The interaction with the controller message queue and its corresponding
auxiliary flags and variables requires the use of the queue_lock which is
costly. Since spi_sync will transfer the complete message anyway, and not
return until it is finished, there is no need to put the message into the
queue if the queue is empty. This can save a lot of overhead.

As an example of how significant this is, when using the MCP2518FD SPI CAN
controller on a i.MX8MM SoC, the time during which the interrupt line
stays active (during 3 relatively short spi_sync messages), is reduced
from 98us to 72us by this patch.

Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-3-david@protonic.nl


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

This enables the possibility to transfer a message that is not at the
current tip of the async message queue.
This is in preparation of the next patch(es) which enable spi_sync messages
to skip the queue altogether.

Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-2-david@protonic.nl


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

Only timeout after at least one iteration of checking the
status registers. In addition, increase the transfer timeout
to 1 second.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20220623140547.71762-1-eajames@linux.ibm.com


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

The topcliff-pch driver requires TX and RX buffers on all transfers, open
coding checks for this. Remove those open coded checks and instead rely on
the core functionality, which has the added bonus that it will fix up any
transfers submitted by drivers as needed rather than erroring out.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220615174138.4060912-1-broonie@kernel.org

It is possible that the error case for devm_clk_get() returns NULL,
in which case zero will be passed to PTR_ERR() as shown by the Smatch
static checker warning:
drivers/spi/spi-microchip-core.c:557 mchp_corespi_probe()
warn: passing zero to 'PTR_ERR'

Remove the NULL check and carry on with a dummy clock in case of an
error. To avoid a potential div zero, abort calculating clkgen if
clk_get_rate(spi->clk) is zero.

Fixes: 9ac8d176 ("spi: add support for microchip fpga spi controllers")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/linux-spi/20220615091633.GI2168@kadam/


Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20220615142028.2991915-1-conor.dooley@microchip.com


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

Return -ENOMEM if the allocation fails.  Don't return success.

Fixes: 6598b91b ("spi: spi.c: Convert statistics to per-cpu u64_stats_t")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/Yqh6bdNYO2XNhPBa@kili


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

If platform_get_irqi() returns 0, the error case will be triggered but
probe() will return 0 rather than an error. Ape the other drivers using
this pattern and return -ENXIO.

Reported-by: Yang Li <yang.lee@linux.alibaba.com>
Link: https://lore.kernel.org/linux-spi/20220609055533.95866-2-yang.lee@linux.alibaba.com/


Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Fixes: 9ac8d176 ("spi: add support for microchip fpga spi controllers")
Link: https://lore.kernel.org/r/20220614065809.1969177-1-conor.dooley@microchip.com


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

Merge series from Krishna Yarlagadda <kyarlagadda@nvidia.com>:

Add multiple chip select lines supported on Tegra 241

Print a warning if the device mode doesn't match the requested mode.
The user doesn't enter the mode in hex so it isn't obvious when
setting the mode succeeds that the mode isn't the requested mode.  The
kernel logs a message, it will be more visible if the test also prints
a warning.  I was testing --quad, which is unsupported, but doesn't
cause the mode request to fail.

Signed-off-by: David Fries <David@Fries.net>
Link: https://lore.kernel.org/r/YqbNnSGtWHe/GG7w@spacedout.fries.net


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

There are pointers being set to null using use. Use NULL instead.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20220612203428.2754823-1-colin.i.king@gmail.com


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

Fix the unreasonable clk_prepare_enable() with clk_disable_unprepare()
before return from mchp_corespi_probe() in the error handling case.

Signed-off-by: Peng Wu <wupeng58@huawei.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20220611021117.40494-1-wupeng58@huawei.com


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

Add new compatible for Tegra241 QSPI controller which has
multiple chip select lines.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
Link: https://lore.kernel.org/r/20220607114659.54314-4-kyarlagadda@nvidia.com


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

Move peripheral properties for Tegra QSPI controller to
nvidia,tegra210-quad-peripheral-props.yaml and add reference
to spi-peripheral-props.yaml file.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
Link: https://lore.kernel.org/r/20220607114659.54314-3-kyarlagadda@nvidia.com


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

Tegra Grace and later chips can support upto 4 chip select lines
for QUAD SPI. Added new compatible for Tegra Grace.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
Link: https://lore.kernel.org/r/20220607114659.54314-2-kyarlagadda@nvidia.com


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

Merge series from Claudiu Beznea <claudiu.beznea@microchip.com>:

The following series adds runtime PM support for atmel-quadspi driver.
clk_disable()/clk_enable() is called on proper
runtime_suspend()/runtime_resume() ops. Along with it 2 minor cleanups
were added (patches 2/3, 3/3).

On 32 bit systems, the following kernel BUG is hit:

BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
caller is debug_smp_processor_id+0x18/0x24
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc1-00001-g6ae0aec8a366 #181
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Backtrace:
 dump_backtrace from show_stack+0x20/0x24
 r7:81024ffd r6:00000000 r5:81024ffd r4:60000013
 show_stack from dump_stack_lvl+0x60/0x78
 dump_stack_lvl from dump_stack+0x14/0x1c
 r7:81024ffd r6:80f652de r5:80bec180 r4:819a2500
 dump_stack from check_preemption_disabled+0xc8/0xf0
 check_preemption_disabled from debug_smp_processor_id+0x18/0x24
 r8:8119b7e0 r7:81205534 r6:819f5c00 r5:819f4c00 r4:c083d724
 debug_smp_processor_id from __spi_sync+0x78/0x220
 __spi_sync from spi_sync+0x34/0x4c
 r10:bb7bf4e0 r9:c083d724 r8:00000007 r7:81a068c0 r6:822a83c0 r5:c083d724
 r4:819f4c00
 spi_sync from spi_mem_exec_op+0x338/0x370
 r5:000000b4 r4:c083d910
 spi_mem_exec_op from spi_nor_read_id+0x98/0xdc
 r10:bb7bf4e0 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:82358040
 r4:819f7c40
 spi_nor_read_id from spi_nor_detect+0x38/0x114
 r7:82358040 r6:00000000 r5:819f7c40 r4:819f7c40
 spi_nor_detect from spi_nor_scan+0x11c/0xbec
 r10:bb7bf4e0 r9:00000000 r8:00000000 r7:c083da4c r6:00000000 r5:00010101
 r4:819f7c40
 spi_nor_scan from spi_nor_probe+0x10c/0x2d0
 r10:bb7bf4e0 r9:bb7bf4d0 r8:00000000 r7:819f4c00 r6:00000000 r5:00000000
 r4:819f7c40

per-cpu access needs to be guarded against preemption.

Fixes: 6598b91b ("spi: spi.c: Convert statistics to per-cpu u64_stats_t")
Reported-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David Jander <david@protonic.nl>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20220609121334.2984808-1-david@protonic.nl


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

The patch has been tested on Unmatched using pm_test. The Unmatched board
uses SD over SPI and it was tested by initiating S2RAM cycles for all
devices while reading/writing files at the same time. We found no dropped
connection to the card or corrupted filesystem during test cycles.

Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Greentime Hu <greentime.hu@sifive.com>
Link: https://lore.kernel.org/r/20220610074459.3261383-2-andy.chiu@sifive.com


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

Align condition to parenthesis.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220609084246.1795419-4-claudiu.beznea@microchip.com


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

Use pm_ptr() for atmel_quadspi_pm_ops.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220609084246.1795419-3-claudiu.beznea@microchip.com


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

Add runtime PM support for atmel-quadspi which will disable/enable
QSPI clocks on proper runtime_suspend/runtime_resume ops.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220609084246.1795419-2-claudiu.beznea@microchip.com


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

Return boolean values ("true" or "false") instead of 1 or 0 from bool
function.

As reported by coccicheck:
./drivers/spi/spi-s3c64xx.c:385:9-10: WARNING: return of 0/1 in function
's3c64xx_spi_can_dma' with return type bool

Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220609071250.59509-1-yang.lee@linux.alibaba.com


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

Remove .owner field if calls are used which set it automatically.

Eliminate the following coccicheck warning:
./drivers/spi/spi-microchip-core.c:624:3-8: No need to set .owner here.
The core will do it.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220609055533.95866-1-yang.lee@linux.alibaba.com


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

Fixes these "make htmldocs" warnings:

include/linux/spi/spi.h:82: warning: Function parameter or member 'syncp' not described in 'spi_statistics'
include/linux/spi/spi.h:213: warning: Function parameter or member 'pcpu_statistics' not described in 'spi_device'
include/linux/spi/spi.h:676: warning: Function parameter or member 'pcpu_statistics' not described in 'spi_controller'

Fixes: 6598b91b ("spi: spi.c: Convert statistics to per-cpu u64_stats_t")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David Jander <david@protonic.nl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220608153309.2899565-1-david@protonic.nl


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

There is a spelling mistake in a dev_err message. Fix it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20220608081912.2083086-1-colin.i.king@gmail.com


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

Merge series from Conor Dooley <conor.dooley@microchip.com>:

Add support for the PolatFire SoC SPI controller, the DT binding was
added previously.

Document RZ/G2U2L SSI bindings. RZ/G2UL SSI is identical to one found
on the RZ/G2L SoC. No driver changes are required as generic compatible
string "renesas,rz-ssi" will be used as a fallback.

While at it add a '.' at the end of dmas description for the first cell.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20220607124231.3248-1-biju.das.jz@bp.renesas.com


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

Add the newly introduced spi driver to the existing PolarFire SoC entry.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20220607073833.2331539-3-conor.dooley@microchip.com


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

Add a driver for Microchip FPGA SPI controllers, specifically
supporting the "hard" controllers on PolarFire SoC.

Co-developed-by: Daire McNamara <daire.mcnamara@microchip.com>
Signed-off-by: Daire McNamara <daire.mcnamara@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20220607073833.2331539-2-conor.dooley@microchip.com


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

Merge series from patrice.chotard@foss.st.com <patrice.chotard@foss.st.com>:

This series cleans up spi-stm32-qspi driver by removing unused parameters

The spi-ti-qspi driver initializes its spi clock by the
spi-max-frequency property from the controller node, and ignores
per-transfer (and per-slave) speed_hz settings.

Isolate clock settings out from ti_qspi_setup() and call it from
ti_qspi_start_transfer_one() and ti_qspi_exec_mem_op(), using
per-transfer speed_hz and per-slave max_speed_hz settings.

Also drop spi_max_frequency from struct ti_qspi and use spi_master's
max_speed_hz.

Signed-off-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
Link: https://lore.kernel.org/r/20220519.084604.966119051165023533.atsushi.nemoto@sord.co.jp


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

This change gives a dramatic performance improvement in the hot path,
since many costly spin_lock_irqsave() calls can be avoided.

On an i.MX8MM system with a MCP2518FD CAN controller connected via SPI,
the time the driver takes to handle interrupts, or in other words the time
the IRQ line of the CAN controller stays low is mainly dominated by the
time it takes to do 3 relatively short sync SPI transfers. The effect of
this patch is a reduction of this time from 136us down to only 98us.

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220524091808.2269898-1-david@protonic.nl


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

SPI bus per device properties must be defined in spi-peripheral-props.yaml
for unevaluatedProperties checks to work correctly on device nodes.

This has the side effect of promoting 'rx-sample-delay-ns' to be a
common property, but functionally it's no different if it was defined in
a Synopsys specific schema file.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220525210053.2488756-1-robh@kernel.org


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

We should have 'n', then 'size', not the opposite.
This is harmless because the 2 values are just multiplied, but having
the correct order silence a (unpublished yet) smatch warning.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/d114558dd0351b863ced8cc01b31754a5a4b960d.1653116362.git.christophe.jaillet@wanadoo.fr


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

ZynqMP GQSPI controller can support up to two chip selects but the current
GQSPI driver only support CS0. With this update and num-cs DT property set
to 2 GQSPI driver can now support two slave devices each connected to one
chip select.

GQSPI driver configures the Lower CS and Upper CS based on the reg DT
property.

Changes tested on ZynqMP board with two SPI-NOR flashes each connected
to a different CS.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@xilinx.com>
Link: https://lore.kernel.org/r/20220512145820.20425-1-amit.kumar-mahapatra@xilinx.com


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

Spelling mistake (triple letters) in comment.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Link: https://lore.kernel.org/r/20220521111145.81697-13-Julia.Lawall@inria.fr


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

Add binding documentation for the MT8365 SoC.

Signed-off-by: Fabien Parent <fparent@baylibre.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220531135026.238475-10-fparent@baylibre.com


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

Currently the spi_master is allocated by devm_spi_alloc_master()
and devres core manages the deallocation, but in probe failure
path spi_master_put() is being handled manually which causes
"refcount underflow use-after-free" warning when probe failure happens
after allocating spi_master.

Trimmed backtrace during failure:

refcount_t: underflow; use-after-free.
pc : refcount_warn_saturate+0xf4/0x144
Call trace:
refcount_warn_saturate
kobject_put
put_device
devm_spi_release_controller
devres_release_all

This commit makes relevant changes to remove spi_master_put() from probe
failure path.

Fixes: 606e5d40 ("spi: cadence-quadspi: Handle spi_unregister_master() in remove()")

Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Link: https://lore.kernel.org/r/20220601071611.11853-1-vaishnav.a@ti.com


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

Current s3c64xx SPI driver acquires DMA channel during driver
probe and holds on it even when channels are not used
(no DMA transfer). This is a problem especially when all the
DMA channels are exhausted (as other IPs on the same DMA
controller also acquires DMA channel) and if a new IP/Device
requests for a DMA channel (on the same DMA controller), it won’t
get DMA channel allocated.
The said issue can be avoided if s3c64xx driver request and
release DMA channel before and after data transfer. Let’s modify
the driver to request and release DMA channel before and after
DMA mode data transfer.

Signed-off-by: Adithya K V <adithya.kv@samsung.com>
Link: https://lore.kernel.org/r/20220524140132.59300-1-adithya.kv@samsung.com


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

The spi_alloc_master() call is not undone in all error handling paths.
Moreover, there is no .remove function to release the allocated memory.

In order to fix both this issues, switch to devm_spi_alloc_master().

This allows further simplification of the probe.

Fixes: ba2fc167 ("spi: altera: Add DFL bus driver for Altera API Controller")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/0607bb59f4073f86abe5c585d35245aef0b045c6.1653805901.git.christophe.jaillet@wanadoo.fr


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

op parameter is not used, remove it.

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://lore.kernel.org/r/20220602092540.369604-4-patrice.chotard@foss.st.com


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