This attribute works the same was as the identically named attribute
for PCI, AMBA, and platform devices.  For reference, see:

commit 3cf38571 ("ARM: 8256/1: driver coamba: add device binding
path 'driver_override'")
commit 3d713e0e ("driver core: platform: add device binding path
'driver_override'")
commit 782a985d ("PCI: Introduce new device binding path using
pci_dev.driver_override")

If the name of a driver is written to this attribute, then the device
will bind to the named driver and only the named driver.

The device will bind to the driver even if the driver does not list the
device in its id table.  This behavior is different than the driver's
bind attribute, which only allows binding to devices that are listed as
supported by the driver.

It can be used to bind a generic driver, like spidev, to a device.
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Reviewed-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Tested-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>

Improve readability a bit.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Certain devices don't work well when a transmit FIFO underrun or
receive FIFO overrun occurs. Example is the SAF400x radio chip when
running at high speed which leads to garbage being sent to/received from
the chip. In which case, it should stall waiting for further data to be
available before proceeding. This patch unset the NOSTALL bit in CFGR1
by default to prevent this issue.
Signed-off-by: Hieu Tran Dang <dangtranhieu2012@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Clang warns when one enumerated type is implicitly converted to another.

drivers/spi/spi-ep93xx.c:342:62: warning: implicit conversion from
enumeration type 'enum dma_transfer_direction' to different enumeration
type 'enum dma_data_direction' [-Wenum-conversion]
        nents = dma_map_sg(chan->device->dev, sgt->sgl, sgt->nents, dir);
                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
./include/linux/dma-mapping.h:428:58: note: expanded from macro
'dma_map_sg'
#define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, 0)
                               ~~~~~~~~~~~~~~~~          ^
drivers/spi/spi-ep93xx.c:348:57: warning: implicit conversion from
enumeration type 'enum dma_transfer_direction' to different enumeration
type 'enum dma_data_direction' [-Wenum-conversion]
                dma_unmap_sg(chan->device->dev, sgt->sgl, sgt->nents, dir);
                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
./include/linux/dma-mapping.h:429:62: note: expanded from macro
'dma_unmap_sg'
#define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, 0)
                                 ~~~~~~~~~~~~~~~~~~          ^
drivers/spi/spi-ep93xx.c:377:56: warning: implicit conversion from
enumeration type 'enum dma_transfer_direction' to different enumeration
type 'enum dma_data_direction' [-Wenum-conversion]
        dma_unmap_sg(chan->device->dev, sgt->sgl, sgt->nents, dir);
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
./include/linux/dma-mapping.h:429:62: note: expanded from macro
'dma_unmap_sg'
#define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, 0)
                                 ~~~~~~~~~~~~~~~~~~          ^
3 warnings generated.

dma_{,un}map_sg expect an enum of type dma_data_direction but this
driver uses dma_transfer_direction for everything. Convert the driver to
use dma_data_direction for these two functions.

There are two places that strictly require an enum of type
dma_transfer_direction: the direction member in struct dma_slave_config
and the direction parameter in dmaengine_prep_slave_sg. To avoid using
an explicit cast, add a simple function, ep93xx_dma_data_to_trans_dir,
to safely map between the two types because they are not 1 to 1 in
meaning.
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

With this commit the DSPI driver on the BK4 board can be used for SPI
transmission managed from user space (via /dev/spidev0.0).

Example usage/testing:
insmod ./spi-fsl-dspi.ko
./spidev_test -D /dev/spidev0.0 -s 3000000 -v -H -b 8 -p "\xCC\x11\x22\x74"
Signed-off-by: Lukasz Majewski <lukma@denx.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

Rewrite switch code block to directly do the expected number
of shifts in each case and have break statements.

Addresses-Coverity-ID: 1056539 ("Missing break in switch")
Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Apparently, this code does not actually fall through to the next case
because the machine restarts before it has a chance. However, for the
sake of maintenance and readability, we better add the missing break
statement.

Addresses-Coverity-ID: 1437892 ("Missing break in switch")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Document RZ/G1N (R8A7744) SoC bindings.
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Mark Brown <broonie@kernel.org>

Document RZ/G1N (r8a7744) SoC specific bindings.
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Mark Brown <broonie@kernel.org>

This patch adds basic spi slave for MT2712.
Signed-off-by: Leilk Liu <leilk.liu@mediatek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

This patch adds a DT binding documentation for the MT2712 soc.
Signed-off-by: Leilk Liu <leilk.liu@mediatek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Use the appropriate SPDX license identifier and drop the previous
license text.
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

On r8a7791/koelsch:

    m25p80 spi0.0: error -22 reading 9f
    m25p80: probe of spi0.0 failed with error -22

Apparently the logic in spi_mem_check_op() is wrong, rejecting the
spi-mem operation if any buswidth is valid, instead of invalid.

Fixes: 38058322 ("spi: spi-mem: Add extra sanity checks on the op param")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Add support for RZ/A2
Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

The __exit section is left out for built-in drivers, so a
'remove' callback must not be marked as such to avoid breaking when
we unbind a device at runtime. This was pointed out by kbuild:

`sprd_spi_remove' referenced in section `.data' of drivers/spi/spi-sprd.o: defined in discarded section `.exit.text' of drivers/spi/spi-sprd.o

Fixes: e7d973a3 ("spi: sprd: Add SPI driver for Spreadtrum SC9860")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

Clang warns when one enumerated type is converted implicitly to another:

drivers/spi/spi-pic32.c:323:8: warning: implicit conversion from
enumeration type 'enum dma_data_direction' to different enumeration type
'enum dma_transfer_direction' [-Wenum-conversion]
                                          DMA_FROM_DEVICE,
                                          ^~~~~~~~~~~~~~~
drivers/spi/spi-pic32.c:333:8: warning: implicit conversion from
enumeration type 'enum dma_data_direction' to different enumeration type
'enum dma_transfer_direction' [-Wenum-conversion]
                                          DMA_TO_DEVICE,
                                          ^~~~~~~~~~~~~
2 warnings generated.

Use the proper enums from dma_transfer_direction (DMA_FROM_DEVICE =
DMA_DEV_TO_MEM = 2, DMA_TO_DEVICE = DMA_MEM_TO_DEV = 1) to satify Clang.

Link: https://github.com/ClangBuiltLinux/linux/issues/159Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Some combinations are simply not valid and should be rejected before
the op is passed to the SPI controller driver.

Add an spi_mem_check_op() helper and use it in spi_mem_exec_op() and
spi_mem_supports_op() to make sure the spi-mem operation is valid.
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

This remove the check and subsequent return of error for the case when
a SPI device requires SPI_CS_WORD and is also configured to use a GPIO
for the CS line.

Commit a134cc414e86 ("spi: always use software fallback for SPI_CS_WORD
when using cs_gio") handles this case now, so this check is no longer
necessary.
Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

This modifies the condition for using the software fallback
implementation for SPI_CS_WORD when the SPI controller is using a GPIO
for the CS line. When using a GPIO for CS, the hardware implementation
won't work, so we just enable the software fallback globally in this
case.
Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Mediatek SPI driver modifies some fields (tx_buf, rx_buf, len, tx_dma,
rx_dma) of the spi_transfer* passed in when doing transfer_one and in
interrupt handler. This is somewhat unexpected, and there are some
caller (e.g. Cr50 spi driver) that reuse the spi_transfer for multiple
messages. Add a field to record how many bytes have been transferred,
and calculate the right len / buffer based on it instead.
Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>

Change-Id: I23e218cd964f16c0b2b26127d4a5ca6529867673
Signed-off-by: Mark Brown <broonie@kernel.org>

If the pll clock needs to be enabled to get its rate, it will also need
to be enabled to provide it. So ensure it is kept enabled through the
lifetime of the device.

Fixes: 0d7412ed ("spi/bcm63xx-hspi: Enable the clock before calling clk_get_rate().")
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

It makes no sense to remove the device on shutdown. And it break things
when the hardware crucial for shutdown (such as the embedded controller)
is attached to the SPI bus.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Mark Brown <broonie@kernel.org>

This adds support for the SPI_CS_WORD flag to the TI DaVinci SPI
driver. This mode can be used as long as we are using the hardware
chip select and not a GPIO chip select.
Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: Provide SPI_CS_WORD

This provides a SPI operation mode which changes chip select after every
word, used by some devices such as ADCs and DACs.

This adds a default software implementation for the SPI_CS_WORD flag for
controllers that don't have such a feature.

The SPI_CS_WORD flag indicates that the CS line should be toggled
between each word sent, not just between each transfer. The
implementation works by using existing functions to split transfers into
one-word-sized transfers and sets the cs_change bit for each of the
new transfers.
Signed-off-by: David Lechner <david@lechnology.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

This adds a new SPI mode flag, SPI_CS_WORD, that is used to indicate
that a SPI device requires the chip select to be toggled after each
word that is transferred.
Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Almost all spi drivers assign spi master->dev.of_node from
its parent platform device without additional refcounting.
It seems of_node_get() in pic32_sqi_probe() is unnecessary
and there is no corresponding of_node_put().

Found by Linux Driver Verification project (linuxtesting.org)
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Mark Brown <broonie@kernel.org>

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/spi/spi-davinci.c: In function 'davinci_spi_setup':
drivers/spi/spi-davinci.c:422:36: warning:
 variable 'pdata' set but not used [-Wunused-but-set-variable]
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

The DaVinci SPI can use either:
- Internal chip selects (inside the SPI host)
- External chip selects (using GPIO)
- External chip selects passed in pdata

The last way of passing external chip selects through
platform data is not used in the kernel. Delete it to make
the code simpler when refactoring GPIO.

Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: Michele Dionisio <michele.dionisio@gmail.com>
Cc: Frode Isaksen <fisaksen@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

We need that to adjust the len of the 2nd transfer (called data in
spi-mem) if it's too long to fit in a SPI message or SPI transfer.

Fixes: c36ff266 ("spi: Extend the core to ease integration of SPI memory controllers")
Cc: <stable@vger.kernel.org>
Signed-off-by: Chuanhua Han <chuanhua.han@nxp.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

There is a logical problem in spi-gpio with host just
assigning a MOSI line and no MISO: this is interpreted
as the host cannot do RX and the host is flagged with
SPI_MASTER_NO_RX.

This is wrong: since GPIO lines can switch direction,
in 3WIRE operation the host will simply reverse the
direction of the GPIO line and start reading from it,
there is even code for doing this in the driver, but
it went unnoticed because it was tested by using a
master with 4 wires but a device using just 3 wires.

Remove the offending flag.

Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

Almost all spi drivers assign spi master->dev.of_node from
its parent platform device without additional refcounting.
It seems of_node_get() in pic32_spi_probe() is unnecessary
and there is no corresponding of_node_put().

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Mark Brown <broonie@kernel.org>

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/spi/spi-pl022.c: In function 'do_polling_transfer':
drivers/spi/spi-pl022.c:1493:20: warning:
 variable 'chip' set but not used [-Wunused-but-set-variable]
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

The spi-dw driver currently only supports 8 or 16 bits per word.

Since the hardware supports 4-16 bits per word, adapt the driver
to also support this.

Tested on socfpga cyclone5 with a 9-bit SPI display.
Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/spi/spi-gpio.c: In function 'spi_gpio_remove':
drivers/spi/spi-gpio.c:450:33: warning:
 variable 'pdata' set but not used [-Wunused-but-set-variable]
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
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>

- Print spaces as spaces,
  - Do not print characters > 126, as they will be shown as garbage
    in the modern UTF-8 era,
  - Use a normal period instead of its hexadecimal ASCII value,
  - Delimit the text part with pipe symbols on both sides (was left side
    only), without any spaces, to make it clear where the decoded text
    starts and ends,
  - Drop a useless comment.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>

Document support for the MSIOF module in the Renesas R-Car E3 (r8a77990)
SoC.

No driver update is needed.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>

Document support for the MSIOF module in the Renesas R-Car D3 (r8a77995)
SoC.

No driver update is needed.
Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>

This change increases the source code readability.
Instead of using `spi->child[cs].direct_access.XXX` use `dir_acc->XXX`.
Instead of using `orion_spi->child[cs].direct_access.vaddr` use `vaddr`.
Signed-off-by: Kosta Zertsekel <zertsekel@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: Mark Brown <broonie@kernel.org>