Commit Graph

463 Commits

Author SHA1 Message Date
Nicolas Saenz Julienne
86f5b09369 spi: Skip zero-length transfers in spi_transfer_one_message()
[ Upstream commit b306320322c9cfaa465bc2c7367acf6072b1ac0e ]

With the introduction of 26751de25d ("spi: bcm2835: Micro-optimise
FIFO loops") it has become apparent that some users might initiate
zero-length SPI transfers. A fact the micro-optimization omitted, and
which turned out to cause crashes[1].

Instead of changing the micro-optimization itself, use a bigger hammer
and skip zero-length transfers altogether for drivers using the default
transfer_one_message() implementation.

Reported-by: Phil Elwell <phil@raspberrypi.com>
Fixes: 26751de25d ("spi: bcm2835: Micro-optimise FIFO loops")
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

[1] https://github.com/raspberrypi/linux/issues/4100
Link: https://lore.kernel.org/r/20210211180820.25757-1-nsaenzjulienne@suse.de

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:38:07 +01:00
Xu Yilun
501e1875da spi: fix the divide by 0 error when calculating xfer waiting time
[ Upstream commit 6170d077bf92c5b3dfbe1021688d3c0404f7c9e9 ]

The xfer waiting time is the result of xfer->len / xfer->speed_hz. This
patch makes the assumption of 100khz xfer speed if the xfer->speed_hz is
not assigned and stays 0. This avoids the divide by 0 issue and ensures
a reasonable tolerant waiting time.

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/1609723749-3557-1-git-send-email-yilun.xu@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-19 18:27:25 +01:00
Uwe Kleine-König
ddbed6d027 spi: fix resource leak for drivers without .remove callback
[ Upstream commit 440408dbadfe47a615afd0a0a4a402e629be658a ]

Consider an spi driver with a .probe but without a .remove callback (e.g.
rtc-ds1347). The function spi_drv_probe() is called to bind a device and
so dev_pm_domain_attach() is called. As there is no remove callback
spi_drv_remove() isn't called at unbind time however and so calling
dev_pm_domain_detach() is missed and the pm domain keeps active.

To fix this always use both spi_drv_probe() and spi_drv_remove() and
make them handle the respective callback not being set. This has the
side effect that for a (hypothetical) driver that has neither .probe nor
remove the clk and pm domain setup is done.

Fixes: 33cf00e570 ("spi: attach/detach SPI device to the ACPI power domain")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20201119161604.2633521-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:17 +01:00
Serge Semin
4fae3a58ab
spi: Take the SPI IO-mutex in the spi_setup() method
I've discovered that due to the recent commit 49d7d695ca ("spi: dw:
Explicitly de-assert CS on SPI transfer completion") a concurrent usage of
the spidev devices with different chip-selects causes the "SPI transfer
timed out" error. The root cause of the problem has turned to be in a race
condition of the SPI-transfer execution procedure and the spi_setup()
method being called at the same time. In particular in calling the
spi_set_cs(false) while there is an SPI-transfer being executed. In my
case due to the commit cited above all CSs get to be switched off by
calling the spi_setup() for /dev/spidev0.1 while there is an concurrent
SPI-transfer execution performed on /dev/spidev0.0. Of course a situation
of the spi_setup() being called while there is an SPI-transfer being
executed for two different SPI peripheral devices of the same controller
may happen not only for the spidev driver, but for instance for MMC SPI +
some another device, or spi_setup() being called from an SPI-peripheral
probe method while some other device has already been probed and is being
used by a corresponding driver...

Of course I could have provided a fix affecting the DW APB SSI driver
only, for instance, by creating a mutual exclusive access to the set_cs
callback and setting/clearing only the bit responsible for the
corresponding chip-select. But after a short research I've discovered that
the problem most likely affects a lot of the other drivers:
- drivers/spi/spi-sun4i.c - RMW the chip-select register;
- drivers/spi/spi-rockchip.c - RMW the chip-select register;
- drivers/spi/spi-qup.c - RMW a generic force-CS flag in a CSR.
- drivers/spi/spi-sifive.c - set a generic CS-mode flag in a CSR.
- drivers/spi/spi-bcm63xx-hsspi.c - uses an internal mutex to serialize
  the bus config changes, but still isn't protected from the race
  condition described above;
- drivers/spi/spi-geni-qcom.c - RMW a chip-select internal flag and set the
  CS state in HW;
- drivers/spi/spi-orion.c - RMW a chip-select register;
- drivers/spi/spi-cadence.c - RMW a chip-select register;
- drivers/spi/spi-armada-3700.c - RMW a chip-select register;
- drivers/spi/spi-lantiq-ssc.c - overwrites the chip-select register;
- drivers/spi/spi-sun6i.c - RMW a chip-select register;
- drivers/spi/spi-synquacer.c - RMW a chip-select register;
- drivers/spi/spi-altera.c - directly sets the chip-select state;
- drivers/spi/spi-omap2-mcspi.c - RMW an internally cached CS state and
  writes it to HW;
- drivers/spi/spi-mt65xx.c - RMW some CSR;
- drivers/spi/spi-jcore.c - directly sets the chip-selects state;
- drivers/spi/spi-mt7621.c - RMW a chip-select register;

I could have missed some drivers, but a scale of the problem is obvious.
As you can see most of the drivers perform an unprotected
Read-modify-write chip-select register modification in the set_cs callback.
Seeing the spi_setup() function is calling the spi_set_cs() and it can be
executed concurrently with SPI-transfers exec procedure, which also calls
spi_set_cs() in the SPI core spi_transfer_one_message() method, the race
condition of the register modification turns to be obvious.

To sum up the problem denoted above affects each driver for a controller
having more than one chip-select lane and which:
1) performs the RMW to some CS-related register with no serialization;
2) directly disables any CS on spi_set_cs(dev, false).
* the later is the case of the DW APB SSI driver.

The controllers which equipped with a single CS theoretically can also
experience the problem, but in practice will not since normally the
spi_setup() isn't called concurrently with the SPI-transfers executed on
the same SPI peripheral device.

In order to generically fix the denoted bug I'd suggest to serialize an
access to the controller IO by taking the IO mutex in the spi_setup()
callback. The mutex is held while there is an SPI communication going on
on the SPI-bus of the corresponding SPI-controller. So calling the
spi_setup() method and disabling/updating the CS state within it would be
safe while there is no any SPI-transfers being executed. Also note I
suppose it would be safer to protect the spi_controller->setup() callback
invocation too, seeing some of the SPI-controller drivers update a HW
state in there.

Fixes: 49d7d695ca ("spi: dw: Explicitly de-assert CS on SPI transfer completion")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20201117094517.5654-1-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-11-20 17:18:22 +00:00
Lukas Wunner
5e844cc37a
spi: Introduce device-managed SPI controller allocation
SPI driver probing currently comprises two steps, whereas removal
comprises only one step:

    spi_alloc_master()
    spi_register_controller()

    spi_unregister_controller()

That's because spi_unregister_controller() calls device_unregister()
instead of device_del(), thereby releasing the reference on the
spi_controller which was obtained by spi_alloc_master().

An SPI driver's private data is contained in the same memory allocation
as the spi_controller struct.  Thus, once spi_unregister_controller()
has been called, the private data is inaccessible.  But some drivers
need to access it after spi_unregister_controller() to perform further
teardown steps.

Introduce devm_spi_alloc_master() and devm_spi_alloc_slave(), which
release a reference on the spi_controller struct only after the driver
has unbound, thereby keeping the memory allocation accessible.  Change
spi_unregister_controller() to not release a reference if the
spi_controller was allocated by one of these new devm functions.

The present commit is small enough to be backportable to stable.
It allows fixing drivers which use the private data in their ->remove()
hook after it's been freed.  It also allows fixing drivers which neglect
to release a reference on the spi_controller in the probe error path.

Long-term, most SPI drivers shall be moved over to the devm functions
introduced herein.  The few that can't shall be changed in a treewide
commit to explicitly release the last reference on the controller.
That commit shall amend spi_unregister_controller() to no longer release
a reference, thereby completing the migration.

As a result, the behaviour will be less surprising and more consistent
with subsystems such as IIO, which also includes the private data in the
allocation of the generic iio_dev struct, but calls device_del() in
iio_device_unregister().

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/272bae2ef08abd21388c98e23729886663d19192.1605121038.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-11-12 15:05:34 +00:00
Sven Van Asbroeck
766c6b63aa
spi: fix client driver breakages when using GPIO descriptors
Commit f3186dd876 ("spi: Optionally use GPIO descriptors for CS GPIOs")
introduced the optional use of GPIO descriptors for chip selects.

A side-effect of this change: when a SPI bus uses GPIO descriptors,
all its client devices have SPI_CS_HIGH set in spi->mode. This flag is
required for the SPI bus to operate correctly.

This unfortunately breaks many client drivers, which use the following
pattern to configure their underlying SPI bus:

static int client_device_probe(struct spi_device *spi)
{
	...
	spi->mode = SPI_MODE_0;
	spi->bits_per_word = 8;
	err = spi_setup(spi);
	..
}

In short, many client drivers overwrite the SPI_CS_HIGH bit in
spi->mode, and break the underlying SPI bus driver.

This is especially true for Freescale/NXP imx ecspi, where large
numbers of spi client drivers now no longer work.

Proposed fix:
-------------
When using gpio descriptors, depend on gpiolib to handle CS polarity.
Existing quirks in gpiolib ensure that this is handled correctly.

Existing gpiolib behaviour will force the polarity of any chip-select
gpiod to active-high (if 'spi-active-high' devicetree prop present) or
active-low (if 'spi-active-high' absent). Irrespective of whether
the gpio is marked GPIO_ACTIVE_[HIGH|LOW] in the devicetree.

Loose ends:
-----------
If this fix is applied:
- is commit 138c9c32f0
  ("spi: spidev: Fix CS polarity if GPIO descriptors are used")
  still necessary / correct ?

Fixes: f3186dd876 ("spi: Optionally use GPIO descriptors for CS GPIOs")
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20201106150706.29089-1-TheSven73@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-11-11 12:34:28 +00:00
Linus Torvalds
e8878ab825 spi: Fixes for v5.9
There's some driver specific fixes here plus one core fix for memory
 leaks that could be triggered by a potential race condition when
 cleaning up after we have split transfers to fit into what the
 controller can support.
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Merge tag 'spi-fix-v5.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi fixes from Mark Brown:
 "There's some driver specific fixes here plus one core fix for memory
  leaks that could be triggered by a potential race condition when
  cleaning up after we have split transfers to fit into what the
  controller can support"

* tag 'spi-fix-v5.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: stm32: fix pm_runtime_get_sync() error checking
  spi: Fix memory leak on splited transfers
  spi: spi-cadence-quadspi: Fix mapping of buffers for DMA reads
  spi: stm32: Rate-limit the 'Communication suspended' message
  spi: spi-loopback-test: Fix out-of-bounds read
  spi: spi-cadence-quadspi: Populate get_name() interface
  MAINTAINERS: add myself as maintainer for spi-fsl-dspi driver
2020-09-11 11:35:55 -07:00
Gustav Wiklander
b59a7ca154
spi: Fix memory leak on splited transfers
In the prepare_message callback the bus driver has the
opportunity to split a transfer into smaller chunks.
spi_map_msg is done after prepare_message.

Function spi_res_release releases the splited transfers
in the message. Therefore spi_res_release should be called
after spi_map_msg.

The previous try at this was commit c9ba7a16d0
which released the splited transfers after
spi_finalize_current_message had been called.
This introduced a race since the message struct could be
out of scope because the spi_sync call got completed.

Fixes this leak on spi bus driver spi-bcm2835.c when transfer
size is greater than 65532:

Kmemleak:
sg_alloc_table+0x28/0xc8
spi_map_buf+0xa4/0x300
__spi_pump_messages+0x370/0x748
__spi_sync+0x1d4/0x270
spi_sync+0x34/0x58
spi_test_execute_msg+0x60/0x340 [spi_loopback_test]
spi_test_run_iter+0x548/0x578 [spi_loopback_test]
spi_test_run_test+0x94/0x140 [spi_loopback_test]
spi_test_run_tests+0x150/0x180 [spi_loopback_test]
spi_loopback_test_probe+0x50/0xd0 [spi_loopback_test]
spi_drv_probe+0x84/0xe0

Signed-off-by: Gustav Wiklander <gustavwi@axis.com>
Link: https://lore.kernel.org/r/20200908151129.15915-1-gustav.wiklander@axis.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-09-09 15:11:43 +01:00
Linus Torvalds
18445bf405 spi: Fixes for v5.9
A bunch of fixes that came in for SPI during the merge window, a bunch
 from ST and others for their controller, one from Lukas for a race
 between device addition and controller unregistration and one from fix
 from Geert for the DT bindings which unbreaks validation.
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Merge tag 'spi-fix-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi fixes from Mark Brown:
 "A bunch of fixes that came in for SPI during the merge window.

  Some from ST and others for their controller, one from Lukas for a
  race between device addition and controller unregistration and one
  from fix from Geert for the DT bindings which unbreaks validation"

* tag 'spi-fix-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  dt-bindings: lpspi: Add missing boolean type for fsl,spi-only-use-cs1-sel
  spi: stm32: always perform registers configuration prior to transfer
  spi: stm32: fixes suspend/resume management
  spi: stm32: fix stm32_spi_prepare_mbr in case of odd clk_rate
  spi: stm32: fix fifo threshold level in case of short transfer
  spi: stm32h7: fix race condition at end of transfer
  spi: stm32: clear only asserted irq flags on interrupt
  spi: Prevent adding devices below an unregistering controller
2020-08-18 14:27:12 -07:00
Linus Torvalds
6d2b84a4e5 This tree adds the sched_set_fifo*() encapsulation APIs to remove
static priority level knowledge from non-scheduler code.
 
 The three APIs for non-scheduler code to set SCHED_FIFO are:
 
  - sched_set_fifo()
  - sched_set_fifo_low()
  - sched_set_normal()
 
 These are two FIFO priority levels: default (high), and a 'low' priority level,
 plus sched_set_normal() to set the policy back to non-SCHED_FIFO.
 
 Since the changes affect a lot of non-scheduler code, we kept this in a separate
 tree.
 
 When merging to the latest upstream tree there's a conflict in drivers/spi/spi.c,
 which can be resolved via:
 
 	sched_set_fifo(ctlr->kworker_task);
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-fifo-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull sched/fifo updates from Ingo Molnar:
 "This adds the sched_set_fifo*() encapsulation APIs to remove static
  priority level knowledge from non-scheduler code.

  The three APIs for non-scheduler code to set SCHED_FIFO are:

   - sched_set_fifo()
   - sched_set_fifo_low()
   - sched_set_normal()

  These are two FIFO priority levels: default (high), and a 'low'
  priority level, plus sched_set_normal() to set the policy back to
  non-SCHED_FIFO.

  Since the changes affect a lot of non-scheduler code, we kept this in
  a separate tree"

* tag 'sched-fifo-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  sched,tracing: Convert to sched_set_fifo()
  sched: Remove sched_set_*() return value
  sched: Remove sched_setscheduler*() EXPORTs
  sched,psi: Convert to sched_set_fifo_low()
  sched,rcutorture: Convert to sched_set_fifo_low()
  sched,rcuperf: Convert to sched_set_fifo_low()
  sched,locktorture: Convert to sched_set_fifo()
  sched,irq: Convert to sched_set_fifo()
  sched,watchdog: Convert to sched_set_fifo()
  sched,serial: Convert to sched_set_fifo()
  sched,powerclamp: Convert to sched_set_fifo()
  sched,ion: Convert to sched_set_normal()
  sched,powercap: Convert to sched_set_fifo*()
  sched,spi: Convert to sched_set_fifo*()
  sched,mmc: Convert to sched_set_fifo*()
  sched,ivtv: Convert to sched_set_fifo*()
  sched,drm/scheduler: Convert to sched_set_fifo*()
  sched,msm: Convert to sched_set_fifo*()
  sched,psci: Convert to sched_set_fifo*()
  sched,drbd: Convert to sched_set_fifo*()
  ...
2020-08-06 11:55:43 -07:00
Lukas Wunner
ddf75be47c
spi: Prevent adding devices below an unregistering controller
CONFIG_OF_DYNAMIC and CONFIG_ACPI allow adding SPI devices at runtime
using a DeviceTree overlay or DSDT patch.  CONFIG_SPI_SLAVE allows the
same via sysfs.

But there are no precautions to prevent adding a device below a
controller that's being removed.  Such a device is unusable and may not
even be able to unbind cleanly as it becomes inaccessible once the
controller has been torn down.  E.g. it is then impossible to quiesce
the device's interrupt.

of_spi_notify() and acpi_spi_notify() do hold a ref on the controller,
but otherwise run lockless against spi_unregister_controller().

Fix by holding the spi_add_lock in spi_unregister_controller() and
bailing out of spi_add_device() if the controller has been unregistered
concurrently.

Fixes: ce79d54ae4 ("spi/of: Add OF notifier handler")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v3.19+
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Octavian Purdila <octavian.purdila@intel.com>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Link: https://lore.kernel.org/r/a8c3205088a969dc8410eec1eba9aface60f36af.1596451035.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-08-03 16:50:43 +01:00
Mark Brown
e126859729
spi: Only defer to thread for cleanup when needed
Currently we always defer idling of controllers to the SPI thread, the goal
being to ensure that we're doing teardown that's not suitable for atomic
context in an appropriate context and to try to batch up more expensive
teardown operations when the system is under higher load, allowing more
work to be started before the SPI thread is scheduled. However when the
controller does not require any substantial work to idle there is no need
to do this, we can instead save the context switch and immediately mark
the controller as idle. This is particularly useful for systems where there
is frequent but not constant activity.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200715163610.9475-1-broonie@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-07-17 00:55:23 +01:00
Marek Szyprowski
60a883d119
spi: use kthread_create_worker() helper
Use kthread_create_worker() helper to simplify the code. It uses
the kthread worker API the right way. It will eventually allow
to remove the FIXME in kthread_worker_fn() and add more consistency
checks in the future.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20200709065007.26896-1-m.szyprowski@samsung.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-07-09 22:41:10 +01:00
Douglas Anderson
d40f0b6f2e
spi: Avoid setting the chip select if we don't need to
On some SPI controllers (like spi-geni-qcom) setting the chip select
is a heavy operation.  For instance on spi-geni-qcom, with the current
code, is was measured as taking upwards of 20 us.  Even on SPI
controllers that aren't as heavy, setting the chip select is at least
something like a MMIO operation over some peripheral bus which isn't
as fast as a RAM access.

While it would be good to find ways to mitigate problems like this in
the drivers for those SPI controllers, it can also be noted that the
SPI framework could also help out.  Specifically, in some situations,
we can see the SPI framework calling the driver's set_cs() with the
same parameter several times in a row.  This is specifically observed
when looking at the way the Chrome OS EC SPI driver (cros_ec_spi)
works but other drivers likely trip it to some extent.

Let's solve this by caching the chip select state in the core and only
calling into the controller if there was a change.  We check not only
the "enable" state but also the chip select mode (active high or
active low) since controllers may care about both the mode and the
enable flag in their callback.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200629164103.1.Ied8e8ad8bbb2df7f947e3bc5ea1c315e041785a2@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-07-01 23:21:27 +01:00
Robin Gong
809b1b04df
spi: introduce fallback to pio
Add fallback to pio mode in case dma transfer failed with error status
SPI_TRANS_FAIL_NO_START.
If spi client driver want to enable this feature please set xfer->error in
the proper place such as dmaengine_prep_slave_sg() failure detect(but no
any data put into spi bus yet). Besides, add master->fallback checking in
its can_dma() so that spi core could switch to pio next time. Please refer
to spi-imx.c.

Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Link: https://lore.kernel.org/r/1592347329-28363-2-git-send-email-yibin.gong@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-06-23 13:38:14 +01:00
Peter Zijlstra
3070da3340 sched,spi: Convert to sched_set_fifo*()
Because SCHED_FIFO is a broken scheduler model (see previous patches)
take away the priority field, the kernel can't possibly make an
informed decision.

No effective change.

Cc: broonie@kernel.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
2020-06-15 14:10:22 +02:00
Mark Brown
c373643b86
spi: Remove note about transfer limit for spi_write_then_read()
Originally spi_write_then_read() used a fixed statically allocated
buffer which limited the maximum message size it could handle.  This
restriction was removed a while ago so that we could dynamically
allocate a buffer if required but the kerneldoc was not updated to
reflect this, do so.

Reported-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200525133120.57273-1-broonie@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-05-26 17:44:54 +01:00
dillon min
aee67fe879
spi: flags 'SPI_CONTROLLER_MUST_RX' and 'SPI_CONTROLLER_MUST_TX' can't be coexit with 'SPI_3WIRE' mode
since chip spi driver need get the transfer direction by 'tx_buf' and
'rx_buf' of 'struct spi_transfer' in 'SPI_3WIRE' mode.

so, we need bypass 'SPI_CONTROLLER_MUST_RX' and 'SPI_CONTROLLER_MUST_TX'
feature in 'SPI_3WIRE' mode

Signed-off-by: dillon min <dillon.minfei@gmail.com>
Link: https://lore.kernel.org/r/1590378348-8115-9-git-send-email-dillon.minfei@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-05-25 15:56:17 +01:00
Mark Brown
8fede89f85
spi: Make spi_delay_exec() warn if called from atomic context
If the delay used is long enough the spi_delay_exec() will use a sleeping
function to implement it. Add a might_sleep() here to help avoid callers
using this from an atomic context and running into problems at runtime on
other systems.

Suggested-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200522155005.46099-1-broonie@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-05-22 20:00:00 +01:00
Mark Brown
c38a4905ca
Merge branch 'for-5.7' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.8 2020-05-20 17:55:07 +01:00
Lukas Wunner
84855678ad
spi: Fix controller unregister order
When an SPI controller unregisters, it unbinds all its slave devices.
For this, their drivers may need to access the SPI bus, e.g. to quiesce
interrupts.

However since commit ffbbdd2132 ("spi: create a message queueing
infrastructure"), spi_destroy_queue() is executed before unbinding the
slaves.  It sets ctlr->running = false, thereby preventing SPI bus
access and causing unbinding of slave devices to fail.

Fix by unbinding slaves before calling spi_destroy_queue().

Fixes: ffbbdd2132 ("spi: create a message queueing infrastructure")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v3.4+
Cc: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/8aaf9d44c153fe233b17bc2dec4eb679898d7e7b.1589557526.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-05-20 15:16:10 +01:00
Mark Brown
f13242d2c5
Merge branch 'for-5.7' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.8 2020-05-05 11:48:25 +01:00
Colin Ian King
49686df5b8
spi: remove redundant assignment to variable ms
The variable ms is being initialized with a value that is never read
and it is being updated later with a new value.  The initialization is
redundant and can be removed.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Addresses-Coverity: ("Unused value")
Link: https://lore.kernel.org/r/20200410122315.17523-1-colin.king@canonical.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-04-14 18:36:31 +01:00
Andy Shevchenko
0dadde344d
spi: Respect DataBitLength field of SpiSerialBusV2() ACPI resource
By unknown reason the commit 64bee4d28c
  ("spi / ACPI: add ACPI enumeration support")
missed the DataBitLength property to encounter when parse SPI slave
device data from ACPI.

Fill the gap here.

Fixes: 64bee4d28c ("spi / ACPI: add ACPI enumeration support")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200413180406.1826-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-04-14 12:39:38 +01:00
Mark Brown
1ba0b52ea7
Merge branch 'spi-5.7' into spi-next 2020-03-27 15:53:00 +00:00
Wolfram Sang
5b16668e63
spi: acpi: remove superfluous parameter check
to_spi_device() already checks 'dev'. No need to do it before calling
it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20200312134507.10000-1-wsa@the-dreams.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-12 17:38:41 +00:00
Mark Brown
b562b304ef spi: Rewrite mtk-quadspi spi-nor driver with spi-mem
This patchset from Chuanhong Guo <gch981213@gmail.com> adds a spi-mem
 driver for Mediatek SPI-NOR controller, which already has limited
 support by mtk-quadspi. This new driver can make use of full quadspi
 capability of this controller.
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Merge tag 'mtk-mtd-spi-move' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.7

spi: Rewrite mtk-quadspi spi-nor driver with spi-mem

This patchset from Chuanhong Guo <gch981213@gmail.com> adds a spi-mem
driver for Mediatek SPI-NOR controller, which already has limited
support by mtk-quadspi. This new driver can make use of full quadspi
capability of this controller.
2020-03-11 19:58:20 +00:00
Chuanhong Guo
671c3bf50a
spi: make spi-max-frequency optional
We only need a spi-max-frequency when we specifically request a
spi frequency lower than the max speed of spi host.
This property is already documented as optional property and current
host drivers are implemented to operate at highest speed possible
when spi->max_speed_hz is 0.
This patch makes spi-max-frequency an optional property so that
we could just omit it to use max controller speed.

Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
Link: https://lore.kernel.org/r/20200306085052.28258-2-gch981213@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-11 19:56:06 +00:00
Linus Torvalds
ae24a21bbd spi: Fixes for v5.6
A selection of small fixes, mostly for drivers, that have arrived since
 the merge window.  None of them are earth shattering in themselves but
 all useful for affected systems.
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Merge tag 'spi-fix-v5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi fixes from Mark Brown:
 "A selection of small fixes, mostly for drivers, that have arrived
  since the merge window. None of them are earth shattering in
  themselves but all useful for affected systems"

* tag 'spi-fix-v5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: spi_register_controller(): free bus id on error paths
  spi: bcm63xx-hsspi: Really keep pll clk enabled
  spi: atmel-quadspi: fix possible MMIO window size overrun
  spi/zynqmp: remove entry that causes a cs glitch
  spi: pxa2xx: Add CS control clock quirk
  spi: spidev: Fix CS polarity if GPIO descriptors are used
  spi: qup: call spi_qup_pm_resume_runtime before suspending
  spi: spi-omap2-mcspi: Support probe deferral for DMA channels
  spi: spi-omap2-mcspi: Handle DMA size restriction on AM65x
2020-03-06 14:50:16 -06:00
Vladimir Oltean
6a726824aa
spi: Do spi_take_timestamp_pre for as many times as necessary
When dealing with a SPI controller driver that is sending more than 1
byte at once (or the entire buffer at once), and the SPI peripheral
driver has requested timestamping for a byte in the middle of the
buffer, we find that spi_take_timestamp_pre never records a "pre"
timestamp.

This happens because the function currently expects to be called with
the "progress" argument >= to what the peripheral has requested to be
timestamped. But clearly there are cases when that isn't going to fly.

And since we can't change the past when we realize that the opportunity
to take a "pre" timestamp has just passed and there isn't going to be
another one, the approach taken is to keep recording the "pre" timestamp
on each call, overwriting the previously recorded one until the "post"
timestamp is also taken.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20200304220044.11193-8-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-05 14:06:19 +00:00
Aaro Koskinen
f9981d4f50
spi: spi_register_controller(): free bus id on error paths
Some error paths leave the bus id allocated. As a result the IDR
allocation will fail after a deferred probe. Fix by freeing the bus id
always on error.

Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Message-Id: <20200304111740.27915-1-aaro.koskinen@nokia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-04 14:28:57 +00:00
John Garry
ea23578611
spi: Allow SPI controller override device buswidth
Currently ACPI firmware description for a SPI device does not have any
method to describe the data buswidth on the board.

So even through the controller and device may support higher modes than
standard SPI, it cannot be assumed that the board does - as such, that
device is limited to standard SPI in such a circumstance.

As a workaround, allow the controller driver supply buswidth override bits,
which are used inform the core code that the controller driver knows the
buswidth supported on that board for that device.

A host controller driver might know this info from DMI tables, for example.

Signed-off-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1582903131-160033-2-git-send-email-john.garry@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-02-28 18:01:42 +00:00
Mark Brown
754a36a58c
Merge branch 'spi-5.6' into spi-next 2020-01-23 12:37:18 +00:00
Geert Uytterhoeven
7d93aecdb5
spi: Add generic support for unused native cs with cs-gpios
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.be
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-01-07 22:32:25 +00:00
Linus Torvalds
ec7b3f5372 spi: Fixes for v5.5
A small collection of fixes here, one to make the newly added PTP
 timestamping code more accurate, a few driver fixes and a fix for the
 core DT binding to document the fact that we support eight wire buses.
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Merge tag 'spi-fix-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi fixes from Mark Brown:
 "A small collection of fixes here, one to make the newly added PTP
  timestamping code more accurate, a few driver fixes and a fix for the
  core DT binding to document the fact that we support eight wire buses"

* tag 'spi-fix-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: Document Octal mode as valid SPI bus width
  spi: spi-dw: Add lock protect dw_spi rx/tx to prevent concurrent calls
  spi: spi-fsl-dspi: Fix 16-bit word order in 32-bit XSPI mode
  spi: Don't look at TX buffer for PTP system timestamping
  spi: uniphier: Fix FIFO threshold
2020-01-06 12:34:44 -08:00
Vladimir Oltean
862dd2a946
spi: Don't look at TX buffer for PTP system timestamping
The API for PTP system timestamping (associating a SPI transaction with
the system time at which it was transferred) is flawed: it assumes that
the xfer->tx_buf pointer will always be present.

This is, of course, not always the case.

So introduce a "progress" variable that denotes how many word have been
transferred.

Fix the Freescale DSPI driver, the only user of the API so far, in the
same patch.

Fixes: b42faeee71 ("spi: Add a PTP system timestamp to the transfer structure")
Fixes: d6b71dfaee ("spi: spi-fsl-dspi: Implement the PTP system timestamping for TCFQ mode")
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20191227012417.1057-1-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-12-27 23:03:43 +00:00
Vladimir Oltean
f971a20744
spi: Catch improper use of PTP system timestamping API
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.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-12-27 22:58:09 +00:00
Mark Brown
ca4196aa10
Merge branch 'spi-5.5' into spi-next 2019-11-22 19:56:35 +00:00
Tony Lindgren
57a9460705
spi: Fix regression to return zero on success instead of positive value
Commit d948e6ca18 ("spi: add power control when set_cs") added generic
runtime PM handling, but also changed the return value to be 1 instead
of 0 that we had earlier as pm_runtime_get functions return a positve
value on success.

This causes SPI devices to return errors for cases where they do:

ret = spi_setup(spi);
if (ret)
	return ret;

As in many cases the SPI devices do not check for if (ret < 0).

Let's fix this by setting the status to 0 on succeess after the
runtime PM calls. Let's not return 0 at the end of the function
as this might break again later on if the function changes and
starts returning status again.

Fixes: d948e6ca18 ("spi: add power control when set_cs")
Cc: Luhua Xu <luhua.xu@mediatek.com>
Cc: wsd_upstream@mediatek.com
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20191111195334.44833-1-tony@atomide.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-11-12 18:23:51 +00:00
Luhua Xu
d948e6ca18
spi: add power control when set_cs
As to set_cs takes effect immediately, power spi
is needed when setup spi.

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Luhua Xu <luhua.xu@mediatek.com>
Link: https://lore.kernel.org/r/1572426234-30019-1-git-send-email-luhua.xu@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-10-31 14:20:58 +01:00
Gregory CLEMENT
15f794bd97
spi: Fix NULL pointer when setting SPI_CS_HIGH for GPIO CS
Even if the flag use_gpio_descriptors is set, it is possible that
cs_gpiods was not allocated, which leads to a kernel crash.

Reported-by: "kernelci.org bot" <bot@kernelci.org>
Fixes: 3e5ec1db8b ("spi: Fix SPI_CS_HIGH setting when using native and GPIO CS")
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191024141309.22434-1-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: <stable@vger.kernel.org>
2019-10-25 11:10:25 +01:00
Andy Shevchenko
be73e323ae
spi: Fix spelling in the comments
Two spelling mistakes are being fixed.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20191023121643.25237-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-10-23 17:49:19 +01:00
Mark Brown
112d6212c8 Linux 5.4-rc3
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Merge tag 'v5.4-rc3' into spi-5.4

Linux 5.4-rc3
2019-10-18 18:30:49 +01:00
Gregory CLEMENT
3e5ec1db8b
spi: Fix SPI_CS_HIGH setting when using native and GPIO CS
When improving the CS GPIO support at core level, the SPI_CS_HIGH
has been enabled for all the CS lines used for a given SPI controller.

However, the SPI framework allows to have on the same controller native
CS and GPIO CS. The native CS may not support the SPI_CS_HIGH, so they
should not be setup automatically.

With this patch the setting is done only for the CS that will use a
GPIO as CS

Fixes: f3186dd876 ("spi: Optionally use GPIO descriptors for CS GPIOs")
Cc: <stable@vger.kernel.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191018152929.3287-1-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-10-18 18:23:43 +01:00
Alexandru Ardelean
3984d39b0e
spi: spi-fsl-espi: convert transfer delay to spi_delay format
The way the max delay is computed for this controller, it looks like it is
searching for the max delay from an SPI message a using that.

No idea if this is valid. But this change should support both `delay_usecs`
and the new `delay` data which is of `spi_delay` type.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-17-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-10-15 11:46:34 +01:00
Alexandru Ardelean
25093bdeb6
spi: implement SW control for CS times
This change implements CS control for setup, hold & inactive delays.

The `cs_setup` delay is completely new, and can help with cases where
asserting the CS, also brings the device out of power-sleep, where there
needs to be a longer (than usual), before transferring data.

The `cs_hold` time can overlap with the `delay` (or `delay_usecs`) from an
SPI transfer. The main difference is that `cs_hold` implies that CS will be
de-asserted.

The `cs_inactive` delay does not have a clear use-case yet. It has been
implemented mostly because the `spi_set_cs_timing()` function implements
it. To some degree, this could overlap or replace `cs_change_delay`, but
this will require more consideration/investigation in the future.

All these delays have been added to the `spi_controller` struct, as they
would typically be configured by calling `spi_set_cs_timing()` after an
`spi_setup()` call.

Software-mode for CS control, implies that the `set_cs_timing()` hook has
not been provided for the `spi_controller` object.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-16-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-10-15 11:46:12 +01:00
Alexandru Ardelean
8105936684
spi: tegra114: change format for spi_set_cs_timing() function
The initial version of `spi_set_cs_timing()` was implemented with
consideration only for clock-cycles as delay.

For cases like `CS setup` time, it's sometimes needed that micro-seconds
(or nano-seconds) are required, or sometimes even longer delays, for cases
where the device needs a little longer to start transferring that after CS
is asserted.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-15-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-10-15 11:45:49 +01:00
Alexandru Ardelean
bebcfd272d
spi: introduce delay field for spi_transfer + spi_transfer_delay_exec()
The change introduces the `delay` field to the `spi_transfer` struct as an
`struct spi_delay` type.
This intends to eventually replace `delay_usecs`.

But, since there are many users of `delay_usecs`, this needs some
intermediate work.
A helper called `spi_transfer_delay_exec()` is also added, which maintains
backwards compatibility with `delay_usecs`, by assigning the value to
`delay` if non-zero.
This should maintain backwards compatibility with current users of
`udelay_usecs`.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-9-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-10-15 11:44:33 +01:00
Alexandru Ardelean
6c613f68aa
spi: core,atmel: convert word_delay_usecs -> word_delay for spi_device
This change does a conversion from the `word_delay_usecs` -> `word_delay`
for the `spi_device` struct.

This allows users to specify inter-word delays in other unit types
(nano-seconds or clock cycles), depending on how users want.

The Atmel SPI driver is the only current user of the `word_delay_usecs`
field (from the `spi_device` struct).
So, it needed a slight conversion to use the `word_delay` as an `spi_delay`
struct.

In SPI core, the only required mechanism is to update the `word_delay`
information per `spi_transfer`. This requires a bit more logic than before,
because it needs that both delays be converted to a common unit
(nano-seconds) for comparison.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-8-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-10-15 11:44:10 +01:00
Alexandru Ardelean
329f0dac4c
spi: make cs_change_delay the first user of the spi_delay logic
Since the logic for `spi_delay` struct + `spi_delay_exec()` has been copied
from the `cs_change_delay` logic, it's natural to make this delay, the
first user.

The `cs_change_delay` logic requires that the default remain 10 uS, in case
it is unspecified/unconfigured. So, there is some special handling needed
to do that.

The ADIS library is one of the few users of the new `cs_change_delay`
parameter for an spi_transfer.

The introduction of the `spi_delay` struct, requires that the users of of
`cs_change_delay` get an update. This change also updates the ADIS library.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-4-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-10-15 11:41:47 +01:00