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| author | Jean Delvare <khali@linux-fr.org> | 2012-10-05 22:23:54 +0200 |
|---|---|---|
| committer | Jean Delvare <khali@endymion.delvare> | 2012-10-05 22:23:54 +0200 |
| commit | 600a711cfeb10769e386c4ce7d39e9f0cc4b471a (patch) | |
| tree | a922d6b426495e70e93d6c144dc15fad22c9d2ae /Documentation/i2c | |
| parent | i2c-mux-gpio: Add support for dynamically allocated GPIO pins (diff) | |
| download | linux-600a711cfeb10769e386c4ce7d39e9f0cc4b471a.tar.xz linux-600a711cfeb10769e386c4ce7d39e9f0cc4b471a.zip | |
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: Jean Delvare <khali@linux-fr.org>
Cc: Peter Korsgaard <peter.korsgaard@barco.com>
Diffstat (limited to 'Documentation/i2c')
| -rw-r--r-- | Documentation/i2c/muxes/i2c-mux-gpio | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/Documentation/i2c/muxes/i2c-mux-gpio b/Documentation/i2c/muxes/i2c-mux-gpio index bd9b2299b739..d4d91a53fc39 100644 --- a/Documentation/i2c/muxes/i2c-mux-gpio +++ b/Documentation/i2c/muxes/i2c-mux-gpio @@ -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. |