driver-api/gpio/drivers-on-gpio.rst

6 the right in-kernel and userspace APIs/ABIs for the job, and that these
10 - leds-gpio: drivers/leds/leds-gpio.c will handle LEDs connected to  GPIO
13 - ledtrig-gpio: drivers/leds/trigger/ledtrig-gpio.c will provide a LED trigger,
14   i.e. a LED will turn on/off in response to a GPIO line going high or low
15   (and that LED may in turn use the leds-gpio as per above).
17 - gpio-keys: drivers/input/keyboard/gpio_keys.c is used when your GPIO line
18   can generate interrupts in response to a key press. Also supports debounce.
20 - gpio-keys-polled: drivers/input/keyboard/gpio_keys_polled.c is used when your
22   by a timer.
24 - gpio_mouse: drivers/input/mouse/gpio_mouse.c is used to provide a mouse with
26   mouse cable and connect the wires to GPIO lines or solder a mouse connector
27   to the lines for a more permanent solution of this type.
29 - gpio-beeper: drivers/input/misc/gpio-beeper.c is used to provide a beep from
30   an external speaker connected to a GPIO line.
32 - extcon-gpio: drivers/extcon/extcon-gpio.c is used when you need to read an
33   external connector status, such as a headset line for an audio driver or an
34   HDMI connector. It will provide a better userspace sysfs interface than GPIO.
36 - restart-gpio: drivers/power/reset/gpio-restart.c is used to restart/reboot
37   the system by pulling a GPIO line and will register a restart handler so
38   userspace can issue the right system call to restart the system.
40 - poweroff-gpio: drivers/power/reset/gpio-poweroff.c is used to power the
41   system down by pulling a GPIO line and will register a pm_power_off()
42   callback so that userspace can issue the right system call to power down the
43   system.
45 - gpio-gate-clock: drivers/clk/clk-gpio.c is used to control a gated clock
46   (off/on) that uses a GPIO, and integrated with the clock subsystem.
48 - i2c-gpio: drivers/i2c/busses/i2c-gpio.c is used to drive an I2C bus
50   appear as any other I2C bus to the system and makes it possible to connect
51   drivers for the I2C devices on the bus like any other I2C bus driver.
53 - spi_gpio: drivers/spi/spi-gpio.c is used to drive an SPI bus (variable number
54   of wires, at least SCK and optionally MISO, MOSI and chip select lines) using
55   GPIO hammering (bitbang). It will appear as any other SPI bus on the system
56   and makes it possible to connect drivers for SPI devices on the bus like
60 - w1-gpio: drivers/w1/masters/w1-gpio.c is used to drive a one-wire bus using
61   a GPIO line, integrating with the W1 subsystem and handling devices on
64 - gpio-fan: drivers/hwmon/gpio-fan.c is used to control a fan for cooling the
65   system, connected to a GPIO line (and optionally a GPIO alarm line),
66   presenting all the right in-kernel and sysfs interfaces to make your system
69 - gpio-regulator: drivers/regulator/gpio-regulator.c is used to control a
70   regulator providing a certain voltage by pulling a GPIO line, integrating
73 - gpio-wdt: drivers/watchdog/gpio_wdt.c is used to provide a watchdog timer
74   that will periodically "ping" a hardware connected to a GPIO line by toggling
75   it from 1-to-0-to-1. If that hardware does not receive its "ping"
76   periodically, it will reset the system.
78 - gpio-nand: drivers/mtd/nand/raw/gpio.c is used to connect a NAND flash chip
79   to a set of simple GPIO lines: RDY, NCE, ALE, CLE, NWP. It interacts with the
80   NAND flash MTD subsystem and provides chip access and partition parsing like
83 - ps2-gpio: drivers/input/serio/ps2-gpio.c is used to drive a PS/2 (IBM) serio
85   any other serio bus to the system and makes it possible to connect drivers
88 - cec-gpio: drivers/media/platform/cec-gpio/ is used to interact with a CEC
90   with devices on the HDMI bus.
92 - gpio-charger: drivers/power/supply/gpio-charger.c is used if you need to do
95   nothing but GPIO lines, this driver provides that and also a clearly defined
102 MTD NOR flash has add-ons for extra GPIO lines too, though the address bus is
108 speed up your embedded hacking in particular by providing ready-made components.