lwn.git/drivers/gpio/gpio-74x164.c, branch v6.9

gpio: 74x164: Enable output pins after registers are reset

2024-03-01T07:23:08+00:00

Chip outputs are enabled[1] before actual reset is performed[2] which might cause pin output value to flip flop if previous pin value was set to 1. Fix that behavior by making sure chip is fully reset before all outputs are enabled. Flip-flop can be noticed when module is removed and inserted again and one of the pins was changed to 1 before removal. 100 microsecond flipping is noticeable on oscilloscope (100khz SPI bus). For a properly reset chip - output is enabled around 100 microseconds (on 100khz SPI bus) later during probing process hence should be irrelevant behavioral change. Fixes: 7ebc194d0fd4 (gpio: 74x164: Introduce 'enable-gpios' property) Link: https://elixir.bootlin.com/linux/v6.7.4/source/drivers/gpio/gpio-74x164.c#L130 [1] Link: https://elixir.bootlin.com/linux/v6.7.4/source/drivers/gpio/gpio-74x164.c#L150 [2] Signed-off-by: Arturas Moskvinas Signed-off-by: Bartosz Golaszewski

spi: make remove callback a void function

2022-02-09T13:00:45+00:00

The value returned by an spi driver's remove function is mostly ignored. (Only an error message is printed if the value is non-zero that the error is ignored.) So change the prototype of the remove function to return no value. This way driver authors are not tempted to assume that passing an error to the upper layer is a good idea. All drivers are adapted accordingly. There is no intended change of behaviour, all callbacks were prepared to return 0 before. Signed-off-by: Uwe Kleine-König Acked-by: Marc Kleine-Budde Acked-by: Andy Shevchenko Reviewed-by: Geert Uytterhoeven Acked-by: Jérôme Pouiller Acked-by: Miquel Raynal Acked-by: Jonathan Cameron Acked-by: Claudius Heine Acked-by: Stefan Schmidt Acked-by: Alexandre Belloni Acked-by: Ulf Hansson # For MMC Acked-by: Marcus Folkesson Acked-by: Łukasz Stelmach Acked-by: Lee Jones Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.de Signed-off-by: Mark Brown

gpio: 74x164: Add SPI device ID table

2021-10-06T11:01:45+00:00

Currently autoloading for SPI devices does not use the DT ID table, it uses SPI modalises. Supporting OF modalises is going to be difficult if not impractical, an attempt was made but has been reverted, so ensure that module autoloading works for this driver by adding a SPI device ID table. Fixes: 96c8395e2166 ("spi: Revert modalias changes") Signed-off-by: Mark Brown Reviewed-by: Linus Walleij Signed-off-by: Bartosz Golaszewski

gpio: 74x164: utilize the for_each_set_clump8 macro

2019-12-05T03:44:12+00:00

Replace verbose implementation in set_multiple callback with for_each_set_clump8 macro to simplify code and improve clarity. Link: http://lkml.kernel.org/r/7ea2df7182a50a1136ca36edc46dffcb2446fd27.1570641097.git.vilhelm.gray@gmail.com Signed-off-by: William Breathitt Gray Suggested-by: Andy Shevchenko Tested-by: Andy Shevchenko Cc: Geert Uytterhoeven Cc: Phil Reid Cc: Arnd Bergmann Cc: Bartosz Golaszewski Cc: Geert Uytterhoeven Cc: Linus Walleij Cc: Lukas Wunner Cc: Masahiro Yamada Cc: Mathias Duckeck Cc: Morten Hein Tiljeset Cc: Rasmus Villemoes Cc: Sean Nyekjaer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

gpio: 74x164: Convert to use SPDX identifier

2019-03-26T17:38:07+00:00

Reduce size of duplicated comments by switching to use SPDX identifier. No functional change. Signed-off-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski

gpio: 74x164: Remove linux/init.h and sort headers

2019-03-26T17:37:47+00:00

There is no need to include linux/init.h when at the same time we include linux/module.h. Remove redundant inclusion. While here, sort header block alphabetically for easy maintenance. Signed-off-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski

gpio: 74x164: Make use of device properties

2019-03-26T17:37:18+00:00

ACPI-enabled platforms can use this device via unified device properties API. Convert driver to support this. Signed-off-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski

Merge tag 'gpio-v4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

2018-01-31T20:25:27+00:00

Pull GPIO updates from Linus Walleij: "The is the bulk of GPIO changes for the v4.16 kernel cycle. It is pretty calm this time around I think. I even got time to get to things like starting to clean up header includes. Core changes: - Disallow open drain and open source flags to be set simultaneously. This doesn't make electrical sense, and would the hardware actually respond to this setting, the result would be short circuit. - ACPI GPIO has a new core infrastructure for handling quirks. The quirks are there to deal with broken ACPI tables centrally instead of pushing the work to individual drivers. In the world of BIOS writers, the ACPI tables are perfect. Until they find a mistake in it. When such a mistake is found, we can patch it with a quirk. It should never happen, the problem is that it happens. So we accomodate for it. - Several documentation updates. - Revert the patch setting up initial direction state from reading the device. This was causing bad things for drivers that can't read status on all its pins. It is only affecting debugfs information quality. - Label descriptors with the device name if no explicit label is passed in. - Pave the ground for transitioning SPI and regulators to use GPIO descriptors by implementing some quirks in the device tree GPIO parsing code. New drivers: - New driver for the Access PCIe IDIO 24 family. Other: - Major refactorings and improvements to the GPIO mockup driver used for test and verification. - Moved the AXP209 driver over to pin control since it gained a pin control back-end. These patches will appear (with the same hashes) in the pin control pull request as well. - Convert the onewire GPIO driver w1-gpio to use descriptors. This is merged here since the W1 maintainers send very few pull requests and he ACKed it. - Start to clean up driver headers using to just use as appropriate" * tag 'gpio-v4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (103 commits) gpio: Timestamp events in hardirq handler gpio: Fix kernel stack leak to userspace gpio: Fix a documentation spelling mistake gpio: Documentation update gpiolib: remove redundant initialization of pointer desc gpio: of: Fix NPE from OF flags gpio: stmpe: Delete an unnecessary variable initialisation in stmpe_gpio_probe() gpio: stmpe: Move an assignment in stmpe_gpio_probe() gpio: stmpe: Improve a size determination in stmpe_gpio_probe() gpio: stmpe: Use seq_putc() in stmpe_dbg_show() gpio: No NULL owner gpio: stmpe: i2c transfer are forbiden in atomic context gpio: davinci: Include proper header gpio: da905x: Include proper header gpio: cs5535: Include proper header gpio: crystalcove: Include proper header gpio: bt8xx: Include proper header gpio: bcm-kona: Include proper header gpio: arizona: Include proper header gpio: amd8111: Include proper header ...

gpio: 74x174: Include proper headers

2018-01-13T21:07:09+00:00

This driver has no business including or . Cut them and include and which is it they really needs. Signed-off-by: Linus Walleij

gpio: 74x164: Fix crash during .remove()

2017-11-30T14:31:14+00:00

Commit 7ebc194d0fd4bb0f ("gpio: 74x164: Introduce 'enable-gpios' property") added a new member gpiod_oe to the end of the struct gen_74x164_chip, after the zero-length buffer array. However, this buffer is a flexible array, allocated together with the structure during .probe(). As the buffer is no longer the last member, writing to it corrupts the newly added member after it. During device removal, the corrupted member will be used as a pointer, leading to a crash. This went unnoticed, as the flexible array was declared as "buffer[0]" instead of "buffer[]", and thus did not trigger a "flexible array member not at end of struct" error from gcc. Move the gpiod_oe field up to fix this, and drop the zero from the array size to prevent future similar bugs. Fixes: 7ebc194d0fd4bb0f ("gpio: 74x164: Introduce 'enable-gpios' property") Signed-off-by: Geert Uytterhoeven Reviewed-by: Fabio Estevam Signed-off-by: Linus Walleij