In the public interface for chipselect, there is always an entry
commented as "Dummy generic FIFO entry" pushed down to the fifo right
after the activate/deactivate command. The dummy entry is 0x0,
irregardless if the intention was to activate or deactive the cs. This
causes the cs line to glitch rather than beeing activated in the case
when there was an activate command.

This has been observed on oscilloscope, and have caused problems for at
least one specific flash device type connected to the qspi port. After
the change the glitch is gone and cs goes active when intended.

The reason why this worked before (except for the glitch) was because
when sending the actual data, the CS bits are once again set. Since
most flashes uses mode 0, there is always a half clk period anyway for
cs to clk active setup time. If someone would rely on timing from a
chip_select call to a transfer_one, it would fail though.

It is unknown why the dummy entry was there in the first place, git log
seems to be of no help in this case. The reference manual gives no
indication of the necessity of this. In fact the lower 8 bits are a
setup (or hold in case of deactivate) time expressed in cycles. So this
should not be needed to fulfill any setup/hold timings.
Signed-off-by: Thommy Jakobsson <thommyj@gmail.com>
Reviewed-by: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
Link: https://lore.kernel.org/r/20200224162643.29102-1-thommyj@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

In some circumstances on Intel LPSS controllers, toggling the LPSS
CS control register doesn't actually cause the CS line to toggle.
This seems to be failure of dynamic clock gating that occurs after
going through a suspend/resume transition, where the controller
is sent through a reset transition. This ruins SPI transactions
that either rely on delay_usecs, or toggle the CS line without
sending data.

Whenever CS is toggled, momentarily set the clock gating register
to "Force On" to poke the controller into acting on CS.
Signed-off-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Evan Green <evgreen@chromium.org>
Link: https://lore.kernel.org/r/20200211223700.110252-1-rajatja@google.comSigned-off-by: Mark Brown <broonie@kernel.org>

Commit f3186dd8 ("spi: Optionally use GPIO descriptors for CS GPIOs")
amended of_spi_parse_dt() to always set SPI_CS_HIGH for SPI slaves whose
Chip Select is defined by a "cs-gpios" devicetree property.

This change broke userspace applications which issue an SPI_IOC_WR_MODE
ioctl() to an spidev:  Chip Select polarity will be incorrect unless the
application is changed to set SPI_CS_HIGH.  And once changed, it will be
incompatible with kernels not containing the commit.

Fix by setting SPI_CS_HIGH in spidev_ioctl() (under the same conditions
as in of_spi_parse_dt()).

Fixes: f3186dd8 ("spi: Optionally use GPIO descriptors for CS GPIOs")
Reported-by: Simon Han <z.han@kunbus.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/fca3ba7cdc930cd36854666ceac4fbcf01b89028.1582027457.git.lukas@wunner.deSigned-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org # v5.1+

spi_qup_suspend() will cause synchronous external abort when
runtime suspend is enabled and applied, as it tries to
access SPI controller register while clock is already disabled
in spi_qup_pm_suspend_runtime().
Signed-off-by: Yuji sasaki <sasakiy@chromium.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20200214074340.2286170-1-vkoul@kernel.orgSigned-off-by: Mark Brown <broonie@kernel.org>

dma_request_channel() can return -EPROBE_DEFER, if DMA driver is not
ready. Currently driver just falls back to PIO mode on probe deferral.
Fix this by requesting all required channels during probe and
propagating EPROBE_DEFER error code.
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20200204124816.16735-3-vigneshr@ti.comSigned-off-by: Mark Brown <broonie@kernel.org>

On AM654, McSPI can only support 4K - 1 bytes per transfer when DMA is
enabled. Therefore populate master->max_transfer_size callback to
inform client drivers of this restriction when DMA channels are
available.
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20200204124816.16735-2-vigneshr@ti.comSigned-off-by: Mark Brown <broonie@kernel.org>

Add NPCM Peripheral SPI reset binding documentation,
Removing unnecessary aliases use.
Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200115162301.235926-4-tmaimon77@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

Modify NPCM perphiral SPI reset support from
direct register access to reset controller support.
Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Link: https://lore.kernel.org/r/20200115162301.235926-5-tmaimon77@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

Improving spi 8 bit per word mode transfer performance
by using 16 bit per word transfer and receive when the data
length is even and larger than one.
Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Link: https://lore.kernel.org/r/20200115162301.235926-3-tmaimon77@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-ti-qspi.c: In function ‘ti_qspi_start_transfer_one’:
drivers/spi/spi-ti-qspi.c:392:8: warning: ‘rx_wlen’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  392 |     if (rx_wlen >= 32)
      |        ^
drivers/spi/spi-ti-qspi.c:318:12: note: ‘rx_wlen’ was declared here
  318 |  u8 rxlen, rx_wlen;
      |            ^~~~~~~

The warning is a false positive; it is not thrown by all compiler versions, e.g.
Red Hat Cross 9.2.1-1 but not Linaro GCC 7.5-2019.12.
Signed-off-by: Jean Pihet <jean.pihet@newoldbits.com>
Link: https://lore.kernel.org/r/20200115100700.3357-1-jean.pihet@newoldbits.comSigned-off-by: Mark Brown <broonie@kernel.org>

No need to 'goto err;' for just doing a return.
return directly from where the error happens.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Link: https://lore.kernel.org/r/2a4a7e11b37cfa0558d68f0d35e90d6da858b059.1579017697.git.christophe.leroy@c-s.frSigned-off-by: Mark Brown <broonie@kernel.org>

Why it does not work at the moment:
- num_chipselect sets the number of cs-gpios that are in the DT.
  This comes from drivers/spi/spi.c
- num_chipselect gets set with devm_spi_register_controller, that is
  called in drivers/spi/spi.c
- devm_spi_register_controller got called after num_chipselect has
  been used.

How this commit fixes the issue:
- devm_spi_register_controller gets called before num_chipselect is
  being used.

Fixes: c7a40259 ("spi: lpspi: use the core way to implement cs-gpio function")
Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Link: https://lore.kernel.org/r/20191204141312.1411251-1-philippe.schenker@toradex.comSigned-off-by: Mark Brown <broonie@kernel.org>

Optimize the 8-bit based transfers, as used by the SPI flash
devices, by reading the data registers by 32 and 128 bits when
possible and copy the contents to the receive buffer.

The speed improvement is 4.9x using quad read.
Signed-off-by: Jean Pihet <jean.pihet@newoldbits.com>
Cc: Ryan Barnett <ryan.barnett@rockwellcollins.com>
Cc: Conrad Ratschan <conrad.ratschan@rockwellcollins.com>
Cc: Arnout Vandecappelle <arnout.vandecappelle@essensium.com>
Link: https://lore.kernel.org/r/20200114124125.361429-3-jean.pihet@newoldbits.comSigned-off-by: Mark Brown <broonie@kernel.org>

The TI QSPI IP has limitations:
- the MMIO region is 64MB in size
- in non-MMIO mode, the transfer can handle 4096 words max.

Add support for bigger devices.
Use MMIO and DMA transfers below the 64MB boundary, use
software generated transfers above.
Signed-off-by: Jean Pihet <jean.pihet@newoldbits.com>
Cc: Ryan Barnett <ryan.barnett@rockwellcollins.com>
Cc: Conrad Ratschan <conrad.ratschan@rockwellcollins.com>
Cc: Arnout Vandecappelle <arnout.vandecappelle@essensium.com>
Link: https://lore.kernel.org/r/20200114124125.361429-2-jean.pihet@newoldbits.comSigned-off-by: Mark Brown <broonie@kernel.org>

Currrently the memory for the clk_bulk_data of the QSPI controller
is allocated with spi_alloc_master(). The bulk data pointer is passed
to devm_clk_bulk_get() which saves it in clk_bulk_devres->clks. When
the device is removed later devm_clk_bulk_release() is called and
uses the bulk data referenced by the pointer to release the clocks.
For this driver this results in accessing memory that has already
been freed, since the memory allocated with spi_alloc_master() is
released by spi_controller_release(), which is called before the
managed resources are released.

Use device managed memory for the clock bulk data to fix the issue
described above.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200108133948.1.I35ceb4db3ad8cfab78f7cd51494aeff4891339f5@changeidSigned-off-by: Mark Brown <broonie@kernel.org>

Set John Garry @ Huawei as the maintainer.
Signed-off-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1575900490-74467-4-git-send-email-john.garry@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>

Add the driver for the HiSilicon v3xx SPI NOR flash controller, commonly
found in hi16xx chipsets.

This is a different controller than that in drivers/mtd/spi-nor/hisi-sfc.c;
indeed, the naming for that driver is poor, since it is really known as
FMC, and can support other memory technologies.

The driver module name is "hisi-sfc-v3xx", as recommended by HW designer,
being an attempt to provide a distinct name - v3xx being the unique
controller versioning.

Only ACPI firmware is supported.

DMA is not supported, and we just use polling mode for operation
completion notification.

The driver uses the SPI MEM OPs.
Signed-off-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1575900490-74467-3-git-send-email-john.garry@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>

Add microchip,sam9x60-spi to DT bindings documentation.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/1578488123-26127-13-git-send-email-claudiu.beznea@microchip.comSigned-off-by: Mark Brown <broonie@kernel.org>

The "RevPi Connect Flat" PLC offered by KUNBUS has 4 slaves attached
to the BCM2835 SPI master.  Raise the maximum number of slaves in the
driver accordingly.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/01453fd062de2d49bd74a847e13a0781cbf8143d.1578572268.git.lukas@wunner.deSigned-off-by: Mark Brown <broonie@kernel.org>

STR is a well-known stringify macro so it should be avoided in drivers
to avoid warnings like this (MIPS architecture while compile testing):

    drivers/spi/spi-sh-msiof.c:76:0: warning: "STR" redefined
     #define STR 0x40 /* Status Register */
    arch/mips/include/asm/mipsregs.h:30:0: note: this is the location of the previous definition
     #define STR(x) __STR(x)

To maintain consistency between all register names add a SI prefix to
all of them.  This also matches register names in datasheet.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200108194319.3171-1-krzk@kernel.orgSigned-off-by: Mark Brown <broonie@kernel.org>

Add support for GPIO chip selects using GPIO descriptors.  As the RSPI
controller always drives a native chip select when performing a
transfer, at least one native chip select must be left unused.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200102133822.29346-7-geert+renesas@glider.beSigned-off-by: Mark Brown <broonie@kernel.org>

RSPI variants on some SuperH or R-Mobile SoCs support multiple native
chip selects. Add support for this by configuring the SSL Assert Signal
Setting.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200102133822.29346-6-geert+renesas@glider.beSigned-off-by: Mark Brown <broonie@kernel.org>

The set_config_register() macro is used in a single place.
Make the code easier to read by just removing it.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200102133822.29346-5-geert+renesas@glider.beSigned-off-by: Mark Brown <broonie@kernel.org>

Use the helper introduced by commit e135303b ("device: Add
dev_<level>_once variants") instead of open-coding the same operation.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200102133822.29346-4-geert+renesas@glider.beSigned-off-by: Mark Brown <broonie@kernel.org>

Currently the MSIOF SPI driver uses custom code to handle the unused
native chip select with GPIO chip selects.
Convert the driver to use the new generic handling in the SPI core.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200102133822.29346-3-geert+renesas@glider.beSigned-off-by: Mark Brown <broonie@kernel.org>

Some SPI master controllers always drive a native chip select when
performing a transfer.  Hence when using both native and GPIO chip
selects, at least one native chip select must be left unused, to be
driven when performing transfers with slave devices using GPIO chip
selects.

Currently, to find an unused native chip select, SPI controller drivers
need to parse and process cs-gpios theirselves.  This is not only
duplicated in each driver that needs it, but also duplicates part of the
work done later at SPI controller registration time.  Note that this
cannot be done after spi_register_controller() returns, as at that time,
slave devices may have been probed already.

Hence add generic support to the SPI subsystem for finding an unused
native chip select.  Optionally, this unused native chip select, and all
other in-use native chip selects, can be validated against the maximum
number of native chip selects available on the controller hardware.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200102133822.29346-2-geert+renesas@glider.beSigned-off-by: Mark Brown <broonie@kernel.org>

Use platform_get_irq_byname_optional() instead of platform_get_irq_byname()
to avoid below error message during probe:

[3.265115] bcm_iproc 68c70200.spi: IRQ spi_lr_fullness_reached not found
[3.272121] bcm_iproc 68c70200.spi: IRQ spi_lr_session_aborted not found
[3.284965] bcm_iproc 68c70200.spi: IRQ spi_lr_impatient not found
[3.291344] bcm_iproc 68c70200.spi: IRQ spi_lr_session_done not found
[3.297992] bcm_iproc 68c70200.spi: IRQ mspi_done not found
[3.303742] bcm_iproc 68c70200.spi: IRQ mspi_halted not found
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Link: https://lore.kernel.org/r/20200107040912.16426-1-rayagonda.kokatanur@broadcom.comSigned-off-by: Mark Brown <broonie@kernel.org>

We can catch whether the SPI controller has declared it can take care of
software timestamping transfers, but didn't. So do it.
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20191227012444.1204-1-olteanv@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

Switch the OC Tiny driver over to handling CS GPIOs using
GPIO descriptors in the core.

This driver is entirely relying on GPIOs to be used for
chipselect, so let the core pick these out using either
device tree or machine descriptors.

There are no in-tree users of this driver so no board files
need to be patched, out-of-tree boardfiles can use machine
descriptor tables, c.f. commit 1dfbf334.

Cc: Thomas Chou <thomas@wytron.com.tw>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20191205092411.64341-1-linus.walleij@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

This adds DMA transfer mode support for UniPhier SPI controller.

Since this controller requires simulteaneous transmission and reception,
this indicates SPI_CONTROLLER_MUST_RX and SPI_CONTROLLER_MUST_TX.

Because the supported dma controller has alignment restiction,
there is also a restriction that 'maxburst' parameters in dma_slave_config
corresponds to one word width.
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/1577149107-30670-6-git-send-email-hayashi.kunihiko@socionext.comSigned-off-by: Mark Brown <broonie@kernel.org>

Fixes coccicheck warning:

drivers/spi/spi-tegra114.c:272:2-17: WARNING: Assignment of 0/1 to bool variable
drivers/spi/spi-tegra114.c:275:2-17: WARNING: Assignment of 0/1 to bool variable
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Link: https://lore.kernel.org/r/1577159526-33689-4-git-send-email-zhengbin13@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>

Fixes coccicheck warning:

drivers/spi/spi-imx.c:1233:2-17: WARNING: Assignment of 0/1 to bool variable
drivers/spi/spi-imx.c:1235:2-17: WARNING: Assignment of 0/1 to bool variable
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Link: https://lore.kernel.org/r/1577159526-33689-3-git-send-email-zhengbin13@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>

Fixes coccicheck warning:

drivers/spi/spi-fsl-lpspi.c:472:2-19: WARNING: Assignment of 0/1 to bool variable
drivers/spi/spi-fsl-lpspi.c:474:2-19: WARNING: Assignment of 0/1 to bool variable
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Link: https://lore.kernel.org/r/1577159526-33689-2-git-send-email-zhengbin13@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>

This adds master->handle_err() callback function to stop transfer due to
error. The function also resets FIFOs and disables interrupt.
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/1577149107-30670-4-git-send-email-hayashi.kunihiko@socionext.comSigned-off-by: Mark Brown <broonie@kernel.org>

This changes each argument of functions uniphier_irq_{enable,disable}()
to uniphier_spi_priv because these functions are used not only for
spi_device but also for the entire controller.
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/1577149107-30670-3-git-send-email-hayashi.kunihiko@socionext.comSigned-off-by: Mark Brown <broonie@kernel.org>

Rx threshold means the value to inform the receiver when the number of words
in Rx FIFO is equal to or more than the value. Similarly, Tx threshold means
the value to inform the sender when the number of words in Tx FIFO is equal
to or less than the value. The controller triggers the driver to start
the transfer.

In case of Rx, the driver wants to detect that the specified number of words
N are in Rx FIFO, so the value of Rx threshold should be N. In case of Tx,
the driver wants to detect that the same number of spaces as Rx are in
Tx FIFO, so the value of Tx threshold should be (FIFO size - N).

For example, in order for the driver to receive at least 3 words from
Rx FIFO, set 3 to Rx threshold.
   +-+-+-+-+-+-+-+-+
   | | | | | |*|*|*|
   +-+-+-+-+-+-+-+-+

In order for the driver to send at least 3 words to Tx FIFO, because
it needs at least 3 spaces, set 8(FIFO size) - 3 = 5 to Tx threshold.
   +-+-+-+-+-+-+-+-+
   |*|*|*|*|*| | | |
   +-+-+-+-+-+-+-+-+

This adds new function uniphier_spi_set_fifo_threshold() to set
threshold value to the register.

And more, FIFO counts by 'words', so this renames 'fill_bytes' with
'fill_words', and fixes the calculation using bytes_per_words.

Fixes: 37ffab81 ("spi: uniphier: introduce polling mode")
Cc: Keiji Hayashibara <hayashibara.keiji@socionext.com>
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/1577149107-30670-2-git-send-email-hayashi.kunihiko@socionext.comSigned-off-by: Mark Brown <broonie@kernel.org>

Convert the STM32 spi binding to DT schema format using json-schema
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
CC: Erwan Leray <erwan.leray@st.com>
CC: Fabrice Gasnier <fabrice.gasnier@st.com>
CC: Amelie Delaunay <amelie.delaunay@st.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20191217090715.13334-1-benjamin.gaignard@st.comSigned-off-by: Mark Brown <broonie@kernel.org>

Use dev_dbg() on -EPROBE_DEFER and dev_err() on all
other errors.
Signed-off-by: Jim Quinlan <jquinlan@broadcom.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20191216230802.45715-2-jquinlan@broadcom.comSigned-off-by: Mark Brown <broonie@kernel.org>

The fclk and its rate are retrieved from DT.
Signed-off-by: Jean Pihet <jean.pihet@newoldbits.com>
Cc: Ryan Barnett <ryan.barnett@rockwellcollins.com>
Cc: Conrad Ratschan <conrad.ratschan@rockwellcollins.com>
Cc: Arnout Vandecappelle <arnout.vandecappelle@essensium.com>
Link: https://lore.kernel.org/r/20191211193954.747745-2-jean.pihet@newoldbits.comSigned-off-by: Mark Brown <broonie@kernel.org>