Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 600a711c authored by Jean Delvare's avatar Jean Delvare Committed by Jean Delvare
Browse files

i2c-mux-gpio: Update documentation 



* Document the possibility to pass relative GPIO pin numbers.
* Document what platform device IDs to use, so that they do not
  collide.

Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
Cc: Peter Korsgaard <peter.korsgaard@barco.com>
parent e7ee5140

Documentation/i2c/muxes/i2c-mux-gpio

+18 −0
Original line number Diff line number Diff line
@@ -63,3 +63,21 @@ static struct platform_device myboard_i2cmux = { 
		.platform_data	= &myboard_i2cmux_data,

	},

};



If you don't know the absolute GPIO pin numbers at registration time,

you can instead provide a chip name (.chip_name) and relative GPIO pin

numbers, and the i2c-gpio-mux driver will do the work for you,

including deferred probing if the GPIO chip isn't immediately

available.



Device Registration

-------------------



When registering your i2c-gpio-mux device, you should pass the number

of any GPIO pin it uses as the device ID. This guarantees that every

instance has a different ID.



Alternatively, if you don't need a stable device name, you can simply

pass PLATFORM_DEVID_AUTO as the device ID, and the platform core will

assign a dynamic ID to your device. If you do not know the absolute

GPIO pin numbers at registration time, this is even the only option.