spi: atmel: Fix clock issue when using devices with different polarities

The current Atmel SPI controller driver (v2) behaves incorrectly when
using two SPI devices with different clock polarities and GPIO CS.

When switching from one device to another, the controller driver first
enables the CS and then applies whatever configuration suits the targeted
device (typically, the polarities). The side effect of such order is the
apparition of a spurious clock edge after enabling the CS when the clock
polarity needs to be inverted wrt. the previous configuration of the
controller.

This parasitic clock edge is problematic when the SPI device uses that edge
for internal processing, which is perfectly legitimate given that its CS
was asserted. Indeed, devices such as HVS8080 driven by driver gpio-sr in
the kernel are shift registers and will process this first clock edge to
perform a first register shift. In this case, the first bit gets lost and
the whole data block that will later be read by the kernel is all shifted
by one.

Current behavior:
The actual switching of the clock polarity only occurs after the CS
when the controller sends the first message:

CLK ------------\ /-\ /-\
| | | | | . . .
\---/ \-/ \
CS -----\
|
\------------------

^ ^ ^
| | |
| | Actual clock of the message sent
| |
| Change of clock polarity, which occurs with the first
| write to the bus. This edge occurs when the CS is
| already asserted, and can be interpreted as
| the first clock edge by the receiver.
|
GPIO CS toggle

This issue is specific to this controller because while the SPI core
performs the operations in the right order, the controller however does
not. In practice, the controller only applies the clock configuration right
before the first transmission.

So this is not a problem when using the controller's dedicated CS, as the
controller does things correctly, but it becomes a problem when you need to
change the clock polarity and use an external GPIO for the CS.

One possible approach to solve this problem is to send a dummy message
before actually activating the CS, so that the controller applies the clock
polarity beforehand.

New behavior:

CLK ------\ /-\ /-\ /-\ /-\
| | | ... | | | | ... | |
\------/ \- -/ \------/ \- -/ \------

CS -\/-----------------------\
|| |
\/ \---------------------
^ ^ ^ ^ ^
| | | | |
| | | | Expected clock cycles when
| | | | sending the message
| | | |
| | | Actual GPIO CS activation, occurs inside
| | | the driver
| | |
| | Dummy message, to trigger clock polarity
| | reconfiguration. This message is not received and
| | processed by the device because CS is low.
| |
| Change of clock polarity, forced by the dummy message. This
| time, the edge is not detected by the receiver.
|
This small spike in CS activation is due to the fact that the
spi-core activates the CS gpio before calling the driver's
set_cs callback, which deactivates this gpio again until the
clock polarity is correct.

To avoid having to systematically send a dummy packet, the driver keeps
track of the clock's current polarity. In this way, it only sends the dummy
packet when necessary, ensuring that the clock will have the correct
polarity when the CS is toggled.

There could be two hardware problems with this patch:
1- Maybe the small CS activation peak can confuse SPI devices
2- If on a design, a single wire is used to select two devices depending
on its state, the dummy message may disturb them.

Fixes: 5ee36c989831 ("spi: atmel_spi update chipselect handling")
Cc: <stable@vger.kernel.org>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
Link: https://msgid.link/r/20231204154903.11607-1-louis.chauvet@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Prevent spi transfers from being killed

Upstream commit e0205d6203c2 ("spi: atmel: Prevent false timeouts on
long transfers") has tried to mitigate the problem of getting spi
transfers canceled because they were lasting too long. On slow buses,
transfers in the MiB range can take more than one second and thus a
calculation was added to progressively increment the timeout value. In
order to not be too problematic from a user point of view (waiting dozen
of seconds or even minutes), the wait call was turned interruptible.

Turning the wait interruptible was a mistake as what we really wanted to
do was to be able to kill a transfer. Any signal interrupting our
transfer would not be suitable at all so a second attempt was made at
turning the wait killable instead.

Link: https://lore.kernel.org/linux-spi/20231127095842.389631-1-miquel.raynal@bootlin.com/

All being well, it was reported that JFFS2 was showing a splat when
interrupting a transfer. After some more debate about whether JFFS2
should be fixed and how, it was also pointed out that the whole
consistency of the filesystem in case of parallel I/O would be
compromised. Changing JFFS2 behavior would in theory be possible but
nobody has the energy and time and knowledge to do this now, so better
prevent spi transfers to be interrupted by the user.

Partially revert the blamed commit to no longer use the interruptible
nor the killable variant of wait_for_completion().

Fixes: e0205d6203c2 ("spi: atmel: Prevent false timeouts on long transfers")
Cc: <stable@vger.kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Ronald Wahl <ronald.wahl@raritan.com>
Link: https://lore.kernel.org/r/20231205083102.16946-1-miquel.raynal@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Drop unused defines

These defines are leftovers from previous versions of the blamed commit,
they are simply unused so drop them.

Fixes: e0205d6203c2 ("spi: atmel: Prevent false timeouts on long transfers")
Reported-by: Ronald Wahl <ronald.wahl@raritan.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20231127095842.389631-2-miquel.raynal@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Do not cancel a transfer upon any signal

The intended move from wait_for_completion_*() to
wait_for_completion_interruptible_*() was to allow (very) long spi memory
transfers to be stopped upon user request instead of freezing the
machine forever as the timeout value could now be significantly bigger.

However, depending on the user logic, applications can receive many
signals for their own "internal" purpose and have nothing to do with the
requested kernel operations, hence interrupting spi transfers upon any
signal is probably not a wise choice. Instead, let's switch to
wait_for_completion_killable_*() to only catch the "important"
signals. This was likely the intended behavior anyway.

Fixes: e0205d6203c2 ("spi: atmel: Prevent false timeouts on long transfers")
Cc: stable@vger.kernel.org
Reported-by: Ronald Wahl <ronald.wahl@raritan.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20231127095842.389631-1-miquel.raynal@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: Rename SPI_MASTER_GPIO_SS to SPI_CONTROLLER_GPIO_SS

Rename SPI_MASTER_GPIO_SS to SPI_CONTROLLER_GPIO_SS and
convert the users to SPI_CONTROLLER_GPIO_SS to follow
the new naming shema.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230710154932.68377-14-andriy.shevchenko@linux.intel.com
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: Get rid of old SPI_MASTER_MUST_TX & SPI_MASTER_MUST_RX

Convert the users from SPI_MASTER_MUST_TX and/or SPI_MASTER_MUST_RX
to SPI_CONTROLLER_MUST_TX and/or SPI_CONTROLLER_MUST_RX respectively
and kill the not used anymore definitions.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230710154932.68377-13-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Use devm_platform_get_and_ioremap_resource()

Convert platform_get_resource(), devm_ioremap_resource() to a single
call to devm_platform_get_and_ioremap_resource(), as this is exactly
what this function does.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Link: https://lore.kernel.org/r/20230706032727.9180-1-frank.li@vivo.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Prevent false timeouts on long transfers

A slow SPI bus clocks at ~20MHz, which means it would transfer about
2500 bytes per second with a single data line. Big transfers, like when
dealing with flashes can easily reach a few MiB. The current DMA timeout
is set to 1 second, which means any working transfer of about 4MiB will
always be cancelled.

With the above derivations, on a slow bus, we can assume every byte will
take at most 0.4ms. Said otherwise, we could add 4ms to the 1-second
timeout delay every 10kiB. On a 4MiB transfer, it would bring the
timeout delay up to 2.6s which still seems rather acceptable for a
timeout.

The consequence of this is that long transfers might be allowed, which
hence requires the need to interrupt the transfer if wanted by the
user. We can hence switch to the _interruptible variant of
wait_for_completion. This leads to a little bit more handling to also
handle the interrupted case but looks really acceptable overall.

While at it, we drop the useless, noisy and redundant WARN_ON() call.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Ryan Wanner <ryan.wanner@microchip.com>
Link: https://lore.kernel.org/r/Message-Id: <20230622090634.3411468-3-miquel.raynal@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: Replace all spi->chip_select and spi->cs_gpiod references with function call

Supporting multi-cs in spi drivers would require the chip_select & cs_gpiod
members of struct spi_device to be an array. But changing the type of these
members to array would break the spi driver functionality. To make the
transition smoother introduced four new APIs to get/set the
spi->chip_select & spi->cs_gpiod and replaced all spi->chip_select and
spi->cs_gpiod references with get or set API calls.
While adding multi-cs support in further patches the chip_select & cs_gpiod
members of the spi_device structure would be converted to arrays & the
"idx" parameter of the APIs would be used as array index i.e.,
spi->chip_select[idx] & spi->cs_gpiod[idx] respectively.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
Acked-by: Heiko Stuebner <heiko@sntech.de> # Rockchip drivers
Reviewed-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org> # Aspeed driver
Reviewed-by: Dhruva Gole <d-gole@ti.com> # SPI Cadence QSPI
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com> # spi-stm32-qspi
Acked-by: William Zhang <william.zhang@broadcom.com> # bcm63xx-hsspi driver
Reviewed-by: Serge Semin <fancer.lancer@gmail.com> # DW SSI part
Link: https://lore.kernel.org/r/167847070432.26.15076794204368669839@mailman-core.alsa-project.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230303172041.2103336-7-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: switch to use modern name

Change legacy name master to modern name host or controller.

No functional changed.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20230110131805.2827248-2-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: remove #ifdef CONFIG_{PM, SLEEP}

Remove #ifdef CONFIG_PM, #ifdef CONFIG_PM_SLEEP and use
SYSTEM_SLEEP_PM_OPS() and RUNTIME_PM_OPS() macros instead which allows
getting also rid of __maybe_unused in the code.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220718071052.1707858-1-claudiu.beznea@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Fix typo

Change 'actualy' to 'actually'

Signed-off-by: Qinghua Jin <qhjin.dev@gmail.com>
Link: https://lore.kernel.org/r/20220107024631.396862-1-qhjin.dev@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Remove setting of deprecated member of struct dma_slave_config

The 'direction' member of 'struct dma_slave_config' is deprecated.
Instead, drivers should use the direction argument to the
device_prep_slave_sg and device_prep_dma_cyclic functions or the
dir field in the dma_interleaved_template structure.
spi-atmel uses the direction argument to dmaengine_prep_slave_sg.
slave_config.direction is not used in neither of the DMA controller
drivers (at_h/xdmac) that spi-atmel is using, we can just remove the
setting of slave_config.direction and live with whatever stack value
is there.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20211125124110.838037-3-tudor.ambarus@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Drop slave_config argument in atmel_spi_dma_slave_config()

The callers passed a pointer to slave_config as an argument of
atmel_spi_dma_slave_config(), but they did not use it afterwards.
Use instead a local variable in atmel_spi_dma_slave_config(), and
stop passing arguments that are not needed in the callers.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20211125124110.838037-2-tudor.ambarus@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Fix PDC transfer setup bug

atmel_spi_dma_map_xfer to never be called in PDC mode. This causes the
driver to silently fail.

This patch changes the conditional to match the behaviour of the
previous commit before the refactor.

Fixes: 5fa5e6dec762 ("spi: atmel: Switch to transfer_one transfer method")
Signed-off-by: Ville Baillie <villeb@bytesnap.co.uk>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210921072132.21831-1-villeb@bytesnap.co.uk
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Fix CS and initialization bug

Commit 5fa5e6dec762 ("spi: atmel: Switch to transfer_one transfer
method") switched to using transfer_one and set_cs. The
core doesn't call set_cs when the chip select lines are gpios. Add the
SPI_MASTER_GPIO_SS flag to the driver to ensure the calls to set_cs
happen since the driver programs configuration registers there.

Fixes: 5fa5e6dec762 ("spi: atmel: Switch to transfer_one transfer method")

Signed-off-by: Dan Sneddon <dan.sneddon@microchip.com>
Link: https://lore.kernel.org/r/20210629192218.32125-1-dan.sneddon@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Reduce spin lock usage

The current implementation of the driver holds a spin lock for the
duration of the transfer, releasing it only to enable interrupts for
short periods of time. As this would prevent any interrupt from
happening, this could cause system performance issues every time a SPI
message is sent. Since the spi core now handles message syncronization
we can reduce the amount of time the spin-lock is held to the regions
where both the calling thread and the interrupt might interract.

Signed-off-by: Dan Sneddon <dan.sneddon@microchip.com>
Link: https://lore.kernel.org/r/20210602160816.4890-2-dan.sneddon@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Switch to transfer_one transfer method

Switch from using our own transfer_one_message routine to using the one
provided by the SPI core.

Signed-off-by: Dan Sneddon <dan.sneddon@microchip.com>
Link: https://lore.kernel.org/r/20210602160816.4890-1-dan.sneddon@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Drop unused variable

The DMA cap mask is no longer used since:
commit 7758e390699f ("spi: atmel: remove compat for non DT board when requesting dma chan")
Drop it now.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20210218132840.131898-1-tudor.ambarus@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Put allocated master before return

The allocated master is not released. Goto error handling label rather
than directly return.

Fixes: 5e9af37e46bc ("spi: atmel: introduce probe deferring")
Signed-off-by: Pan Bian <bianpan2016@163.com>
Fixes: 5e9af37e46bc ("spi: atmel: introduce probe deferring")
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20210120050025.25426-1-bianpan2016@163.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Downgrade to dev_dbg when dma_request_chan() fails

The IP's DMA capabilities are described in the SoC dtsi, to spare
users duplicating the DMA bindings in their board device tree. Users
that don't want to use DMA, have to overwrite the DMA bindings in
their board device tree. An example is:
commit ddcdaeb88242 ("ARM: dts: at91: sama5d2: Add DMA bindings for the SPI and UART flx4 functions")

When the DMA bindings are overwritten, one could see on the console:
atmel_spi fc018400.spi: error -ENODEV: No TX DMA channel, DMA is disabled
atmel_spi fc018400.spi: Atmel SPI Controller using PIO only

Choosing to not use DMA is not a reason to print an error message.
More, the user is already informed when PIO is used: "Atmel SPI Controller
using PIO only". Downgrade to dev_dbg when dma_request_chan() fails.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20201030121116.869105-1-tudor.ambarus@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Exposing effective spi speed

This patch implements the reporting of the effectively used speed_hz for
the transfer by setting xfer->effective_speed_hz.

See the following patch, which adds this feature to the SPI core for more
information:
commit 5d7e2b5ed585 ("spi: core: allow reporting the effectivly used speed_hz for a transfer")

Signed-off-by: Thomas Kopp <thomas.kopp@microchip.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20200921071036.2091-1-thomas.kopp@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: remove unnecessary include

Since commit d5fab59cab18 ("spi: atmel: trivial: remove unused fields in
DMA structure"), the driver is not using any definitions from
linux/platform_data/dma-atmel.h, stop including it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20200930145353.3043699-1-alexandre.belloni@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Simplify with dev_err_probe()

Common pattern of handling deferred probe can be simplified with
dev_err_probe(). Less code and the error value gets printed.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20200901152713.18629-3-krzk@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: remove redundant label out_free

The error exit label out_free is no longer being used, it is redundant
and can be removed.

Cleans up warning:
drivers/spi/spi-atmel.c:1680:1: warning: label ‘out_free’ defined but not used [-Wunused-label]

Fixes: 2d9a744685bc ("spi: atmel: No need to call spi_master_put() if spi_alloc_master() failed")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20200709101203.1374117-1-colin.king@canonical.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: No need to call spi_master_put() if spi_alloc_master() failed

There is no need to call spi_master_put() if spi_alloc_master()
failed, it should return -ENOMEM directly.

Signed-off-by: Peng Fan <fanpeng@loongson.cn>
Link: https://lore.kernel.org/r/1594111842-9468-1-git-send-email-fanpeng@loongson.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Add missing annotation for atmel_spi_next_xfer_dma_submit()

Sparse reports a warning at atmel_spi_next_xfer_dma_submit()

warning: context imbalance in atmel_spi_next_xfer_dma_submit()
- unexpected unlock

The root cause is the missing annotation
at atmel_spi_next_xfer_dma_submit()

Add the missing __must_hold(&as->lock) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Link: https://lore.kernel.org/r/20200429225723.31258-3-jbi.octave@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Use dma_request_chan() instead dma_request_slave_channel()

dma_request_slave_channel() is a wrapper on top of dma_request_chan()
eating up the error code.

By using dma_request_chan() directly the driver can support deferred
probing against DMA.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20191212135550.4634-2-peter.ujfalusi@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Use dma_request_chan() directly for channel request

dma_request_slave_channel_reason() is:
#define dma_request_slave_channel_reason(dev, name) \
dma_request_chan(dev, name)

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20191113094256.1108-3-peter.ujfalusi@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: fix handling of cs_change set on non-last xfer

The driver does the wrong thing when cs_change is set on a non-last
xfer in a message. When cs_change is set, the driver deactivates the
CS and leaves it off until a later xfer again has cs_change set whereas
it should be briefly toggling CS off and on again.

This patch brings the behaviour of the driver back in line with the
documentation and common sense. The delay of 10 us is the same as is
used by the default spi_transfer_one_message() function in spi.c.
[gregory: rebased on for-5.5 from spi tree]
Fixes: 8090d6d1a415 ("spi: atmel: Refactor spi-atmel to use SPI framework queue")
Signed-off-by: Mans Rullgard <mans@mansr.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191018153504.4249-1-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Improve CS0 case support on AT91RM9200

Thanks to the recent change in this driver, it is now possible to
prevent using the CS0 with GPIO during setup. It then allows to remove
the special handling of this case in the cs_activate() and
cs_deactivate() functions.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-8-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Improve and fix GPIO CS usage

In the previous implementation of this driver, the index of the GPIO
used as CS was linked to the offset of the CS register used to
configure the transfer.

With this new implementation the first CS register not used by
internal CS is associated to all the GPIO CS. It allows to not be
anymore limited to have only 4 CS managed, now it is possible to have
in the same time until 3 internal CS and no more limit for the CS
GPIO.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-7-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Remove platform data support

This driver is now only used through the device tree. Simplify code
by explicitly depend on device tree.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-6-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Remove useless private field

Since the conversion to GPIO descriptor, the GPIO used as chip select,
can be directly access from the spi_device struct. So there is no need
to keep the field npcs_pin.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-5-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Configure GPIO per CS instead of by controller

Instead of setting up the GPIO configuration for the whole controller,
do it at CS level. It will allow to mix internal CS and GPIO CS, which
is not possible with the current implementation.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-4-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Fix CS high support

Until a few years ago, this driver was only used with CS GPIO. The
only exception is CS0 on AT91RM9200 which has to use internal CS. A
limitation of the internal CS is that they don't support CS High.

So by using the CS GPIO the CS high configuration was available except
for the particular case CS0 on RM9200.

When the support for the internal chip-select was added, the check of
the CS high support was not updated. Due to this the driver accepts
this configuration for all the SPI controller v2 (used by all SoCs
excepting the AT91RM9200) whereas the hardware doesn't support it for
infernal CS.

This patch fixes the test to match the hardware capabilities.

Fixes: 4820303480a1 ("spi: atmel: add support for the internal chip-select of the spi controller")
Cc: <stable@vger.kernel.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-3-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Remove and fix erroneous comments

Since CSAAT functionality support has been added. Some comments become
wrong. Fix them to match the current driver behavior.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-2-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: use new `spi_transfer_delay_exec` helper where straightforward

For many places in the spi drivers, using the new `spi_transfer_delay`
helper is straightforward.
It's just replacing:
```
if (t->delay_usecs)
udelay(t->delay_usecs);
```
with `spi_transfer_delay(t)` which handles both `delay_usecs` and the new
`delay` field.

This change replaces in all places (in the spi drivers) where this change
is simple.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-10-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: core,atmel: convert `word_delay_usecs` -> `word_delay` for spi_device

This change does a conversion from the `word_delay_usecs` -> `word_delay`
for the `spi_device` struct.

This allows users to specify inter-word delays in other unit types
(nano-seconds or clock cycles), depending on how users want.

The Atmel SPI driver is the only current user of the `word_delay_usecs`
field (from the `spi_device` struct).
So, it needed a slight conversion to use the `word_delay` as an `spi_delay`
struct.

In SPI core, the only required mechanism is to update the `word_delay`
information per `spi_transfer`. This requires a bit more logic than before,
because it needs that both delays be converted to a common unit
(nano-seconds) for comparison.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-8-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Remove AVR32 leftover

AV32 support has been from the kernel a few release ago, but there was
still some specific macro for this architecture in this driver. Lets
remove it.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20190919154034.7489-1-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: add tracing to custom .transfer_one_message callback

Driver specific implementations for .transfer_one_message need to call
the tracing stuff themself. This is necessary to make spi tracing
actually useful.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Link: https://lore.kernel.org/r/20190801204710.27309-1-uwe@kleine-koenig.org
Signed-off-by: Mark Brown <broonie@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spi-atmel: support inter-word delay

If the SPI slave requires an inter-word delay, configure the DLYBCT
register accordingly.

Tested on a SAMA5D2 board (derived from SAMA5D2-Xplained reference
board).

Signed-off-by: Jonas Bonn <jonas@norrbonn.se>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
CC: Nicolas Ferre <nicolas.ferre@microchip.com>
CC: Mark Brown <broonie@kernel.org>
CC: Alexandre Belloni <alexandre.belloni@bootlin.com>
CC: Ludovic Desroches <ludovic.desroches@microchip.com>
CC: linux-spi@vger.kernel.org
CC: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Convert to use CS GPIO descriptors

This converts the Atmel SPI master driver to use GPIO descriptors
for chip select handling.

The Atmel driver has duplicate code to look up and initialize CS
GPIOs from the device tree, so this is removed. It further has code
to retrieve a CS GPIO from .controller_data but this seems to be
completely unused in the kernel (legacy codepath?) so I deleted
this support. It keeps track of polarity when switching the CS, but
this is not needed anymore since we moved this over to the gpiolib.

The local handling of the "npcs_pin" (I guess this might mean
"negative polarity chip select pin") is preserved, but I strongly
suspect this can be switched over to handling by the core and
using the SPI_MASTER_GPIO_SS flag on the master to assure that
the additional CS handling in the driver is also done.

Cc: Eugen Hristev <eugen.hristev@microchip.com>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Radu Pirea <radu.pirea@microchip.com>
Cc: Linuxarm <linuxarm@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: Do not print a message if spi_controller_{suspend,resume}() fails

spi_controller_{suspend,resume}() already prints an error message on
failure, so there is no need to repeat this in individual drivers.

Note: spi_master_{suspend,resume}() is an alias for
spi_controller_{suspend,resume}().

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Daniel Mack <daniel@zonque.org>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-atmel: Use correct enum for DMA transfer direction

Use enum dma_transfer_direction as required by the functions
dmaengine_prep_slave_(sg|single)() instead of enum dma_data_direction.
This won't change behavior in practice as the enum values are
equivalent.

This fixes two warnings when building with clang:
drivers/spi/spi-atmel.c:771:12: warning: implicit conversion from enumeration
type 'enum dma_data_direction' to different enumeration type
'enum dma_transfer_direction'
[-Wenum-conversion]
DMA_FROM_DEVICE,
^~~~~~~~~~~~~~~
...

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: init FIFOs before spi enable

The datasheet recommends initializing FIFOs before
SPI enable. If we do not do it like this, there may be
a strange behavior. We noticed that DMA does not work properly
with FIFOs if we do not clear them beforehand or enable them
before SPIEN.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

spi: atmel: Implements transfers with bounce buffer

This patch enables SPI DMA transfers for Atmel SAM9 SoCs and implements a
bounce buffer for transfers which have vmalloc allocated buffers. Those
buffers are not cache coherent even if they have been transformed into sg
lists. UBIFS is affected by this cache coherency issue.

In this patch I also reverted "spi: atmel: fix corrupted data issue on SAM9
family SoCs"(7094576ccdc3acfe1e06a1e2ab547add375baf7f).

Signed-off-by: Radu Pirea <radu.pirea@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: fixed spin_lock usage inside atmel_spi_remove

The only part of atmel_spi_remove which needs to be atomic is hardware
reset.

atmel_spi_stop_dma calls dma_terminate_all and this needs interrupts
enabled.
atmel_spi_release_dma calls dma_release_channel and dma_release_channel
locks a mutex inside of spin_lock.

So the call of these functions can't be inside a spin_lock.

Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Radu Pirea <radu.pirea@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: fix corrupted data issue on SAM9 family SoCs

This patch disables the use of the DMA for data transfer and forces the
use of PIO transfers instead as a quick fixup to solve the cache aliasing
issue on ARM9 based cores, which embeds a VIVT data cache.

Indeed in the case of VIVT data caches, it is not safe to call dma_map_*()
functions to map buffers for DMA transfers when those buffers have been
allocated by vmalloc() or from any DMA-unsafe area.

Further patches may propose a better solution based on the use of a bounce
buffer at the SPI sub-system level but such solution needs more time to be
discussed. Then the use of DMA transfers could be enabled again to improve
the performances but before that, this patch already solves the issue.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

spi: atmel: print version only after successful registration

Don't print the version at the beginning of atmel_spi_probe(). This avoids
spamming the log whenever a deferred probe runs.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: add deepest PM support to SAMA5D2

This adds deepest (Backup+Self-Refresh) PM support to the ATMEL SAMA5D2
SoC's SPI controller.

When resuming from deepest state, it is required to restore MR register
as the registers are lost since VDD core has been shut down when
entering deepest state on the SAMA5D2.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: factorize reusable code for SPI controller init

The SPI controller configuration during the init can be reused, for the
resume function for example.

Let's move this configuration to a separate function.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: remove the use of private channel fields

For DMA transfers, we now use the core DMA framework which provides
channel fields in the spi_master structure. Remove the private channels
from atmel_spi stucture which were located in a sub-structure. This
last one (atmel_spi_dma) which is now empty is also removed.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: trivial: remove unused fields in DMA structure

The atmel_spi_dma structure was cluttered with unused fields relative
to older DMA channel selection API. Remove them.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Use SPI core DMA mapping framework

Use the SPI core DMA mapping framework instead of our own
in case of DMA support. PDC support is not converted to this
framework.

The driver is now able to transfer a complete sg list through DMA.
This eventually fix an issue with vmalloc'ed DMA memory that is
provided for example by UBI/UBIFS layers.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
[nicolas.ferre@atmel.com: restrict the use to non-PDC DMA]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Use core SPI_MASTER_MUST_[RT]X handling

We need both RX and TX data for each transfer in any case (PIO, PDC, DMA).
So convert the driver to the core dummy buffer handling with the
SPI_MASTER_MUST_RX/SPI_MASTER_MUST_TX infrastructure.

This move changes the maximum PDC/DMA buffer handling to 65535 bytes
instead of a single page and sets master->max_dma_len to this value.

All dummy buffer management is removed from the driver.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: trivial: move info banner to latest probe action

The info banner is here to tell that everything went well, so place
it at the very end of the probe function.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Fix scheduling while atomic

A call to clk_get_rate appears to be called in the context of an interrupt,
cache the bus clock for the frequency calculations in transmission.

This fixes a 'BUG: scheduling while atomic' and
'WARNING: CPU: 0 PID: 777 at kernel/sched/core.c:2960 atmel_spi_unlock'

Signed-off-by: Ben Whitten <ben.whitten@lairdtech.com>
Signed-off-by: Steve deRosier <steve.derosier@lairdtech.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: fix indenting in atmel_spi_gpio_cs()

These lines were indented one extra tab.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: use managed resource for gpio chip select

Use the managed gpio CS pin request so that we avoid having trouble
in the cleanup code.
In fact, if module was configured with DT, cleanup code released
invalid pin. Since resource wasn't freed, module cannot be reinserted.

This require to extract the gpio request call from the "setup" function
and call it in the appropriate probe function.

Reported-by: Alexander Morozov <linux@meltdown.ru>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: fix gpio chip-select in case of non-DT platform

The non-DT platform that uses this driver (actually the AVR32) was taking a bad
branch for determining if the IP would use gpio for CS.
Adding the presence of DT as a condition fixes this issue.

Fixes: 4820303480a1 ("spi: atmel: add support for the internal chip-select of the spi controller")
Reported-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
[nicolas.ferre@atmel.com: extract from ml discussion]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Tested-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

spi: atmel: Fix DMA-setup for transfers with more than 8 bits per word

The DMA-slave configuration depends on the whether <= 8 or > 8 bits
are transferred per word, so we need to call
atmel_spi_dma_slave_config() with the correct value.

Signed-off-by: David Mosberger <davidm@egauge.net>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

spi: atmel: Remove needless bits_per_word and speed_hz tests

SPI core validates both bits_per_word and speed_hz transfer parameters and
defaults to spi->bits_per_word and spi->max_speed_hz in case these per
transfer parameters are not set. This makes possible to remove two if
statements and remove one code block that is never executed.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Remove needless bits_per_word and speed_hz tests

SPI core validates both bits_per_word and speed_hz transfer parameters and
defaults to spi->bits_per_word and spi->max_speed_hz in case these per
transfer parameters are not set. This makes possible to remove two if
statements and remove one code block that is never executed.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: remove warning when !CONFIG_PM_SLEEP

When CONFIG_PM is defined but not CONFIG_PM_SLEEP (this happens when
CONFIG_SUSPEND is not defined), there is the following warning:

drivers/spi/spi-atmel.c:1723:12: warning: ‘atmel_spi_suspend’ defined but not used [-Wunused-function]
drivers/spi/spi-atmel.c:1741:12: warning: ‘atmel_spi_resume’ defined but not used [-Wunused-function]

Enclose both atmel_spi_suspend and atmel_spi_resume in #ifdef
CONFIG_PM_SLEEP/#endif to solve that.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: remove useless include

Definitions from linux/platform_data/atmel.h are not used, remove the
include.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: add support to FIFOs

The latest SPI controllers embedded inside sama5d2x SoCs come with FIFOs.
When FIFOs are enabled, they can either work in SINGLE data mode or
MULTIPLE data mode. The selected mode depends on the configuration of the
SPI controller (see below).

In SINGLE data mode (or legacy mode), for a single I/O access, only one
data can be read from the Receive Data Register (RDR) or written into the
Transmit Data Register (TDR). On the other hand, in MULTIPLE data mode, up
to 4 data can be read from the RDR or up 2 data can be written into the
TDR in a single 32bit I/O access. So programmers should take good care of
the width of the I/O access to read/write the right number of data. The
exact number of read/written data depends on both the I/O access width and
the data width (from 8 up to 16 bits).

To enable the FIFO feature a "atmel,fifo-size" property must be set to
provide the maximum number of data (not bytes) the RX and TX FIFOs can
store. Hence a 32 data FIFO can always store up to 32 data unrelated with
the actual data width.

When FIFOs are enabled, the RX one is forced to operate in SINGLE data
mode because this driver configures the spi controller as a master. In
master mode only, the Received Data Register has an additionnal Peripheral
Chip Select field, which prevents us from reading more than a single data
at each register access.

Besides, the TX FIFO operates in MULTIPLE data mode. However, even when a
8bit data size is used, only two data by access could be written into the
Transmit Data Register. Indeed the first data has to be written into the
lowest 16 bits whereas the second data has to be written into the highest
16 bits of the TDR. When DMA transfers are used to send data, we don't
rework the transmit buffer to cope with this hardware limitation: the
additional copies required to prepare a new input buffer suited to both
the DMA controller and the spi controller would waste all the benefit of
the DMA transfer. Instead, the DMA controller is configured to write only
one data at time into the TDR.

In pio mode, two data are written in the TDR in a single access.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: add support for the internal chip-select of the spi controller

This patch relies on the CSAAT (Chip Select Active After Transfer) feature
introduced by the version 2 of the spi controller. This new mode allows to
use properly the internal chip-select output pin of the spi controller
instead of using external gpios. Consequently, the "cs-gpios" device-tree
property becomes optional.

When the new CSAAT bit is set into the Chip Select Register, the internal
chip-select output pin remains asserted till both the following conditions
become true:
- the LASTXFER bit is set into the Control Register (or the Transmit Data
Register)
- the Transmit Data Register and its shift register are empty.

WARNING: if the LASTXFER bit is set into the Control Register then new
data are written into the Transmit Data Register fast enough to keep its
shifter not empty, the chip-select output pin remains asserted. Only when
the shifter becomes empty, the chip-select output pin is unasserted.

When the CSAAT bit is clear in the Chip Select Register, the LASTXFER bit
is ignored in both the Control Register and the Transmit Data Register.
The internal chip-select output pin remains active as long as the Transmit
Data Register or its shift register are not empty.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: use endian agnostic IO

Use the endian agnositc IO functions instead of the __raw ones for when
the driver is in use on big-endian systems.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: Fix interrupt setup for PDC transfers

Additionally to the current DMA transfer the PDC allows to set up a next DMA
transfer. This is useful for larger SPI transfers.

The driver currently waits for ENDRX as end of the transfer. But ENDRX is set
when the current DMA transfer is done (RCR = 0), i.e. it doesn't include the
next DMA transfer.
Thus a subsequent SPI transfer could be started although there is currently a
transfer in progress. This can cause invalid accesses to the SPI slave devices
and to SPI transfer errors.

This issue has been observed on a hardware with a M25P128 SPI NOR flash.

So instead of ENDRX we should wait for RXBUFF. This flag is set if there is
no more DMA transfer in progress (RCR = RNCR = 0).

Signed-off-by: Torsten Fleischer <torfl6749@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

spi: atmel: cleanup wait_for_completion return handling

return type of wait_for_completion_timeout is unsigned long not int, this
patch adds an appropriate variable and fixes up the assignment. It removes
the else branch as the only thing it was doing is assigning ret = 0; - but
ret is never used thereafter so that is not needed. As the string in
dev_err already states "timeout" there is little point in printing the 0.
A typo in "trasfer" -> transfer is also fixed.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: introduce probe deferring

Return probe defer if requesting a dma channel without a dma controller
probed.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: atmel: remove compat for non DT board when requesting dma chan

All boards with a dma controller have DT support so using
dma_request_slave_channel_compat is no more needed.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi/atmel: improve the system suspend/resume functions implementation

To make it cleaner, the system suspend/resume directly call
the runtime suspend/resume functions
and remove the wapper of CONFIG_PM_RUNTIME, CONFIG_PM_SLEEP.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: drop owner assignment from platform_drivers

A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

spi/atmel: fix simple_return.cocci warnings

drivers/spi/spi-atmel.c:1518:1-4: WARNING: end returns can be simpified and declaration on line 1514 can be dropped

Simplify a trivial if-return sequence. Possibly combine with a
preceding function call.
Generated by: scripts/coccinelle/misc/simple_return.cocci

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi/atmel: add support for runtime PM

Drivers should put the device into low power states proactively whenever the
device is not in use. Thus implement support for runtime PM and use the
autosuspend feature to make sure that we can still perform well in case we see
lots of SPI traffic within short period of time.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi/atmel: use dmaengine_terminate_all() API

The drivers should use dmaengine_terminate_all() API instead of
accessing the device_control which will be deprecated soon

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi/atmel: Fix pointer to int conversion warnings on 64 bit builds

On 64 bit systems integers are generally still 32 bit but long values and
pointers are usually 64 bit. GCC warns when casting a 64 bit pointer into
a 32 bit integer so cast to a long instead in order to avoid warnings.

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

spi: atmel: Use dmaengine_prep_slave_sg() API

Use the inline wrapper introduced by commit
16052827d98fbc13c31ebad560af4bd53e2b4dd5 ("dmaengine/dma_slave: introduce
inline wrappers").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: fix incorrect comparison

Found using smatch:
drivers/spi/spi-atmel.c:878 atmel_spi_pump_pio_data() warn: unsigned
'as->current_remaining_bytes' is never less than zero.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: Fix scheduling while atomic bug

atmel_spi_lock does a spin_lock_irqsave, so we need to renable the
interrupts when we want to schedule.

Signed-off-by: Alexander Stein <alexanders83@web.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: Make current_remaining_bytes to be int

Don't use unsigned for current_remaining_bytes so we can check
current_remaining_bytes < 0 case.
Use int is enough for current_remaining_bytes.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: fix printk format warnings

Fix printk format warning by using %p extension 'ad' for dma_addr_t.

drivers/spi/spi-atmel.c:1228:3: warning: format '%x' expects argument of type 'unsigned int', but argument 7 has type 'dma_addr_t' [-Wformat]
drivers/spi/spi-atmel.c:1228:3: warning: format '%x' expects argument of type 'unsigned int', but argument 9 has type 'dma_addr_t' [-Wformat]

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: add missing spi_master_{resume,suspend} calls to PM callbacks

The PM callbacks implemented by the spi-atmel driver don't call
spi_master_{resume,suspend}, fix that.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: adopt pinctrl support

Amend the spi atmel pin controller to optionally take a pin control
handle and set the state of the pins to:

- "default" on boot, resume and before performing an spitransfer
- "sleep" on suspend()

This should make it possible to optimize energy usage for the pins
both for the suspend/resume cycle

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: Let spi core handle validating transfer length

spi core will handle validating transfer length since commit 4d94bd21b333
"spi: core: Validate length of the transfers in message".
So remove the same checking in this driver.

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

spi: atmel: Remove redundant list_empty checking

This checking is already done in __spi_validate().

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

spi: Remove duplicate code to check chip_select

In spi_add_device(), we have the code to validate spi->chip_select.
So remove the duplicate code in various drivers.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: delete non-required instances of include <linux/init.h>

None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

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

spi: atmel: Refactor spi-atmel to use SPI framework queue

Replace the deprecated master->transfer with transfer_one_message()
and allow the SPI subsystem handle all the queuing of messages.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Tested-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: add support for changing message transfer speed

The only speed available was max_speed (the maximum speed declared for a
device).
This patch adds the support for spi_tranfer->speed_hz parameter.
We can now set a different speed for each spi message.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: Use devm_*() functions

Use devm_*() functions to make cleanup paths simpler.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: fix return value check in atmel_spi_probe()

In case of error, the function devm_ioremap_resource() returns ERR_PTR()
and never returns NULL. The NULL test in the return value check should be
replaced with IS_ERR().

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/atmel: Convert to devm_ioremap_resource()

This simplifies error handling.

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

spi: Don't break user-visible strings to multiple source lines in drivers

User-visible strings are more difficult to grep from sources if they are
separated to multiple source lines. This is worse than over 80 columns long
line code style violation.

Fix this by making those to single-line strings or by breaking them between
variables.

While at there, convert if (printk_ratelimit()) dev_warn() to use
dev_warn_ratelimited in spi-pxa2xx.c.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: Fix checkpatch issue

Fix the following checkpatch warning.

WARNING: quoted string split across lines

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: Fix incorrect error path

'irq' was not released when clk_prepare_enable failed.
Fix it.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: Silence checkpatch errors

Fixes the following types of checkpatch errors and warning:
ERROR: space required after that ',' (ctx:VxV)
WARNING: sizeof *as should be sizeof(*as)

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: convert from legacy pm ops to dev_pm_ops

Instead of using legacy suspend/resume methods, using newer
dev_pm_ops structure allows better control over power management.
Also, duplicated 'return' is removed from atmel_spi_resume().

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: Fix incorrect error path

'irq' was not released when clk_prepare_enable failed.
Fix it.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/atmel: Fix format specifier warnings

This patch fixes the following sparse warnings.
dma_addr_t can be either u32 or u64 so we should cast to the
largest type and use the format specifier %llx.

drivers/spi/spi-atmel.c: In function ‘atmel_spi_next_xfer_dma_submit’:
drivers/spi/spi-atmel.c:631:2: warning:
format ‘%x’ expects argument of type ‘unsigned int’,
but argument 7 has type ‘dma_addr_t’ [-Wformat]
drivers/spi/spi-atmel.c:631:2: warning:
format ‘%x’ expects argument of type ‘unsigned int’,
but argument 9 has type ‘dma_addr_t’ [-Wformat]
drivers/spi/spi-atmel.c: In function ‘atmel_spi_pdc_next_xfer’:
drivers/spi/spi-atmel.c:734:3: warning:
format ‘%x’ expects argument of type ‘unsigned int’,
but argument 7 has type ‘dma_addr_t’ [-Wformat]
drivers/spi/spi-atmel.c:734:3: warning:
format ‘%x’ expects argument of type ‘unsigned int’,
but argument 9 has type ‘dma_addr_t’ [-Wformat]
drivers/spi/spi-atmel.c:773:3: warning:
format ‘%x’ expects argument of type ‘unsigned int’,
but argument 7 has type ‘dma_addr_t’ [-Wformat]
drivers/spi/spi-atmel.c:773:3: warning:
format ‘%x’ expects argument of type ‘unsigned int’,
but argument 9 has type ‘dma_addr_t’ [-Wformat]

Signed-off-by: Emil Goode <emilgoode@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/atmel: Annotate lock/unlock functions

Let checkers like sparse know that the locking imbalances are intentional
in these functions.

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

spi: atmel: prepare clk before calling enable

Replace clk_enable/disable with clk_prepare_enable/disable_unprepare to
avoid common clk framework warnings.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: atmel: convert to dma_request_slave_channel_compat()

Use generic DMA DT helper.
Platforms booting with or without DT populated are both supported.

Based on Ludovic Desroches <ludovic.desroches@atmel.com> patchset
"ARM: at91: move to generic DMA device tree binding"

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Ludovic Desroches <ludovic.desroches@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi: convert drivers to use bits_per_word_mask

Fill in the recently added spi_master.bits_per_word_mask field in as
many drivers as possible. Make related cleanups, such as removing any
redundant error-checking, or empty setup callbacks.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

spi/spi-atmel: BUG: fix doesn' support 16 bits transfers using PIO

Fix using PIO transfer mode only support 8 bits transfer, doesn't support 16 bits.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
[wenyou.yang@atmel.com: submit the patch]
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

spi/spi-atmel: add dmaengine support

Add dmaengine support.

Using "has_dma_support" member of struct is used to select
the transfer mode: dmaengine or pdc.

For the dmaengine transfer mode, it supports both 8 bits and 16 bits transfer.

For the dmaengine transfer mode, if it fails to config dmaengine,
or if the message length is less than 16 bytes, it will use the PIO transfer mode.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
[wenyou.yang@atmel.com: using "has_dma_support" to select dmaengine as the spi xfer mode]
[wenyou.yang@atmel.com: fix DMA: OOPS if buffer > 4096 bytes]
[wenyou.yang@atmel.com: submit the patch]
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
[richard.genoud@gmail.com: update with dmaengine interface]
[richard.genoud@gmail.com: fix __init/__devinit sections mismatch]
[richard.genoud@gmail.com: adapt to slave_config changes]
[richard.genoud@gmail.com: add support t0 16 bits transfer]
Tested-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

spi/spi-atmel: add flag to controller data for lock operations

Will allow to drop the lock during DMA operations.

Replacing non-irqsave versions with irqsave versions of the lock
to make it correct in both pdc and dmaengine transfer mode

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
[wenyou.yang@atmel.com: submit the patch]
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Tested-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

spi/spi-atmel: add physical base address

Needed for future use with dmaengine enabled driver.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
[wenyou.yang@atmel.com: submit the patch]
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Tested-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

spi/atmel: fix speed_hz check in atmel_spi_transfer()

atmel_spi_transfer() would check speed_hz and fail if
the speed was changed in the transfer. After commit
"spi: make sure all transfer has proper speed set"
this would happen on all transfers.

Change speed_hz check to only fail if a lower speed
than max is requested.

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

spi/spi-atmel: status information passed through controller data

The status of transfer is stored in controller data structure
so that it can be used not only by atmel_spi_msg_done() function.
This will be useful for upcoming dmaengine enabled driver.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

spi/spi-atmel: call unmapping on transfers buffers

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

spi/spi-atmel: add support transfer on CS1,2,3, not only on CS0

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

spi/spi-atmel: detect the capabilities of SPI core by reading the VERSION register.

The "has_dma_support" needed for future use with dmaengine driver.

[Fixed some unneded ternery operators -- broonie]

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

spi: Remove erroneous __init, __exit and __exit_p() references in drivers

Some of the spi driver module remove hooks were annotated with __exit
and referenced with __exit_p(). Presumably these were supposed to be
__devinit, __devexit and __devexit_p() since __init/__exit for a
probe/remove hook has never been correct. They also got missed during
the big __devinit/__devexit purge since they didn't match the pattern.
Remove then now to be rid of it.

v2: purge __init also

Reported-by: Arnd Bergmann <arnd@arndb.de>
[Arnd set a patch cleaning up one, and then I found more]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

spi/atmel: add DT support

Use the newly introduce cs-gpios dt support on atmel.
We do not use the hardware cs as it's wired and has bugs and limitations.
As the controller believes that only active-low devices/systems exists.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

spi: Remove HOTPLUG section attributes

CONFIG_HOTPLUG is going away as an option. As result the __dev*
markings will be going away.

Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.

Bill Pemberton has done most of the legwork on this series. I've used
his script to purge the attributes from the drivers/gpio tree.

Reported-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

arm: at91: move platfarm_data to include/linux/platform_data/atmel.h

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>

atmel/spi: fix missing probe

Commit 940ab889 "drivercore: Add helper macro for platform_driver boilerplate"
converted this driver to use module_platform_driver, but due to the use
of platform_driver_probe(), this resulted in the call to atmel_spi_probe being
lost. Place the call to this function into the driver structure.

fix section missmatch

atmel_spi_probe is marked __init where it's supposed to be __devinit
atmel_spi_remove is marked __exit where it's supposed to be __devexit

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

drivercore: Add helper macro for platform_driver boilerplate

For simple modules that contain a single platform_driver without any
additional setup code then ends up being a block of duplicated
boilerplate. This patch adds a new macro, module_platform_driver(),
which replaces the module_init()/module_exit() registrations with
template functions.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Reviewed-by: Magnus Damm <magnus.damm@gmail.com>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>

ARM: gpio: at91: convert drivers to use asm/gpio.h rather than mach/gpio.h

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

spi: reorganize drivers

Sort the SPI makefile and enforce the naming convention spi_*.c for
spi drivers.

This change also rolls the contents of atmel_spi.h into the .c file
since there is only one user of that particular include file.

v2: - Use 'spi-' prefix instead of 'spi_' to match what seems to be
be the predominant pattern for subsystem prefixes.
- Clean up filenames in Kconfig and header comment blocks

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>