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

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 <arturas.moskvinas@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

spi: make remove callback a void function

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 <u.kleine-koenig@pengutronix.de>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Claudius Heine <ch@denx.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Acked-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Łukasz Stelmach <l.stelmach@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

gpio: 74x164: Add SPI device ID table

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 <broonie@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: 74x164: utilize the for_each_set_clump8 macro

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 <vilhelm.gray@gmail.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Phil Reid <preid@electromag.com.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Mathias Duckeck <m.duckeck@kunbus.de>
Cc: Morten Hein Tiljeset <morten.tiljeset@prevas.dk>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gpio: 74x164: Convert to use SPDX identifier

Reduce size of duplicated comments by switching to use SPDX identifier.

No functional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

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

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 <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: 74x164: Make use of device properties

ACPI-enabled platforms can use this device via unified device
properties API. Convert driver to support this.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: 74x174: Include proper headers

This driver has no business including <linux/gpio.h> or
<linux/of_gpio.h>. Cut them and include <linux/gpio/driver.h>
and <linux/gpio/consumer.h> which is it they really needs.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

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

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 <geert+renesas@glider.be>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: Introduce 'enable-gpios' property

74HC595 has an /OE (output enable) pin that can be controlled by a GPIO.

Introduce an optional property called 'enable-gpios' that allows
controlling the /OE pin.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: Use spi_write() helper instead of open coding

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: add dt support for nxp's 74x594

The chip is also an 8 bit shift register which works out of the box as a GPO
expander with this patch

Signed-off-by: Nicolas Saenz Julienne <nicolassaenzj@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: Implement gpiochip.set_multiple()

This allows to set multiple outputs using a single SPI transfer.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: use gpiochip data pointer

This makes the driver use the data pointer added to the gpio_chip
to store a pointer to the state container instead of relying on
container_of().

Cc: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: Use a single SPI transfer instead of multiple transfers

Currently the 74x164 driver assembles an SPI message from an array of
one-byte SPI transfers, one for each daisy-chained shift register, as
the first byte sent will end up in the last register.
This array is allocated and deallocated on each GPIO write access.

By storing the data in the internal buffer in reverse order, we can
use a single SPI transfer with the internal buffer directly, simplifying
the code a lot, and avoiding memory (de)allocations.

This also avoids transient values on the GPIO outputs when using an SPI
master that cannot keep the hardware chip select asserted in between
multiple transfers (and would need cs-gpios for proper operation).

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Mark Brown <broonie@kernel.org>
[Rebased changing .dev to .parent]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: Allocate buffer with gen_74x164_chip

By moving the internal buffer to the end of struct gen_74x164_chip and
converting it from a pointer to a zero-sized array, it can be allocated
together with gen_74x164_chip, reducing the number of managed
allocations.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: change member .dev to .parent

The name .dev in a struct is normally reserved for a struct device
that is let us say a superclass to the thing described by the struct.
struct gpio_chip stands out by confusingly using a struct device *dev
to point to the parent device (such as a platform_device) that
represents the hardware. As we want to give gpio_chip:s real devices,
this is not working. We need to rename this member to parent.

This was done by two coccinelle scripts, I guess it is possible to
combine them into one, but I don't know such stuff. They look like
this:

@@
struct gpio_chip *var;
@@
-var->dev
+var->parent

and:

@@
struct gpio_chip var;
@@
-var.dev
+var.parent

and:

@@
struct bgpio_chip *var;
@@
-var->gc.dev
+var->gc.parent

Plus a few instances of bgpio that I couldn't figure out how
to teach Coccinelle to rewrite.

This patch hits all over the place, but I *strongly* prefer this
solution to any piecemal approaches that just exercise patch
mechanics all over the place. It mainly hits drivers/gpio and
drivers/pinctrl which is my own backyard anyway.

Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Rafał Miłecki <zajec5@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Alek Du <alek.du@intel.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

spi: Drop owner assignment from spi_drivers

An spi_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

gpio: remove all usage of gpio_remove retval in driver/gpio

Signed-off-by: abdoulaye berthe <berthe.ab@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: Driver cleanup

- Removed excess "spi" field from private data.
- Removed excess check for spi_get_drvdata() in remove().
- Removed unneeded message in remove().
- Simplify error path in probe().
- Fixed warnings by scripts/checkfile.pl.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: Remove non-DT support

Commit 20bc4d5d565159eb2b942bf4b7fae86fba94e32c
(gpio: 74x164: Add support for the daisy-chaining) introduce check
for DT for the driver, so driver cannot be used without DT.
There are no in-tree users of this driver, so remove non-DT support
completely.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Acked-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio/pinctrl: make gpio_chip members typed boolean

This switches the two members of struct gpio_chip that were
defined as unsigned foo:1 to bool, because that is indeed what
they are. Switch all users in the gpio and pinctrl subsystems
to assign these values with true/false instead of 0/1. The
users outside these subsystems will survive since true/false
is 1/0, atleast we set some kind of more strict typing example.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: gpio-74x164: Remove redundant of_match_ptr

'gen_74x164_dt_ids' is always compiled in. Hence the macro is not
necessary.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: gpio-74x164: Remove redundant spi_set_drvdata

Driver core sets driver data to NULL upon failure or remove.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: use dev_get_platdata()

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: use spi_get_drvdata() and spi_set_drvdata()

Use the wrapper functions for getting and setting the driver data
using spi_device instead of using dev_{get|set}_drvdata with
&spi->dev, so we can directly pass a struct spi_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: remove use of __devexit

CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Peter Tyser <ptyser@xes-inc.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

gpio: remove use of __devinit

CONFIG_HOTPLUG is going away as an option so __devinit is no longer
needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Peter Tyser <ptyser@xes-inc.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

gpio: remove use of __devexit_p

CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Peter Tyser <ptyser@xes-inc.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

gpio-74x164: Fix buffer allocation size

The new registers handling in the gpio-74x164 driver allocates chip->registers
* 8 bytes where only one byte per register is necessary. This patch fixes this.

Signed-off-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: Add support for the daisy-chaining

The shift registers have an output pin that, when enabled, propagates
the values of its internal register to the pins. If another value comes
to the register while the output pin is disabled, this new value will
makae the older shift into the next register in the chain.

This patch adds support for daisy-chaining the registers, using the
regular SPI chip select mechanism to manage the output pin, and the
registers-number dt property to set the number of chained registers.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: Add device tree support

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: Use dynamic gpio number assignment if no pdata is present

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: Use devm_kzalloc

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: 74x164: Use module_spi_driver boiler plate function

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio: Fix drivers who are implicit users of module.h

A pending cleanup will mean that module.h won't be implicitly
everywhere anymore. Make sure the modular drivers in gpio
are actually calling out for <module.h> explicitly in advance.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

gpio/74x164: fix clash with gpiolib namespace

The 74x164 GPIO driver has a static inline helper called
gpio_to_chip which clashes with the gpiolib namespace if we
try to expose the function with the same name from gpiolib,
and it's still confusing even if we don't do that. So rename
it to gpio_to_74x164_chip().

Reported-by: H Hartley Sweeten <hartleys@visionengravers.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

gpio: reorganize drivers

Sort the gpio makefile and enforce the naming convention gpio-*.c for
gpio drivers.

v2: cleaned up filenames in Kconfig and comment blocks
v3: fixup use of BASIC_MMIO to GENERIC_GPIO for mxc

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>