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authorJ. Bruce Fields <bfields@redhat.com>2012-10-09 18:35:22 -0400
committerJ. Bruce Fields <bfields@redhat.com>2012-10-09 18:35:22 -0400
commitf474af7051212b4efc8267583fad9c4ebf33ccff (patch)
tree1aa46ebc8065a341f247c2a2d9af2f624ad1d4f8 /Documentation/i2c/muxes/i2c-mux-gpio
parent0d22f68f02c10d5d10ec5712917e5828b001a822 (diff)
parente3dd9a52cb5552c46c2a4ca7ccdfb4dab5c72457 (diff)
downloadlinux-f474af7051212b4efc8267583fad9c4ebf33ccff.tar.bz2
nfs: disintegrate UAPI for nfs
This is to complete part of the Userspace API (UAPI) disintegration for which the preparatory patches were pulled recently. After these patches, userspace headers will be segregated into: include/uapi/linux/.../foo.h for the userspace interface stuff, and: include/linux/.../foo.h for the strictly kernel internal stuff. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'Documentation/i2c/muxes/i2c-mux-gpio')
-rw-r--r--Documentation/i2c/muxes/i2c-mux-gpio18
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.