There is no need to set the DMA mapped flag of the message if it has
no mapped transfers. Moreover, it may give the code a chance to take
the wrong paths, i.e. to exercise DMA related APIs on unmapped data.
Make __spi_map_msg() to bail earlier on the above mentioned cases.

Fixes: 99adef31 ("spi: Provide core support for DMA mapping transfers")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://msgid.link/r/20240522171018.3362521-2-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

Currently, the DesignWare SPI controller driver supports only host mode.
However, spi2 on the Kendryte K210 SoC supports only target mode,
triggering an error message on e.g. SiPEED MAiXBiT since commit
98d75b9e ("spi: dw: Drop default number of CS setting"):

    dw_spi_mmio 50240000.spi: error -22: problem registering spi host
    dw_spi_mmio 50240000.spi: probe with driver dw_spi_mmio failed with error -22

As spi2 rightfully has no "num-cs" property, num_chipselect is now zero,
causing spi_alloc_host() to fail to register the controller.  Before,
the driver silently registered an SPI host controller with 4 chip
selects.

Reject target mode early on and warn the user, getting rid of the
error message.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/7ae28d83bff7351f34782658ae1bb69cc731693e.1715163113.git.geert+renesas@glider.beSigned-off-by: Mark Brown <broonie@kernel.org>

Both dma_unmap_sgtable() and sg_free_table() in spi_unmap_buf_attrs()
have checks for orig_nents against 0. No need to duplicate this.
All the same applies to other DMA mapping API calls.

Also note, there is no other user in the kernel that does this kind of
checks.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240507201028.564630-1-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

Commit a403997c ("spi: airoha: add SPI-NAND Flash controller driver")
adds a new section AIROHA SPI SNFI DRIVER referring to the file
spi-airoha.c. The commit however adds the file spi-airoha-snfi.c.

Hence, ./scripts/get_maintainer.pl --self-test=patterns complains about a
broken reference.

Repair this file entry in the AIROHA SPI SNFI DRIVER section.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@redhat.com>
Link: https://lore.kernel.org/r/20240507141449.177538-1-lukas.bulwahn@redhat.comSigned-off-by: Mark Brown <broonie@kernel.org>

The documentation had been removed, so should TOC entry.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 2d069c11 ("spi: pxa2xx: Remove outdated documentation")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Closes: https://lore.kernel.org/r/20240507163131.183813ee@canb.auug.org.au
Link: https://lore.kernel.org/r/20240507132002.71938-1-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

Merge series from Andy Shevchenko <andriy.shevchenko@linux.intel.com>:

As Arnd suggested we may drop linux/spi/pxa2xx_spi.h as most of
its content is being used solely internally to SPI subsystem
(PXA2xx drivers). Hence this refactoring series with the additional
win of getting rid of legacy documentation.

Note, that we have the only user of a single plain integer field
in the entire kernel for that. Switching to software nodes does not
diminish any of type checking as we only pass an integer.

Merge series from Serge Semin <fancer.lancer@gmail.com>:

The main goal of the short series is to provide a procedure implementing
the auto-detection of the number of native Chip-Select signals supported
by the controller. The suggested algorithm is straightforward. It relies
on the fact that the SER register writable flags reflects the actual
number of available native chip-select signals. So the DW APB/AHB SSI
driver now tests the SER register for having the writable bits,
calculates the number of CS signals based on the number of set flags and
then initializes the num_cs private data field based on that, which then
will be passed to the SPI-core subsystem indicating the number of
supported hardware chip-selects. The implemented procedure will be useful
for the DW SSI device nodes not having the explicitly set "num-cs"
property. In case if the property is specified it will be utilized instead
of the auto-detection procedure.

Besides of that a small cleanup patch is introduced in the head of the
series. It converts the driver to using the BITS_TO_BYTES() macro instead
of the hard-coded DIV_ROUND_UP()-based calculation of the number of
bytes-per-transfer-word.

Now the struct chip_data is local to spi-pxa2xx.c, move
its definition to the C file. This will slightly speed up
a build and also hide badly named data type (too generic).
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240417110334.2671228-10-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

The timeout field is used only once and assigned to a predefined
constant. Replace all that by using the constant directly.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240417110334.2671228-9-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

The DMA related fields are set once and never modified. It effectively
repeats the content of the same fields in struct pxa2xx_spi_controller.
With that, remove DMA parameters from struct chip_data.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240417110334.2671228-8-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

No more users.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240417110334.2671228-7-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

Update header inclusions to follow IWYU (Include What You Use)
principle.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240417110334.2671228-6-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

The documentation is referring to the legacy enumeration of the SPI
host controllers and target devices. It has nothing to do with the
modern way, which is the only supported in kernel right now. Hence,
remove outdated documentation file.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240417110334.2671228-5-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

There is no user of the linux/spi/pxa2xx_spi.h. Move its contents
to the drivers/spi/spi-pxa2xx.h.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240417110334.2671228-4-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

Since driver can parse num-cs device property, replace platform data
with this new approach. This pursues the following objectives:

- getting rid of the public header that barely used outside of
  the SPI subsystem (more specifically the SPI PXA2xx drivers)

- making a trampoline for the driver to support non-default number
  of the chip select pins in case the original code is going to be
  converted to Device Tree model

It's not expected to have more users in board files except this one.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240417110334.2671228-3-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

In some cases the number of the chip select pins might come from
the device property. Allow driver to use it.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240417110334.2671228-2-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

Convert txt binding of TI's qspi controller (found on their omap SoCs) to
dtschema to allow for validation.

The changes, w.r.t. the original txt binding, are:

- Introduce "clocks" and "clock-names" which was never mentioned.
- Reflect that "ti,hwmods" is deprecated and is not a "required"
  property anymore.
- Introduce "num-cs" which allows for setting the number of chip
  selects.
- Drop "qspi_ctrlmod".
Signed-off-by: Kousik Sanagavarapu <five231003@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240501165203.13763-1-five231003@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

The modpost script is not happy

  WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/spi/spi-bitbang.o

because there is a missing module description.

Add it to the module.

While at it, update the terminology in Kconfig section to be in align
with added description along with the code comments.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240502171518.2792895-1-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

Use NSEC_PER_*SEC rather than the hard coded value of 1000s.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240502154825.2752464-1-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

DW APB/AHB SSI core now supports the procedure automatically detecting the
number of native chip-select lines. Thus there is no longer point in
defaulting to four CS if the platform doesn't specify the real number
especially seeing the default number didn't correspond to any original DW
APB/AHB databook.
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://lore.kernel.org/r/20240424150657.9678-5-fancer.lancer@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

Number of native chip-select lines is either retrieved from the "num-cs"
DT-property or auto-detected in the generic DW APB/AHB SSI probe method.
In the former case the property is supposed to be of the "u32" size.
Convert the field type to being u32 then to be able to drop the temporary
variable afterwards.
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://lore.kernel.org/r/20240424150657.9678-4-fancer.lancer@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

Aside with the FIFO depth and DFS field size it's possible to auto-detect
a number of native chip-select synthesized in the DW APB/AHB SSI IP-core.
It can be done just by writing ones to the SER register. The number of
writable flags in the register is limited by the SSI_NUM_SLAVES IP-core
synthesize parameter. All the upper flags are read-only and wired to zero.
Based on that let's add the number of native CS auto-detection procedure
so the low-level platform drivers wouldn't need to manually set it up
unless it's required to set a constraint due to platform-specific reasons
(for instance, due to a hardware bug).
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://lore.kernel.org/r/20240424150657.9678-3-fancer.lancer@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

Since commit dd3e7cba ("ocfs2/dlm: move BITS_TO_BYTES() to bitops.h
for wider use") there is a generic helper available to calculate a number
of bytes needed to accommodate the specified number of bits. Let's use it
instead of the hard-coded DIV_ROUND_UP() macro function.
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240424150657.9678-2-fancer.lancer@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

Merge series from Wolfram Sang <wsa+renesas@sang-engineering.com>:

There is a confusing pattern in the kernel to use a variable named 'timeout' to
store the result of wait_for_*() functions causing patterns like:

        timeout = wait_for_completion_timeout(...)
        if (!timeout) return -ETIMEDOUT;

with all kinds of permutations. Use 'time_left' as a variable to make the code
obvious and self explaining.

This is part of a tree-wide series. The rest of the patches can be found here
(some parts may still be WIP):

git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git i2c/time_left

Because these patches are generated, I audit them before sending. This is why I
will send series step by step. Build bot is happy with these patches, though.
No functional changes intended.

Merge series from Lorenzo Bianconi <lorenzo@kernel.org>:

Introduce support for SPI-NAND driver of the Airoha NAND Flash Interface
found on Airoha ARM EN7581 SoCs.

There are macros spi_valid_txbuf() and spi_valid_rxbuf() for determining
if an xfer actually intended to send or receive data.

These checks were hard-coded in spi_statistics_add_transfer_stats(). We
can make use of the macros instead to make the code more readable and
more robust against potential future changes in case the definition of
what valid means changes.

The macro takes the spi_message as an argument, so we need to change
spi_statistics_add_transfer_stats() to take the spi_message as an
argument instead of the controller.
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://lore.kernel.org/r/20240430201530.2138095-3-dlechner@baylibre.comSigned-off-by: Mark Brown <broonie@kernel.org>

There is a confusing pattern in the kernel to use a variable named 'timeout' to
store the result of wait_for_completion_timeout() causing patterns like:

	timeout = wait_for_completion_timeout(...)
	if (!timeout) return -ETIMEDOUT;

with all kinds of permutations. Use 'time_left' as a variable to make the code
self explaining.

Fix to the proper variable type 'unsigned long' while here.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20240430114142.28551-9-wsa+renesas@sang-engineering.comSigned-off-by: Mark Brown <broonie@kernel.org>

There is a confusing pattern in the kernel to use a variable named 'timeout' to
store the result of wait_for_completion_timeout() causing patterns like:

	timeout = wait_for_completion_timeout(...)
	if (!timeout) return -ETIMEDOUT;

with all kinds of permutations. Use 'time_left' as a variable to make the code
self explaining.

Fix to the proper variable type 'unsigned long' while here.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Link: https://lore.kernel.org/r/20240430114142.28551-8-wsa+renesas@sang-engineering.comSigned-off-by: Mark Brown <broonie@kernel.org>

There is a confusing pattern in the kernel to use a variable named 'timeout' to
store the result of wait_for_completion_timeout() causing patterns like:

	timeout = wait_for_completion_timeout(...)
	if (!timeout) return -ETIMEDOUT;

with all kinds of permutations. Use 'time_left' as a variable to make the code
self explaining.

Fix to the proper variable type 'unsigned long' while here.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Link: https://lore.kernel.org/r/20240430114142.28551-7-wsa+renesas@sang-engineering.comSigned-off-by: Mark Brown <broonie@kernel.org>

There is a confusing pattern in the kernel to use a variable named 'timeout' to
store the result of wait_for_completion_timeout() causing patterns like:

	timeout = wait_for_completion_timeout(...)
	if (!timeout) return -ETIMEDOUT;

with all kinds of permutations. Use 'time_left' as a variable to make the code
self explaining.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20240430114142.28551-6-wsa+renesas@sang-engineering.comSigned-off-by: Mark Brown <broonie@kernel.org>

There is a confusing pattern in the kernel to use a variable named 'timeout' to
store the result of wait_for_completion_timeout() causing patterns like:

	timeout = wait_for_completion_timeout(...)
	if (!timeout) return -ETIMEDOUT;

with all kinds of permutations. Use 'time_left' as a variable to make the code
self explaining.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20240430114142.28551-5-wsa+renesas@sang-engineering.comSigned-off-by: Mark Brown <broonie@kernel.org>

There is a confusing pattern in the kernel to use a variable named 'timeout' to
store the result of wait_for_completion_timeout() causing patterns like:

	timeout = wait_for_completion_timeout(...)
	if (!timeout) return -ETIMEDOUT;

with all kinds of permutations. Use 'time_left' as a variable to make the code
self explaining.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20240430114142.28551-4-wsa+renesas@sang-engineering.comSigned-off-by: Mark Brown <broonie@kernel.org>

There is a confusing pattern in the kernel to use a variable named 'timeout' to
store the result of wait_for_completion_timeout() causing patterns like:

	timeout = wait_for_completion_timeout(...)
	if (!timeout) return -ETIMEDOUT;

with all kinds of permutations. Use 'time_left' as a variable to make the code
self explaining.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20240430114142.28551-3-wsa+renesas@sang-engineering.comSigned-off-by: Mark Brown <broonie@kernel.org>

There is a confusing pattern in the kernel to use a variable named 'timeout' to
store the result of wait_for_completion_timeout() causing patterns like:

	timeout = wait_for_completion_timeout(...)
	if (!timeout) return -ETIMEDOUT;

with all kinds of permutations. Use 'time_left' as a variable to make the code
self explaining.

Fix to the proper variable type 'unsigned long' while here.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20240430114142.28551-2-wsa+renesas@sang-engineering.comSigned-off-by: Mark Brown <broonie@kernel.org>

Introduce Airoha EN7581 SPI NAND controller binding
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Rajeev Kumar <Rajeev.Kumar@airoha.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/f3377b323f00589e6b7ed7950c4840d18129238b.1714377864.git.lorenzo@kernel.orgSigned-off-by: Mark Brown <broonie@kernel.org>

Introduce support for SPI-NAND driver of the Airoha NAND Flash Interface
found on Airoha ARM SoCs.
Tested-by: Rajeev Kumar <Rajeev.Kumar@airoha.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/6c9db20505b01a66807995374f2af475a23ce5b2.1714377864.git.lorenzo@kernel.orgSigned-off-by: Mark Brown <broonie@kernel.org>

Declare a new mobileye,eyeq5-ospi compatible.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240423-cdns-qspi-mbly-v4-4-3d2a7b535ad0@bootlin.comSigned-off-by: Mark Brown <broonie@kernel.org>

Call readl_relaxed_poll_timeout() with no sleep at the start of
cqspi_wait_for_bit(). If its short timeout expires, a sleeping
readl_relaxed_poll_timeout() call takes the relay.

The reason is to avoid hrtimer interrupts on the system. All read
operations are expected to take less than 100µs.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240423-cdns-qspi-mbly-v4-3-3d2a7b535ad0@bootlin.comSigned-off-by: Mark Brown <broonie@kernel.org>

Support reads through polling, without any IRQ. The main reason is
performance; profiling shows that the first IRQ comes quickly on our
specific hardware. Once this IRQ arrives, we poll until all data is
retrieved. Avoid initial sleep to reduce IRQ count.

Hide this behavior behind a quirk flag.

This is confirmed through micro-benchmarks, but also end-to-end
performance tests. Mobileye EyeQ5, octal flash, reading 235M on a UBIFS
filesystem:
 - No optimizations, ~10.34s, ~22.7 MB/s, 199230 IRQs
 - CQSPI_SLOW_SRAM,  ~10.34s, ~22.7 MB/s,  70284 IRQs
 - CQSPI_RD_NO_IRQ,   ~9.37s, ~25.1 MB/s,    521 IRQs
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240423-cdns-qspi-mbly-v4-2-3d2a7b535ad0@bootlin.comSigned-off-by: Mark Brown <broonie@kernel.org>

If FIFO depth DT property is provided, check it matches what hardware
reports and warn otherwise. Else, use hardware provided value.

Hardware exposes FIFO depth indirectly because
CQSPI_REG_SRAMPARTITION is partially read-only.

Move probe cqspi->ddata assignment prior to cqspi_of_get_pdata() call.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240423-cdns-qspi-mbly-v4-1-3d2a7b535ad0@bootlin.comSigned-off-by: Mark Brown <broonie@kernel.org>