From 50a5ba876908147b36441c754e835588143c6b54 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Wed, 13 Jan 2016 15:29:27 +0100 Subject: 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 Acked-by: Rob Herring Signed-off-by: Wolfram Sang --- .../ABI/testing/sysfs-platform-i2c-demux-pinctrl | 23 ++++++++++++++++++++++ 1 file changed, 23 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-platform-i2c-demux-pinctrl (limited to 'Documentation/ABI') 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//cur_master +Date: January 2016 +KernelVersion: 4.6 +Contact: Wolfram Sang +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 -- cgit v1.2.3