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: ram: support noinc semantics

Support noinc semantics in RAM backed regmaps, for testing purposes. Add
a new callback that selects registers which should have noinc behavior.
Bulk writes to a noinc register will cause the last value in the buffer
to be assigned to the register, while bulk reads will copy the same
value repeatedly into the buffer.

This patch only adds support to regmap-raw-ram, since regmap-ram does
not support bulk operations.

Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com>
Link: https://lore.kernel.org/r/20231102203039.3069305-1-ben.wolsieffer@hefring.com
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: Don't check for changes in regcache_set_val()

The only user of regcache_set_val() ignores the return value so we may as
well not bother checking if the value we are trying to set is the same as
the value already stored.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230609-regcache-set-val-no-ret-v1-1-9a6932760cf8@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: maple: Implement block sync for the maple tree cache

For register maps where we can write multiple values in a single bus
operation it is generally much faster to do so. Improve the performance of
maple tree cache syncs on such devices by identifying blocks of adjacent
registers that need to be written out and combining them into a single
operation.

Combining writes does mean that we need to allocate a scratch buffer and
format the data into it but it is expected that for most cases where caches
are in use the cost of I/O will be much greater than the cost of doing the
allocation and format.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230609-regcache-maple-sync-raw-v1-1-8ddeb4e2b9ab@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Provide a ram backed regmap with raw support

Provide a simple, 16 bit only, RAM backed regmap which supports raw I/O for
use in testing.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230610-regcache-raw-kunit-v1-1-583112cd28ac@kernel.org
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: Add maple tree based register cache

The current state of the art for sparse register maps is the
rbtree cache. This works well for most applications but isn't
always ideal for sparser register maps since the rbtree can get
deep, requiring a lot of walking. Fortunately the kernel has a
data structure intended to address this very problem, the maple
tree. Provide an initial implementation of a register cache
based on the maple tree to start taking advantage of it.

The entries stored in the maple tree are arrays of register
values, with the maple tree keys holding the register addresses.
We store data in host native format rather than device native
format as we do for rbtree, this will be a benefit for devices
where we don't marshal data within regmap and simplifies the code
but will result in additional CPU overhead when syncing the cache
on devices where we do marshal data in regmap.

This should work well for a lot of devices, though there's some
additional areas that could be looked at such as caching the
last accessed entry like we do for rbtree and trying to minimise
the maple tree level locking. We should also use bulk writes
rather than single register writes when resyncing the cache where
possible, even if we don't store in device native format.

Very small register maps may continue to to better with rbtree
longer term.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230325-regcache-maple-v3-2-23e271f93dc7@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Factor out single value register syncing

In order to support sparse caches that don't store data in raw format
factor out the parts of the raw block sync implementation that deal with
writing a single register via _regmap_write().

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230325-regcache-maple-v3-1-23e271f93dc7@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add RAM backed register map

Add a register map that is a simple array of memory, for use in
KUnit testing of the framework. This is not exposed in regmap.h
since I can't think of a non-test use case, it is purely for use
internally. To facilitate testing we track if registers have been
read or written to.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230324-regmap-kunit-v2-1-b208801dc2c8@kernel.org

regmap: Removed compressed cache support

The compressed register cache support has assumptions that make it hard to
cover in testing, mainly that it requires raw registers defaults be
provided. Rather than either address these assumptions or leave it untested
by the forthcoming KUnit tests let's remove it, the use case is quite thin
and there are no current users.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230324-regcache-lzo-v1-1-08c5d63e2a5e@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: 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: 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: 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 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: 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: 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: fix comment for regmap.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: 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: 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: 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: 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: Fix implicit inclusion of device.h

internal.h is using dev_name() but doesn't include device.h which
defines it. Add an explicit include to avoid build problems due to
this.

Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regcache: Introduce the index parsing API by stride order

Here introduces regcache_get_index_by_order() for regmap cache,
which uses the register stride order and bit rotation, to improve
the performance.

Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.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: 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>

debugfs: Pass bool pointer to debugfs_create_bool()

Its a bit odd that debugfs_create_bool() takes 'u32 *' as an argument,
when all it needs is a boolean pointer.

It would be better to update this API to make it accept 'bool *'
instead, as that will make it more consistent and often more convenient.
Over that bool takes just a byte.

That required updates to all user sites as well, in the same commit
updating the API. regmap core was also using
debugfs_{read|write}_file_bool(), directly and variable types were
updated for that to be bool as well.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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: 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: 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: 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: Use regcache_mark_dirty() to indicate power loss or reset

Existing regmap users call regcache_mark_dirty() as part of the
suspend/resume sequence, to tell regcache that non-default values need to
be resynced post-resume. Add an internal "no_sync_defaults" regmap flag
to remember this state, so that regcache_sync() can differentiate between
these two cases:

1) HW was reset, so any cache values that match map->reg_defaults can be
safely skipped. On some chips there are a lot of registers in the
reg_defaults list, so this optimization speeds things up quite a bit.

2) HW was not reset (maybe it was just clock-gated), so if we cached
any writes, they should be sent to the hardware regardless of whether
they match the HW default. Currently this will write out all values in
the regcache, since we don't maintain per-register dirty bits.

Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Kevin Cernekee <cernekee@chromium.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: Move spinlock_flags into the union

This patch move struct regmap.spinlock_flags into the union of
spinlock, so that we can shrink struct regmap size.

Signed-off-by: Yalin Wang <yalin.wang@sonymobile.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: change struct regmap's internal locks as union

this patch change struct regmap->mutex and struct regmap->spinlock
as an union, because these 2 members are only used one of them,
we change it to shrink the struct size.

Signed-off-by: Yalin Wang <yalin.wang@sonymobile.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Fix regcache debugfs initialization

Commit 6cfec04bcc05 ("regmap: Separate regmap dev initialization") moved the
regmap debugfs initialization after regcache initialization. This means
that the regmap debugfs directory is not created yet when the cache
initialization runs and so any debugfs files registered by the regcache are
created in the debugfs root directory rather than the debugfs directory of
the regmap instance. Fix this by adding a separate callback for the
regcache debugfs initialization which will be called after the parent
debugfs entry has been created.

Fixes: 6cfec04bcc05 (regmap: Separate regmap dev initialization)
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.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: 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: 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: rbtree: Make cache_present bitmap per node

With devices which have a dense and small register map but placed at a large
offset the global cache_present bitmap imposes a huge memory overhead. Making
the cache_present per rbtree node avoids the issue and easily reduces the memory
footprint by a factor of ten. For devices with a more sparse map or without a
large base register offset the memory usage might increase slightly by a few
bytes, but not significantly. E.g. for a device which has ~50 registers at
offset 0x4000 the memory footprint of the register cache goes down form 2496
bytes to 175 bytes.

Moving the bitmap to a per node basis means that the handling of the bitmap is
now cache implementation specific and can no longer be managed by the core. The
regcache_sync_block() function is extended by a additional parameter so that the
cache implementation can tell the core which registers in the block are set and
which are not. The parameter is optional and if NULL the core assumes that all
registers are set. The rbtree cache also needs to implement its own drop
callback instead of relying on the core to handle this.

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

regmap: fix regcache_reg_present() for empty cache

In the initial case when no reg_defaults values are
provided and no register value was added to the cache
yet, the cache_present bitmap is NULL. If this function
is invoked for any register it should return false
(i.e. the register is not cached) instead of true.

Signed-off-by: Ionut Nicu <ioan.nicu.ext@nsn.com>
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: 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: Add support for discarding parts of the register cache

Allow drivers to discard parts of the register cache, for example if part
of the hardware has been reset.

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

regmap: cache: Factor out block sync

The idea of holding blocks of registers in device format is shared between
at least rbtree and lzo cache formats so split out the loop that does the
sync from the rbtree code so optimisations on it can be reused.

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

regmap: cache: Factor out reg_present support from rbtree cache

The idea of maintaining a bitmap of present registers is something that
can usefully be used by other cache types that maintain blocks of cached
registers so move the code out of the rbtree cache and into the generic
regcache code.

Refactor the interface slightly as we go to wrap the set bit and enlarge
bitmap operations (since we never do one without the other) and make it
more robust for reads of uncached registers by bounds checking before we
look at the bitmap.

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

regmap: cache: Provide a get address of value operation

Provide a helper to do the size based index into a block of registers and
use it when reading a value.

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: debugfs: Add a registers `range' file

This file lists the register ranges in the register map. The condition
to split the range is based on whether the block is readable or not.

Ensure that we lock the `debugfs_off_cache' list whenever we access
and modify the list. There is a possible race otherwise between the
read() operations of the `registers' file and the `range' file.

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

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: cache: Pass the map rather than the word size when updating values

It's more idiomatic to pass the map structure around and this means we
can use other bits of information from the map.

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

regmap: debugfs: Add a `max_reg' member in struct regmap_debugfs_off_cache

We are keeping track of the maximum register as well, this will make
things easier for us in sharing this code with the code implementing
the register ranges functionality. It also simplifies a bit the
calculations when looking for the relevant block:offset from within
the cache.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.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: 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: flat: Add flat cache type

While for I2C and SPI devices the overhead of using rbtree for devices with
only one block of registers is negligible the same isn't always going to
be true for MMIO devices where the I/O costs are very much lower. Cater
for these devices by adding a simple flat array type for them where the
lookups are simple array accesses, taking us right back to the original
ASoC cache implementation.

Thanks to Magnus Damm for the discussion which prompted this.

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

regmap: debugfs: Cache offsets of valid regions for dump

Avoid doing a linear scan of the entire register map for each read() of
the debugfs register dump by recording the offsets where valid registers
exist when we first read the registers file. This assumes the set of
valid registers never changes, if this is not the case invalidation of
the cache will be required.

This could be further improved for large blocks of contiguous registers
by calculating the register we will read from within the block - currently
we do a linear scan of the block. An rbtree may also be worthwhile.

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

regmap: Cache register and value sizes for debugfs

No point in calculating them every time.

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: 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: 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: 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: 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: 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: 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: fix compilation when !CONFIG_DEBUG_FS

Commit 79c64d5 "regmap: allow regmap instances to be named" changed the
prototype of regmap_debugfs_init, but didn't update the dummy inline used
when !CONFIG_DEBUGFS. Fix this.

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: 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: 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: fix compilation when !CONFIG_DEBUG_FS

Commit 79c64d5 "regmap: allow regmap instances to be named" changed the
prototype of regmap_debugfs_init, but didn't update the dummy inline used
when !CONFIG_DEBUGFS. Fix this.

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: 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: Supply ranges to the sync operations

In order to allow us to support partial sync operations add minimum and
maximum register arguments to the sync operation and update the rbtree
and lzo caches to use this new information. The LZO implementation is
obviously not good, we could exit the iteration earlier, but there may
be room for more wide reaching optimisation there.

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

regmap: Don't use bitfields for booleans

This was a cut'n'paste from some older code.

Since we're about to add debugfs support don't do the obvious thing and
use bool, use u32 instead (which debugfs has been using since time
immemorial).

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: 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: Remove indexed cache type

There should be no situation where it offers any advantage over rbtree
and there are no current users so remove the code for simplicity.

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: 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: Make _regmap_write() global

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

regmap: Add the LZO cache support

This patch adds support for LZO compression when storing the register
cache.

For a typical device whose register map would normally occupy 25kB or 50kB
by using the LZO compression technique, one can get down to ~5-7kB. There
might be a performance penalty associated with each individual read/write
due to decompressing/compressing the underlying cache, however that should not
be noticeable. These memory benefits depend on whether the target architecture
can get rid of the memory occupied by the original register defaults cache
which is marked as __devinitconst. Nevertheless there will be some memory
gain even if the target architecture can't get rid of the original register
map, this should be around ~30-32kB instead of 50kB.

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

regmap: Add the rbtree cache support

This patch adds support for the rbtree cache compression type.

Each rbnode manages a variable length block of registers. There can be no
two nodes with overlapping blocks. Each block has a base register and a
currently top register, all the other registers, if any, lie in between these
two and in ascending order.

The reasoning behind the construction of this rbtree is simple. In the
snd_soc_rbtree_cache_init() function, we iterate over the register defaults
provided by the regcache core. For each register value that is non-zero we
insert it in the rbtree. In order to determine in which rbnode we need
to add the register, we first look if there is another register already
added that is adjacent to the one we are about to add. If that is the case
we append it in that rbnode block, otherwise we create a new rbnode
with a single register in its block and add it to the tree.

There are various optimizations across the implementation to speed up lookups
by caching the most recently used rbnode.

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 the indexed cache support

This is the simplest form of a cache available in regcache. Any
registers whose default value is 0 are ignored. If any of those
registers are modified in the future, they will be placed in the
cache on demand. The cache layout is essentially using the provided
register defaults by the regcache core directly and does not re-map
it to another representation.

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

regmap: Introduce caching support

This patch introduces caching support for regmap. The regcache API
has evolved essentially out of ASoC soc-cache so most of the actual
caching types (except LZO) have been tested in the past.

The purpose of regcache is to optimize in time and space the handling
of register caches. Time optimization is achieved by not having to go
over a slow bus like I2C to read the value of a register, instead it is
cached locally in memory and can be retrieved faster. Regarding space
optimization, some of the cache types are better at packing the caches,
for e.g. the rbtree and the LZO caches. By doing this the sacrifice in
time still wins over doing I2C transactions.

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: Make debugfs stubs static inline

Make the debugfs stubs static inline to avoid future compilation issues due to
duplicated symbols when CONFIG_DEBUG_FS=n once internal.h is included by
multiple source files.

Signed-off-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: 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>

regmap: Provide register map dump via debugfs

Copy over the read parts of the ASoC debugfs implementation into regmap,
allowing users to see what the register values the device has are at
runtime. The implementation, especially the support for seeking, is
mostly due to Dimitris Papastamos' work in ASoC.

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

regmap: Use a local header for API internals

Allowing the implementation to be multi-file.

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