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2020-06-17spi: bcm2835aux: Fix controller unregister orderLukas Wunner
commit b9dd3f6d417258ad0beeb292a1bc74200149f15d upstream. The BCM2835aux SPI driver uses devm_spi_register_master() on bind. As a consequence, on unbind, __device_release_driver() first invokes bcm2835aux_spi_remove() before unregistering the SPI controller via devres_release_all(). This order is incorrect: bcm2835aux_spi_remove() turns off the SPI controller, including its interrupts and clock. The SPI controller is thus no longer usable. When the SPI controller is subsequently unregistered, it unbinds all its slave devices. If their drivers need to access the SPI bus, e.g. to quiesce their interrupts, unbinding will fail. As a rule, devm_spi_register_master() must not be used if the ->remove() hook performs teardown steps which shall be performed after unbinding of slaves. Fix by using the non-devm variant spi_register_master(). Note that the struct spi_master as well as the driver-private data are not freed until after bcm2835aux_spi_remove() has finished, so accessing them is safe. Fixes: 1ea29b39f4c8 ("spi: bcm2835aux: add bcm2835 auxiliary spi device driver") Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org # v4.4+ Cc: Martin Sperl <kernel@martin.sperl.org> Link: https://lore.kernel.org/r/32f27f4d8242e4d75f9a53f7e8f1f77483b08669.1589557526.git.lukas@wunner.de Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04spi: bcm2835aux: use devm_platform_ioremap_resource() to simplify codeYueHaibing
Use devm_platform_ioremap_resource() to simplify the code a bit. This is detected by coccinelle. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Link: https://lore.kernel.org/r/20190904135918.25352-6-yuehaibing@huawei.com Signed-off-by: Mark Brown <broonie@kernel.org>
2019-08-02spi: Remove dev_err() usage after platform_get_irq()Stephen Boyd
We don't need dev_err() messages when platform_get_irq() fails now that platform_get_irq() prints an error message itself when something goes wrong. Let's remove these prints with a simple semantic patch. // <smpl> @@ expression ret; struct platform_device *E; @@ ret = ( platform_get_irq(E, ...) | platform_get_irq_byname(E, ...) ); if ( \( ret < 0 \| ret <= 0 \) ) { ( -if (ret != -EPROBE_DEFER) -{ ... -dev_err(...); -... } | ... -dev_err(...); ) ... } // </smpl> While we're here, remove braces on if statements that only have one statement (manually). Cc: Mark Brown <broonie@kernel.org> Cc: linux-spi@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20190730181557.90391-42-swboyd@chromium.org Signed-off-by: Mark Brown <broonie@kernel.org>
2019-06-10Merge tag 'v5.2-rc4' into spi-5.3Mark Brown
Linux 5.2-rc4
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157Thomas Gleixner
Based on 3 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [graeme] [gregory] [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema] [hk] [hemahk]@[ti] [com] this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1105 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-13spi: bcm2835aux: Remove spi_alloc_master() error printingHoan Nguyen An
Printing an error on memory allocation failure is unnecessary, as the memory allocation core code already takes care of that. Signed-off-by: Hoan Nguyen An <na-hoan@jinso.co.jp> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-08spi: bcm2835aux: Fix build error without CONFIG_DEBUG_FSYueHaibing
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>
2019-04-04spi: bcm2835aux: polling_limit_us can be statickbuild test robot
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>
2019-04-03spi: bcm2835aux: add driver stats to debugfsMartin Sperl
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: bcm2835aux: make the polling duration limits configurableMartin Sperl
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 Sperl
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 Sperl
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 Sperl
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 Sperl
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 Sperl
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 Sperl
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>
2019-04-03spi: bcm2835aux: unifying code between polling and interrupt driven codeMartin Sperl
Sharing more code between polling and interrupt-driven mode. 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>
2019-01-23spi: bcm2835aux: remove unneeded NULL check of devm_clk_getYueHaibing
Fix a static code checker warning: drivers/spi/spi-bcm2835aux.c:460 bcm2835aux_spi_probe() warn: passing zero to 'PTR_ERR' In case of error, the function devm_clk_get() returns ERR_PTR() and not returns NULL. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-11-14spi: bcm2835: make license text and module license matchStefan Wahren
The license text is specifying GPL v2 or later but the MODULE_LICENSE is set to GPL v2 which means GNU Public License v2 only. So choose the license text as the correct one. Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Acked-by: Florian Kauer <florian.kauer@koalo.de> Acked-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-05-04spi: bcm2835aux: ensure interrupts are enabled for shared handlerRob Herring
The BCM2835 AUX SPI has a shared interrupt line (with AUX UART). Downstream fixes this with an AUX irqchip to demux the IRQ sources and a DT change which breaks compatibility with older kernels. The AUX irqchip was already rejected for upstream[1] and the DT change would break working systems if the DTB is updated to a newer one. The latter issue was brought to my attention by Alex Graf. The root cause however is a bug in the shared handler. Shared handlers must check that interrupts are actually enabled before servicing the interrupt. Add a check that the TXEMPTY or IDLE interrupts are enabled. [1] https://patchwork.kernel.org/patch/9781221/ Cc: Alexander Graf <agraf@suse.de> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Mark Brown <broonie@kernel.org> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: linux-spi@vger.kernel.org Cc: linux-rpi-kernel@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Rob Herring <robh@kernel.org> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-02-14spi: bcm2835aux: Avoid 64-bit arithmetic in xfer len calcTrent Piepho
We want to check for xfers that are over 30 microseconds. Rather than find how many µs a xfer will take, instead find how many bytes can be transferred in 30 µs. The latter must be less than 32 bits (since our clock speed is limited to 32 bits), while the former involves 64 bit quantities and more arithmetic operations. Signed-off-by: Trent Piepho <tpiepho@impinj.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-11Merge remote-tracking branches 'spi/topic/acpi', 'spi/topic/axi-engine', ↵Mark Brown
'spi/topic/bcm2835' and 'spi/topic/bcm2835aux' into spi-next
2016-02-15spi: bcm2835aux: fix CPOL/CPHA settingStephan Olbrich
The auxiliary spi supports only CPHA=0 modes as the first bit is always output to the pin before the first clock cycle. In CPHA=1 modes the first clock edge outputs the second bit hence the slave can never read the first bit. Also the CPHA registers switch between clocking data in/out on rising/falling edge hence depend on the CPOL setting. Signed-off-by: Stephan Olbrich <stephanolbrich@gmx.de> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-15spi: bcm2835aux: set up spi-mode before asserting cs-gpioStephan Olbrich
When using reverse polarity for clock (spi-cpol) on a device the clock line gets altered after chip-select has been asserted resulting in an additional clock beat, which confuses hardware. This happens due to the fact, the the hardware was initialized and reset at the begin and end of each transfer which results in default state for all lines except chip-select which is handled by the spi-subsystem as gpio-cs is used. To avoid this situation this patch moves the setup of polarity (spi-cpol and spi-cpha) outside of the chip-select into prepare_message, which is run prior to asserting chip-select. Signed-off-by: Stephan Olbrich <stephanolbrich@gmx.de> Reviewed-by: Martin Sperl <kernel@martin.sperl.org> Tested-by: Martin Sperl <kernel@martin.sperl.org> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-10spi: bcm2835aux: disable tx fifo empty irqStephan Olbrich
The tx empty irq can be disabled when all data was copied. This prevents unnecessary interrupts while the last bytes are sent. Signed-off-by: Stephan Olbrich <stephanolbrich@gmx.de> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-10spi: bcm2835aux: fix bitmask definesStephan Olbrich
The bitmasks for txempty and idle interrupts were interchanged. Signed-off-by: Stephan Olbrich <stephanolbrich@gmx.de> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-16spi: bcm2835aux: change initialization order and switch to platform_get_irqMartin Sperl
Change the initialization order of the HW so that the interrupt is only requested after the HW is initialized Also the use of irq_of_parse_and_map is replaced by platform_get_irq. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-16spi: bcm2835aux: fixed bad data on longer transfersMartin Sperl
There are strange issues with the auxiliary spi device that result in "lost" data in the RX path if the fifo is filled by too much (even though the status register is checked if new data can get filled in). This has been observed primarily for the interrupt case. Polling works fine, probably because the RX fifo is pulled immediately when in the tight polling loop. For that reason we have to limit the pending bytes to less than 15 when filling the fifo in interrupt mode. There also was an issue returning the "wrong" last 1/2 bytes of a transfer when the transfer is not a multiple of 3 bytes. (this impacted polling and interrupt modes) Also fixed an overflow in the estimation of the transfer time used to decide if we run in interrupt or polling mode (found with the spi-bcm2835.c driver originally). Reported-by: Georgii Staroselskii <georgii.staroselskii@emlid.com> Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-07spi: bcm2835aux: add bcm2835 auxiliary spi device driverMartin Sperl
The bcm2835 has 2 auxiliary spi bus masters spi1 and spi2. This implements the driver to enable these devices. The driver does not implement native chip-selects but uses the aribtrary GPIO-chip-selects provided by the spi-chipselect. Note that this driver relies on the fact that the clock is implemented by the clk-bcm2835-aux driver, which enables/disables the HW block when requesting/releasing the clock. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Acked-by: Eric Anholt <eric@anholt.net> Signed-off-by: Mark Brown <broonie@kernel.org>