linux-toradex.git/include/linux/gpio/machine.h, branch v5.19-rc3

ARM/pxa/mfd/power/sound: Switch Tosa to GPIO descriptors

2022-05-07T20:55:33+00:00

The Tosa device (Sharp SL-6000) has a mishmash driver set-up
for the Toshiba TC6393xb MFD that includes a battery charger
and touchscreen and has some kind of relationship to the SoC
sound driver for the AC97 codec. Other devices define a chip
like this but seem only half-implemented, not really handling
battery charging etc.

This patch switches the Toshiba MFD device to provide GPIO
descriptors to the battery charger and SoC codec. As a result
some descriptors need to be moved out of the Tosa boardfile
and new one added: all SoC GPIO resources to these drivers
now comes from the main boardfile, while the MFD provide
GPIOs for its portions.

As a result we can request one GPIO from our own GPIO chip
and drop two hairy callbacks into the board file.

This platform badly needs to have its drivers split up and
converted to device tree probing to handle this quite complex
relationship in an orderly manner. I just do my best in solving
the GPIO descriptor part of the puzzle. Please don't ask me
to fix everything that is wrong with these driver to todays
standards, I am just trying to fix one aspect. I do try to
use modern devres resource management and handle deferred
probe using new functions where appropriate.

Cc: Dmitry Eremin-Solenikov 
Cc: Dirk Opfer 
Cc: Robert Jarzmik 
Cc: Daniel Mack 
Cc: Haojian Zhuang 
Cc: Lee Jones 
Cc: Liam Girdwood 
Reviewed-by: Dmitry Baryshkov 
Acked-by: Mark Brown 
Acked-by: Sebastian Reichel 
Signed-off-by: Linus Walleij 
Signed-off-by: Arnd Bergmann

gpiolib: provide gpiod_remove_hogs()

2021-12-17T11:26:12+00:00

Currently all users of gpiod_add_hogs() call it only once at system
init so there never was any need for a mechanism allowing to remove
them. Now the upcoming gpio-sim will need to tear down chips with hogged
lines so provide a function that allows to remove hogs.

Signed-off-by: Bartosz Golaszewski 
Reviewed-by: Andy Shevchenko 
Acked-by: Linus Walleij

gpio: aggregator: Use compound literal from the header

2021-02-15T10:43:32+00:00

Instead of doing it in place, convert GPIO_LOOKUP_IDX() and GPIO_HOG()
to be compund literals that's allow to use them as rvalue in assignments.

Due to above conversion, use compound literal from the header
in the gpio-aggregator.c.

Signed-off-by: Andy Shevchenko 
Reviewed-by: Geert Uytterhoeven

gpiolib: Add support for GPIO lookup by line name

2020-05-18T08:12:42+00:00

Currently a GPIO lookup table can only refer to a specific GPIO by a
tuple, consisting of a GPIO controller label and a GPIO offset inside
the controller.

However, a GPIO may also carry a line name, defined by DT or ACPI.
If present, the line name is the most use-centric way to refer to a
GPIO.  Hence add support for looking up GPIOs by line name.
Note that there is no guarantee that GPIO line names are globally
unique, so this will use the first match found.

Implement this by reusing the existing gpiod_lookup infrastructure.
Rename gpiod_lookup.chip_label to gpiod_lookup.key, to make it clear
that this field can have two meanings, and update the kerneldoc and
GPIO_LOOKUP*() macros.

Signed-off-by: Geert Uytterhoeven 
Tested-by: Eugeniu Rosca 
Reviewed-by: Ulrich Hecht 
Reviewed-by: Eugeniu Rosca 
Link: https://lore.kernel.org/r/20200511145257.22970-4-geert+renesas@glider.be
Signed-off-by: Linus Walleij

gpio: Add comments on #if/#else/#endif

2019-06-27T14:56:50+00:00

Improve readability a bit by commenting #if/#else/#endif statements
with the checked preprocessor symbols.

Signed-off-by: Enrico Weigelt 
Signed-off-by: Linus Walleij

gpiolib: Introduce GPIO_LOOKUP_FLAGS_DEFAULT

2019-04-23T08:55:10+00:00

Since GPIO library operates with enumerator when it's subject to handle
the GPIO lookup flags, it will be better to clearly see what default means.

Thus, introduce GPIO_LOOKUP_FLAGS_DEFAULT entry to describe
the default assumptions.

While here, replace 0 by newly introduced constant.

Signed-off-by: Andy Shevchenko 
Reviewed-by: Mika Westerberg 
Signed-off-by: Linus Walleij

gpiolib: Make use of enum gpio_lookup_flags consistent

2019-04-23T08:55:07+00:00

The library uses enum gpio_lookup_flags to define the possible
characteristics of GPIO pin. Since enumerator listed only individual
bits the common use of it is in a form of a bitmask of
gpio_lookup_flags GPIO_* values. The more correct type for this is
unsigned long.

Due to above convert all users to use unsigned long instead of
enum gpio_lookup_flags except enumerator definition.

While here, make field and parameter descriptions consistent as well.

Suggested-by: Mika Westerberg 
Signed-off-by: Andy Shevchenko 
Reviewed-by: Mika Westerberg 
Signed-off-by: Linus Walleij

gpiolib: Indent entry values of enum gpio_lookup_flags

2019-04-23T08:54:42+00:00

Indent entry values in the enum gpio_lookup_flags for better readability.

No functional change.

Signed-off-by: Andy Shevchenko 
Acked-by: Hans de Goede 
Reviewed-by: Mika Westerberg 
Signed-off-by: Linus Walleij

gpio: add core support for pull-up/pull-down configuration

2019-02-13T08:10:14+00:00

This commit adds support for configuring the pull-up and pull-down
resistors available in some GPIO controllers. While configuring
pull-up/pull-down is already possible through the pinctrl subsystem,
some GPIO controllers, especially simple ones such as GPIO expanders
on I2C, don't have any pinmuxing capability and therefore do not use
the pinctrl subsystem.

This commit implements the GPIO_PULL_UP and GPIO_PULL_DOWN flags,
which can be used from the Device Tree, to enable a pull-up or
pull-down resistor on a given GPIO.

The flag is simply propagated all the way to the core GPIO subsystem,
where it is used to call the gpio_chip ->set_config callback with the
appropriate existing PIN_CONFIG_BIAS_* values.

Signed-off-by: Thomas Petazzoni 
Signed-off-by: Linus Walleij

gpiolib: add hogs support for machine code

2018-05-16T12:35:24+00:00

Board files constitute a significant part of the users of the legacy
GPIO framework. In many cases they only export a line and set its
desired value. We could use GPIO hogs for that like we do for DT and
ACPI but there's no support for that in machine code.

This patch proposes to extend the machine.h API with support for
registering hog tables in board files.

Signed-off-by: Bartosz Golaszewski 
Signed-off-by: Linus Walleij