Commit Graph

603 Commits

Author SHA1 Message Date
Greg Kroah-Hartman 4ccf359849
spi: remove spi_set_cs_timing()
No one seems to be using this global and exported function, so remove it
as it is no longer needed.

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210609071918.2852069-1-gregkh@linuxfoundation.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-06-09 11:55:46 +01:00
Mark Brown 1a435466b0
Merge branch 'for-5.13' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.14 2021-06-01 18:33:33 +01:00
Andy Shevchenko 5cb4e1f33e
spi: Enable tracing of the SPI setup CS selection
It is helpful to see what state of CS signal was during one
or another SPI operation. All the same for SPI setup.

Enable tracing of the SPI setup and CS selection.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Message-Id: <20210526195655.75691-1-andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-05-26 21:22:13 +01:00
Saravana Kannan 27e7db56cf
spi: Don't have controller clean up spi device before driver unbind
When a spi device is unregistered and triggers a driver unbind, the
driver might need to access the spi device. So, don't have the
controller clean up the spi device before the driver is unbound. Clean
up the spi device after the driver is unbound.

Fixes: c7299fea67 ("spi: Fix spi device unregister flow")
Reported-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Tested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210505164734.175546-1-saravanak@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-05-14 13:24:56 +01:00
Andy Shevchenko 6b69546912
spi: Assume GPIO CS active high in ACPI case
Currently GPIO CS handling, when descriptors are in use, doesn't
take into consideration that in ACPI case the default polarity
is Active High and can't be altered. Instead we have to use the
per-chip definition provided by SPISerialBus() resource.

Fixes: 766c6b63aa ("spi: fix client driver breakages when using GPIO descriptors")
Cc: Liguang Zhang <zhangliguang@linux.alibaba.com>
Cc: Jay Fang <f.fangjian@huawei.com>
Cc: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Xin Hao <xhao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210511140912.30757-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-05-12 13:01:44 +01:00
Andy Shevchenko 40b82c2d9a
spi: Use SPI_MODE_X_MASK
Use SPI_MODE_X_MASK instead of open coded variant.

While at it, fix format specifier and drop explicit casting.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210510131217.49357-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-05-11 15:42:46 +01:00
Andy Shevchenko 86b8bff7e3
spi: Convert to use predefined time multipliers
We have a lot of hard coded values in nanoseconds or other units.
Use predefined constants to make it more clear.

While at it, add or amend comments in the corresponding functions.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210510131120.49253-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-05-11 10:06:52 +01:00
Leilk Liu dc5fa59027
spi: take the SPI IO-mutex in the spi_set_cs_timing method
this patch takes the io_mutex to prevent an unprotected HW
register modification in the set_cs_timing callback.

Fixes: 4cea6b8cc3 ("spi: add power control when set_cs_timing")
Signed-off-by: Leilk Liu <leilk.liu@mediatek.com>
Link: https://lore.kernel.org/r/20210508060214.1485-1-leilk.liu@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-05-10 13:00:28 +01:00
Saravana Kannan c7299fea67
spi: Fix spi device unregister flow
When an SPI device is unregistered, the spi->controller->cleanup() is
called in the device's release callback. That's wrong for a couple of
reasons:

1. spi_dev_put() can be called before spi_add_device() is called. And
   it's spi_add_device() that calls spi_setup(). This will cause clean()
   to get called without the spi device ever being setup.

2. There's no guarantee that the controller's driver would be present by
   the time the spi device's release function gets called.

3. It also causes "sleeping in atomic context" stack dump[1] when device
   link deletion code does a put_device() on the spi device.

Fix these issues by simply moving the cleanup from the device release
callback to the actual spi_unregister_device() function.

[1] - https://lore.kernel.org/lkml/CAHp75Vc=FCGcUyS0v6fnxme2YJ+qD+Y-hQDQLa2JhWNON9VmsQ@mail.gmail.com/

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210426235638.1285530-1-saravanak@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-28 16:34:58 +01:00
Andy Shevchenko 86527bcbc8
spi: Rename enable1 to activate in spi_set_cs()
The enable1 is confusing name. Change it to clearly show what is
the intention behind it. No functional changes.

Fixes: 25093bdeb6 ("spi: implement SW control for CS times")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210420131846.75983-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-23 15:36:18 +01:00
Andy Shevchenko 31ed8ebc7a
spi: Make error handling of gpiod_count() call cleaner
Each time we call spi_get_gpio_descs() the num_chipselect is overwritten
either by new value or by the old one. This is an extra operation in case
gpiod_count() returns an error. Besides that it slashes the error handling
of gpiod_count().

Refactor the code to make error handling of gpiod_count() call cleaner.

Note, that gpiod_count() never returns 0, take this into account as well.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210420164040.40055-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-21 16:07:04 +01:00
Andy Shevchenko f60d7270c8
spi: Avoid undefined behaviour when counting unused native CSs
ffz(), that has been used to count unused native CSs,
might cause undefined behaviour when called against ~0U.
To fix that, open code it with ffs(~value) - 1.

Fixes: 7d93aecdb5 ("spi: Add generic support for unused native cs with cs-gpios")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210420164425.40287-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-21 15:49:54 +01:00
Andy Shevchenko dbaca8e56e
spi: Allow to have all native CSs in use along with GPIOs
The commit 7d93aecdb5 ("spi: Add generic support for unused native cs
with cs-gpios") excludes the valid case for the controllers that doesn't
need to switch native CS in order to perform the transfer, i.e. when

  0		native
  ...		...
  <n> - 1	native
  <n>		GPIO
  <n> + 1	GPIO
  ...		...

where <n> defines maximum of native CSs supported by the controller.

To allow this, bail out from spi_get_gpio_descs() conditionally for
the controllers which explicitly marked with SPI_MASTER_GPIO_SS.

Fixes: 7d93aecdb5 ("spi: Add generic support for unused native cs with cs-gpios")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210420164425.40287-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-21 15:49:53 +01:00
Charles Keepax 0e793ba77c
spi: Make of_register_spi_device also set the fwnode
Currently, the SPI core doesn't set the struct device fwnode pointer
when it creates a new SPI device. This means when the device is
registered the fwnode is NULL and the check in device_add which sets
the fwnode->dev pointer is skipped. This wasn't previously an issue,
however these two patches:

commit 4731210c09 ("gpiolib: Bind gpio_device to a driver to enable
fw_devlink=on by default")
commit ced2af4195 ("gpiolib: Don't probe gpio_device if it's not the
primary device")

Added some code to the GPIO core which relies on using that
fwnode->dev pointer to determine if a driver is bound to the fwnode
and if not bind a stub GPIO driver. This means the GPIO providers
behind SPI will get both the expected driver and this stub driver
causing the stub driver to fail if it attempts to request any pin
configuration. For example on my system:

madera-pinctrl madera-pinctrl: pin gpio5 already requested by madera-pinctrl; cannot claim for gpiochip3
madera-pinctrl madera-pinctrl: pin-4 (gpiochip3) status -22
madera-pinctrl madera-pinctrl: could not request pin 4 (gpio5) from group aif1  on device madera-pinctrl
gpio_stub_drv gpiochip3: Error applying setting, reverse things back
gpio_stub_drv: probe of gpiochip3 failed with error -22

The firmware node on the device created by the GPIO framework is set
through the of_node pointer hence things generally actually work,
however that fwnode->dev is never set, as the check was skipped at
device_add time. This fix appears to match how the I2C subsystem
handles the same situation.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20210421101402.8468-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-21 15:49:52 +01:00
Joe Burmeister c914dbf88f
spi: Handle SPI device setup callback failure.
If the setup callback failed, but the controller has auto_runtime_pm
and set_cs, the setup failure could be missed.

Signed-off-by: Joe Burmeister <joe.burmeister@devtank.co.uk>
Link: https://lore.kernel.org/r/20210419130631.4586-1-joe.burmeister@devtank.co.uk
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-19 14:18:46 +01:00
David Bauer d347b4aaa1
spi: sync up initial chipselect state
When initially probing the SPI slave device, the call for disabling an
SPI device without the SPI_CS_HIGH flag is not applied, as the
condition for checking whether or not the state to be applied equals the
one currently set evaluates to true.

This however might not necessarily be the case, as the chipselect might
be active.

Add a force flag to spi_set_cs which allows to override this
early exit condition. Set it to false everywhere except when called
from spi_setup to sync up the initial CS state.

Fixes commit d40f0b6f2e ("spi: Avoid setting the chip select if we don't
need to")

Signed-off-by: David Bauer <mail@david-bauer.net>
Link: https://lore.kernel.org/r/20210416195956.121811-1-mail@david-bauer.net
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-19 14:18:45 +01:00
Mark Brown c7ed5fd5fb
Merge branch 'for-5.12' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.13 2021-04-15 19:29:40 +01:00
Tian Tao 59ebbe40fb
spi: simplify devm_spi_register_controller
Use devm_add_action_or_reset() instead of devres_alloc() and
devres_add(), which works the same. This will simplify the
code. There is no functional changes.

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/1617843307-53853-1-git-send-email-tiantao6@hisilicon.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-09 13:43:58 +01:00
William A. Kennington III 794aaf0144
spi: Fix use-after-free with devm_spi_alloc_*
We can't rely on the contents of the devres list during
spi_unregister_controller(), as the list is already torn down at the
time we perform devres_find() for devm_spi_release_controller. This
causes devices registered with devm_spi_alloc_{master,slave}() to be
mistakenly identified as legacy, non-devm managed devices and have their
reference counters decremented below 0.

------------[ cut here ]------------
WARNING: CPU: 1 PID: 660 at lib/refcount.c:28 refcount_warn_saturate+0x108/0x174
[<b0396f04>] (refcount_warn_saturate) from [<b03c56a4>] (kobject_put+0x90/0x98)
[<b03c5614>] (kobject_put) from [<b0447b4c>] (put_device+0x20/0x24)
 r4:b6700140
[<b0447b2c>] (put_device) from [<b07515e8>] (devm_spi_release_controller+0x3c/0x40)
[<b07515ac>] (devm_spi_release_controller) from [<b045343c>] (release_nodes+0x84/0xc4)
 r5:b6700180 r4:b6700100
[<b04533b8>] (release_nodes) from [<b0454160>] (devres_release_all+0x5c/0x60)
 r8:b1638c54 r7:b117ad94 r6:b1638c10 r5:b117ad94 r4:b163dc10
[<b0454104>] (devres_release_all) from [<b044e41c>] (__device_release_driver+0x144/0x1ec)
 r5:b117ad94 r4:b163dc10
[<b044e2d8>] (__device_release_driver) from [<b044f70c>] (device_driver_detach+0x84/0xa0)
 r9:00000000 r8:00000000 r7:b117ad94 r6:b163dc54 r5:b1638c10 r4:b163dc10
[<b044f688>] (device_driver_detach) from [<b044d274>] (unbind_store+0xe4/0xf8)

Instead, determine the devm allocation state as a flag on the
controller which is guaranteed to be stable during cleanup.

Fixes: 5e844cc37a ("spi: Introduce device-managed SPI controller allocation")
Signed-off-by: William A. Kennington III <wak@google.com>
Link: https://lore.kernel.org/r/20210407095527.2771582-1-wak@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-04-08 15:08:53 +01:00
Colin Ian King 9d902c2a9a
spi: Fix spelling mistake "softwade" -> "software"
There is a spelling mistake in a dev_err message. Fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210317093936.5572-1-colin.king@canonical.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-03-17 13:10:48 +00:00
Mark Brown 4152c4d0d9
Merge series "spi: Adding support for software nodes" from Heikki Krogerus <heikki.krogerus@linux.intel.com>:
Hi,

The older API used to supply additional device properties for the
devices - so mainly the function device_add_properties() - is going to
be removed. The reason why the API will be removed is because it gives
false impression that the properties are assigned directly to the
devices, which has actually never been the case - the properties have
always been assigned to a software fwnode which was then just directly
linked with the device when the old API was used. By only accepting
device properties instead of complete software nodes, the subsystems
remove any change of taking advantage of the other features the
software nodes have.

The change that is required from the spi subsystem and the drivers is
trivial. Basically only the "properties" member in struct
spi_board_info, which was a pointer to struct property_entry, is
replaced with a pointer to a complete software node.

thanks,

Heikki Krogerus (4):
  spi: Add support for software nodes
  ARM: pxa: icontrol: Constify the software node
  ARM: pxa: zeus: Constify the software node
  spi: Remove support for dangling device properties

 arch/arm/mach-pxa/icontrol.c | 12 ++++++++----
 arch/arm/mach-pxa/zeus.c     |  6 +++++-
 drivers/spi/spi.c            | 21 ++++++---------------
 include/linux/spi/spi.h      |  7 +++----
 4 files changed, 22 insertions(+), 24 deletions(-)

--
2.30.1

base-commit: a38fd87484
2021-03-16 17:55:41 +00:00
Heikki Krogerus df41a5dad5
spi: Remove support for dangling device properties
>From now on only accepting complete software nodes.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210303152814.35070-5-heikki.krogerus@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-03-16 13:29:44 +00:00
Heikki Krogerus 47afc77bbf
spi: Add support for software nodes
Making it possible for the drivers to assign complete
software fwnodes to the devices instead of only the device
properties in those nodes.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210303152814.35070-2-heikki.krogerus@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-03-16 13:29:41 +00:00
Alexandru Ardelean 3ab1cce553
spi: core: remove 'delay_usecs' field from spi_transfer
The 'delay' field in the spi_transfer struct is meant to replace the
'delay_usecs' field. However some cleanup was required to remove the
uses of 'delay_usecs'. Now that it's been cleaned up, we can remove it
from the kernel tree.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210308145502.1075689-10-aardelean@deviqon.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-03-12 14:30:50 +00:00
Linus Torvalds a2590d6989 spi: Updates for v5.12
The main focus of this release from a framework point of view has been
 spi-mem where we've acquired support for a few new hardware features
 which enable better performance on suitable hardware.  Otherwise mostly
 thanks to Arnd's cleanup efforts on old platforms we've removed several
 obsolete drivers which just about balance out the newer drivers we've
 added this cycle.
 
  - Allow drivers to flag if they are unidirectional.
  - Support for DTR mode and hardware acceleration of dummy cycles in spi-mem.
  - Support for Allwinder H616, Intel Lightning Mountain, nVidia Tegra
    QuadSPI, Realtek RTL838x and RTL839x.
  - Removal of obsolute EFM32, Txx9 and SIRF Prima and Atlas drivers.
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Merge tag 'spi-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "The main focus of this release from a framework point of view has been
  spi-mem where we've acquired support for a few new hardware features
  which enable better performance on suitable hardware.

  Otherwise mostly thanks to Arnd's cleanup efforts on old platforms
  we've removed several obsolete drivers which just about balance out
  the newer drivers we've added this cycle.

  Summary:

   - Allow drivers to flag if they are unidirectional.

   - Support for DTR mode and hardware acceleration of dummy cycles in
     spi-mem.

   - Support for Allwinder H616, Intel Lightning Mountain, nVidia Tegra
     QuadSPI, Realtek RTL838x and RTL839x.

   - Removal of obsolete EFM32, Txx9 and SIRF Prima and Atlas drivers"

* tag 'spi-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (76 commits)
  spi: Skip zero-length transfers in spi_transfer_one_message()
  spi: dw: Avoid stack content exposure
  spi: cadence-quadspi: Use spi_mem_dtr_supports_op()
  spi: spi-mem: add spi_mem_dtr_supports_op()
  spi: atmel-quadspi: Disable the QSPI IP at suspend()
  spi: pxa2xx: Add IDs for the controllers found on Intel Lynxpoint
  spi: pxa2xx: Fix the controller numbering for Wildcat Point
  spi: Change provied to provided in the file spi.h
  spi: mediatek: add set_cs_timing support
  spi: support CS timing for HW & SW mode
  spi: add power control when set_cs_timing
  spi: stm32: make spurious and overrun interrupts visible
  spi: stm32h7: replace private SPI_1HZ_NS with NSEC_PER_SEC
  spi: stm32: defer probe for reset
  spi: stm32: driver uses reset controller only at init
  spi: stm32h7: ensure message are smaller than max size
  spi: stm32: use bitfield macros
  spi: stm32: do not mandate cs_gpio
  spi: stm32: properly handle 0 byte transfer
  spi: clps711xx: remove redundant white-space
  ...
2021-02-22 09:19:08 -08:00
Mark Brown eec262d179
Merge remote-tracking branch 'spi/for-5.12' into spi-next 2021-02-12 14:00:22 +00:00
Nicolas Saenz Julienne b306320322
spi: Skip zero-length transfers in spi_transfer_one_message()
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>
2021-02-12 12:41:59 +00:00
leilk.liu 0486d9f91d
spi: support CS timing for HW & SW mode
this patch supports the controller's HW CS and SW CS via use cs_gpio.

Signed-off-by: leilk.liu <leilk.liu@mediatek.com>
Link: https://lore.kernel.org/r/20210207030953.9297-3-leilk.liu@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-02-08 11:41:22 +00:00
leilk.liu 4cea6b8cc3
spi: add power control when set_cs_timing
As to set_cs_timing takes effect immediately, power spi
is needed when call spi_set_cs_timing.

Signed-off-by: leilk.liu <leilk.liu@mediatek.com>
Link: https://lore.kernel.org/r/20210207030953.9297-2-leilk.liu@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-02-08 11:41:21 +00:00
Bjorn Helgaas 10e927249c ACPI: Test for ACPI_SUCCESS rather than !ACPI_FAILURE
The double negative makes it hard to read "if (!ACPI_FAILURE(status))".
Replace it with "if (ACPI_SUCCESS(status))".

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-01-27 18:43:07 +01:00
Mark Brown e4aad9998e Linux 5.11-rc3
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Merge v5.11-rc3
2021-01-13 17:57:11 +00:00
Xu Yilun 6170d077bf
spi: fix the divide by 0 error when calculating xfer waiting time
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>
2021-01-04 14:24:58 +00:00
Tudor Ambarus 6820e812da
spi: Fix the clamping of spi->max_speed_hz
If spi->controller->max_speed_hz is zero, a non-zero spi->max_speed_hz
will be overwritten by zero. Make sure spi->controller->max_speed_hz
is not zero when clamping spi->max_speed_hz.

Put the spi->controller->max_speed_hz non-zero check higher in the if,
so that we avoid a superfluous init to zero when both spi->max_speed_hz
and spi->controller->max_speed_hz are zero.

Fixes: 9326e4f1e5 ("spi: Limit the spi device max speed to controller's max speed")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20201216092321.413262-1-tudor.ambarus@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-12-30 13:45:23 +00:00
Dragos Bogdan d962608ce2
spi: Add SPI_NO_TX/RX support
Transmit/receive only is a valid SPI mode. For example, the MOSI/TX line
might be missing from an ADC while for a DAC the MISO/RX line may be
optional. This patch adds these two new modes: SPI_NO_TX and
SPI_NO_RX. This way, the drivers will be able to identify if any of
these two lines is missing and to adjust the transfers accordingly.

Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20201221152936.53873-2-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-12-28 14:21:31 +00:00
Mark Brown 127a7a95df
Merge remote-tracking branch 'spi/for-5.10' into spi-5.11 2020-12-17 17:09:51 +00:00
Mark Brown 3e98a021cc
Merge remote-tracking branch 'spi/for-5.11' into spi-next 2020-12-11 17:49:01 +00:00
Tudor Ambarus 9326e4f1e5
spi: Limit the spi device max speed to controller's max speed
Make sure the max_speed_hz of spi_device does not override
the max_speed_hz of controller.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20201209173514.93328-1-tudor.ambarus@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-12-11 13:21:36 +00:00
Mark Brown db4a831997
Merge branch 'for-5.10' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.11 2020-11-27 16:18:32 +00:00
Marek Szyprowski a6f483b2e4
spi: Fix potential NULL pointer dereference in spi_shutdown()
Shutdown bus function might be called on the unbound device, so add a
check if there is a driver before calling its shutdown function.

This fixes following kernel panic obserbed during system reboot:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000018
...
Call trace:
 spi_shutdown+0x10/0x38
 kernel_restart_prepare+0x34/0x40
 kernel_restart+0x14/0x88
 __do_sys_reboot+0x148/0x248
 __arm64_sys_reboot+0x1c/0x28
 el0_svc_common.constprop.3+0x74/0x198
 do_el0_svc+0x20/0x98
 el0_sync_handler+0x140/0x1a8
 el0_sync+0x140/0x180
Code: f9403402 d1008041 f100005f 9a9f1021 (f9400c21)
---[ end trace 266c07205a2d632e ]---

Fixes: 9db34ee64c (spi: Use bus_type functions for probe, remove and shutdown)
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20201124131523.32287-1-m.szyprowski@samsung.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-11-24 14:14:39 +00:00
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
Uwe Kleine-König 7795d47575
spi: Warn when a driver's remove callback returns an error
The driver core ignores the return value of struct device_driver::remove
(because in general there is nothing that can be done about that). So
add a warning when an spi driver returns an error.

This simplifies the quest to make struct device_driver::remove return void.
A consequent change would be to make struct spi_driver::remove return void,
but I'm keeping this quest for later (or someone else).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20201119161604.2633521-3-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-11-20 13:49:12 +00:00
Uwe Kleine-König 9db34ee64c
spi: Use bus_type functions for probe, remove and shutdown
The eventual goal is to get rid of the callbacks in struct
device_driver. Other than not using driver callbacks there should be no
side effect of this patch.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20201119161604.2633521-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-11-20 13:49:11 +00:00
Uwe Kleine-König 440408dbad
spi: fix resource leak for drivers without .remove callback
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>
2020-11-20 13:49:10 +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
Mauro Carvalho Chehab ce2424d76f
spi: fix a typo inside a kernel-doc markup
spi_split_tranfers_maxsize -> spi_split_transfers_maxsize

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/a103f4f48735caa1a09fad94c5d76e73e2ce37b8.1603469755.git.mchehab+huawei@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-10-28 21:38:59 +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
Alexandru Ardelean b2c98153f4
spi: introduce spi_delay struct as "value + unit" & spi_delay_exec()
There are plenty of delays that have been introduced in SPI core. Most of
them are in micro-seconds, some need to be in nano-seconds, and some in
clock-cycles.

For some of these delays (related to transfers & CS timing) it may make
sense to have a `spi_delay` struct that abstracts these a bit.

The important element of these delays [for unification] seems to be the
`unit` of the delay.
It looks like micro-seconds is good enough for most people, but every-once
in a while, some delays seem to require other units of measurement.

This change adds the `spi_delay` struct & a `spi_delay_exec()` function
that processes a `spi_delay` object/struct to execute the delay.
It's a copy of the `cs_change_delay` mechanism, but without the default
for 10 uS.

The clock-cycle delay unit is a bit special, as it needs to be bound to an
`spi_transfer` object to execute.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-3-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-10-15 11:41:25 +01:00
Alexandru Ardelean 6b3f236a99
spi: move `cs_change_delay` backwards compat logic outside switch
The `cs_change_delay` backwards compatibility value could be moved outside
of the switch statement.
The only reason to do it, is to make the next patches easier to diff.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-2-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-10-15 11:41:04 +01:00
Vladimir Oltean b42faeee71
spi: Add a PTP system timestamp to the transfer structure
SPI is one of the interfaces used to access devices which have a POSIX
clock driver (real time clocks, 1588 timers etc). The fact that the SPI
bus is slow is not what the main problem is, but rather the fact that
drivers don't take a constant amount of time in transferring data over
SPI. When there is a high delay in the readout of time, there will be
uncertainty in the value that has been read out of the peripheral.
When that delay is constant, the uncertainty can at least be
approximated with a certain accuracy which is fine more often than not.

Timing jitter occurs all over in the kernel code, and is mainly caused
by having to let go of the CPU for various reasons such as preemption,
servicing interrupts, going to sleep, etc. Another major reason is CPU
dynamic frequency scaling.

It turns out that the problem of retrieving time from a SPI peripheral
with high accuracy can be solved by the use of "PTP system
timestamping" - a mechanism to correlate the time when the device has
snapshotted its internal time counter with the Linux system time at that
same moment. This is sufficient for having a precise time measurement -
it is not necessary for the whole SPI transfer to be transmitted "as
fast as possible", or "as low-jitter as possible". The system has to be
low-jitter for a very short amount of time to be effective.

This patch introduces a PTP system timestamping mechanism in struct
spi_transfer. This is to be used by SPI device drivers when they need to
know the exact time at which the underlying device's time was
snapshotted. More often than not, SPI peripherals have a very exact
timing for when their SPI-to-interconnect bridge issues a transaction
for snapshotting and reading the time register, and that will be
dependent on when the SPI-to-interconnect bridge figures out that this
is what it should do, aka as soon as it sees byte N of the SPI transfer.
Since spi_device drivers are the ones who'd know best how the peripheral
behaves in this regard, expose a mechanism in spi_transfer which allows
them to specify which word (or word range) from the transfer should be
timestamped.

Add a default implementation of the PTP system timestamping in the SPI
core. This is not going to be satisfactory performance-wise, but should
at least increase the likelihood that SPI device drivers will use PTP
system timestamping in the future.
There are 3 entry points from the core towards the SPI controller
drivers:

- transfer_one: The driver is passed individual spi_transfers to
  execute. This is the easiest to timestamp.

- transfer_one_message: The core passes the driver an entire spi_message
  (a potential batch of spi_transfers). The core puts the same pre and
  post timestamp to all transfers within a message. This is not ideal,
  but nothing better can be done by default anyway, since the core has
  no insight into how the driver batches the transfers.

- transfer: Like transfer_one_message, but for unqueued drivers (i.e.
  the driver implements its own queue scheduling).

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20190905010114.26718-3-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-10-07 19:45:23 +01:00
Linus Torvalds 4feaab05dc LED updates for 5.4-rc1
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Merge tag 'leds-for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED updates from Jacek Anaszewski:
 "In this cycle we've finally managed to contribute the patch set
  sorting out LED naming issues. Besides that there are many changes
  scattered among various LED class drivers and triggers.

  LED naming related improvements:

   - add new 'function' and 'color' fwnode properties and deprecate
     'label' property which has been frequently abused for conveying
     vendor specific names that have been available in sysfs anyway

   - introduce a set of standard LED_FUNCTION* definitions

   - introduce a set of standard LED_COLOR_ID* definitions

   - add a new {devm_}led_classdev_register_ext() API with the
     capability of automatic LED name composition basing on the
     properties available in the passed fwnode; the function is
     backwards compatible in a sense that it uses 'label' data, if
     present in the fwnode, for creating LED name

   - add tools/leds/get_led_device_info.sh script for retrieving LED
     vendor, product and bus names, if applicable; it also performs
     basic validation of an LED name

   - update following drivers and their DT bindings to use the new LED
     registration API:

        - leds-an30259a, leds-gpio, leds-as3645a, leds-aat1290, leds-cr0014114,
          leds-lm3601x, leds-lm3692x, leds-lp8860, leds-lt3593, leds-sc27xx-blt

  Other LED class improvements:

   - replace {devm_}led_classdev_register() macros with inlines

   - allow to call led_classdev_unregister() unconditionally

   - switch to use fwnode instead of be stuck with OF one

  LED triggers improvements:

   - led-triggers:
        - fix dereferencing of null pointer
        - fix a memory leak bug

   - ledtrig-gpio:
        - GPIO 0 is valid

  Drop superseeded apu2/3 support from leds-apu since for apu2+ a newer,
  more complete driver exists, based on a generic driver for the AMD
  SOCs gpio-controller, supporting LEDs as well other devices:

   - drop profile field from priv data

   - drop iosize field from priv data

   - drop enum_apu_led_platform_types

   - drop superseeded apu2/3 led support

   - add pr_fmt prefix for better log output

   - fix error message on probing failure

  Other misc fixes and improvements to existing LED class drivers:

   - leds-ns2, leds-max77650:
        - add of_node_put() before return

   - leds-pwm, leds-is31fl32xx:
        - use struct_size() helper

   - leds-lm3697, leds-lm36274, leds-lm3532:
        - switch to use fwnode_property_count_uXX()

   - leds-lm3532:
        - fix brightness control for i2c mode
        - change the define for the fs current register
        - fixes for the driver for stability
        - add full scale current configuration
        - dt: Add property for full scale current.
        - avoid potentially unpaired regulator calls
        - move static keyword to the front of declarations
        - fix optional led-max-microamp prop error handling

   - leds-max77650:
        - add of_node_put() before return
        - add MODULE_ALIAS()
        - Switch to fwnode property API

   - leds-as3645a:
        - fix misuse of strlcpy

   - leds-netxbig:
        - add of_node_put() in netxbig_leds_get_of_pdata()
        - remove legacy board-file support

   - leds-is31fl319x:
        - simplify getting the adapter of a client

   - leds-ti-lmu-common:
        - fix coccinelle issue
        - move static keyword to the front of declaration

   - leds-syscon:
        - use resource managed variant of device register

   - leds-ktd2692:
        - fix a typo in the name of a constant

   - leds-lp5562:
        - allow firmware files up to the maximum length

   - leds-an30259a:
        - fix typo

   - leds-pca953x:
        - include the right header"

* tag 'leds-for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds: (72 commits)
  leds: lm3532: Fix optional led-max-microamp prop error handling
  led: triggers: Fix dereferencing of null pointer
  leds: ti-lmu-common: Move static keyword to the front of declaration
  leds: lm3532: Move static keyword to the front of declarations
  leds: trigger: gpio: GPIO 0 is valid
  leds: pwm: Use struct_size() helper
  leds: is31fl32xx: Use struct_size() helper
  leds: ti-lmu-common: Fix coccinelle issue in TI LMU
  leds: lm3532: Avoid potentially unpaired regulator calls
  leds: syscon: Use resource managed variant of device register
  leds: Replace {devm_}led_classdev_register() macros with inlines
  leds: Allow to call led_classdev_unregister() unconditionally
  leds: lm3532: Add full scale current configuration
  dt: lm3532: Add property for full scale current.
  leds: lm3532: Fixes for the driver for stability
  leds: lm3532: Change the define for the fs current register
  leds: lm3532: Fix brightness control for i2c mode
  leds: Switch to use fwnode instead of be stuck with OF one
  leds: max77650: Switch to fwnode property API
  led: triggers: Fix a memory leak bug
  ...
2019-09-17 18:40:42 -07:00
Lukas Wunner 229e6af102
spi: Guarantee cacheline alignment of driver-private data
__spi_alloc_controller() uses a single allocation to accommodate struct
spi_controller and the driver-private data, but places the latter behind
the former.  This order does not guarantee cacheline alignment of the
driver-private data.  (It does guarantee cacheline alignment of struct
spi_controller but the structure doesn't make any use of that property.)

Round up struct spi_controller to cacheline size.  A forthcoming commit
leverages this to grant DMA access to driver-private data of the BCM2835
SPI master.

An alternative, less economical approach would be to use two allocations.

A third approach consists of reversing the order to conserve memory.
But Mark Brown is concerned that it may result in a performance penalty
on architectures that don't like unaligned accesses.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/01625b9b26b93417fb09d2c15ad02dfe9cdbbbe5.1568187525.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-09-11 15:53:11 +01:00
Vladimir Oltean d1c44c9342
spi: Use an abbreviated pointer to ctlr->cur_msg in __spi_pump_messages
This helps a bit with line fitting now (the list_first_entry call) as
well as during the next patch which needs to iterate through all
transfers of ctlr->cur_msg so it timestamps them.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20190905010114.26718-2-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-09-05 18:20:12 +01:00
Linus Walleij 43004f31eb
spi: Rename of_spi_register_master() function
Rename this function to of_spi_get_gpio_numbers() as this
is what the function does, it does not register a master,
it is called in the path of registering a master so the
name is logical in a convoluted way, but it is better to
follow Rusty Russell's ABI level no 7:
"The obvious use is (probably) the correct one"

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20190808150321.23319-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-08-08 20:43:13 +01:00
Peter Zijlstra 4ff13d00eb
spi: Reduce kthread priority
The SPI thingies request FIFO-99 by default, reduce this to FIFO-50.

FIFO-99 is the very highest priority available to SCHED_FIFO and
it not a suitable default; it would indicate the SPI work is the
most important work on the machine.

Cc: Benson Leung <bleung@chromium.org>
Cc: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20190801111541.917256884@infradead.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-08-02 12:15:24 +01:00
Geert Uytterhoeven cc8b465949
spi: core: Use DEVICE_ATTR_RW() for SPI slave control sysfs attribute
Convert the SPI slave control sysfs attribute from DEVICE_ATTR() to
DEVICE_ATTR_RW(), to reduce boilerplate.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20190731124738.14519-1-geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-08-01 14:08:37 +01:00
Suzuki K Poulose 00500147cb drivers: Introduce device lookup variants by ACPI_COMPANION device
Add a generic helper to match a device by the ACPI_COMPANION device
and provide wrappers for the device lookup APIs.

Cc: Len Brown <lenb@kernel.org>
Cc: linux-acpi@vger.kernel.org
Cc: linux-spi@vger.kernel.org
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: linux-i2c@vger.kernel.org
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # I2C parts
Link: https://lore.kernel.org/r/20190723221838.12024-6-suzuki.poulose@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-30 13:07:42 +02:00
Suzuki K Poulose cfba5de9b9 drivers: Introduce device lookup variants by of_node
Introduce wrappers for {bus/driver/class}_find_device() to
locate devices by its of_node.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: devicetree@vger.kernel.org
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: linux-i2c@vger.kernel.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-spi@vger.kernel.org
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Alan Tull <atull@kernel.org>
Cc: linux-fpga@vger.kernel.org
Cc: Peter Rosin <peda@axentia.se>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Thor Thayer <thor.thayer@linux.intel.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Peter Rosin <peda@axentia.se>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # I2C part
Acked-by: Moritz Fischer <mdf@kernel.org> # For FPGA part
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20190723221838.12024-3-suzuki.poulose@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-30 13:07:41 +02:00
Linus Torvalds f632a8170a Driver Core and debugfs changes for 5.3-rc1
Here is the "big" driver core and debugfs changes for 5.3-rc1
 
 It's a lot of different patches, all across the tree due to some api
 changes and lots of debugfs cleanups.  Because of this, there is going
 to be some merge issues with your tree at the moment, I'll follow up
 with the expected resolutions to make it easier for you.
 
 Other than the debugfs cleanups, in this set of changes we have:
 	- bus iteration function cleanups (will cause build warnings
 	  with s390 and coresight drivers in your tree)
 	- scripts/get_abi.pl tool to display and parse Documentation/ABI
 	  entries in a simple way
 	- cleanups to Documenatation/ABI/ entries to make them parse
 	  easier due to typos and other minor things
 	- default_attrs use for some ktype users
 	- driver model documentation file conversions to .rst
 	- compressed firmware file loading
 	- deferred probe fixes
 
 All of these have been in linux-next for a while, with a bunch of merge
 issues that Stephen has been patient with me for.  Other than the merge
 issues, functionality is working properly in linux-next :)
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core and debugfs updates from Greg KH:
 "Here is the "big" driver core and debugfs changes for 5.3-rc1

  It's a lot of different patches, all across the tree due to some api
  changes and lots of debugfs cleanups.

  Other than the debugfs cleanups, in this set of changes we have:

   - bus iteration function cleanups

   - scripts/get_abi.pl tool to display and parse Documentation/ABI
     entries in a simple way

   - cleanups to Documenatation/ABI/ entries to make them parse easier
     due to typos and other minor things

   - default_attrs use for some ktype users

   - driver model documentation file conversions to .rst

   - compressed firmware file loading

   - deferred probe fixes

  All of these have been in linux-next for a while, with a bunch of
  merge issues that Stephen has been patient with me for"

* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
  debugfs: make error message a bit more verbose
  orangefs: fix build warning from debugfs cleanup patch
  ubifs: fix build warning after debugfs cleanup patch
  driver: core: Allow subsystems to continue deferring probe
  drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
  arch_topology: Remove error messages on out-of-memory conditions
  lib: notifier-error-inject: no need to check return value of debugfs_create functions
  swiotlb: no need to check return value of debugfs_create functions
  ceph: no need to check return value of debugfs_create functions
  sunrpc: no need to check return value of debugfs_create functions
  ubifs: no need to check return value of debugfs_create functions
  orangefs: no need to check return value of debugfs_create functions
  nfsd: no need to check return value of debugfs_create functions
  lib: 842: no need to check return value of debugfs_create functions
  debugfs: provide pr_fmt() macro
  debugfs: log errors when something goes wrong
  drivers: s390/cio: Fix compilation warning about const qualifiers
  drivers: Add generic helper to match by of_node
  driver_find_device: Unify the match function with class_find_device()
  bus_find_device: Unify the match callback with class_find_device
  ...
2019-07-12 12:24:03 -07:00
Mark Brown 26ac56506b
Merge remote-tracking branch 'spi/topic/pump-rt' into spi-next 2019-07-04 17:35:11 +01:00
Ard Biesheuvel b28944c6f6
spi/acpi: avoid spurious matches during slave enumeration
In the new SPI ACPI slave enumeration code, we use the value of
lookup.max_speed_khz as a flag to decide whether a match occurred.
However, doing so only makes sense if we initialize its value to
zero beforehand, or otherwise, random junk from the stack will
cause spurious matches.

So zero initialize the lookup struct fully, and only set the non-zero
members explicitly.

Fixes: 4c3c59544f ("spi/acpi: enumerate all SPI slaves in the namespace")
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: andy.shevchenko@gmail.com
Cc: masahisa.kojima@linaro.org
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: linux-acpi@vger.kernel.org
Cc: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-06-24 17:30:34 +01:00
Suzuki K Poulose 418e3ea157 bus_find_device: Unify the match callback with class_find_device
There is an arbitrary difference between the prototypes of
bus_find_device() and class_find_device() preventing their callers
from passing the same pair of data and match() arguments to both of
them, which is the const qualifier used in the prototype of
class_find_device().  If that qualifier is also used in the
bus_find_device() prototype, it will be possible to pass the same
match() callback function to both bus_find_device() and
class_find_device(), which will allow some optimizations to be made in
order to avoid code duplication going forward.  Also with that, constify
the "data" parameter as it is passed as a const to the match function.

For this reason, change the prototype of bus_find_device() to match
the prototype of class_find_device() and adjust its callers to use the
const qualifier in accordance with the new prototype of it.

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Andreas Noever <andreas.noever@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Corey Minyard <minyard@acm.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Kershner <david.kershner@unisys.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: David Airlie <airlied@linux.ie>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michael Jamet <michael.jamet@intel.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Sebastian Ott <sebott@linux.ibm.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Yehezkel Bernat <YehezkelShB@gmail.com>
Cc: rafael@kernel.org
Acked-by: Corey Minyard <minyard@acm.org>
Acked-by: David Kershner <david.kershner@unisys.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # for the I2C parts
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-24 05:22:31 +02:00
Tudor Ambarus f9481b0822
spi: fix ctrl->num_chipselect constraint
at91sam9g25ek showed the following error at probe:
atmel_spi f0000000.spi: Using dma0chan2 (tx) and dma0chan3 (rx)
for DMA transfers
atmel_spi: probe of f0000000.spi failed with error -22

Commit 0a919ae492 ("spi: Don't call spi_get_gpio_descs() before device name is set")
moved the calling of spi_get_gpio_descs() after ctrl->dev is set,
but didn't move the !ctrl->num_chipselect check. When there are
chip selects in the device tree, the spi-atmel driver lets the
SPI core discover them when registering the SPI master.
The ctrl->num_chipselect is thus expected to be set by
spi_get_gpio_descs().

Move the !ctlr->num_chipselect after spi_get_gpio_descs() as it was
before the aforementioned commit. While touching this block, get rid
of the explicit comparison with 0 and update the commenting style.

Fixes: 0a919ae492 ("spi: Don't call spi_get_gpio_descs() before device name is set")
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-06-20 13:08:48 +01:00
Ard Biesheuvel b5e3cf410b
spi/acpi: fix incorrect ACPI parent check
The ACPI device object parsing code for SPI slaves enumerates the
entire ACPI namespace to look for devices that refer to the master
in question via the 'resource_source' field in the 'SPISerialBus'
resource. If that field does not refer to a valid ACPI device or
if it refers to the wrong SPI master, we should disregard the
device.

Current, the valid device check is wrong, since it gets the
polarity of 'status' wrong. This could cause issues if the
'resource_source' field is bogus but parent_handle happens to
refer to the correct master (which is not entirely imaginary
since this code runs in a loop)

So test for ACPI_FAILURE() instead, to make the code more
self explanatory.

Fixes: 4c3c59544f ("spi/acpi: enumerate all SPI slaves in the namespace")
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: andy.shevchenko@gmail.com
Cc: masahisa.kojima@linaro.org
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: linux-acpi@vger.kernel.org
Cc: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-06-19 11:54:29 +01:00
Vladimir Zapolskiy f569436994
spi: don't open code list_for_each_entry_safe_reverse()
The loop declaration in function spi_res_release() can be simplified
by reusing the common list_for_each_entry_safe_reverse() helper
macro.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-06-18 19:19:14 +01:00
Andy Shevchenko ebc37af5e0
spi: No need to assign dummy value in spi_unregister_controller()
The device_for_each_child() doesn't require the returned value to be checked.
Thus, drop the dummy variable completely and have no warning anymore:

drivers/spi/spi.c: In function ‘spi_unregister_controller’:
drivers/spi/spi.c:2480:6: warning: variable ‘dummy’ set but not used [-Wunused-but-set-variable]
  int dummy;
      ^~~~~

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-06-17 13:50:52 +01:00
Ard Biesheuvel 4c3c59544f
spi/acpi: enumerate all SPI slaves in the namespace
Currently, the ACPI enumeration that takes place when registering a
SPI master only considers immediate child devices in the ACPI namespace,
rather than checking the ResourceSource field in the SpiSerialBus()
resource descriptor.

This is incorrect: SPI slaves could reside anywhere in the ACPI
namespace, and so we should enumerate the entire namespace and look for
any device that refers to the newly registered SPI master in its
resource descriptor.

So refactor the existing code and use a lookup structure so that
allocating the SPI device structure is deferred until we have identified
the device as an actual child of the controller. This approach is
loosely based on the way the I2C subsystem handles ACPI enumeration.

Note that Apple x86 hardware does not rely on SpiSerialBus() resources
in _CRS but uses nested devices below the controller's device node in
the ACPI namespace, with a special set of device properties. This means
we have to take care to only parse those properties for device nodes
that are direct children of the controller node.

Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: linux-spi@vger.kernel.org
Cc: broonie@kernel.org
Cc: andy.shevchenko@gmail.com
Cc: masahisa.kojima@linaro.org
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: linux-acpi@vger.kernel.org
Cc: Lukas Wunner <lukas@wunner.de>

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-06-13 20:04:32 +01:00
Gustavo A. R. Silva aef9752274
spi: Use struct_size() helper
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct spi_replaced_transfers {
	...
        struct spi_transfer inserted_transfers[];
};

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

So, replace the following form:

insert * sizeof(struct spi_transfer) + sizeof(struct spi_replaced_transfers)

with:

struct_size(rxfer, inserted_transfers, insert)

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-06-10 15:42:09 +01:00
Mark Brown d9424d6d48
Merge branch 'spi-5.2' into spi-5.3 2019-05-23 14:47:04 +01:00
Douglas Anderson 924b5867e7
spi: Allow SPI devices to request the pumping thread be realtime
Right now the only way to get the SPI pumping thread bumped up to
realtime priority is for the controller to request it.  However it may
be that the controller works fine with the normal priority but
communication to a particular SPI device on the bus needs realtime
priority.

Let's add a way for devices to request realtime priority when they set
themselves up.

NOTE: this will just affect the priority of transfers that end up on
the SPI core's pumping thread.  In many cases transfers happen in the
context of the caller so if you need realtime priority for all
transfers you should ensure the calling context is also realtime
priority.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-05-23 14:44:02 +01:00
Super Liu f3440d9a0d
spi: abort spi_sync if failed to prepare_transfer_hardware
There is no chance to wait spi message complete if failed to
prepare_transfer_hardware(). Therefore, finalize this message and abort
transfer with corresponding return status to release this block case.

Logs:

[17400.283005] c7   3267 PM: PM: suspend entry 2019-05-04 03:01:14.403097147 UTC
[17400.283013] c7   3267 PM: suspend entry (deep)
[17400.283016] c6   3267 PM: Syncing filesystems ... done.
[17400.584395] c1    753 spi_geni 890000.spi: spi_geni_prepare_transfer_hardware:Error enabling SE resources -13
[17400.584404] c1    753 spi_master spi1: failed to prepare transfer hardware
[17400.664611] c4   3267 PM: PM: suspend exit 2019-05-04 03:01:15.235273018 UTC

Flow:

__spi_sync@spi.c
|    if (status == 0) {
|        /* Push out the messages in the calling context if we
|         * can.
|         */
|        if (ctlr->transfer == spi_queued_transfer) {
|            SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
|		spi_sync_immediate);
|            SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
|		spi_sync_immediate);
|		__spi_pump_messages(ctlr, false);
|        }
|
|        wait_for_completion(&done);	<== stuck here!!!
|        status = message->status;
|    }
|    message->context = NULL;
|    return status;
|
-->	__spi_pump_messages@spi.c
	|    if (!was_busy && ctlr->prepare_transfer_hardware) {
	|        ret = ctlr->prepare_transfer_hardware(ctlr);
	|        if (ret) {
	|            dev_err(&ctlr->dev,
	|		"failed to prepare transfer hardware\n");
	|
	|        if (ctlr->auto_runtime_pm)
	|            pm_runtime_put(ctlr->dev.parent);
	|            mutex_unlock(&ctlr->io_mutex);
	|            return;
	|        }
	|    }
	|
	-->	spi_geni_prepare_transfer_hardware@spi-geni-qcom.c
		|    ret = pm_runtime_get_sync(mas->dev);
		|    if (ret < 0) {
		|        dev_err(mas->dev,
		|		"%s:Error enabling SE resources %d\n",
		|		__func__, ret);
		|    pm_runtime_put_noidle(mas->dev);
		|    goto exit_prepare_transfer_hardware;

Signed-off-by: Super Liu <supercjliu@google.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-05-23 14:36:13 +01:00
Martin Sperl 5d7e2b5ed5
spi: core: allow reporting the effectivly used speed_hz for a transfer
Provide a means for the spi bus driver to report the effectively used
spi clock frequency used for each spi_transfer.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-05-13 13:11:36 +01:00
Mark Brown 0ed56252c9
spi: Fix Raspberry Pi breakage
This reverts commit c9ba7a16d0 (Release spi_res after finalizing
message) which causes races during cleanup.

Reported-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-05-09 11:27:17 +09:00
Martin Sperl d5864e5bed
spi: core: allow defining time that cs is deasserted as a multiple of SCK
Support setting a delay between cs assert and deassert as
a multiple of spi clock length.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-05-08 18:30:01 +09:00
Martin Sperl 0ff2de8bb1
spi: core: allow defining time that cs is deasserted
For some SPI devices that support speed_hz > 1MHz the default 10 us delay
when cs_change = 1 is typically way to long and may result in poor spi bus
utilization.

This patch makes it possible to control the delay at micro or nano second
resolution on a per spi_transfer basis. It even allows an "as fast as
possible" mode with:
    xfer.cs_change_delay_unit = SPI_DELAY_UNIT_NSECS;
    xfer.cs_change_delay = 0;

The delay code is shared between delay_usecs and cs_change_delay for
consistency and reuse, so in the future this change_delay_unit could also
apply to delay_usec as well.

Note that on slower SOCs/CPU actually reaching ns deasserts on cs is not
realistic as the gpio overhead alone (without any delays added ) may
already leave cs deasserted for more than 1us - at least on a raspberry pi.
But at the very least this way we can keep it as short as possible.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-05-08 18:28:51 +09:00
Serge Semin d61ad23cb3
spi: Clear SPI_CS_HIGH flag from bad_bits for GPIO chip-select
When GPIO chip-select is used nothing prevents any available SPI
controllers to work with both CS-high and traditional CS-low modes.
In fact the SPI bus core code already does it, so we don't need to
introduce any modification there. But spi_setup() still fails to
switch the interface settings if CS-high flag is set for the case
of GPIO-driven slave chip-select when the SPI controller doesn't
support the hardwired CS-inversion. Lets fix it by clearing the
SPI_CS_HIGH flag out from bad_bits (unsupported by controller) when
client chip is selected by GPIO.

This feature is useful for slave devices, which in accordance with
communication protocol can work with both active-high and active-low
chip-selects. I am aware of one such device. It is MMC-SPI interface,
when at init sequence the driver needs to perform a read operation with
low and high chip-select sequentially (requirement of 74 clock cycles
with both chipselect, see the mmc_spi driver for details).

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-05-02 10:38:00 +09:00
Noralf Trønnes c9ba7a16d0
spi: Release spi_res after finalizing message
spi_split_transfers_maxsize() can be used to split a transfer. This
function uses spi_res to lifetime manage the added transfer structures.
So in order to finalize the current message while it contains the split
transfers, spi_res_release() must be called after finalizing.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-05-02 10:37:51 +09:00
Noralf Trønnes 4d1841d645
spi: Remove warning in spi_split_transfers_maxsize()
Don't warn about splitting transfers, the info is available in the
statistics if needed.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-05-02 10:37:50 +09:00
Jarkko Nikula 76d2f7ee68
spi: Remove one needless transfer speed fall back case
Falling back to maximum speed of the controller in case of SPI slave
maximum speed is not set is needless. It already defaults to maximum
speed of the controller since commit 052eb2d490 ("spi: core: Set
max_speed_hz of spi_device default to max_speed_hz of controller").

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-05-02 10:37:49 +09:00
Sowjanya Komatineni f1ca9992ce
spi: add a method for configuring CS timing
This patch creates set_cs_timing SPI master optional method for
SPI masters to implement configuring CS timing if applicable.

This patch also creates spi_cs_timing accessory for SPI clients to
use for requesting SPI master controllers to configure device requested
CS setup time, hold time and inactive delay.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-08 14:14:10 +07:00
Sergei Shtylyov b93318a22f
spi: kill useless initializer in spi_register_controller()
The 'status' local variable is initialized but this value is never used,
thus kill that initializer.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-08 14:05:40 +07:00
Andrey Smirnov 0a919ae492
spi: Don't call spi_get_gpio_descs() before device name is set
Move code calling spi_get_gpio_descs() to happen after ctlr->dev's
name is set in order to have proper GPIO consumer names.

Before:

cat /sys/kernel/debug/gpio
gpiochip0: GPIOs 0-31, parent: platform/40049000.gpio, vf610-gpio:
 gpio-6   (                    |regulator-usb0-vbus ) out lo

gpiochip1: GPIOs 32-63, parent: platform/4004a000.gpio, vf610-gpio:
 gpio-36  (                    |scl                 ) in  hi
 gpio-37  (                    |sda                 ) in  hi
 gpio-40  (                    |(null) CS1          ) out lo
 gpio-41  (                    |(null) CS0          ) out lo ACTIVE LOW
 gpio-42  (                    |miso                ) in  hi
 gpio-43  (                    |mosi                ) in  lo
 gpio-44  (                    |sck                 ) out lo

After:

cat /sys/kernel/debug/gpio
gpiochip0: GPIOs 0-31, parent: platform/40049000.gpio, vf610-gpio:
 gpio-6   (                    |regulator-usb0-vbus ) out lo

gpiochip1: GPIOs 32-63, parent: platform/4004a000.gpio, vf610-gpio:
 gpio-36  (                    |scl                 ) in  hi
 gpio-37  (                    |sda                 ) in  hi
 gpio-40  (                    |spi0 CS1            ) out lo
 gpio-41  (                    |spi0 CS0            ) out lo ACTIVE LOW
 gpio-42  (                    |miso                ) in  hi
 gpio-43  (                    |mosi                ) in  lo
 gpio-44  (                    |sck                 ) out lo

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Chris Healy <cphealy@gmail.com>
Cc: linux-spi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-05 10:23:28 +07:00
Mark Brown e1a7d16730
Merge branch 'spi-5.1' into spi-5.2 2019-04-05 10:19:10 +07:00
Geert Uytterhoeven 1723fdec5f
spi: Add missing error handling for CS GPIOs
While devm_gpiod_get_index_optional() returns NULL if the GPIO is not
present (i.e. -ENOENT), it may still return other error codes, like
-EPROBE_DEFER.  Currently these are not handled, leading to
unrecoverable failures later in case of probe deferral:

    gpiod_set_consumer_name: invalid GPIO (errorpointer)
    gpiod_direction_output: invalid GPIO (errorpointer)
    gpiod_set_value_cansleep: invalid GPIO (errorpointer)
    gpiod_set_value_cansleep: invalid GPIO (errorpointer)
    gpiod_set_value_cansleep: invalid GPIO (errorpointer)

Detect and propagate errors to fix this.

Fixes: f3186dd876 ("spi: Optionally use GPIO descriptors for CS GPIOs")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-04 12:58:18 +07:00
Arnd Bergmann ca1438dcb3
spi: export tracepoint symbols to modules
The newly added tracepoints in the spi-mxs driver cause a link
error when the driver is a loadable module:

ERROR: "__tracepoint_spi_transfer_stop" [drivers/spi/spi-mxs.ko] undefined!
ERROR: "__tracepoint_spi_transfer_start" [drivers/spi/spi-mxs.ko] undefined!

I'm not quite sure where to put the export statements, but
directly after the inclusion of the header seems as good as
any other place.

Fixes: f3fdea3af4 ("spi: mxs: add tracing to custom .transfer_one_message callback")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-21 15:05:07 +00:00
Chris Lesiak 5442dcaa0d
spi: Fix zero length xfer bug
This fixes a bug for messages containing both zero length and
unidirectional xfers.

The function spi_map_msg will allocate dummy tx and/or rx buffers
for use with unidirectional transfers when the hardware can only do
a bidirectional transfer.  That dummy buffer will be used in place
of a NULL buffer even when the xfer length is 0.

Then in the function __spi_map_msg, if he hardware can dma,
the zero length xfer will have spi_map_buf called on the dummy
buffer.

Eventually, __sg_alloc_table is called and returns -EINVAL
because nents == 0.

This fix prevents the error by not using the dummy buffer when
the xfer length is zero.

Signed-off-by: Chris Lesiak <chris.lesiak@licor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-11 16:40:00 +00:00
Felix Fietkau 28f7604f48
spi: use gpio[d]_set_value_cansleep for setting chipselect GPIO
Sleeping is safe inside spi_transfer_one_message, and some
GPIO chips are running on slow busses (such as I2C GPIO
expanders) and need to sleep for setting values.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-02-12 16:41:11 +00:00
Jonas Bonn b7bb367afa
spi: support inter-word delay requirement for devices
Some devices are slow and cannot keep up with the SPI bus and therefore
require a short delay between words of the SPI transfer.

The example of this that I'm looking at is a SAMA5D2 with a minimum SPI
clock of 400kHz talking to an AVR-based SPI slave.  The AVR cannot put
bytes on the bus fast enough to keep up with the SoC's SPI controller
even at the lowest bus speed.

This patch introduces the ability to specify a required inter-word
delay for SPI devices.  It is up to the controller driver to configure
itself accordingly in order to introduce the requested delay.

Note that, for spi_transfer, there is already a field word_delay that
provides similar functionality.  This field, however, is specified in
clock cycles (and worse, SPI controller cycles, not SCK cycles); that
makes this value dependent on the master clock instead of the device
clock for which the delay is intended to provide some relief.  This
patch leaves this old word_delay in place and provides a time-based
word_delay_us alongside it; the new field fits in the struct padding
so struct size is constant.  There is only one in-kernel user of the
word_delay field and presumably that driver could be reworked to use
the time-based value instead.

The time-based delay is limited to 8 bits as these delays are intended
to be short.  The SAMA5D2 that I've tested this on limits delays to a
maximum of ~100us, which is already many word-transfer periods even at
the minimum transfer speed supported by the controller.

Signed-off-by: Jonas Bonn <jonas@norrbonn.se>
CC: Mark Brown <broonie@kernel.org>
CC: Rob Herring <robh+dt@kernel.org>
CC: Mark Rutland <mark.rutland@arm.com>
CC: linux-spi@vger.kernel.org
CC: devicetree@vger.kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-01-30 23:02:10 +00:00
Linus Walleij 2df201e006
spi: Support high CS when using descriptors
All controllers using GPIO descriptors can by definition
support high CS connections, so just enforce this when
registering an SPI controller.

This fixes a regression where controllers were missing
SPI_CS_HIGH, the drivers would fail like this:

spi spi0.0: setup: unsupported mode bits 4
cdns-spi fd0b0000.spi: can't setup spi0.0, status -22

This is because as using descriptors moves the CS inversion
logic over to gpiolib, all such controllers are registered
with CS active high.

Cc: Jan Kotas <jank@cadence.com>
Reported-by: Jan Kotas <jank@cadence.com>
Tested-by: Jan Kotas <jank@cadence.com>
Fixes: f3186dd876 ("spi: Optionally use GPIO descriptors for CS GPIOs")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-01-24 19:01:05 +00:00
Mark Brown f0125f1a55
spi: Go back to immediate teardown
Commit 412e603732 ("spi: core: avoid waking pump thread from spi_sync
instead run teardown delayed") introduced regressions on some boards,
apparently connected to spi_mem not triggering shutdown properly any
more.  Since we've thus far been unable to figure out exactly where the
breakage is revert the optimisation for now.

Reported-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: kernel@martin.sperl.org
2019-01-23 17:29:53 +00:00
Martin Sperl 412e603732
spi: core: avoid waking pump thread from spi_sync instead run teardown delayed
When spi_sync is running alone with no other spi devices connected
to the bus the worker thread is woken during spi_finalize_current_message
to run the teardown code every time.

This is totally unnecessary in the case that there is no message queued.

On a multi-core system this results in one wakeup of the thread for each
spi_message processed via spi_sync where in most cases the teardown does
not happen as the hw is already in use.

This patch now delays the teardown by 1 second by using a separate
kthread_delayed_work for the teardown.

This avoids waking the kthread too often.

For spi_sync transfers in a tight loop (say 40k messages/s) this
avoids the penalty of waking the worker thread 40k times/s.
On a rasperry pi 3 with 4 cores the results in 32% of a single core
only to find out that there is nothing in the queue and it can go back
to sleep.

With this patch applied the spi-worker is woken exactly once: after
the load finishes and the spi bus is idle for 1 second.

I believe I have also seen situations where during a spi_sync loop
the worker thread (triggered by the last message finished) is slightly
faster and _wins_ the race to process the message, so we are actually
running the kthread and letting it do some work...

This is also no longer observed with this patch applied as.

Tested with a new CAN controller driver for the mcp2517fd which
uses spi_sync for interrupt handling and spi_async for scheduling
of can frames for transmission (in a different thread)

Some statistics when receiving 100000 CAN frames with the mcp25xxfd driver
on a Raspberry pi 3:

without the patch:
------------------
root@raspcm3:~# for x in $(pgrep spi0) $(pgrep irq/94-mcp25xxf) ; do awk '{printf "%-20s %6i\n", $2,$15}' /proc/$x/stat; done
(spi0)                    5
(irq/94-mcp25xxf)         0
root@raspcm3:~# vmstat 1
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 1  0      0 821960  13592  50848    0    0    80     2 1986  105  1  2 97  0  0
 0  0      0 821968  13592  50876    0    0     0     0 8046   30  0  0 100  0  0
 0  0      0 821936  13592  50876    0    0     0     0 8032   24  0  0 100  0  0
 0  0      0 821936  13592  50876    0    0     0     0 8035   30  0  0 100  0  0
 0  0      0 821936  13592  50876    0    0     0     0 8033   22  0  0 100  0  0
 2  0      0 821936  13592  50876    0    0     0     0 11598 7129  0  3 97  0  0
 1  0      0 821872  13592  50876    0    0     0     0 37741 59003  0 31 69  0  0
 2  0      0 821840  13592  50876    0    0     0     0 37762 59078  0 29 71  0  0
 2  0      0 821776  13592  50876    0    0     0     0 37593 58792  0 28 72  0  0
 1  0      0 821744  13592  50876    0    0     0     0 37642 58881  0 30 70  0  0
 2  0      0 821680  13592  50876    0    0     0     0 37490 58602  0 27 73  0  0
 1  0      0 821648  13592  50876    0    0     0     0 37412 58418  0 29 71  0  0
 1  0      0 821584  13592  50876    0    0     0     0 37337 58288  0 27 73  0  0
 1  0      0 821552  13592  50876    0    0     0     0 37584 58774  0 27 73  0  0
 0  0      0 821520  13592  50876    0    0     0     0 18363 20566  0  9 91  0  0
 0  0      0 821520  13592  50876    0    0     0     0 8037   32  0  0 100  0  0
 0  0      0 821520  13592  50876    0    0     0     0 8031   23  0  0 100  0  0
 0  0      0 821520  13592  50876    0    0     0     0 8034   26  0  0 100  0  0
 0  0      0 821520  13592  50876    0    0     0     0 8033   24  0  0 100  0  0
^C
root@raspcm3:~# for x in $(pgrep spi0) $(pgrep irq/94-mcp25xxf) ; do awk '{printf "%-20s %6i\n", $2,$15}' /proc/$x/stat; done
(spi0)                  228
(irq/94-mcp25xxf)       794
root@raspcm3:~# cat /proc/interrupts
           CPU0       CPU1       CPU2       CPU3
 17:         34          0          0          0  ARMCTRL-level   1 Edge      3f00b880.mailbox
 27:          1          0          0          0  ARMCTRL-level  35 Edge      timer
 33:    1416870          0          0          0  ARMCTRL-level  41 Edge      3f980000.usb, dwc2_hsotg:usb1
 34:          1          0          0          0  ARMCTRL-level  42 Edge      vc4
 35:          0          0          0          0  ARMCTRL-level  43 Edge      3f004000.txp
 40:       1753          0          0          0  ARMCTRL-level  48 Edge      DMA IRQ
 42:         11          0          0          0  ARMCTRL-level  50 Edge      DMA IRQ
 44:         11          0          0          0  ARMCTRL-level  52 Edge      DMA IRQ
 45:          0          0          0          0  ARMCTRL-level  53 Edge      DMA IRQ
 66:          0          0          0          0  ARMCTRL-level  74 Edge      vc4 crtc
 69:          0          0          0          0  ARMCTRL-level  77 Edge      vc4 crtc
 70:          0          0          0          0  ARMCTRL-level  78 Edge      vc4 crtc
 77:         20          0          0          0  ARMCTRL-level  85 Edge      3f205000.i2c, 3f804000.i2c, 3f805000.i2c
 78:       6346          0          0          0  ARMCTRL-level  86 Edge      3f204000.spi
 80:        205          0          0          0  ARMCTRL-level  88 Edge      mmc0
 81:        493          0          0          0  ARMCTRL-level  89 Edge      uart-pl011
 89:          0          0          0          0  bcm2836-timer   0 Edge      arch_timer
 90:       4291       3821       2180       1649  bcm2836-timer   1 Edge      arch_timer
 94:      14289          0          0          0  pinctrl-bcm2835  16 Level     mcp25xxfd
IPI0:          0          0          0          0  CPU wakeup interrupts
IPI1:          0          0          0          0  Timer broadcast interrupts
IPI2:       3645     242371       7919       1328  Rescheduling interrupts
IPI3:        112        543        273        194  Function call interrupts
IPI4:          0          0          0          0  CPU stop interrupts
IPI5:          1          0          0          0  IRQ work interrupts
IPI6:          0          0          0          0  completion interrupts
Err:          0

top shows 93% for the mcp25xxfd interrupt handler, 31% for spi0.

with the patch:
---------------
root@raspcm3:~# for x in $(pgrep spi0) $(pgrep irq/94-mcp25xxf) ; do awk '{printf "%-20s %6i\n", $2,$15}' /proc/$x/stat; done
(spi0)                    0
(irq/94-mcp25xxf)         0
root@raspcm3:~# vmstat 1
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
 0  0      0 804768  13584  62628    0    0     0     0 8038   24  0  0 100  0  0
 0  0      0 804768  13584  62628    0    0     0     0 8042   25  0  0 100  0  0
 1  0      0 804704  13584  62628    0    0     0     0 9603 2967  0 20 80  0  0
 1  0      0 804672  13584  62628    0    0     0     0 9828 3380  0 24 76  0  0
 1  0      0 804608  13584  62628    0    0     0     0 9823 3375  0 23 77  0  0
 1  0      0 804608  13584  62628    0    0     0    12 9829 3394  0 23 77  0  0
 1  0      0 804544  13584  62628    0    0     0     0 9816 3362  0 22 78  0  0
 1  0      0 804512  13584  62628    0    0     0     0 9817 3367  0 23 77  0  0
 1  0      0 804448  13584  62628    0    0     0     0 9822 3370  0 22 78  0  0
 1  0      0 804416  13584  62628    0    0     0     0 9815 3367  0 23 77  0  0
 0  0      0 804352  13584  62628    0    0     0    84 9222 2250  0 14 86  0  0
 0  0      0 804352  13592  62620    0    0     0    24 8131  209  0  0 93  7  0
 0  0      0 804320  13592  62628    0    0     0     0 8041   27  0  0 100  0  0
 0  0      0 804352  13592  62628    0    0     0     0 8040   26  0  0 100  0  0
root@raspcm3:~# for x in $(pgrep spi0) $(pgrep irq/94-mcp25xxf) ; do awk '{printf "%-20s %6i\n", $2,$15}' /proc/$x/stat; done
(spi0)                    0
(irq/94-mcp25xxf)       767
root@raspcm3:~# cat /proc/interrupts
           CPU0       CPU1       CPU2       CPU3
 17:         29          0          0          0  ARMCTRL-level   1 Edge      3f00b880.mailbox
 27:          1          0          0          0  ARMCTRL-level  35 Edge      timer
 33:    1024412          0          0          0  ARMCTRL-level  41 Edge      3f980000.usb, dwc2_hsotg:usb1
 34:          1          0          0          0  ARMCTRL-level  42 Edge      vc4
 35:          0          0          0          0  ARMCTRL-level  43 Edge      3f004000.txp
 40:       1773          0          0          0  ARMCTRL-level  48 Edge      DMA IRQ
 42:         11          0          0          0  ARMCTRL-level  50 Edge      DMA IRQ
 44:         11          0          0          0  ARMCTRL-level  52 Edge      DMA IRQ
 45:          0          0          0          0  ARMCTRL-level  53 Edge      DMA IRQ
 66:          0          0          0          0  ARMCTRL-level  74 Edge      vc4 crtc
 69:          0          0          0          0  ARMCTRL-level  77 Edge      vc4 crtc
 70:          0          0          0          0  ARMCTRL-level  78 Edge      vc4 crtc
 77:         20          0          0          0  ARMCTRL-level  85 Edge      3f205000.i2c, 3f804000.i2c, 3f805000.i2c
 78:       6417          0          0          0  ARMCTRL-level  86 Edge      3f204000.spi
 80:        237          0          0          0  ARMCTRL-level  88 Edge      mmc0
 81:        489          0          0          0  ARMCTRL-level  89 Edge      uart-pl011
 89:          0          0          0          0  bcm2836-timer   0 Edge      arch_timer
 90:       4048       3704       2383       1892  bcm2836-timer   1 Edge      arch_timer
 94:      14287          0          0          0  pinctrl-bcm2835  16 Level     mcp25xxfd
IPI0:          0          0          0          0  CPU wakeup interrupts
IPI1:          0          0          0          0  Timer broadcast interrupts
IPI2:       2361       2948       7890       1616  Rescheduling interrupts
IPI3:         65        617        301        166  Function call interrupts
IPI4:          0          0          0          0  CPU stop interrupts
IPI5:          1          0          0          0  IRQ work interrupts
IPI6:          0          0          0          0  completion interrupts
Err:          0
top shows 91% for the mcp25xxfd interrupt handler, 0% for spi0

So we see that spi0 is no longer getting scheduled wasting CPU cycles
There are a lot less context switches and corresponding Rescheduling interrupts
All of these show that this improves efficiency of the system and reduces
CPU utilization.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-01-09 19:16:18 +00:00
Linus Walleij f3186dd876
spi: Optionally use GPIO descriptors for CS GPIOs
This augments the SPI core to optionally use GPIO descriptors
for chip select on a per-master-driver opt-in basis.

Drivers using this will rely on the SPI core to look up
GPIO descriptors associated with the device, such as
when using device tree or board files with GPIO descriptor
tables.

When getting descriptors from the device tree, this will in
turn activate the code in gpiolib that was
added in commit 6953c57ab1
("gpio: of: Handle SPI chipselect legacy bindings")
which means that these descriptors are aware of the active
low semantics that is the default for SPI CS GPIO lines
and we can assume that all of these are "active high" and
thus assign SPI_CS_HIGH to all CS lines on the DT path.

The previously used gpio_set_value() would call down into
gpiod_set_raw_value() and ignore the polarity inversion
semantics.

It seems like many drivers go to great lengths to set up the
CS GPIO line as non-asserted, respecting SPI_CS_HIGH. We pull
this out of the SPI drivers and into the core, and by simply
requesting the line as GPIOD_OUT_LOW when retrieveing it from
the device and relying on the gpiolib to handle any inversion
semantics. This way a lot of code can be simplified and
removed in each converted driver.

The end goal after dealing with each driver in turn, is to
delete the non-descriptor path (of_spi_register_master() for
example) and let the core deal with only descriptors.

The different SPI drivers have complex interactions with the
core so we cannot simply change them all over, we need to use
a stepwise, bisectable approach so that each driver can be
converted and fixed in isolation.

This patch has the intended side effect of adding support for
ACPI GPIOs as it starts relying on gpiod_get_*() to get
the GPIO handle associated with the device.

Cc: Linuxarm <linuxarm@huawei.com>
Acked-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Tested-by: Fangjian (Turing) <f.fangjian@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-01-09 12:39:25 +00:00
Rob Herring 194276b073
spi: Use of_node_name_eq for node name comparisons
Convert string compares of DT node names to use of_node_name_eq helper
instead. This removes direct access to the node name pointer.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-12-06 20:15:43 +00:00
Yogesh Narayan Gaur 6b03061f88
spi: add support for octal mode I/O data transfer
Add flags for Octal mode I/O data transfer
Required for the SPI controller which can do the data transfer (TX/RX)
on 8 data lines e.g. NXP FlexSPI controller.
 SPI_TX_OCTAL: transmit with 8 wires
 SPI_RX_OCTAL: receive with 8 wires

Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur@nxp.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-12-03 17:14:53 +00:00
Mark Brown 787f4889a6
spi: Fix formatting of header block
Make everything look intentional by having a C++ comment for the whole
block, not just the SPDX line.

Signed-off-by: Mark Brown <broonie@kernel.org>
2018-11-29 16:24:37 +00:00
Mark Brown d57e79601b
spi: Fix core transfer waits after slave support
The refactoring done as part of adding the core support for handling
waiting for slave transfer dropped a conditional which meant that we
started waiting for completion of all transfers, not just those that the
controller asked for.  This caused hangs and massive delays on platforms
that don't need the core delay.  Re-add the delay to fix this.

Fixes: 810923f3bf (spi: Deal with slaves that return from transfer_one() unfinished)
Reported-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-11-15 16:08:32 -08:00
Lubomir Rintel 810923f3bf
spi: Deal with slaves that return from transfer_one() unfinished
Some drivers, such as spi-pxa2xx return from the transfer_one callback
immediately, idicating that the transfer will be finished asynchronously.

Normally, spi_transfer_one_message() synchronously waits for the
transfer to finish with wait_for_completion_timeout(). For slaves, we
don't want the transaction to time out as it can complete in a long time
in future. Use wait_for_completion_interruptible() instead.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-11-13 10:01:23 -08:00
Mark Brown 7b9734dbc5
Merge remote-tracking branch 'spi/topic/of' into spi-next 2018-10-21 17:00:17 +01:00
Mark Brown 4b51c747e4
Merge branch 'spi-4.20' into spi-next 2018-10-21 17:00:14 +01:00
Phil Elwell 25972d0c33
spi: Make GPIO CSs honour the SPI_NO_CS flag
The SPI configuration state includes an SPI_NO_CS flag that disables
all CS line manipulation, for applications that want to manage their
own chip selects. However, this flag is ignored by the GPIO CS code
in the SPI framework.

Correct this omission with a trivial patch.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-10-12 18:47:28 +02:00
Trent Piepho 5039563e7c
spi: Add driver_override SPI device attribute
This attribute works the same was as the identically named attribute
for PCI, AMBA, and platform devices.  For reference, see:

commit 3cf3857134 ("ARM: 8256/1: driver coamba: add device binding
path 'driver_override'")
commit 3d713e0e38 ("driver core: platform: add device binding path
'driver_override'")
commit 782a985d7a ("PCI: Introduce new device binding path using
pci_dev.driver_override")

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

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

It can be used to bind a generic driver, like spidev, to a device.

Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Reviewed-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Tested-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-10-10 13:40:45 +01:00
Marco Felsch 5f143af750
spi: make OF helper available for others
The of_find_spi_device_by_node() helper function is useful for other
modules too. Export the funciton as GPL like all other spi helper
functions and make it available if CONFIG_OF is enabled, because it isn't
related to the CONFIG_OF_DYNAMIC context. Finally add a stub if
CONFIG_OF isn't enabled, so others must not care about it.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-27 23:36:03 +01:00
Marco Felsch b445bfcb90
spi: switch to SPDX license identifier
Use the appropriate SPDX license identifier and drop the previous
license text.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-27 23:30:48 +01:00
David Lechner 71388b2156
spi: always use software fallback for SPI_CS_WORD when using cs_gio
This modifies the condition for using the software fallback
implementation for SPI_CS_WORD when the SPI controller is using a GPIO
for the CS line. When using a GPIO for CS, the hardware implementation
won't work, so we just enable the software fallback globally in this
case.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-18 10:40:32 -07:00
David Lechner cbaa62e009
spi: add software implementation for SPI_CS_WORD
This adds a default software implementation for the SPI_CS_WORD flag for
controllers that don't have such a feature.

The SPI_CS_WORD flag indicates that the CS line should be toggled
between each word sent, not just between each transfer. The
implementation works by using existing functions to split transfers into
one-word-sized transfers and sets the cs_change bit for each of the
new transfers.

Signed-off-by: David Lechner <david@lechnology.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-17 14:14:18 -07:00
Geert Uytterhoeven 04b2d03a75
spi: Fix double IDR allocation with DT aliases
If the SPI bus number is provided by a DT alias, idr_alloc() is called
twice, leading to:

    WARNING: CPU: 1 PID: 1 at drivers/spi/spi.c:2179 spi_register_controller+0x11c/0x5d8
    couldn't get idr

Fix this by moving the handling of fixed SPI bus numbers up, before the
DT handling code fills in ctlr->bus_num.

Fixes: 1a4327fbf4 ("spi: fix IDR collision on systems with both fixed and dynamic SPI bus numbers")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-08-28 20:46:27 +01:00
Kirill Kapranov 1a4327fbf4
spi: fix IDR collision on systems with both fixed and dynamic SPI bus numbers
On systems where some controllers get a dynamic ID assigned and some have
a fixed number (e.g. from ACPI tables), the current implementation might
run into an IDR collision: in case of a fixed bus number is gotten by a
driver (but not marked busy in IDR tree) and a driver with dynamic bus
number gets the same ID and predictably fails.

Fix this by means of checking-in fixed IDsin IDR as far as dynamic ones
at the moment of the controller registration.

Fixes: 9b61e30221 (spi: Pick spi bus number from Linux idr or spi alias)
Signed-off-by: Kirill Kapranov <kirill.kapranov@compulab.co.il>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2018-08-15 15:44:07 +01:00