[ Upstream commit fc70d643a2 ]
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: 5ee36c9898 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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>
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>
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>
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: 5fa5e6dec7 ("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>
Commit 5fa5e6dec7 ("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: 5fa5e6dec7 ("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>
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>
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 ddcdaeb882 ("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>
The amount of changes is smaller at this round (what a surprise),
but lots of activity is seen. Most of changes are about ASoC
driver development, especially Intel platforms.
Here are some highlights:
General:
* Replace all tasklet usages with other alternatives
* Cleanup of the ASoC error unwinding code
* Fixes for trivial issues caught by static checker
* Spell fixes allover the places
ALSA Core:
* Lockdep fix for control devices
* Fix for potential OSS sequencer mutex stalls
HD-audio and USB-audio:
* SoundBlaster AE-7 support
* Changes in quirk table for the rename handling
* Quirks for HP and ASUS machines, Pioneer DJ DJM-250MK2.
ASoC:
* Lots of updates for Intel SOF and SoundWire enablement
* Replacement of the DSP driver for some older x86 systems;
the new code was written from scratch, better maintenance
expected
* Helpers for parsing auxiluary devices from the device tree
* New support for AllWinner A64, Cirrus Logic CS4234, Mediatek
MT6359 Microchip S/PDIF TX and RX controllers, Realtek RT1015P,
and Texas Instruments J721E, TAS2110, TAS2564 and TAS2764
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Merge tag 'sound-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound updates from Takashi Iwai:
"The amount of changes is smaller at this round (what a surprise), but
lots of activity is seen. Most of changes are about ASoC driver
development, especially Intel platforms. Here are some highlights:
General:
- Replace all tasklet usages with other alternatives
- Cleanup of the ASoC error unwinding code
- Fixes for trivial issues caught by static checker
- Spell fixes allover the places
ALSA Core:
- Lockdep fix for control devices
- Fix for potential OSS sequencer mutex stalls
HD-audio and USB-audio:
- SoundBlaster AE-7 support
- Changes in quirk table for the rename handling
- Quirks for HP and ASUS machines, Pioneer DJ DJM-250MK2.
ASoC:
- Lots of updates for Intel SOF and SoundWire enablement
- Replacement of the DSP driver for some older x86 systems; the new
code was written from scratch, better maintenance expected
- Helpers for parsing auxiluary devices from the device tree
- New support for AllWinner A64, Cirrus Logic CS4234, Mediatek MT6359
Microchip S/PDIF TX and RX controllers, Realtek RT1015P, and Texas
Instruments J721E, TAS2110, TAS2564 and TAS2764"
* tag 'sound-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (498 commits)
ALSA: hda/hdmi: fix incorrect locking in hdmi_pcm_close
ALSA: hda: fix jack detection with Realtek codecs when in D3
ALSA: fireworks: use semicolons rather than commas to separate statements
ALSA: hda: use semicolons rather than commas to separate statements
ALSA: hda/i915 - fix list corruption with concurrent probes
ASoC: dmaengine: Document support for TX only or RX only streams
ASoC: mchp-spdiftx: remove 'TX' from playback stream name
ASoC: ti: davinci-mcasp: Use &pdev->dev for early dev_warn
ASoC: tas2764: Add the driver for the TAS2764
dt-bindings: tas2764: Add the TAS2764 binding doc
ASoC: Intel: catpt: Add explicit DMADEVICES kconfig dependency
ASoC: Intel: catpt: Fix compilation when CONFIG_MODULES is disabled
ASoC: stm32: dfsdm: add actual resolution trace
ASoC: stm32: dfsdm: change rate limits
ASoC: qcom: sc7180: Add support for audio over DP
Asoc: qcom: lpass-platform : Increase buffer size
ASoC: qcom: Add support for lpass hdmi driver
Asoc: qcom: lpass:Update lpaif_dmactl members order
Asoc:qcom:lpass-cpu:Update dts property read API
ASoC: dt-bindings: Add dt binding for lpass hdmi
...
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 5d7e2b5ed5 ("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>
Since commit d5fab59cab ("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>
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>
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: 2d9a744685 ("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>
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>
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>
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>
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: 8090d6d1a4 ("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>
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>
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>
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>
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>
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: 4820303480 ("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>
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>
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>
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>
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>
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>
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>
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>
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_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>
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>
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
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"(7094576ccd).
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>
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>
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
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>
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>
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>
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>
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>
Louis Chauvet