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
11   lines, giving you the LED sysfs interface
13 - ledtrig-gpio: drivers/leds/trigger/ledtrig-gpio.c will provide a LED trigger,
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
20 - gpio-keys-polled: drivers/input/keyboard/gpio_keys_polled.c is used when your
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
32 - extcon-gpio: drivers/extcon/extcon-gpio.c is used when you need to read an
36 - restart-gpio: drivers/power/reset/gpio-restart.c is used to restart/reboot
40 - poweroff-gpio: drivers/power/reset/gpio-poweroff.c is used to power the
45 - gpio-gate-clock: drivers/clk/clk-gpio.c is used to control a gated clock
48 - i2c-gpio: drivers/i2c/busses/i2c-gpio.c is used to drive an I2C bus
49   (two wires, SDA and SCL lines) by hammering (bitbang) two GPIO lines. It will
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
57   any other SPI bus driver. For example any MMC/SD card can then be connected
58   to this SPI by using the mmc_spi host from the MMC/SD card subsystem.
60 - w1-gpio: drivers/w1/masters/w1-gpio.c is used to drive a one-wire bus using
64 - gpio-fan: drivers/hwmon/gpio-fan.c is used to control a fan for cooling the
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
73 - gpio-wdt: drivers/watchdog/gpio_wdt.c is used to provide a watchdog timer
75   it from 1-to-0-to-1. If that hardware does not receive its "ping"
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
83 - ps2-gpio: drivers/input/serio/ps2-gpio.c is used to drive a PS/2 (IBM) serio
84   bus, data and clock line, by bit banging two GPIO lines. It will appear as
88 - cec-gpio: drivers/media/platform/cec-gpio/ is used to interact with a CEC
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
99 - gpio-mux: drivers/mux/gpio.c is used for controlling a multiplexer using
100   n GPIO lines such that you can mux in 2^n different devices by activating
101   different GPIO lines. Often the GPIOs are on a SoC and the devices are
102   some SoC-external entities, such as different components on a PCB that
105 Apart from this there are special GPIO drivers in subsystems like MMC/SD to
106 read card detect and write protect GPIO lines, and in the TTY serial subsystem
107 to emulate MCTRL (modem control) signals CTS/RTS by using two GPIO lines. The
108 MTD NOR flash has add-ons for extra GPIO lines too, though the address bus is
114 speed up your embedded hacking in particular by providing ready-made components.