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: use rb_entry()

To make the code clearer, use rb_entry() instead of container_of() to
deal with rbtree.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: fix deadlock on _regmap_raw_write() error path

Commit 815806e39bf6 ("regmap: drop cache if the bus transfer error")
added a call to regcache_drop_region() to error path in
_regmap_raw_write(). However that path runs with regmap lock taken,
and regcache_drop_region() tries to re-take it, causing a deadlock.
Fix that by calling map->cache_ops->drop() directly.

Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add missing little endian functions

This with the longer read and write masks allow supporting more
exotic devices. For example a little endian SPI device:

static const struct regmap_config foo_regmap_config = {
.reg_bits = 16,
.reg_stride = 4,
.val_bits = 16,
.write_flag_mask = 0x8000,
.reg_format_endian = REGMAP_ENDIAN_LITTLE,
.val_format_endian = REGMAP_ENDIAN_LITTLE,
...
};

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Allow longer flag masks for read and write

We currently only support masking the top bit for read and write
flags. Let's make the mask unsigned long and mask the bytes based
on the configured register length to make things more generic.

This allows using regmap for more exotic combinations like SPI
devices that need little endian addressing.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: drop cache if the bus transfer error

regmap_write
->_regmap_raw_write
-->regcache_write first and than use map->bus->write to wirte i2c or spi
But if the i2c or spi transfer failed, But the cache is updated, So if I use
regmap_read will get the cache data which is not the real register value.

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add a function to check if a regmap register is cached

Add a function to check if a regmap register is cached. This will be used
in debugfs to dump the cached values of write only registers.

Signed-off-by: Cristian Birsan <cristian.birsan@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Support bulk writes for devices without raw formatting

When doing a bulk writes from a device which lacks raw I/O support we
fall back to doing register at a time reads but we still use the raw
formatters in order to render the data into the word size used by the
device (since bulk reads still operate on the device word size rather
than unsigned ints). This means that devices without raw formatting
such as those that provide reg_read() are not supported. Provide
handling for them by copying the values read into native endian values
of the appropriate size.

This complements commit d5b98eb12420 ("regmap: Support bulk reads for
devices without raw formatting").

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: replace regmap_write_bits()

commit 23b92e4cf5fd ("regmap: remove regmap_write_bits()")
removed regmap_write_bits(), but MFD driver was using it.
So, commit e30fccd6771d ("regmap: Keep regmap_write_bits()")
turns out it, but it is using original style.
This patch uses regmap_update_bits_base() for regmap_write_bits()

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add regmap_fields_force_xxx() macros

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: merge regmap_fields_update_bits() into macro

This patch merges regmap_fields_update_bits() into macro
by using regmap_field_update_bits_base().

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: merge regmap_fields_write() into macro

This patch merges regmap_fields_write() into macro
by using regmap_fields_update_bits_base().

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add regmap_fields_update_bits_base()

This patch adds new regmap_fields_update_bits_base() which is using
regmap_update_bits_base().
Current regmap_fields_xxx() can be merged into it by macro.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: merge regmap_field_update_bits() into macro

This patch merges regmap_field_update_bits() into macro
by using regmap_field_update_bits_base().

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: merge regmap_field_write() into macro

This patch merges regmap_field_write() into macro
by using regmap_field_update_bits_base().

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add regmap_field_update_bits_base()

This patch adds new regmap_field_update_bits_base() which is using
regmap_update_bits_base().
Current regmap_field_xxx() can be merged into it by macro.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: merge regmap_update_bits_check_async() into macro

Current regmap has many similar update functions like below,
but the difference is very few.
regmap_update_bits()
regmap_update_bits_async()
regmap_update_bits_check()
regmap_update_bits_check_async()
Furthermore, we can add *force* write option too in the future.

This patch merges regmap_update_bits_check_async() into macro
by using regmap_update_bits_base().

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: merge regmap_update_bits_check() into macro

Current regmap has many similar update functions like below,
but the difference is very few.
regmap_update_bits()
regmap_update_bits_async()
regmap_update_bits_check()
regmap_update_bits_check_async()
Furthermore, we can add *force* write option too in the future.

This patch merges regmap_update_bits_check() into macro
by using regmap_update_bits_base().

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: merge regmap_update_bits_async() into macro

Current regmap has many similar update functions like below,
but the difference is very few.
regmap_update_bits()
regmap_update_bits_async()
regmap_update_bits_check()
regmap_update_bits_check_async()
Furthermore, we can add *force* write option too in the future.

This patch merges regmap_update_bits_async() into macro
by using regmap_update_bits_base().

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: merge regmap_update_bits() into macro

Current regmap has many similar update functions like below,
but the difference is very few.
regmap_update_bits()
regmap_update_bits_async()
regmap_update_bits_check()
regmap_update_bits_check_async()
Furthermore, we can add *force* write option too in the future.

This patch merges regmap_update_bits() into macro
by using regmap_update_bits_base().

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add regmap_update_bits_base()

Current regmap has many similar update functions like below,
but the difference is very few.
regmap_update_bits()
regmap_update_bits_async()
regmap_update_bits_check()
regmap_update_bits_check_async()
Furthermore, we can add *force* write option too in the future.

This patch adds new regmap_update_bits_base() which is feature
merged function. Above functions can be merged into it by macro.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: core: Introduce register stride order

Since the register stride should always equal to 2^N, and bit rotation is
much faster than multiplication and division. So introducing the stride
order and using bit rotation to get the offset of the register from the
index to improve the performance.

Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Return an error if a caller attempts to do an unsupported raw read

regmaps without raw I/O access can't implement raw I/O operations,
return an error if someone tries to do that rather than crashing.

Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add explict native endian flag to DT bindings

Currently the binding document says that if no endianness is configured
we use native endian but this is not in fact true for all binding types
and we do have some devices that really want native endianness such as
Broadcom MIPS SoCs where switching the endianness of the CPU also
switches the endianness of external IPs.

Provide an explicit option for this.

Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: use IS_ALIGNED instead of % to improve the performance

The stride value should always equal to 2^n, so we can use bit
rotation instead of % to improve the performance.

Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: missing case statement

This new code is unreachable. Presumably there was supposed to be a
case statement there similar to the earlier code.

Fixes: afcc00b91f18 ('regmap: add 64-bit mode support')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: shift wrapping bugs in 64 bit code

We should cast these to 64bit so that we don't truncate away the high
bits.

Fixes: afcc00b91f18 ('regmap: add 64-bit mode support')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: fix the warning about unused variable

The variable 'u64 *u64' should be only visible on 64-BIT platform.

Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add 64-bit mode support

Since the mmio has support the 64-bit has been supported for the
64-bit platform, so should the regmap core too.

Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Allow installing custom reg_update_bits function

This commit allows installing a custom reg_update_bits function for cases where
the hardware provides a mechanism to set or clear register bits without a
read/modify/write cycle. Such is the case with the Microchip ENCX24J600.

If a custom reg_update_bits function is provided, it will only be used against
volatile registers.

Signed-off-by: Jon Ringle <jringle@gridpoint.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Revert "regmap: Allow installing custom reg_update_bits function"

This reverts commit 7741c373cf3ea1f5383fa97fb7a640a429d3dd7c.

regmap: Allow installing custom reg_update_bits function

This commit allows installing a custom reg_update_bits function for cases where
the hardware provides a mechanism to set or clear register bits without a
read/modify/write cycle. Such is the case with the Microchip ENCX24J600.

Signed-off-by: Jon Ringle <jringle@gridpoint.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

regmap: Allocate buffers with GFP_ATOMIC when fast_io == true

If a regmap is using fast_io, allocate the scratch buffer in
regmap_bulk_write() with GFP_ATOMIC instead of GFP_KERNEL.
Otherwise we may schedule while atomic.

Reported-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: fix a NULL pointer dereference in __regmap_init

__regmap_init() may receive a NULL `struct regmap_bus *bus' pointer,
for example, from snd_hdac_regmap_init(), and it make sure that it
does not NULL deference `bus`, except around ->max_raw_read and
->max_raw_write initialisation. Add missing check.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Support bulk reads for devices without raw formatting

When doing a bulk read from a device which lacks raw I/O support we fall
back to doing register at a time reads but we still use the raw
formatters in order to render the data into the word size used by the
device (since bulk reads still operate on the device word size rather
than unsigned ints). This means that devices without raw formatting
such as those that provide reg_read() are not supported. Provide
handling for them by copying the values read into native endian values
of the appropriate size.

Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add raw_write/read checks for max_raw_write/read sizes

Check in regmap_raw_read() and regmap_raw_write() for correct maximum
sizes of the operations. Return -E2BIG if this size is not supported
because it is too big.

Also this patch causes an uninitialized variable warning so it
initializes ret (although not necessary).

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: regmap max_raw_read/write getter functions

Add functions to access the maximum size we can read/write using
regmap_raw_read/write().

This helps drivers that need to know how much they can write with the
raw functions without problems. There are some devices (e.g. bmc150)
that have fifos as registers which need to be read in specific chunks
otherwise samples are dropped.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Introduce max_raw_read/write for regmap_bulk_read/write

There are some buses which have a limit on the maximum number of bytes
that can be send/received. An example for this is
I2C_FUNC_SMBUS_I2C_BLOCK which does not support any reads/writes of more
than 32 bytes. The regmap_bulk operations should still be able to
utilize the full 32 bytes in this case.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: No multi_write support if bus->write does not exist

There is no multi_write support available if we cannot use raw_write.
This is the case if bus->write is not implemented.

This patch adds a condition that we need bus and bus->write so that
can_multi_write is true.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Split use_single_rw internally into use_single_read/write

use_single_rw currently reflects the capabilities of the connected
device. The capabilities of the bus are currently missing for this
variable.

As there are read only and write only buses we need seperate values for
use_single_rw to also reflect tha capabilities of the bus.

This patch splits use_single_rw into use_single_read and
use_single_write. The initialization is changed to check the
configuration for use_single_rw and to check the capabilities of the
used bus.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Fix regmap_bulk_write for bus writes

The regmap config does not prohibit val_bytes that are not powers of
two. But the current code of regmap_bulk_write for use_single_rw does
limit the possible val_bytes to 1, 2 and 4.

This patch fixes the behaviour to allow bus writes with non-standard
val_bytes sizes.

Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: regmap_raw_read return error on !bus->read

Return -ENOTSUPP if map->bus->read is not implemented and we do not use
the cache. This code path would directly use bus->read would run into an
NULL pointer for the read function.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Fix regmap_can_raw_write check

This function is missing a check if map->bus->write is implemented. If
it is not implemented arbitrary raw writes are not possible.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: fix typos in regmap.c

There are two typos in drivers/base/regmap/regmap.c, and they may
introduce some noise when checking new patches.

Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Fix integertypes for register address and value

These values are defined as unsigned int in the struct and are assigned
to int values.

This patch fixes the type to be unsigned int instead.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Move documentation to regmap.h

Init functions defined in regmap*.c files are now prefixed with
__, take lockdep key and class parameters, and should not be
called directly: move the documentation to regmap.h, where the
macros are defined.

Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Use different lockdep class for each regmap init call

Lockdep validator complains about recursive locking and deadlock
when two different regmap instances are called in a nested order.
That happens anytime a regmap read/write call needs to access
another regmap.

This is because, for performance reason, lockdep groups all locks
initialized by the same mutex_init() in the same lock class.
Therefore all regmap mutexes are in the same lock class, leading
to lockdep "nested locking" warnings if a regmap accesses another
regmap.

In general, it is impossible to establish in advance the hierarchy
of regmaps, so we make sure that each regmap init call initializes
its own static lock_class_key. This is done by wrapping all
regmap_init calls into macros.

This also allows us to give meaningful names to the lock_class_key.
For example, in rt5677 case, we have in /proc/lockdep_chains:
irq_context: 0
[ffffffc0018d2198] &dev->mutex
[ffffffc0018d2198] &dev->mutex
[ffffffc001bd7f60] rt5677:5104:(&rt5677_regmap)->_lock
[ffffffc001bd7f58] rt5677:5096:(&rt5677_regmap_physical)->_lock
[ffffffc001b95448] &(&base->lock)->rlock

The above would have resulted in a lockdep recursive warning
previously. This is not the case anymore as the lockdep validator
now clearly identifies the 2 regmaps as separate.

Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Apply optional delay in multi_reg_write/register_patch

Add an optional delay_us field in reg_sequence to allow the client to
specify a delay (in microseconds) to be applied after any given write
in a sequence of writes.

We treat a delay in a sequence the same way we treat a page change as
they are logically similar in that you can coalesce all write before
a delay (in the same way you can coalesce all writes before a page
change is needed)

Signed-off-by: Nariman Poushin <nariman@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Use reg_sequence for multi_reg_write / register_patch

Separate the functionality using sequences of register writes from the
functions that take register defaults. This change renames the arguments
in order to support the extension of reg_sequence to take an optional
delay to be applied after any given register in a sequence is written.
This avoids adding an int to all register defaults, which could
substantially increase memory usage for regmaps with large default tables.

This also updates all the clients of multi_reg_write/register_patch.

Signed-off-by: Nariman Poushin <nariman@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Silence warning on invalid zero length read

Zero length reads make no sense in a regmap context and are likely to
trigger bugs further down the stack so insert an error check, also
silencing compiler warnings about use of ret in cases where we iterate
per register.

Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add better support for devices without readback support

Currently regmap requires that a reg_read callback is supplied, otherwise a
warning is emitted each time regmap_read() is called. This means a device
or bus without readback support needs to supply dummy reg_read callback.
Apart from that regmap_read() will still work fine if a cache is used.

Remove the warning and let regmap_readable() return false if not reg_read
callback is supplied. This means a device no longer has to supply a dummy
callback if it does not support readback and it also doesn't have to have a
readable_reg callback that always returns false since this is now implicit.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add regmap_fields_force_write()

regmap_fields_force_write() is similar to regmap_fields_write(),
but regmap_fields_force_write() write data to register even though
it is same value.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add regmap_write_bits()

regmap_write_bits() is similar to regmap_update_bits(),
but regmap_write_bits() write data to register even though
it is same value.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add force_write option on _regmap_update_bits()

Sometimes we want to write data even though it doesn't change value.
Then, force_write option on _regmap_update_bits() helps this purpose.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Fix possible shift overflow in regmap_field_init()

The way the mask is generated in regmap_field_init() is wrong.
Indeed, a field initialized with msb = 31 and lsb = 0 provokes a shift
overflow while calculating the mask field.

On some 32 bits architectures, such as x86, the generated mask is 0,
instead of the expected 0xffffffff.

This patch uses GENMASK() to fix the problem, as this macro is already safe
regarding shift overflow.

Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

regmap: Fix regmap_bulk_read in BE mode

In big endian mode regmap_bulk_read gives incorrect data
for byte reads.

This is because memcpy of a single byte from an address
after full word read gives different results when
endianness differs. ie. we get little-end in LE and big-end in BE.

Signed-off-by: Arun Chandran <achandran@mvista.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

regmap: drop unneeded goto

Delete jump to a label on the next line, when that label is not
used elsewhere.

A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r@
identifier l;
@@

-if (...) goto l;
-l:
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Introduce regmap_get_reg_stride

This patch introduces regmap_get_reg_stride() function which would
be used by the infrastructures like nvmem framework built on top of
regmap. Mostly this function would be used for sanity checks on inputs
within such infrastructure.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Introduce regmap_get_max_register

This patch introduces regmap_get_max_register() function which would be
used by the infrastructures like nvmem framework built on top of
regmap.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Move tracing header into drivers/base/regmap

The tracing events for regmap are confined to the regmap subsystem. It
also requires accessing an internal header. Instead of including the
internal header from a generic file location, move the tracing file
into the regmap directory.

Also rename the regmap tracing header to trace.h, as it is redundant to
keep the regmap.h name when it is in the regmap directory.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: introduce regmap_name to fix syscon regmap trace events

This patch fixes a NULL pointer dereference when enabling regmap event
tracing in the presence of a syscon regmap, introduced by commit bdb0066df96e
("mfd: syscon: Decouple syscon interface from platform devices").
That patch introduced syscon regmaps that have their dev field set to NULL.
The regmap trace events expect it to point to a valid struct device and feed
it to dev_name():

$ echo 1 > /sys/kernel/debug/tracing/events/regmap/enable

Unable to handle kernel NULL pointer dereference at virtual address 0000002c
pgd = 80004000
[0000002c] *pgd=00000000
Internal error: Oops: 17 [#1] SMP ARM
Modules linked in: coda videobuf2_vmalloc
CPU: 0 PID: 304 Comm: kworker/0:2 Not tainted 4.0.0-rc2+ #9197
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Workqueue: events_freezable thermal_zone_device_check
task: 9f25a200 ti: 9f1ee000 task.ti: 9f1ee000
PC is at ftrace_raw_event_regmap_block+0x3c/0xe4
LR is at _regmap_raw_read+0x1bc/0x1cc
pc : [<803636e8>] lr : [<80365f2c>] psr: 600f0093
sp : 9f1efd78 ip : 9f1efdb8 fp : 9f1efdb4
r10: 00000004 r9 : 00000001 r8 : 00000001
r7 : 00000180 r6 : 00000000 r5 : 9f00e3c0 r4 : 00000003
r3 : 00000001 r2 : 00000180 r1 : 00000000 r0 : 9f00e3c0
Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel
Control: 10c5387d Table: 2d91004a DAC: 00000015
Process kworker/0:2 (pid: 304, stack limit = 0x9f1ee210)
Stack: (0x9f1efd78 to 0x9f1f0000)
fd60: 9f1efda4 9f1efd88
fd80: 800708c0 805f9510 80927140 800f0013 9f1fc800 9eb2f490 00000000 00000180
fda0: 808e3840 00000001 9f1efdfc 9f1efdb8 80365f2c 803636b8 805f8958 800708e0
fdc0: a00f0013 803636ac 9f16de00 00000180 80927140 9f1fc800 9f1fc800 9f1efe6c
fde0: 9f1efe6c 9f732400 00000000 00000000 9f1efe1c 9f1efe00 80365f70 80365d7c
fe00: 80365f3c 9f1fc800 9f1fc800 00000180 9f1efe44 9f1efe20 803656a4 80365f48
fe20: 9f1fc800 00000180 9f1efe6c 9f1efe6c 9f732400 00000000 9f1efe64 9f1efe48
fe40: 803657bc 80365634 00000001 9e95f910 9f1fc800 9f1efeb4 9f1efe8c 9f1efe68
fe60: 80452ac0 80365778 9f1efe8c 9f1efe78 9e93d400 9e93d5e8 9f1efeb4 9f72ef40
fe80: 9f1efeac 9f1efe90 8044e11c 80452998 8045298c 9e93d608 9e93d400 808e1978
fea0: 9f1efecc 9f1efeb0 8044fd14 8044e0d0 ffffffff 9f25a200 9e93d608 9e481380
fec0: 9f1efedc 9f1efed0 8044fde8 8044fcec 9f1eff1c 9f1efee0 80038d50 8044fdd8
fee0: 9f1ee020 9f72ef40 9e481398 00000000 00000008 9f72ef54 9f1ee020 9f72ef40
ff00: 9e481398 9e481380 00000008 9f72ef40 9f1eff5c 9f1eff20 80039754 80038bfc
ff20: 00000000 9e481380 80894100 808e1662 00000000 9e4f2ec0 00000000 9e481380
ff40: 800396f8 00000000 00000000 00000000 9f1effac 9f1eff60 8003e020 80039704
ff60: ffffffff 00000000 ffffffff 9e481380 00000000 00000000 9f1eff78 9f1eff78
ff80: 00000000 00000000 9f1eff88 9f1eff88 9e4f2ec0 8003df30 00000000 00000000
ffa0: 00000000 9f1effb0 8000eb60 8003df3c 00000000 00000000 00000000 00000000
ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
ffe0: 00000000 00000000 00000000 00000000 00000013 00000000 ffffffff ffffffff
Backtrace:
[<803636ac>] (ftrace_raw_event_regmap_block) from [<80365f2c>] (_regmap_raw_read+0x1bc/0x1cc)
r9:00000001 r8:808e3840 r7:00000180 r6:00000000 r5:9eb2f490 r4:9f1fc800
[<80365d70>] (_regmap_raw_read) from [<80365f70>] (_regmap_bus_read+0x34/0x6c)
r10:00000000 r9:00000000 r8:9f732400 r7:9f1efe6c r6:9f1efe6c r5:9f1fc800
r4:9f1fc800
[<80365f3c>] (_regmap_bus_read) from [<803656a4>] (_regmap_read+0x7c/0x144)
r6:00000180 r5:9f1fc800 r4:9f1fc800 r3:80365f3c
[<80365628>] (_regmap_read) from [<803657bc>] (regmap_read+0x50/0x70)
r9:00000000 r8:9f732400 r7:9f1efe6c r6:9f1efe6c r5:00000180 r4:9f1fc800
[<8036576c>] (regmap_read) from [<80452ac0>] (imx_get_temp+0x134/0x1a4)
r6:9f1efeb4 r5:9f1fc800 r4:9e95f910 r3:00000001
[<8045298c>] (imx_get_temp) from [<8044e11c>] (thermal_zone_get_temp+0x58/0x74)
r7:9f72ef40 r6:9f1efeb4 r5:9e93d5e8 r4:9e93d400
[<8044e0c4>] (thermal_zone_get_temp) from [<8044fd14>] (thermal_zone_device_update+0x34/0xec)
r6:808e1978 r5:9e93d400 r4:9e93d608 r3:8045298c
[<8044fce0>] (thermal_zone_device_update) from [<8044fde8>] (thermal_zone_device_check+0x1c/0x20)
r5:9e481380 r4:9e93d608
[<8044fdcc>] (thermal_zone_device_check) from [<80038d50>] (process_one_work+0x160/0x3d4)
[<80038bf0>] (process_one_work) from [<80039754>] (worker_thread+0x5c/0x4f4)
r10:9f72ef40 r9:00000008 r8:9e481380 r7:9e481398 r6:9f72ef40 r5:9f1ee020
r4:9f72ef54
[<800396f8>] (worker_thread) from [<8003e020>] (kthread+0xf0/0x108)
r10:00000000 r9:00000000 r8:00000000 r7:800396f8 r6:9e481380 r5:00000000
r4:9e4f2ec0
[<8003df30>] (kthread) from [<8000eb60>] (ret_from_fork+0x14/0x34)
r7:00000000 r6:00000000 r5:8003df30 r4:9e4f2ec0
Code: e3140040 1a00001a e3140020 1a000016 (e596002c)
---[ end trace 193c15c2494ec960 ]---

Fixes: bdb0066df96e (mfd: syscon: Decouple syscon interface from platform devices)
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

regmap: Export regmap_get_val_endian

We'll need to call it from regmap-i2c.c, which can be built as module.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: fix possible ZERO_SIZE_PTR pointer dereferencing error.

Since we cannot make sure the 'val_count' will always be none zero
here, and then if it equals to zero, the kmemdup() will return
ZERO_SIZE_PTR, which equals to ((void *)16).

So this patch fix this with just doing the zero check before calling
kmemdup().

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

regmap: fix NULL pointer dereference in _regmap_write/read

If LOG_DEVICE is defined and map->dev is NULL it will lead to NULL
pointer dereference. This patch fixes this issue by adding check for
dev->NULL in all such places in regmap.c

Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

regmap: fix NULL pointer dereference in regmap_get_val_endian

Recents commits for getting reg endianness causing NULL pointer
dereference if dev is passed NULL in regmap_init_mmio. This patch
fixes this issue, and allows to parse reg endianness only if dev
and dev->of_node exist.

Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Split regmap_get_endian() in two functions

Split regmap_get_endian() in two functions, regmap_get_reg_endian() and
regmap_get_val_endian().

This allows to:
- Get rid of the three switch()es on "type", incl. error handling in
three "default" cases,
- Get rid of the regmap_endian_type enum,
- Get rid of the non-NULL check of "config" (regmap_init() already
checks for that),
- Get rid of the "endian" output parameters, and just return the
regmap_endian enum value, as the functions can no longer fail.

This saves 21 lines of code (despite the still-present
one-comment-per-line over-documentation), and 30 bytes of code on ARM
V7.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Fix handling of volatile registers for format_write() chips

A previous over-zealous factorisation of code means that we only treat
registers as volatile if they are readable. For most devices this is fine
since normally most registers can be read and volatility implies
readability but for format_write() devices where there is no readback from
the hardware and we use volatility to mean simply uncacheability this means
that we end up treating all registers as cacheble.

A bigger refactoring of the code to clarify this is in order but as a fix
make a minimal change and only check readability when checking volatility
if there is no format_write() operation defined for the device.

Signed-off-by: Mark Brown <broonie@linaro.org>
Tested-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: stable@vger.kernel.org

regmap: of_regmap_get_endian() cleanup

Commit d647c199510c ("regmap: add DT endianness binding support") had
some issues. Commit ba1b53feb8ca ("regmap: Fix DT endianess parsing
logic") fixed the main problem. This patch fixes the other.

Specifically, restore the overall default of REGMAP_ENDIAN_BIG if none of
the config, DT, or the bus specify any endianness. Without this,
of_regmap_get_endian() could return REGMAP_ENDIAN_DEFAULT, which the
calling code can't handle. Since all busses do specify an endianness in
the current code, this makes no difference right now, but I saw no
justification in the patch description for removing this final default.

Also, clean up the code a bit:

* s/of_regmap_get_endian/regmap_get_endian/ since the function isn't DT-
specific, even if the reason it was originally added was to add some
DT-specific features.
* After potentially reading an endianess specification from DT, the code
checks whether DT did specify an endianness, and if so, returns it. Move
this test outside the whole switch statement so that if the
REGMAP_ENDIAN_REG case ever modifies *endian, this check will pick that
up. This partially reverts part of commit ba1b53feb8ca ("regmap: Fix DT
endianess parsing logic"), while maintaining the bug-fix that commit
made to this code.
* Make the comments briefer, and only refer to the specific action taken
at their location. This makes most of the comments independent of DT,
and easier to follow.

Cc: Xiubo Li <Li.Xiubo@freescale.com>
Cc: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Cc: Thierry Reding <treding@nvidia.com>
Fixes: d647c199510c ("regmap: add DT endianness binding support")
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Fix DT endianess parsing logic

Commit d647c199510c ("regmap: add DT endianness binding support.")
added support to parse the device endianness from the device tree
but unfortunately the added logic doesn't have the same semantics
than the old code. This leads to a NULL dereference pointer error
when these properties are not provided by the Device Tree:

Unable to handle kernel NULL pointer dereference at virtual address 00000044
pgd = c0004000
[00000044] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 5 PID: 1 Comm: swapper/0 Not tainted 3.17.0-rc1-next-20140818ccu #671
task: ea412800 ti: ea484000 task.ti: ea484000
PC is at regmap_update_bits+0xc/0x5c

The problem is that platforms that rely on the default value now
gets different values due two related issues in the current code:

a) It only parses the endianness from DT for the regmap registers
and not for the regmap values but it checks unconditionally in
both cases if the resulting endiannes is REGMAP_ENDIAN_NATIVE.

b) REGMAP_ENDIAN_NATIVE is not even a valid DT property according
to the regmap DT binding documentation so it shouldn't be set.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: add DT endianness binding support.

For many drivers which will support rich endianness of Devices
need define DT properties by itself with the binding support.

The endianness using regmap:
Index Device Properties if needs bytes-swap,
or just ignore it
-------------------------------------------------------------
1 BE 'big-endian'
2 LE 'little-endian'

The properties include all the register values and the buffers.
And these properties are very usful for the MMIO devices:

Such as: a memory-mapped device, on one SoC is in BE mode, while
in another SoC will be in LE mode, and the CPU will always in LE
mode.

For the first case, we must use cpu_to_be32/be32_to_cpu for
32-bit registers accessing, so the 'big-endian' property is needed.

For the second case, we can just ignore the bytes-swap
functions like cpu_to_le32/le32_to_cpu, so the 'little-endian'
property could be abscent.

And vice versa...

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Allow regmap_get_device() to be used by modules

Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Add regmap_get_device

Add a new function regmap_get_device to obtain the underlying struct
device from a regmap.

Signed-off-by: Tuomas Tynkkynen <ttynkkynen@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Add missing initialization of this_page

drivers/base/regmap/regmap.c: In function ‘_regmap_range_multi_paged_reg_write’:
drivers/base/regmap/regmap.c:1665: warning: ‘this_page’ may be used uninitialized in this function

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Fix possible ZERO_SIZE_PTR pointer dereferencing error.

Since we cannot make sure the 'len = pair_size * num_regs' will always
be none zero from the users, and then if 'num_regs' equals to zero by
mistake or other reasons, the kzalloc() will return ZERO_SIZE_PTR, which
equals to ((void *)16).

So this patch fix this with just doing the 'len' zero check before calling
kzalloc().

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: add reg_read/reg_write callbacks to regmap_bus struct

Some busses do not support sending/receiving multiple registers in one go.
Such kind of busses just unpack the registers that have been previously
packed by the regmap core or pack registers that will be later unpacked by
the core code.

Add reg_write and reg_read callbacks in order to optimize access through
this kind of busses.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: implement LE formatting/parsing for 16/32-bit values.

Allow busses to request little endianness formatting and
parsing for 16- and 32-bit values. This will be useful to
support regmap-mmio.

For the following the scenarios using the regmap-mmio,
for example:

Index CPU Device Endianess flag for values
----------------------------------------------------------
1 LE LE REGMAP_ENDIAN_DEFAULT/NATIVE
2 LE BE REGMAP_ENDIAN_BIG
3 BE BE REGMAP_ENDIAN_DEFAULT/NATIVE
4 BE LE REGMAP_ENDIAN_LITTLE

For one device driver, which will support all the cases above,
needs two boolean properties in DT node like: 'big-endian'
for case 2 and 'little-endian' for case 4, and for cases 1
and 3 they all will be absent.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: adds missing braces in regmap_init()

It need to add curly braces because the inner for "if" has
two statements.

coccicheck says:
drivers/base/regmap/regmap.c:765:2-44:
code aligned with following code on line 766

Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Fix possible sleep-in-atomic in regmap_bulk_write()

regmap deploys the spinlock for the protection when set up in fast_io
mode. This may lead to sleep-in-atomic by memory allocation with
GFP_KERNEL in regmap_bulk_write(). This patch fixes it by moving the
allocation out of the lock.

[Fix excessively large locked region -- broonie]

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Ensure regmap_register_patch() is compatible with fast_io

With fast_io we use mutexes to lock the I/O operations so we would need
to do GFP_ATOMIC allocations if we wanted to do allocations inside the
lock as we do currently. Since it is unlikely that we will want to register
a patch outside of init where concurrency shouldn't be an issue move the
allocation of the patch data outside the lock.

Reported-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Implementation for regmap_multi_reg_write

This is the implementation of regmap_multi_reg_write()

There is a new capability 'can_multi_write' that device drivers
must set in order to use this multi reg write mode.

This replaces the first definition, which just defined the API.

Signed-off-by: Anthony Olech <anthony.olech.opensource@diasemi.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: add regmap_parse_val api

In some cases, we need regmap's format parse_val function
to do be/le translation according to the bus configuration.
For example, snd_soc_bytes_put() uses regmap to write/read values,
and use cpu_to_be() directly to covert MASK into big endian. This
is a defect, and should use regmap's format function to do it according
to bus configuration.

Signed-off-by: Nenghua Cao <nhcao@marvell.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Base regmap_register_patch on _regmap_multi_reg_write

Since we now have an internal version of regmap_multi_reg_write use this
to apply the register patch.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Add bypassed version of regmap_multi_reg_write

Devices with more complex boot proceedures may occasionally apply the
register patch manual. regmap_multi_reg_write is a logical way to do so,
however the patch must be applied with cache bypass on, such that it
doesn't override any user settings. This patch adds a
regmap_multi_reg_write_bypassed function that applies a set of writes
with the bypass enabled.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Mark reg_defaults in regmap_multi_reg_write as const

There should be no need for the writes supplied to this function to be
edited by it so mark them as const.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: fix coccinelle warnings

/drivers/base/regmap/regmap.c:717:6-33: WARNING:
Comparison to bool.

More information about semantic patching is available at
http://coccinelle.lip6.fr/

Signed-off-by: Nenghua Cao <nhcao@marvell.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Check stride of register patch as we register it

Currently, we check the registers in the patch are aligned to the
register stride everytime we sync the cache and the first time the patch
is written out is unchecked.

This patch checks the register patch when we first register it so the
first writes are no longer unchecked and then doesn't check on
subsequent syncs as the patch will be unchanged.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Clean up _regmap_update_bits()

Since sometimes the 'config' parameter has no use, it should be NULL.
And make the code simplifier.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Separate regmap dev initialization

Create special function regmap_attach_dev
which can be called separately out of regmap_init.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Check readable regs in _regmap_read

Check if regs are readable.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Allow regmap_bulk_write() to work for "no-bus" regmaps

regmap_bulk_write() should decay to performing individual writes
if we're using a "no-bus" regmap. Unfortunately, it returns an
error because there is no map->bus pointer. Fix it.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Allow regmap_bulk_read() to work for "no-bus" regmaps

regmap_bulk_read() should decay to performing individual reads if
we're using a "no-bus" regmap. Unfortunately, it returns an
error because there is no map->bus pointer. Fix it.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Fix 'ret' would return an uninitialized value

This patch give a warning when calling regmap_register_patch with
parameter num_regs <= 0.

When the num_regs parameter is zero and krealloc doesn't fail,
then the code would return an uninitialized value. However,
calling this function with num_regs == 0, would be a waste as it
essentially does nothing.

Signed-off-by: Cai Zhiyong <caizhiyong@huawei.com>
Reviewed-by: Geyslan G. Bem <geyslan@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: make sure we unlock on failure in regmap_bulk_write

Signed-off-by: Courtney Cavin <courtney.cavin@sonymobile.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: trivial comment fix (copy'n'paste error)

fix a trivial copy'n'paste error in the regmap kerneldoc, s/write/read/
for the regmap_read(), regmap_raw_read() and regmap_bulk_read() routines

Signed-off-by: Gerhard Sittig <gsi@denx.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Only send a single buffer for async I/O if writing one register

Extend the interface for async I/O by allowing the value buffer to be
omitted and sending the value as part of the register buffer, minimising
the number of separate hardware operations required.

Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: new API regmap_multi_reg_write() definition

New API regmap_multi_reg_write() is defined that allows a set of reg,val
pairs to be written to a I2C client device as one block transfer from the
point of view of a single I2C master system.

A simple demonstration implementation is included that just splits the
block write request into a sequence of single register writes.

The implementation will be modified later to support those I2C clients
that implement the alternative non-standard MULTIWRITE block write mode
so to achieve a single I2C transfer that will be atomic even in multiple
I2C master systems.

Signed-off-by: Anthony Olech <anthony.olech.opensource@diasemi.com>
Signed-off-by: David Dajun Chen <david.chen@diasemi.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Use async I/O for patch application

Try to speed up patch application a little using async I/O.

Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Fix regmap_bulk_write single-rw mutex deadlock

When regmap_bulk_write() is called with the map->use_single_rw flag set
an immediate mutex deadlock happens because regmap_raw_write() is called
after obtaining the mutex and regmap_raw_write() itself then tries to
obtain the mutex as well.

It is obvious that no one other than myself tried it with a real device.
I did, but only for the purposes of an experiment and demonstration.

But even if this situation will never ever happen with a real device, it
is a bug and therefore should be fixed.

Signed-off-by: Anthony Olech <anthony.olech.opensource@diasemi.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Provide asynchronous write and update bits operations

Make it easier for drivers to include single register writes in
asynchronous sequences by providing async versions of the write
and update bits operations. The update bits operations are only
likely to be effective when used with devices that have caches
but this is common enough to be useful.

Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Simplify the initiation of async I/O

Rather than passing a flag around through the entire call stack store it
in the regmap struct and read it when required. This minimises the
visibility of the feature through the API, minimising the code updates
needed to use it more widely.

Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Don't generate gather writes for single register raw writes

Since it is quite common for single register raw or async writes to be
generated by rbtree cache syncs or firmware downloads and essentially all
hardware will be faster with only a single transfer optimise this case by
copying single values into the internal scratch buffer before sending.

Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Cache async work structures

Rather than allocating and deallocating the structures used to manage async
transfers each time we do one keep the structures around as long as the
regmap is around. This should provide a small performance improvement.

Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Add regmap_fields APIs

Current Linux kernel is supporting regmap_field method
and it is very useful feature.
It needs one regmap_filed for one register access.

OTOH, there is multi port device which
has many same registers in the market.
The difference for each register access is
only its address offset.

Current API needs many regmap_field for such device,
but it is not good.
This patch adds new regmap_fileds API which can care
about multi port/offset access via regmap.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: add regmap_field_update_bits()

Current regmap_field is supporting read/write functions.
This patch adds new update_bits function for it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Allow multiple patches to be registered

It may be useful to register multiple patches with regmap, for example
one that depends on the device revision and one that depends on the system
configuration. Add support for doing this, appending any new patches to
the existing patches.

Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: regcache: allow read-only regs to be cached

The regmap_writeable() check should not be done in
regcache_write() because this prevents read-only
registers to be cached. After a read on a read-only
register its value will not be stored in the cache
and the next time someone will try to read it the
value will be read from the bus instead of the
cache.

Instead the regmap_writeable() check should be done
in _regmap_write() to prevent callers from writing
to read-only registers.

Signed-off-by: Ionut Nicu <ioan.nicu.ext@nsn.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: core: allow a virtual range to cover its own data window

I see no reason why a virtual range shouldn't be allowed to cover its
own data window if the page selection register is in the same place
on every page.
For chips which use paged access for all of their registers, but only
when connected via I2C, and which can access the whole register space
directly when connected via SPI, this allows to avoid acrobatics with
the register ranges by simply mapping the I2C ranges over the data
window beginning at 0x0, and then using linear access for the SPI
variant.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Provide __acquires/__releases annotations

Fix the following sparse warnings:

drivers/base/regmap/regmap.c:305:13: warning: context imbalance in 'regmap_lock_spinlock' - wrong count at exit
drivers/base/regmap/regmap.c:314:13: warning: context imbalance in 'regmap_unlock_spinlock' - unexpected unlock

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: cache: bail in regmap_async_complete() for bus-less maps

Commit f8bd822cb ("regmap: cache: Factor out block sync") made
regcache_rbtree_sync() call regmap_async_complete(), which in turn does
not check for map->bus before dereferencing it.

This causes a NULL pointer dereference on bus-less maps.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Cc: stable@vger.kernel.org [v3.10 only]
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Add regmap_field APIs

It is common to access regmap registers at bit level, using
regmap_update_bits or regmap_read functions, however the end user has to
take care of a mask or shifting. This becomes overhead when such use
cases are high. Having a common function to do this is much convenient
and less error prone.

The idea of regmap_field is simple, regmap_field gives a logical
structure to bits of the regmap register, and the driver can use this
logical entity without the knowledge of the bit positions and masks all
over the code. This way code looks much neat and it need not handle the
masks, shifts every time it access the those entities.

With this new regmap_field_read/write apis the end user can setup a
regmap field using regmap_field_init and use the return regmap_field to
read write the register field without worrying about the masks or
shifts.

Also this apis will be useful for drivers which are based on regmaps,
like some clocks or pinctrls which can work on the regmap_fields
directly without having to worry about bit positions.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: core: Cache all registers by default when cache is enabled

Currently all register maps with a cache need to provide a volatile
callback since the default is to assume all registers are volatile.
This is not sensible if we have a cache so change the default to be
fully cached if a cache is provided.

Signed-off-by: Mark Brown <broonie@linaro.org>

regmap: Make regmap-mmio usable from atomic contexts

regmap-mmio uses a spinlock with spin_lock() and spin_unlock() for locking.
To be able to use the regmap API from different contexts (atomic vs non-atomic),
without the risk of race conditions, we need to use spin_lock_irqsave() and
spin_lock_irqrestore() instead. A new field, the spinlock_flags field, is added
to regmap struct to store the flags between regmap_{,un}lock_spinlock(). The
spinlock_flags field itself is also protected by the spinlock.

Thanks to Stephen Warren for the suggestion of this particular solution.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Make regmap_check_range_table() a public API

Allow drivers to use an access table as part of their implementation.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: don't corrupt work buffer in _regmap_raw_write()

_regmap_raw_write() contains code to call regcache_write() to write
values to the cache. That code calls memcpy() to copy the value data to
the start of the work_buf. However, at least when _regmap_raw_write() is
called from _regmap_bus_raw_write(), the value data is in the work_buf,
and this memcpy() operation may over-write part of that value data,
depending on the value of reg_bytes + pad_bytes. At least when using
reg_bytes==1 and pad_bytes==0, corruption of the value data does occur.

To solve this, remove the memcpy() operation, and modify the subsequent
.parse_val() call to parse the original value buffer directly.

At least in the case of 8-bit register address and 16-bit values, and
writes of single registers at a time, this memcpy-then-parse combination
used to cancel each-other out; for a work-buffer containing xx 89 03,
the memcpy changed it to 89 03 03, and the parse_val changed it back to
89 89 03, thus leaving the value uncorrupted. This appears completely
accidental though. Since commit 8a819ff "regmap: core: Split out in
place value parsing", .parse_val only returns the parsed value, and does
not modify the buffer, and hence does not (accidentally) undo the
corruption caused by memcpy(). This caused bogus values to get written
to HW, thus preventing e.g. audio playback on systems with a WM8903
CODEC. This patch fixes that.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Back out work buffer fix

This reverts commit bc8ce4 (regmap: don't corrupt work buffer in
_regmap_raw_write()) since it turns out that it can cause issues when
taken in isolation from the other changes in -next that lead to its
discovery. On the basis that nobody noticed the problems for quite some
time without that subsequent work let's drop it from v3.9.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: async: Add missing return

Let's only write once...

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: core: Provide regmap_can_raw_write() operation

Mainly useful internally but exported since this is a public API that's
being checked for.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: core: Make raw write available to regcache

This allows the cache to sync values directly to the device when stored
in native format and also allows asynchronous I/O.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: core: Warn on invalid operation combinations

Don't grind to a screaming halt, just generate a warning.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: don't corrupt work buffer in _regmap_raw_write()

_regmap_raw_write() contains code to call regcache_write() to write
values to the cache. That code calls memcpy() to copy the value data to
the start of the work_buf. However, at least when _regmap_raw_write() is
called from _regmap_bus_raw_write(), the value data is in the work_buf,
and this memcpy() operation may over-write part of that value data,
depending on the value of reg_bytes + pad_bytes. At least when using
reg_bytes==1 and pad_bytes==0, corruption of the value data does occur.

To solve this, remove the memcpy() operation, and modify the subsequent
.parse_val() call to parse the original value buffer directly.

At least in the case of 8-bit register address and 16-bit values, and
writes of single registers at a time, this memcpy-then-parse combination
used to cancel each-other out; for a work-buffer containing xx 89 03,
the memcpy changed it to 89 03 03, and the parse_val changed it back to
89 89 03, thus leaving the value uncorrupted. This appears completely
accidental though. Since commit 8a819ff "regmap: core: Split out in
place value parsing", .parse_val only returns the parsed value, and does
not modify the buffer, and hence does not (accidentally) undo the
corruption caused by memcpy(). This caused bogus values to get written
to HW, thus preventing e.g. audio playback on systems with a WM8903
CODEC. This patch fixes that.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Initialize `map->debugfs' before regcache

In the rbtree code we are exposing statistics relating to the
number of nodes/registers of the rbtree cache for each of the
devices. Ensure that `map->debugfs' has been initialized before
we attempt to initialize the debugfs entry for the rbtree cache.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org

regmap: core: Split out in place value parsing

Currently the value parsing operations both return the parsed value and
modify the passed buffer. This precludes their use in places like the cache
code so split out the in place modification into a new parse_inplace()
operation.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: async: Add tracepoints for async I/O

Trace when we start and complete async writes, and when we start and
finish blocking for their completion. This is useful for performance
analysis of the resulting I/O patterns.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Export regmap_async_complete()

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Export regmap_async_complete_cb

This fixes below build error when CONFIG_REGMAP=y && CONFIG_REGMAP_SPI=m

ERROR: "regmap_async_complete_cb" [drivers/base/regmap/regmap-spi.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: include linux/sched.h to fix build

This fixes:

drivers/base/regmap/regmap.c: In function 'regmap_async_complete_cb':
drivers/base/regmap/regmap.c:1656:3: error: 'TASK_NORMAL' undeclared (first use in this function)
drivers/base/regmap/regmap.c:1656:3: note: each undeclared identifier is reported only once for each function it appears in
drivers/base/regmap/regmap.c: In function 'regmap_async_complete':
drivers/base/regmap/regmap.c:1688:2: error: 'TASK_UNINTERRUPTIBLE' undeclared (first use in this function)
drivers/base/regmap/regmap.c:1688:2: error: implicit declaration of function 'schedule'

An alternative might be to adjust linux/wait.h to include linux/sched.h,
but since that hasn't been done before, I assume we're consciously
avoiding doing that.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add asynchronous I/O support

Some use cases like firmware download can transfer a lot of data in quick
succession. With high speed buses these use cases can benefit from having
multiple transfers scheduled at once since this allows the bus to minimise
the delay between transfers.

Support this by adding regmap_raw_write_async(), allowing raw transfers to
be scheduled, and regmap_async_complete() to wait for them to finish.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add "no-bus" option for regmap API

This commit adds provision for "no-bus" usage of the regmap API. In
this configuration user can provide API with two callbacks 'reg_read'
and 'reg_write' which are to be called when reads and writes to one of
device's registers is performed. This is useful for devices that
expose registers but whose register access sequence does not fit the 'bus'
abstraction.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: fix small typo in regmap_bulk_write comment

Signed-off-by: Nestor Ovroy <novroy@riseup.net>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add provisions to have user-defined write operation

This commit is a preparatory commit to provide "no-bus" configuration
option for regmap API. It adds necessary plumbing needed to have the
ability to provide user define register write function.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add provisions to have user-defined read operation

This commit is a preparatory commit to provide "no-bus" configuration
option for regmap API. It adds necessary plumbing needed to have the
ability to provide user define register read function.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add support for 24 bit wide register addresses

Since regmap already has support for formatting 24 bit wide values, so adding
support for 24 bit wide registers is pretty much straight forward.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: introduce tables for readable/writeable/volatile/precious checks

Many of the regmap enabled drivers implementing one or more of the
readable, writeable, volatile and precious methods use the same code
pattern:

return ((reg >= X && reg <= Y) || (reg >= W && reg <= Z) || ...)

Switch to a data driven approach, using tables to describe
readable/writeable/volatile and precious registers ranges instead.
The table based check can still be overridden by passing the usual function
pointers via struct regmap_config.

Signed-off-by: Davide Ciminaghi <ciminaghi@gnudd.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: core: Report registers in hex when we can't cache

This seems to be the most common way of reporting register numbers, it's
certainly what we do for trace.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Fix printing of size_t variable

val_bytes is of 'size_t', so it should be printed as '%zu'.

Fixes the following build warning on x86:

drivers/base/regmap/regmap.c:872:4: warning: format '%d' expects argument of type 'int', but argument 5 has type 'size_t' [-Wformat]

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: make lock/unlock functions customizable

It is sometimes convenient for a regmap user to override the standard
regmap lock/unlock functions with custom functions.
For instance this can be useful in case an already existing spinlock
or mutex has to be used for locking a set of registers instead of the
internal regmap spinlock/mutex.
Note that the fast_io field of struct regmap_bus is ignored in case
custom locking functions are used.

Signed-off-by: Davide Ciminaghi <ciminaghi@gnudd.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: silence GCC warning

Building regmap.o triggers this GCC warning:
drivers/base/regmap/regmap.c: In function ‘regmap_raw_read’:
drivers/base/regmap/regmap.c:1172:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]

Long story short: Jakub Jelinek pointed out that there is a type
mismatch between 'num' in regmap_volatile_range() and 'val_count' in
regmap_raw_read(). And indeed, converting 'num' to the type of
'val_count' (ie, size_t) makes this warning go away.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Split raw writes that cross window boundaries

If a block write covers a paged memory region and crosses a window
boundary then rather than failing the write split the transfer up
into multiple writes, making the whole process more transparent for
drivers.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Make return code checks consistent

The range code was written to check for return codes less than zero as
errors but throughout the rest of the API return codes not equal to zero
are errors. Change all these checks to match the house style.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Factor range lookup out of page selection

This will support a subsequent update to allow bulk writes to cross window
boundaries.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Provide debugfs read of register ranges

If a register range is named then provide a debugfs file showing the
contents of the range separately.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Allow ranges to be named

For more useful diagnostics.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: When we sanity check during range adds say what errors we find

Rather than just returning a single error code for every possible thing we
can notice print an error message saying what the problem was. This makes
it very much easier to figure out what's wrong and fix it.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Rename n_ranges to num_ranges

This makes things consistent with the rest of the API and is actually what
the documentation says. We don't currently have any in tree users so low
cost.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Don't lock in regmap_reinit_cache()

When bus->fast_io is set, the locking here is done with spinlocks.
This is currently true for the regmap-mmio bus implementation.

While holding a spinlock we can't go to sleep, various operations
like removing the debugfs entries or re-initializing the cache will
sleep, therefore, shift the locking up to the user.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add hook for printk logging for debugging during early init

Sometimes for failures during very early init the trace infrastructure
isn't available early enough to be used. For this sort of problem
defining LOG_DEVICE will add printks for basic register I/O on a specific
device, allowing trace to be extracted when the trace system doesn't come
up early enough to work with.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Fix work_buf switching for page update during virtual range access.

After page update, orginal work_buf has to be restored regardless of
the result.

Signed-off-by: Krystian Garbaciak <krystian.garbaciak@diasemi.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add support for register indirect addressing.

Devices with register paging or indirectly accessed registers can configure
register mapping to map those on virtual address range. During access to
virtually mapped register range, indirect addressing is processed
automatically, in following steps:
1. selector for page or indirect register is updated (when needed);
2. register in data window is accessed.

Configuration should provide minimum and maximum register for virtual range,
details of selector field for page selection, minimum and maximum register of
data window for indirect access.

Virtual range registers are managed by cache as well as direct access
registers. In order to make indirect access more efficient, selector register
should be declared as non-volatile, if possible.

struct regmap_config is extended with the following:
struct regmap_range_cfg *ranges;
unsigned int n_ranges;

[Also reordered debugfs init to later on since the cleanup code was
conflicting with the new cleanup code for ranges anyway -- broonie]

Signed-off-by: Krystian Garbaciak <krystian.garbaciak@diasemi.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Move lock out from internal function _regmap_update_bits().

Locks are moved to regmap_update_bits(), which allows to reenter internal
function _regmap_update_bits() from inside of regmap read/write routines.

Signed-off-by: Krystian Garbaciak <krystian.garbaciak@diasemi.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Export regmap_reinit_cache()

It's supposed to be there for drivers.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Fix the size calculation for map->format.buf_size

The word to be transmitted/received via regmap is composed by the following
parts:

config->reg_bits
config->val_bits
config->pad_bits

,so the total size should be calculated by summing up the number of bits of
each element and using a DIV_ROUND_UP to return the number of bytes.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: clean up debugfs if regmap_init fails

If debugfs isn't cleaned up, stale files will be left in the filesystem
which will cause an OOPS when accessed the first time, and hang the
accessing application when accessed again, presumably due to some lock
being left held.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: allow busses to request formatting with specific endianness

Add a field to struct regmap_bus that allows bus drivers to request that
register addresses and values be formatted with a specific endianness.

The default endianness is unchanged from current operation: Big.

Implement native endian formatting/parsing for 16- and 32-bit values.
This will be enough to support regmap-mmio.c.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: fix possible memory corruption in regmap_bulk_read()

The function regmap_bulk_read() calls the regmap_read() for
each register if set of register has volatile and cache is
enabled. In this case, last few register read makes the memory
corruption if the register size is not the size of unsigned int.
The regam_read() takes argument as unsigned int for returning
value and it update the value as
*val = map->format.parse_val(map->work_buf);
This causes complete 4 bytes (size of unsigned int) to get written.
Now if client pass the memory pointer for value which is equal to the
required size of register count in regmap_bulk_read() then last few
register read actually update the memory beyond passed pointer size.

Avoid this by using local variable for read and then do memcpy()
for actual byte copy to passed pointer based on register size.

I allocated one pointer ptr and take first 16 bytes dump of that
pointer then call regmap_bulk_read() with pointer which is just
on top of this allocated pointer and register count of 128. Here
register size is 1 byte.
The memory trace of last 5 register read are as follows:

[ 5.438589] regmap_bulk_read after regamp_read() for register 122
[ 5.447421] 0xef993c20 0xef993c00 0x00000000 0x00000001
[ 5.467535] regmap_bulk_read after regamp_read() for register 123
[ 5.476374] 0xef993c20 0xef993c00 0x00000000 0x00000001
[ 5.496425] regmap_bulk_read after regamp_read() for register 124
[ 5.505260] 0xef993c20 0xef993c00 0x00000000 0x00000001
[ 5.525372] regmap_bulk_read after regamp_read() for register 125
[ 5.534205] 0xef993c00 0xef993c00 0x00000000 0x00000001
[ 5.554258] regmap_bulk_read after regamp_read() for register 126
[ 5.563100] 0xef990000 0xef993c00 0x00000000 0x00000001
[ 5.554258] regmap_bulk_read after regamp_read() for register 127
[ 5.587108] 0xef000000 0xef993c00 0x00000000 0x00000001

Here it is observed that the memory content at first word started changing
on last 3 regmap_read() and so corruption happened.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Implement dev_get_regmap()

Use devres to implement dev_get_regmap(). This should mean that in almost
all cases devices wishing to take advantage of framework features based on
regmap shouldn't need to explicitly pass the regmap into the framework.
This simplifies device setup a bit.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Devices using format_write don't support bulk operations

Set the use_single_rw flag for devices that use format_write() since
format_write() doesn't support any form of block operation.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Converts group operation into single read write operations

Some devices does not support bulk read and write operations, for them
we have series of single write and read operations.

Signed-off-by: Anthony Olech <Anthony.Olech@diasemi.com>
Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
[Fixed coding style, don't check use_single_rw before assign --broonie ]
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Cache single values read from the chip

If we don't have a cached value for a register and we can cache it then
when we do a read a value we should add it to the cache to save rereading
it later on. Do this for single register reads, for block reads the code
would be a little more complex and this covers most practical usage.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: implement register striding

regmap_config.reg_stride is introduced. All extant register addresses
are a multiple of this value. Users of serial-oriented regmap busses will
typically set this to 1. Users of the MMIO regmap bus will typically set
this based on the value size of their registers, in bytes, so 4 for a
32-bit register.

Throughout the regmap code, actual register addresses are used. Wherever
the register address is used to index some array of values, the address
is divided by the stride to determine the index, or vice-versa. Error-
checking is added to all entry-points for register address data to ensure
that register addresses actually satisfy the specified stride. The MMIO
bus ensures that the specified stride is large enough for the register
size.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: allow regmap instances to be named

Some devices have multiple separate register regions. Logically, one
regmap would be created per region. One issue that prevents this is that
each instance will attempt to create the same debugfs files. Avoid this
by allowing regmaps to be named, and use the name to construct the
debugfs directory name.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: validate regmap_raw_read/write val_len

val_len should be a multiple of val_bytes. If it's not, error out early.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: introduce fast_io busses, and use a spinlock for them

Some bus types have very fast IO. For these, acquiring a mutex for every
IO operation is a significant overhead. Allow busses to indicate their IO
is fast, and enhance regmap to use a spinlock for those busses.

[Currently limited to native endian registers -- broonie]

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: introduce explicit bus_context for bus callbacks

The only context needed by I2C and SPI bus definitions is the device
itself; this can be converted to an i2c_client or spi_device in order
to perform IO on the device. However, other bus types may need more
context in order to perform IO. Enable this by having regmap_init accept
a bus_context parameter, and pass this to all bus callbacks. The
existing callbacks simply pass the struct device here. Future bus types
may pass something else.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Use pad_bits and reg_bits when determining register format.

This change combines any padding bits into the register address bits when
determining register format handlers to use the next byte-divisible
register size.
A reg_shift member is introduced to the regmap struct to enable fixup
of the reg format.
Format handlers now take an extra parameter specifying the number of
bits to shift the value by.

Signed-off-by: Marc Reilly <marc@cpdesign.com.au>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add support for device with 24 data bits.

Add support for devices with 24 data bits.

Signed-off-by: Marc Reilly <marc@cpdesign.com.au>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: implement register striding

regmap_config.reg_stride is introduced. All extant register addresses
are a multiple of this value. Users of serial-oriented regmap busses will
typically set this to 1. Users of the MMIO regmap bus will typically set
this based on the value size of their registers, in bytes, so 4 for a
32-bit register.

Throughout the regmap code, actual register addresses are used. Wherever
the register address is used to index some array of values, the address
is divided by the stride to determine the index, or vice-versa. Error-
checking is added to all entry-points for register address data to ensure
that register addresses actually satisfy the specified stride. The MMIO
bus ensures that the specified stride is large enough for the register
size.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: allow regmap instances to be named

Some devices have multiple separate register regions. Logically, one
regmap would be created per region. One issue that prevents this is that
each instance will attempt to create the same debugfs files. Avoid this
by allowing regmaps to be named, and use the name to construct the
debugfs directory name.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: validate regmap_raw_read/write val_len

val_len should be a multiple of val_bytes. If it's not, error out early.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: introduce fast_io busses, and use a spinlock for them

Some bus types have very fast IO. For these, acquiring a mutex for every
IO operation is a significant overhead. Allow busses to indicate their IO
is fast, and enhance regmap to use a spinlock for those busses.

[Currently limited to native endian registers -- broonie]

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: introduce explicit bus_context for bus callbacks

The only context needed by I2C and SPI bus definitions is the device
itself; this can be converted to an i2c_client or spi_device in order
to perform IO on the device. However, other bus types may need more
context in order to perform IO. Enable this by having regmap_init accept
a bus_context parameter, and pass this to all bus callbacks. The
existing callbacks simply pass the struct device here. Future bus types
may pass something else.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Use pad_bits and reg_bits when determining register format.

This change combines any padding bits into the register address bits when
determining register format handlers to use the next byte-divisible
register size.
A reg_shift member is introduced to the regmap struct to enable fixup
of the reg format.
Format handlers now take an extra parameter specifying the number of
bits to shift the value by.

Signed-off-by: Marc Reilly <marc@cpdesign.com.au>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add support for device with 24 data bits.

Add support for devices with 24 data bits.

Signed-off-by: Marc Reilly <marc@cpdesign.com.au>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

device.h: cleanup users outside of linux/include (C files)

For files that are actively using linux/device.h, make sure
that they call it out. This will allow us to clean up some
of the implicit uses of linux/device.h within include/*
without introducing build regressions.

Yes, this was created by "cheating" -- i.e. the headers were
cleaned up, and then the fallout was found and fixed, and then
the two commits were reordered. This ensures we don't introduce
build regressions into the git history.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

regmap: Fix future missing prototype of devres_alloc() and friends

[Fix for breakage which will be introduced during the merge window via
header reworks in another tree, the regmap tree does include device.h
but Paul's tree breaks that. Reworded subject to reflect -- broonie]

regmap.s uses devres_alloc() and others that are prototyped in device.h.
Include that to solve the following:

drivers/base/regmap/regmap.c: In function 'devm_regmap_init':
drivers/base/regmap/regmap.c:331:2: error: implicit declaration of function 'devres_alloc' [-Werror=implicit-function-declaration]
drivers/base/regmap/regmap.c:338:3: error: implicit declaration of function 'devres_add' [-Werror=implicit-function-declaration]
drivers/base/regmap/regmap.c:340:3: error: implicit declaration of function 'devres_free' [-Werror=implicit-function-declaration]
drivers/base/regmap/regmap.c: In function '_regmap_raw_write':
drivers/base/regmap/regmap.c:421:5: error: implicit declaration of function 'dev_err' [-Werror=implicit-function-declaration]

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: delete unused module.h from drivers/base/regmap files

Remove unused module.h and/or replace with export.h
as required.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Support raw reads from cached registers

Fall back to a register by register read to do so; most likely we'll be
cache only so the overhead will be low.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Allow users to query the size of register values

Generic infrastructure based on top of regmap may want to operate on
blocks of data and therefore find it useful to find the size of the
register values. Provide an accessor operation for this.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Implement support for 32 bit registers and values

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: add regmap_bulk_write() for register write

The bulk_write() supports the data transfer to multi
register which takes the data into cpu_endianness format
and does formatting of data to device format before
sending to device.
The transfer can be completed in single transfer or multiple
transfer based on data formatting.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Support for caching in reg_raw_write()

Adding support for caching of data into the
non-volatile register from the call of reg_raw_write().

This will allow the larger block of data write into multiple
register without worrying whether register is cached or not
through reg_raw_write().

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Fix kcalloc parameters swapped

The first parameter should be "number of elements" and the second parameter
should be "element size".

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Implement managed regmap_init()

Save error handling and unwinding code in drivers by providing managed
versions of the regmap init functions, simplifying usage.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: if format_write is used, declare all registers as "unreadable"

Using .format_write means, we have a custom function to write to the
chip, but not to read back. Also, mark registers as "not precious" and
"not volatile" which is implicit because we cannot read them. Make those
functions use 'regmap_readable' to reuse the checks done there.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Properly round reg_bytes and val_bytes

For the upcoming 2/6-format, we don't see debugfs output otherwise,
since the current division results in 0. I'd think 10/14 is broken
currently, too.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add support for 2/6 register formating

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Reset device debugfs when reinitialising the cache

Most of the data exposed via debugfs is for or from the cache so reset
all the debugfs configuration to make sure everything is up to date with
the latest configuration, especially if we're changing cache type.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Support register patch sets

Device manufacturers frequently provide register sequences, usually not
fully documented, to be run at startup in order to provide better defaults
for devices (for example, improving performance in the light of silicon
evaluation). Support such updates by allowing drivers to register update
sets with the core. These updates will be written to the device immediately
and will also be rewritten when the cache is synced.

The assumption is that the reason for resyncing the cache will always be
that the device has been powered off. If this turns out to not be the case
then a separate operation can be provided.

Currently the implementation only allows a single set of updates to be
specified for a device, this could be extended in future.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Reset cache status when reinitialsing the cache

When we reinitialise the cache make sure that we reset the cache access
flags, ensuring that the reinitialised cache is in the default state
which is what callers would and do expect given the function name.

This is particularly likely to cause issues in systems where there was no
cache previously as those systems have cache bypass enabled, as for the
wm8994 driver where this was noticed.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add support for padding between register and address

Some devices, especially those with high speed control interfaces, require
padding between the register and the data. Support this in the regmap API
by providing a pad_bits configuration parameter.

Only devices with integer byte counts are supported.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Move initialization of regcache related fields to regcache_init

Move the initialization regcache related fields of the regmap struct to
regcache_init. This allows us to keep regmap and regcache code better
separated.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Allow drivers to reinitialise the register cache at runtime

Sometimes the register map information may change in ways that drivers can
discover at runtime. For example, new revisions of a device may add new
registers. Support runtime discovery by drivers by allowing the register
cache to be reinitialised with a new function regmap_reinit_cache() which
discards the existing cache and creates a new one.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Allow regmap_update_bits() users to detect changes

Some users of regmap_update_bits() would like to be able to tell their
users if they actually did an update so provide a variant which also
returns a flag indicating if an update took place. We could return a
tristate in the return value of regmap_update_bits() but this makes the
API more cumbersome to use and doesn't fit with the general zero for
success idiom we have.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Do debugfs init before cache init

This allows caches to add custom debugfs files.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Suppress noop writes in regmap_update_bits()

If the new register value is identical to the original one then suppress
the write to the hardware in regmap_update_bits(), saving some I/O cost.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add support for 10/14 register formating

This patch adds support for 10 bits register, 14 bits value type register
formating. This is for example used by the Analog Devices AD5380.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Try cached read before checking if a hardware read is possible

For some register format types we do not provide a parse_val so we can not do a
hardware read. But a cached read is still possible, so try to read from the
cache first, before checking whether a hardware read is possible. Otherwise the
cache becomes pretty useless for these register types.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Move initialization of regcache related fields to regcache_init

Move the initialization regcache related fields of the regmap struct to
regcache_init. This allows us to keep regmap and regcache code better
separated.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: return ERR_PTR instead of NULL in regmap_init

The regmap_init documentation states that it will either return a pointer to a
valid regmap structure or a ERR_PTR in case of an error. Currently it returns a
NULL pointer in case no bus or no config was given. Since NULL is not a
ERR_PTR a caller might assume that it is a pointer to a valid regmap structure,
so return a ERR_PTR(-EINVAL) instead.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Fix memory leak in regmap_init error path

If regcache initialization fails regmap_init will currently exit without
freeing work_buf.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Support some more block operations on cached devices

Commit 10a08d9f ("regmap: Support some block operations on cached devices")
allowed raw read operations without throwing a warning when using caches if
all registers are volatile. This patch does the same for raw write operations.

This is for example useful when loading a firmware in a predefined volatile
region on a chip where we otherwise want registers to be cached.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add helper function for checking if a register range is volatile

We already have the same code for checking whether a register range is volatile
in two different places. Instead of duplicating it once more add a small helper
function for checking whether a register range is voltaile.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Track if the register cache is dirty and suppress unneeded syncs

Allow drivers to optimise out the register cache sync if they didn't need
to do one. If the hardware is desynced from the register cache (by power
loss for example) then the driver should call regcache_mark_dirty() to
let the core know about this.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Fix typo in kerneldoc for regmap_update_bits()

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Support some block operations on cached devices

Support raw reads if all the registers being read are volatile, the cache
will have no impact for tem.

Support bulk reads either directly (if all the registers are volatile) or
by falling back to iterating over single register reads otherwise.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Warn on raw I/O as well as bulk reads that bypass cache

As with the bulk reads we really should be able to make these play
nicely with the cache but warn for now.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>

regmap: Make _regmap_write() global

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Incorporate the regcache core into regmap

This patch incorporates the regcache core code into regmap. All previous
patches have been no-ops essentially up to this point.

The bulk read operation is not supported by regcache at the moment. This
will be implemented incrementally.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Tested-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add support for device specific write and read flag masks.

Some buses like SPI have no standard notation of read or write operations.
The general scheme here is to set or clear specific bits in the register
address to indicate whether the operation is a read or write. We already
support having a read flag mask per bus, but as there is no standard
the bits which need to be set or cleared differ between devices and vendors,
thus we need a mechanism to specify them per device.

This patch adds two new entries to the regmap_config struct, read_flag_mask and
write_flag_mask. These will be or'ed onto the top byte when doing a read or
write operation. If both masks are empty the device will fallback to the
regmap_bus masks.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Remove bitrotted module_put()s

The conversion to per bus type registration functions means we don't need
to do module_get()s to hold the bus types in memory (their users will link
to them) so we removed all those calls. This left module_put() calls in
the cleanup paths which aren't needed and which cause unbalanced puts if
we ever try to unload anything.

Reported-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Add functions to check for access on registers

We're going to be using these in quite a few places so factor out the
readable/writable/volatile/precious checks.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

regmap: Skip precious registers when dumping registers via debugfs

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>