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path: root/drivers/spi
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2019-05-02spi: Remove warning in spi_split_transfers_maxsize()Noralf Trønnes1-5/+0
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>
2019-05-02spi: Remove one needless transfer speed fall back caseJarkko Nikula1-2/+0
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 052eb2d49006 ("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>
2019-05-02spi: pxa2xx: use a module softdep for dw_dmacFlavio Suligoi1-0/+2
With dw_dmac, sometimes the request of a DMA channel fails because the DMA driver is not ready, so an explicit dependency request is necessary. Signed-off-by: Flavio Suligoi <f.suligoi@asem.it> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-29spi: zynqmp: Fix build breakOlof Johansson1-0/+1
Missing include: drivers/spi/spi-zynqmp-gqspi.c:1025:13: error: implicit declaration of function 'zynqmp_pm_get_eemi_ops'; did you mean 'zynqmp_process_dma_irq'? [-Werror=implicit-function-declaration] Fixes: 3d0313786470a ('drivers: Defer probe if firmware is not ready') Cc: Rajan Vaja <rajan.vaja@xilinx.com> Cc: Jolly Shah <jollys@xilinx.com> Cc: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Olof Johansson <olof@lixom.net>
2019-04-08spi: add a method for configuring CS timingSowjanya Komatineni1-0/+15
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>
2019-04-08spi: tegra114: add support for interrupt maskSowjanya Komatineni1-5/+48
This patch creates tegra_spi_soc_data structure to maintain and implement SPI HW feature differences between different Tegra chips and also creates a separate compatible string for T124/T210. Tegra210 and later has a separate interrupt mask register SPI_INTR_MASK for enabling or disabling interrupts while Tegra124 and prior uses interrupt enable bits in SPI_DMA_CTL register. This patch creates flag has_intr_mask_reg in tegra_spi_soc_data to identify this and implements accordingly. Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-08spi: tegra114: add 3 wire transfer mode supportSowjanya Komatineni1-1/+6
This patch adds 3 wire transfer support to SPI mode list along with its implementation. 3 wire or Bi-directional mode uses only one serial data pin for the transfer. SPI in master mode uses MOSI data line only and MISO data line is not used. Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-08spi: tegra114: add dual mode supportSowjanya Komatineni1-1/+7
This patch adds support for dual mode SPI transfer. Dual mode uses both MOSI and MISO lines in parallel where the data is interleaved on MOSI and MISO lines increasing the throughput. Packet from Tx FIFO is transmitted on both MOSI and MISO lines and packet to Rx FIFO is received from both MOSI and MISO lines. Even bits are transmitted or received on the MOSI data line and odd bits are transmitted or received on the MISO data line. Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-08spi: gpio: Use devm_spi_register_master()Andrey Smirnov1-15/+4
Replace spi_bitbang_start() with a combination of spi_bitbang_init() and devm_spi_register_master() and drop all of the explicit cleanup-related code that's no longer necessary. 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>
2019-04-08spi: bitbang: Introduce spi_bitbang_init()Andrey Smirnov1-27/+39
Move all of the code doing struct spi_bitbang initialization, so that it can be paired with devm_spi_register_master() in order to avoid having to call spi_bitbang_stop() explicitly. 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>
2019-04-08spi: gpio: Make sure spi_master_put() is called in every error pathAndrey Smirnov1-7/+10
There's a number of failure paths in spi_gpio_probe() that do not call spi_master_put() potentially leaking memory. Fix this problem by registering a cleanup funciont via devm_add_action_or_reset() right after SPI controller is allocated. 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>
2019-04-08spi: pxa2xxx: change "no DMA channels..." msg from debug to warningFlavio Suligoi1-1/+1
Change the type of the diagnostic message: "no DMA channels available, using PIO" from debug to warning. The lack of an available DMA channel is very important regard the spi-pxa2xx performance. The transfer speed can be reduced more than 50%. So it is very important to warn the user about this, without enabling the full SPI debug with CONFIG_SPI_DEBUG. Moreover, enabling the full SPI debug only to enable this specific debug message, the dmesg buffer fills quickly with a lot of repetitive information during the SPI data transfer. This cause the loss of all the first important messages written during the initialization. Signed-off-by: Flavio Suligoi <f.suligoi@asem.it> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-08spi: fsl-lpspi: Clean up fsl_lpspi_probeAxel Lin1-6/+5
Use is_slave local variable to avoid calling of_property_read_bool() twice. Remove redudant assignment for controller->bus_num, set it once is enough. Move setting controller->bits_per_word_mask close to the code init other controller fields. Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-08spi: fsl-lpspi: Fix build warning when !CONFIG_PMAxel Lin1-0/+2
Add #ifdef CONFIG_PM guard to fix build warning when !CONFIG_PM drivers/spi/spi-fsl-lpspi.c:810:12: warning: ‘fsl_lpspi_runtime_suspend’ defined but not used [-Wunused-function] static int fsl_lpspi_runtime_suspend(struct device *dev) ^~~~~~~~~~~~~~~~~~~~~~~~~ drivers/spi/spi-fsl-lpspi.c:789:12: warning: ‘fsl_lpspi_runtime_resume’ defined but not used [-Wunused-function] static int fsl_lpspi_runtime_resume(struct device *dev) ^~~~~~~~~~~~~~~~~~~~~~~~ Fixes: 944c01a889d9 ("spi: lpspi: enable runtime pm for lpspi") Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-08spi: fsl-lpspi: Fix problematic dev_set_drvdata callAxel Lin1-3/+8
The original code already set controller as drvdata: platform_set_drvdata(pdev, controller); But commit 944c01a889d9 ("spi: lpspi: enable runtime pm for lpspi") added dev_set_drvdata(&pdev->dev, fsl_lpspi); so fsl_lpspi_remove() will get wrong pointer by platform_get_drvdata(). Fixes: 944c01a889d9 ("spi: lpspi: enable runtime pm for lpspi") Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-08spi-mem: fix kernel-doc for spi_mem_dirmap_{read|write}()Sergei Shtylyov1-2/+2
The function names in the kernel-doc comments were mistyped, with a word "dirmap" being repeated twice, so fix them. Fixes: aa167f3fed0c ("spi: spi-mem: Add a new API to support direct mapping") Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-08spi: bcm2835aux: Fix build error without CONFIG_DEBUG_FSYueHaibing1-1/+2
When building CONFIG_DEBUG_FS is not set gcc warn this: drivers/spi/spi-bcm2835aux.c: In function bcm2835aux_spi_probe: drivers/spi/spi-bcm2835aux.c:591:2: error: too many arguments to function bcm2835aux_debugfs_create bcm2835aux_debugfs_create(bs, dev_name(&pdev->dev)); ^~~~~~~~~~~~~~~~~~~~~~~~~ drivers/spi/spi-bcm2835aux.c:145:13: note: declared here static void bcm2835aux_debugfs_create(struct bcm2835aux_spi *bs) Reported-by: Hulk Robot <hulkci@huawei.com> Fixes: 8048d151eb4d ("spi: bcm2835aux: add driver stats to debugfs") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Mukesh Ojha <mojha@codeaurora.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-08spi: kill useless initializer in spi_register_controller()Sergei Shtylyov1-1/+1
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>
2019-04-05spi: spi-mem: Add support for Zynq QSPI controllerNaga Sureshkumar Relli3-1/+771
Add support for QSPI controller driver used by Xilinx Zynq SOC. Signed-off-by: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-05spi: gpio: Drop unused pdev field in struct spi_gpioAndrey Smirnov1-3/+0
There's no code using 'pdev' field in struct spi_gpio. Drop it. 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>
2019-04-05spi: gpio: Drop mflags argument from spi_gpio_request()Andrey Smirnov1-15/+13
The logic of setting mflags in spi_gpio_request() is very simple and there isn't much benefit in having it in that function. Move all of that code outside into spi_gpio_probe() in order to simplify things. 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>
2019-04-05spi: Don't call spi_get_gpio_descs() before device name is setAndrey Smirnov1-18/+19
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>
2019-04-05spi: gpio: Don't request CS GPIO in DT use-caseAndrey Smirnov1-75/+59
DT use-case already relies on SPI core to control CS (requested by of_spi_register_master() and controlled spi_set_cs()), so there's no need to try to request those GPIO in spi-gpio code. Change the code such that spi-gpio's CS related code is only used if device is probed via pdata. 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>
2019-04-05spi: tegra114: set bus number based on idSowjanya Komatineni1-0/+4
This patch sets SPI device id from the device tree as the bus number. Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-05spi: tegra114: use unpacked mode for below 4 bytesSowjanya Komatineni1-1/+2
Packed mode expects minimum transfer length of 4 bytes. This patch fixes this by using unpacked mode for transfers less than 4 bytes. Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-05spi: tegra114: set supported bits per wordSowjanya Komatineni1-0/+1
Tegra SPI supports 4 through 32 bits per word. This patch sets bits_per_word_mask accordingly to support transfer with these bits per word. Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-05spi: tegra114: dump SPI registers during timeoutSowjanya Komatineni1-0/+18
This patch dumps SPI registers on transfer error or timeout for debug purpose. Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-05Merge branch 'spi-5.1' into spi-5.2Mark Brown7-71/+173
2019-04-05spi: tegra114: avoid reset call in atomic contextSowjanya Komatineni1-4/+5
This patch moves SPI controller reset out of spin lock. Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-05spi: tegra114: de-assert CS before SPI mode changeSowjanya Komatineni1-6/+16
With SW CS, during the transfer completion CS is de-asserted by writing default command1 register value to SPI_COMMAND1 register. With this both mode and CS state are set at the same time and if current transfer mode is different to default SPI mode and if mode change happens prior to CS de-assert, clock polarity can change while CS is active before transfer finishes. This causes Slave to see spurious clock edges resulting in data mismatch. This patch fixes this by de-asserting CS before writing SPI_COMMAND1 to its default value so through out the transfer it will be in same SPI mode. Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-04spi: sh-msiof: Convert to use GPIO descriptorsGeert Uytterhoeven1-16/+4
Convert GPIO chip selects in the Renesas MSIOF SPI driver from legacy GPIO numbers to GPIO descriptors. Notes: - The board file for the SH7724-based Ecovec24 development board now registers a GPIO descriptor lookup, instead of passing a GPIO number through controller_data, - sh_msiof_get_cs_gpios() must release all GPIOs, else spi_get_gpio_descs() cannot claim them during SPI controller registration. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-04spi: bcm2835aux: polling_limit_us can be statickbuild test robot1-1/+1
Fixes: 5fd917afc4bf ("spi: bcm2835aux: make the polling duration limits configurable") Signed-off-by: kbuild test robot <lkp@intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-04spi: Add missing error handling for CS GPIOsGeert Uytterhoeven1-0/+2
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: f3186dd876697e69 ("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>
2019-04-04spi: spi-gpio: Remove spi->controller_data commentGeert Uytterhoeven1-1/+0
The conversion from GPIO numbers to GPIO descriptors removed the use of spi->controller_data, but forgot to update a comment referring to it. Fixes: 9b00bc7b901ff672 ("spi: spi-gpio: Rewrite to use GPIO descriptors") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-03spi: bcm2835aux: add driver stats to debugfsMartin Sperl1-0/+56
To estimate efficiency add statistics on transfer types (polling and interrupt) used to debugfs. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-03spi: sh-msiof: Add reset of registers before starting transferGeert Uytterhoeven1-0/+18
In accordance with hardware specification Ver 1.0, reset register transmission / reception setting before transfer. Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com> [geert: Use readl_poll_timeout_atomic()] Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-03spi: sh-msiof: Use readl_poll_timeout_atomic() instead of open-codingGeert Uytterhoeven1-9/+3
Replace the open-coded loop in sh_msiof_modify_ctr_wait() by a call to the readl_poll_timeout_atomic() helper macro. Suggested-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-03spi: lpspi: add missing complete in abort func at dma modeClark Wang1-1/+7
Add the missing complete operations for dma_completion to fix the problem of blocking at the wait_for_completion_interruptible() function when use spi_slave_abort(). Signed-off-by: Clark Wang <xiaoning.wang@nxp.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-03spi: gpio: Drop unused pdata copy in struct spi_gpioAndrey Smirnov1-3/+0
Drop unused pdata copy in struct spi_gpio. No functional change intended. 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>
2019-04-03spi: gpio: Simplify SPI_MASTER_NO_TX check in spi_gpio_probe()Andrey Smirnov1-6/+6
Swap branches of the if statement in order to simplify it's logical condition being checked. No functional change intended. 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>
2019-04-03spi: gpio: Add local struct spi_bitbang pointer in spi_gpio_probe()Andrey Smirnov1-13/+14
Use a local "struct spi_bitbang *bb" in spi_gpio_probe() for brevity. No functional change intended. 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>
2019-04-03spi: gpio: Add local struct device pointer in spi_gpio_probe()Andrey Smirnov1-5/+6
Use a local "struct device *dev" in spi_gpio_probe() for brevity. No functional change intended. 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>
2019-04-03spi: gpio: Drop unused spi_to_pdata()Andrey Smirnov1-6/+0
Spi_to_pdata() is not used anywhere in the code. Drop it. 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>
2019-04-03spi: bcm2835aux: make the polling duration limits configurableMartin Sperl1-11/+14
Under some circumstances the default 30 us polling limit is not optimal and may lead to long delays because we are waiting on an interrupt. with this patch we have the possibility to influence this policy. So make this limit (in us) configurable via a module parameters (but also modifyable via /sys/modules/...) Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Acked-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-03spi: bcm2835aux: setup gpio-cs to output and correct level during setupMartin Sperl1-2/+14
Setup gpio-cs to the correct levels during setup and also make the gpio definitely an output GPIO. This is transparently fixing some badly configured DTs in the process where cs-gpio is set but the gpios are still configured with native cs. It also makes 100% sure that the initial CS levels are as expected - especially on systems with devices on a bus with mixed CS_HIGH/CS_LOW settings. Fixes: 1ea29b39f4c812ec ("spi: bcm2835aux: add bcm2835 auxiliary spi device...") Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Acked-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-03spi: bcm2835aux: warn in dmesg that native cs is not really supportedMartin Sperl1-0/+33
From personal bad experience (even as the author of the original driver) it shows that native-cs is "somewhat" supported by the spi bus driver when using a buggy device tree. So make sure that the driver is warning in dmesg about this fact that we are running in a not supported mode that may have surprizing limitations. Fixes: 1ea29b39f4c812ec ("spi: bcm2835aux: add bcm2835 auxiliary spi device...") Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Acked-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-03spi: bcm2835aux: fix driver to not allow 65535 (=-1) cs-gpiosMartin Sperl1-1/+12
The original driver by default defines num_chipselects as -1. This actually allicates an array of 65535 entries in of_spi_register_master. There is a side-effect for buggy device trees that (contrary to dt-binding documentation) have no cs-gpio defined. This mode was never supported by the driver due to limitations of native cs and additional code complexity and is explicitly not stated to be implemented. To keep backwards compatibility with such buggy DTs we limit the number of chip_selects to 1, as for all practical purposes it is only ever realistic to use a single chip select in native cs mode without negative side-effects. Fixes: 1ea29b39f4c812ec ("spi: bcm2835aux: add bcm2835 auxiliary spi device...") Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Acked-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-03spi: bcm2835aux: remove dead codeMartin Sperl1-3/+0
Remove dead code that never can get reached, as we limit count to a max of 3. Suggested-by: Hubert Denkmair <h.denkmair@intence.de> Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Acked-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-03spi: bcm2835aux: fix corruptions for longer spi transfersMartin Sperl1-4/+4
On long running tests with a mcp2517fd can controller it showed that on rare occations the data read shows corruptions for longer spi transfers. Example of a 22 byte transfer: expected (as captured on logic analyzer): FF FF 78 00 00 00 08 06 00 00 91 20 77 56 84 85 86 87 88 89 8a 8b read by the driver: FF FF 78 00 00 00 08 06 00 00 91 20 77 56 84 88 89 8a 00 00 8b 9b To fix this use BCM2835_AUX_SPI_STAT_RX_LVL to determine when we may read data from the fifo reliably without any corruption. Surprisingly the only values ever empirically read in BCM2835_AUX_SPI_STAT_RX_LVL are 0x00, 0x10, 0x20 and 0x30. So whenever the mask is not 0 we can read from the fifo in a safe manner. The patch has now been tested intensively and we are no longer able to reproduce the "RX" issue any longer. Fixes: 1ea29b39f4c812ec ("spi: bcm2835aux: add bcm2835 auxiliary spi device...") Reported-by: Hubert Denkmair <h.denkmair@intence.de> Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Acked-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-03spi: bcm2835aux: remove dangerous uncontrolled read of fifoMartin Sperl1-7/+0
This read of the fifo is a potential candidate for a race condition as the spi transfer is not necessarily finished and so can lead to an early read of the fifo that still misses data. So it has been removed. Fixes: 1ea29b39f4c812ec ("spi: bcm2835aux: add bcm2835 auxiliary spi device...") Suggested-by: Hubert Denkmair <h.denkmair@intence.de> Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Acked-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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