diff options
| author | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2016-01-13 15:29:27 +0100 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2016-02-12 19:16:04 +0100 |
| commit | 50a5ba876908147b36441c754e835588143c6b54 (patch) | |
| tree | c280d50a5f6d1a4fde1537a13e87cd423cb775bd /Documentation/ABI/testing/sysfs-platform-i2c-demux-pinctrl | |
| parent | 388f7b1d6e8ca06762e2454d28d6c3c55ad0fe95 (diff) | |
i2c: mux: demux-pinctrl: add driver
This driver allows an I2C bus to switch between multiple masters. This
is not hot-switching because connected I2C slaves will be
re-instantiated. It is meant to select the best I2C core at runtime once
the task is known. Example: Prefer i2c-gpio over another I2C core
because of HW errata affecting your use case.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-platform-i2c-demux-pinctrl')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-platform-i2c-demux-pinctrl | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-platform-i2c-demux-pinctrl b/Documentation/ABI/testing/sysfs-platform-i2c-demux-pinctrl new file mode 100644 index 000000000000..7ac7d7262bb7 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-platform-i2c-demux-pinctrl @@ -0,0 +1,23 @@ +What: /sys/devices/platform/<i2c-demux-name>/cur_master +Date: January 2016 +KernelVersion: 4.6 +Contact: Wolfram Sang <wsa@the-dreams.de> +Description: + +This file selects the active I2C master for a demultiplexed bus. + +Write 0 there for the first master, 1 for the second etc. Reading the file will +give you a list with the active master marked. Example from a Renesas Lager +board: + +root@Lager:~# cat /sys/devices/platform/i2c@8/cur_master +* 0 - /i2c@9 + 1 - /i2c@e6520000 + 2 - /i2c@e6530000 + +root@Lager:~# echo 2 > /sys/devices/platform/i2c@8/cur_master + +root@Lager:~# cat /sys/devices/platform/i2c@8/cur_master + 0 - /i2c@9 + 1 - /i2c@e6520000 +* 2 - /i2c@e6530000 |