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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-08 10:31:52 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-08 10:31:52 -0700 |
commit | ea125dedbc14b305307889c40d74d564c4419851 (patch) | |
tree | 0f11a7256b5fa0871ff323521f00f3a55a7ccb65 /Documentation/driver-api/gpio | |
parent | fdea70d26a471e002f2afc3a48821323b699f1e6 (diff) | |
parent | 6310b930ccbba55168f30b610fae681d73bd7bd2 (diff) | |
download | linux-ea125dedbc14b305307889c40d74d564c4419851.tar.bz2 |
Merge tag 'gpio-v4.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO updates from Linus Walleij:
"This is the bulk of GPIO changes for the v4.18 development cycle.
Core changes:
- We have killed off VLA from the core library and all drivers.
The background should be clear for everyone at this point:
https://lwn.net/Articles/749064/
Also I just don't like VLA's, kernel developers hate it when
compilers do things behind their back. It's as simple as that.
I'm sorry that they even slipped in to begin with. Kudos to Laura
Abbott for exorcising them.
- Support GPIO hogs in machines/board files.
New drivers and chip support:
- R-Car r8a77470 (RZ/G1C)
- R-Car r8a77965 (M3-N)
- R-Car r8a77990 (E3)
- PCA953x driver improvements to accomodate more variants.
Improvements and new features:
- Support one interrupt per line on port A in the DesignWare dwapb
driver.
Misc:
- Random cleanups, right header files in the drivers, some size
optimizations etc"
* tag 'gpio-v4.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (73 commits)
gpio: davinci: fix build warning when !CONFIG_OF
gpio: dwapb: Fix rework support for 1 interrupt per port A GPIO
gpio: pxa: Include the right header
gpio: pl061: Include the right header
gpio: pch: Include the right header
gpio: pcf857x: Include the right header
gpio: pca953x: Include the right header
gpio: palmas: Include the right header
gpio: omap: Include the right header
gpio: octeon: Include the right header
gpio: mxs: Switch to SPDX identifier
gpio: Remove VLA from stmpe driver
gpio: mxc: Switch to SPDX identifier
gpio: mxc: add clock operation
gpio: Remove VLA from gpiolib
gpio: aspeed: Use a cache of output data registers
gpio: aspeed: Set output latch before changing direction
gpio: pca953x: fix address calculation for pcal6524
gpio: pca953x: define masks for addressing common and extended registers
gpio: pca953x: set the PCA_PCAL flag also when matching by DT
...
Diffstat (limited to 'Documentation/driver-api/gpio')
-rw-r--r-- | Documentation/driver-api/gpio/board.rst | 16 | ||||
-rw-r--r-- | Documentation/driver-api/gpio/drivers-on-gpio.rst | 4 |
2 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/driver-api/gpio/board.rst b/Documentation/driver-api/gpio/board.rst index 25d62b2e9fd0..2c112553df84 100644 --- a/Documentation/driver-api/gpio/board.rst +++ b/Documentation/driver-api/gpio/board.rst @@ -177,3 +177,19 @@ mapping and is thus transparent to GPIO consumers. A set of functions such as gpiod_set_value() is available to work with the new descriptor-oriented interface. + +Boards using platform data can also hog GPIO lines by defining GPIO hog tables. + +.. code-block:: c + + struct gpiod_hog gpio_hog_table[] = { + GPIO_HOG("gpio.0", 10, "foo", GPIO_ACTIVE_LOW, GPIOD_OUT_HIGH), + { } + }; + +And the table can be added to the board code as follows:: + + gpiod_add_hogs(gpio_hog_table); + +The line will be hogged as soon as the gpiochip is created or - in case the +chip was created earlier - when the hog table is registered. diff --git a/Documentation/driver-api/gpio/drivers-on-gpio.rst b/Documentation/driver-api/gpio/drivers-on-gpio.rst index 7da0c1dd1f7a..f3a189320e11 100644 --- a/Documentation/driver-api/gpio/drivers-on-gpio.rst +++ b/Documentation/driver-api/gpio/drivers-on-gpio.rst @@ -85,6 +85,10 @@ hardware descriptions such as device tree or ACPI: any other serio bus to the system and makes it possible to connect drivers for e.g. keyboards and other PS/2 protocol based devices. +- cec-gpio: drivers/media/platform/cec-gpio/ is used to interact with a CEC + Consumer Electronics Control bus using only GPIO. It is used to communicate + with devices on the HDMI bus. + Apart from this there are special GPIO drivers in subsystems like MMC/SD to read card detect and write protect GPIO lines, and in the TTY serial subsystem to emulate MCTRL (modem control) signals CTS/RTS by using two GPIO lines. The |