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2021-05-11spi: Use SPI_MODE_X_MASKAndy Shevchenko1-2/+2
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>
2021-05-11spi: Convert to use predefined time multipliersAndy Shevchenko1-13/+28
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>
2021-05-10spi: take the SPI IO-mutex in the spi_set_cs_timing methodLeilk Liu1-2/+7
this patch takes the io_mutex to prevent an unprotected HW register modification in the set_cs_timing callback. Fixes: 4cea6b8cc34e ("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>
2021-04-28spi: Fix spi device unregister flowSaravana Kannan1-6/+12
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>
2021-04-23spi: Rename enable1 to activate in spi_set_cs()Andy Shevchenko1-5/+4
The enable1 is confusing name. Change it to clearly show what is the intention behind it. No functional changes. Fixes: 25093bdeb6bc ("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>
2021-04-21spi: Make error handling of gpiod_count() call cleanerAndy Shevchenko1-6/+7
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>
2021-04-21spi: Avoid undefined behaviour when counting unused native CSsAndy Shevchenko1-1/+1
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: 7d93aecdb58d ("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>
2021-04-21spi: Allow to have all native CSs in use along with GPIOsAndy Shevchenko1-2/+3
The commit 7d93aecdb58d ("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: 7d93aecdb58d ("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>
2021-04-21spi: Make of_register_spi_device also set the fwnodeCharles Keepax1-0/+1
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 4731210c09f5 ("gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default") commit ced2af419528 ("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>
2021-04-19spi: Handle SPI device setup callback failure.Joe Burmeister1-1/+8
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>
2021-04-19spi: sync up initial chipselect stateDavid Bauer1-8/+8
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 d40f0b6f2e21 ("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>
2021-04-15Merge branch 'for-5.12' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.13Mark Brown1-7/+2
2021-04-09spi: simplify devm_spi_register_controllerTian Tao1-14/+5
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>
2021-04-08spi: Fix use-after-free with devm_spi_alloc_*William A. Kennington III1-7/+2
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: 5e844cc37a5c ("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>
2021-03-17spi: Fix spelling mistake "softwade" -> "software"Colin Ian King1-1/+1
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>
2021-03-16Merge series "spi: Adding support for software nodes" from Heikki Krogerus <heikki.krogerus@linux.intel.com>:Mark Brown1-15/+6
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: a38fd8748464831584a19438cbb3082b5a2dab15
2021-03-16spi: Remove support for dangling device propertiesHeikki Krogerus1-21/+3
>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>
2021-03-16spi: Add support for software nodesHeikki Krogerus1-2/+11
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>
2021-03-12spi: core: remove 'delay_usecs' field from spi_transferAlexandru Ardelean1-1/+0
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>
2021-02-22Merge tag 'spi-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spiLinus Torvalds1-11/+48
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 ...
2021-02-12Merge remote-tracking branch 'spi/for-5.12' into spi-nextMark Brown1-10/+47
2021-02-12spi: Skip zero-length transfers in spi_transfer_one_message()Nicolas Saenz Julienne1-1/+1
With the introduction of 26751de25d25 ("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: 26751de25d25 ("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>
2021-02-08spi: support CS timing for HW & SW modeleilk.liu1-3/+6
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>
2021-02-08spi: add power control when set_cs_timingleilk.liu1-3/+22
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>
2021-01-27ACPI: Test for ACPI_SUCCESS rather than !ACPI_FAILUREBjorn Helgaas1-1/+1
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>
2021-01-13Merge v5.11-rc3Mark Brown1-3/+8
2021-01-04spi: fix the divide by 0 error when calculating xfer waiting timeXu Yilun1-1/+5
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>
2020-12-30spi: Fix the clamping of spi->max_speed_hzTudor Ambarus1-2/+3
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: 9326e4f1e5dd ("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>
2020-12-28spi: Add SPI_NO_TX/RX supportDragos Bogdan1-5/+20
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>
2020-12-17Merge remote-tracking branch 'spi/for-5.10' into spi-5.11Mark Brown1-1/+2
2020-12-11Merge remote-tracking branch 'spi/for-5.11' into spi-nextMark Brown1-29/+38
2020-12-11spi: Limit the spi device max speed to controller's max speedTudor Ambarus1-1/+2
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>
2020-11-27Merge branch 'for-5.10' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.11Mark Brown1-18/+68
2020-11-24spi: Fix potential NULL pointer dereference in spi_shutdown()Marek Szyprowski1-3/+5
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: 9db34ee64ce4 (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>
2020-11-20spi: Take the SPI IO-mutex in the spi_setup() methodSerge Semin1-0/+5
I've discovered that due to the recent commit 49d7d695ca4b ("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: 49d7d695ca4b ("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>
2020-11-20spi: Warn when a driver's remove callback returns an errorUwe Kleine-König1-3/+10
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>
2020-11-20spi: Use bus_type functions for probe, remove and shutdownUwe Kleine-König1-17/+16
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>
2020-11-20spi: fix resource leak for drivers without .remove callbackUwe Kleine-König1-9/+10
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: 33cf00e57082 ("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>
2020-11-12spi: Introduce device-managed SPI controller allocationLukas Wunner1-1/+57
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>
2020-11-11spi: fix client driver breakages when using GPIO descriptorsSven Van Asbroeck1-17/+6
Commit f3186dd87669 ("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 138c9c32f090 ("spi: spidev: Fix CS polarity if GPIO descriptors are used") still necessary / correct ? Fixes: f3186dd87669 ("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>
2020-10-28spi: fix a typo inside a kernel-doc markupMauro Carvalho Chehab1-3/+3
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>
2020-09-11Merge tag 'spi-fix-v5.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spiLinus Torvalds1-2/+7
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
2020-09-09spi: Fix memory leak on splited transfersGustav Wiklander1-2/+7
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 c9ba7a16d0f1 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>
2020-08-18Merge tag 'spi-fix-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spiLinus Torvalds1-1/+20
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
2020-08-06Merge tag 'sched-fifo-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-3/+1
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*() ...
2020-08-03spi: Prevent adding devices below an unregistering controllerLukas Wunner1-1/+20
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: ce79d54ae447 ("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>
2020-07-17spi: Only defer to thread for cleanup when neededMark Brown1-7/+19
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>
2020-07-09spi: use kthread_create_worker() helperMarek Szyprowski1-14/+12
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>
2020-07-01spi: Avoid setting the chip select if we don't need toDouglas Anderson1-0/+11
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>
2020-06-23spi: introduce fallback to pioRobin Gong1-0/+12
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>