spi: pxa2xx: Fix style of and typos in the comments and messages

Fix style of the comments and messages along with typos in them.

While at it, update Intel Copyright year.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210517140351.901-8-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: pxa2xx: Extract read_SSSR_bits() helper

There are few places that repeat the logic of "read some bits from SSSR".
Extract read_SSSR_bits() helper to deduplicate that.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210510124134.24638-13-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: pxa2xx: Extract clear_SSCR1_bits() helper

There are few places that repeat the logic of "clear some bits in SSCR1".
Extract clear_SSCR1_bits() helper to deduplicate that.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210510124134.24638-12-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: pxa2xx: Use pxa_ssp_enable()/pxa_ssp_disable() in the driver

There are few places that repeat the logic of pxa_ssp_enable() and
pxa_ssp_disable(). Use them instead of open coded variants.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210510124134.24638-10-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: pxa2xx: Replace header inclusions by forward declarations

When the data structure is only referred by pointer, compiler may not need
to see the contents of the data type. Thus, we may replace header inclusions
by respective forward declarations. Due to above add missed headers as well.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210423182441.50272-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: pxa2xx: Utilize struct device from struct ssp_device

We have a duplication of struct device in the struct driver_data,
get rid of it and reuse member from struct ssp_device instead.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210423182441.50272-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: pxa2xx: Utilize MMIO and physical base from struct ssp_device

We have a duplication of MMIO and physical base addresses in
the struct driver_data, get rid of it and reuse members from
struct ssp_device instead.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210423182441.50272-3-andriy.shevchenko@linux.intel.com
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: pxa2xx: Introduce DMA burst size support

Some masters may have different DMA burst size than hard coded default.
In such case respect the value given by DMA burst size provided via
platform data.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

pxa2xx: replace spi_master with spi_controller

It's also a slave controller driver now, calling it "master" is slightly
misleading.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: pxa2xx: Use core message processing loop

Convert the pump_transfers() transfer tasklet to transfer_one() hook the
SPI core calls to process single transfer instead of handling message
processing and chip select handling in the driver. This not only
simplifies the driver but also brings transfer statistics from the core.

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

spi: pxa2xx: Remove unused argument from pxa2xx_spi_dma_prepare()

Current DMA engine implementation of pxa2xx_spi_dma_prepare() don't use
the dma_burst argument. Remove it since it became unused after
commit 6356437e65c2 ("spi: spi-pxa2xx: remove legacy PXA DMA bits").

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

spi: pxa2xx: Convert to generalized SPI controller API

Convert to generalized SPI controller API introduced by the
commit 8caab75fd2c2 ("spi: Generalize SPI "master" to "controller"").
Inside driver variable name "master" is still used to indicate the driver
is master only.

While at it, change "unsigned cs" to "unsigned int cs" in
pxa2xx_spi_fw_translate_cs() to suppress checkpatch warning.

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

spi: pxa2xx: Remove pointer to chip data from driver data

Transfer state machine in this driver does not need to set/unset pointer
to chip data between queueing and finalizing message as it is not
actually used as a state info itself but just pointer passing.

Since this per SPI device specific chip data is already carried in
ctldata use that and remove pointer to chip data from driver data.

While at it, group initialized variables before uninitialized variables
in pump_transfers().

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

spi: pxa2xx: Remove pointer to current SPI message from driver data

There is no need to carry pointer to current SPI message in driver data
because cur_msg in struct spi_master holds it already when driver is using
the message queueing infrastructure from the SPI core.

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

spi: pxa2xx: Do not needlessly initialize stack variables

All of these variables are unconditionally set before their use.

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

spi: pxa2xx: Switch to SPI core DMA mapping functionality

SPI core provides DMA mapping with scatterlists. Start using it instead
of own implementation in spi-pxa2xx. Major difference in addition to
bunch of removed boilerplate code is that SPI core does
mapping/unmapping for all transfers in a message before and after the
message sending where spi-pxa2xx did mapping/unmapping for each
transfers separately.

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

spi: pxa2xx: Use dummy buffers provided by SPI core

Dummy buffer is used for half duplex transfers that don't have TX or RX
buffer set. Instead of own dummy buffer management here let the SPI core to
handle it by setting the SPI_MASTER_MUST_RX and SPI_MASTER_MUST_TX flags.
Then core makes sure both transfer buffers are set.

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

spi: pxa2xx: Remove rx_/tx_map_len members from struct driver_data

spi-pxa2xx-dma.c DMA engine implementation stopped using PIO for
unaligned trailing bytes in the commit 111e0a9dc71e ("spi/pxa2xx: Prevent
DMA from transferring too many bytes"). This means there is no need to
update tx/rx transfer buffer pointers after DMA completion. These buffer
pointers will be set to new buffers when handling the next transfer.

Because this buffer pointer update was only remaining use for rx_map_len
and tx_map_len members in struct driver_data after removing the legacy PXA
DMA implementation they can be removed now.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: pxa2xx: handle error of pxa2xx_spi_dma_prepare()

If by some reason pxa2xx_spi_dma_prepare() fails we have not to ignore its
error. In such case we abort the transfer and return the error to upper
level.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[Jarkko: Avoid leaking TX descriptors in case RX descriptor allocation
fails. Noted by Robert Jarzmik <robert.jarzmik@free.fr>.
Unmap also buffers in case of failure.]
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: pxa2xx: Use newer more explicit DMAengine terminate API

Commit b36f09c3c441 ("dmaengine: Add transfer termination
synchronization support") marked dmaengine_terminate_all() as
deprecated and is being replaced by explicit synchronous and asynchronous
terminate functions.

Here DMA termination are done in two cases: FIFO overrun and module
removal.

FIFO overrun is handled in interrupt context and converting
dmaengine_terminate_all() to dmaengine_terminate_async() does the same than
before.

Using synchronous termination in module removal however adds a bit more
robustness as it waits all completion callbacks have finished. Although it
looks all known DMA engines used with spi-pxa2xx don't implement
device_synchronize() callback so this too appears to be a no-op in
practice.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: pxa2xx: Remove empty function pxa2xx_spi_dma_resume()

This was leftover from the legacy pxa2xx DMA implementation and not needed
anymore so remove it.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: pxa2xx: Cleanup register access macros

Currently SSP registers are accessed by having an own read and write macros
for each register. For instance read_SSSR(iobase) and write_SSSR(iobase).

In my opinion this hurts readability and requires new macros to be defined
for each new added register. Let's define and use instead common
pxa2xx_spi_read() and pxa2xx_spi_write() accessors.

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

spi/pxa2xx: Don't use slave_id of dma_slave_config

That field has been deprecated in favour of getting the necessary
information from ACPI/DT.

However, we still need to deal systems that are PCI only (no ACPI to back
up). In order to support such systems, we allow the DMA filter function and
its corresponding parameter via pxa2xx_spi_master platform data. Then when
the pxa2xx_spi_dma_setup() doesn't find the channel via ACPI, it falls back
to use the given filter function.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

spi/pxa2xx: change default supported DMA burst size to 1

This is to fix the SPI DMA transfer failure for speed less than 1M.
If using current DMA burst size setting (16), the Rx data bytes are
invalid due to each data byte is multiplied according to the burst
size setting.

Let's said supposedly we shall receive the following 18 bytes of data:
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18
Instead, the data bytes received consist of "16 bytes of '01' +
2 bytes of '02'" :
01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 02 02

Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

spi/pxa2xx: Prevent DMA from transferring too many bytes

In case we are doing DMA transfer and the size of the buffer is not multiple
of 4 bytes the driver truncates that to 4-byte boundary and tries to handle
remaining bytes using PIO.

Or that is what it tried to do. What actually happens is that it calls
ALIGN() to the buffer size which aligns it to the next 4-byte boundary
(doesn't truncate). Doing this results 1-3 bytes extra to be transferred.
Furthermore we handle remaining bytes using PIO which results one extra
byte to be transferred. In worst case the driver transfers 4 extra bytes.

While investigating this it turned out that the DMA hardware doesn't even
have such limitation so we can solve this by dropping the code that tries
to handle unaligned bytes.

Reported-by: Chiau Ee Chew <chiau.ee.chew@intel.com>
Reported-by: Hock Leong Kweh <hock.leong.kweh@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.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/pxa2xx: use GFP_ATOMIC in sg table allocation

pxa2xx_spi_map_dma_buffer() gets called in tasklet context so we can't
sleep when we allocate a new sg table. Use GFP_ATOMIC here instead.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org

spi/pxa2xx: convert to dma_request_slave_channel_compat()

Now that we have these nice DMA API helper functions we can take advantage
of those instead of open-coding the channel/request line extraction from
ACPI. Use the _compat version which still allows passing the
channel/request line from platform data.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

spi/pxa2xx: add support for DMA engine

To be able to use DMA with this driver on non-PXA platforms we implement
support for the generic DMA engine API. This lets user to use different DMA
engines with little or no modification to the driver.

Request lines and channel numbers can be passed to the driver from the
platform specific data.

The DMA engine implementation will be selected by default even on PXA
platform. User can select the legacy DMA API by enabling Kconfig option
CONFIG_SPI_PXA2XX_PXADMA.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Lu Cao <lucao@marvell.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>