Commit 5fa5e6de ("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: 5fa5e6de ("spi: atmel: Switch to transfer_one transfer method")
Signed-off-by: NDan Sneddon <dan.sneddon@microchip.com>
Link: https://lore.kernel.org/r/20210629192218.32125-1-dan.sneddon@microchip.comSigned-off-by: NMark 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: NDan Sneddon <dan.sneddon@microchip.com>
Link: https://lore.kernel.org/r/20210602160816.4890-2-dan.sneddon@microchip.comSigned-off-by: NMark Brown <broonie@kernel.org>

Switch from using our own transfer_one_message routine to using the one
provided by the SPI core.
Signed-off-by: NDan Sneddon <dan.sneddon@microchip.com>
Link: https://lore.kernel.org/r/20210602160816.4890-1-dan.sneddon@microchip.comSigned-off-by: NMark Brown <broonie@kernel.org>

The DMA cap mask is no longer used since:
commit 7758e390 ("spi: atmel: remove compat for non DT board when requesting dma chan")
Drop it now.
Signed-off-by: NTudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20210218132840.131898-1-tudor.ambarus@microchip.comSigned-off-by: NMark Brown <broonie@kernel.org>

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

Fixes: 5e9af37e ("spi: atmel: introduce probe deferring")
Signed-off-by: NPan Bian <bianpan2016@163.com>
Fixes: 5e9af37e ("spi: atmel: introduce probe deferring")
Reviewed-by: NTudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20210120050025.25426-1-bianpan2016@163.comSigned-off-by: NMark 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 ddcdaeb8 ("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: NTudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20201030121116.869105-1-tudor.ambarus@microchip.comSigned-off-by: NMark Brown <broonie@kernel.org>

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 5d7e2b5e ("spi: core: allow reporting the effectivly used speed_hz for a transfer")
Signed-off-by: NThomas Kopp <thomas.kopp@microchip.com>
Reviewed-by: NTudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20200921071036.2091-1-thomas.kopp@microchip.comSigned-off-by: NMark Brown <broonie@kernel.org>

Since commit d5fab59c ("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: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20200930145353.3043699-1-alexandre.belloni@bootlin.comSigned-off-by: NMark 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: NKrzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20200901152713.18629-3-krzk@kernel.orgSigned-off-by: NMark 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: 2d9a7446 ("spi: atmel: No need to call spi_master_put() if spi_alloc_master() failed")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20200709101203.1374117-1-colin.king@canonical.comSigned-off-by: NMark Brown <broonie@kernel.org>

There is no need to call spi_master_put() if spi_alloc_master()
failed, it should return -ENOMEM directly.
Signed-off-by: NPeng Fan <fanpeng@loongson.cn>
Link: https://lore.kernel.org/r/1594111842-9468-1-git-send-email-fanpeng@loongson.cnSigned-off-by: NMark 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: NJules Irenge <jbi.octave@gmail.com>
Link: https://lore.kernel.org/r/20200429225723.31258-3-jbi.octave@gmail.comSigned-off-by: NMark 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: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20191212135550.4634-2-peter.ujfalusi@ti.comSigned-off-by: NMark 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: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20191113094256.1108-3-peter.ujfalusi@ti.comSigned-off-by: NMark 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: 8090d6d1 ("spi: atmel: Refactor spi-atmel to use SPI framework queue")
Signed-off-by: NMans Rullgard <mans@mansr.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191018153504.4249-1-gregory.clement@bootlin.comSigned-off-by: NMark 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: NGregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-8-gregory.clement@bootlin.comSigned-off-by: NMark 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: NGregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-7-gregory.clement@bootlin.comSigned-off-by: NMark Brown <broonie@kernel.org>

This driver is now only used through the device tree. Simplify code
by explicitly depend on device tree.
Signed-off-by: NGregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-6-gregory.clement@bootlin.comSigned-off-by: NMark 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: NGregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-5-gregory.clement@bootlin.comSigned-off-by: NMark 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: NGregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-4-gregory.clement@bootlin.comSigned-off-by: NMark 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: 48203034 ("spi: atmel: add support for the internal chip-select of the spi controller")
Cc: <stable@vger.kernel.org>
Signed-off-by: NGregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-3-gregory.clement@bootlin.comSigned-off-by: NMark 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: NGregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-2-gregory.clement@bootlin.comSigned-off-by: NMark 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: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-10-alexandru.ardelean@analog.comSigned-off-by: NMark 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: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-8-alexandru.ardelean@analog.comSigned-off-by: NMark 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: NGregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20190919154034.7489-1-gregory.clement@bootlin.comSigned-off-by: NMark 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: NUwe Kleine-König <uwe@kleine-koenig.org>
Link: https://lore.kernel.org/r/20190801204710.27309-1-uwe@kleine-koenig.orgSigned-off-by: NMark 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: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NEnrico Weigelt <info@metux.net>
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NAllison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.deSigned-off-by: NGreg 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: NJonas Bonn <jonas@norrbonn.se>
Acked-by: NNicolas 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: NMark 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: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMark 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: NGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: NDaniel Mack <daniel@zonque.org>
Acked-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: NMark 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: NStefan Agner <stefan@agner.ch>
Acked-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NMark 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: NEugen Hristev <eugen.hristev@microchip.com>
Acked-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: NMark 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"(7094576c).
Signed-off-by: NRadu Pirea <radu.pirea@microchip.com>
Acked-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: NMark 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: NJia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: NRadu Pirea <radu.pirea@microchip.com>
Signed-off-by: NMark 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: NCyrille Pitchen <cyrille.pitchen@microchip.com>
Acked-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: NMark 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: NBaruch Siach <baruch@tkos.co.il>
Acked-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: NMark 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: NQuentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: NMark 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: NQuentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: NMark 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: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NMark 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: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>