150a5ba87SWolfram SangWhat: /sys/devices/platform/<i2c-demux-name>/cur_master 250a5ba87SWolfram SangDate: January 2016 350a5ba87SWolfram SangKernelVersion: 4.6 450a5ba87SWolfram SangContact: Wolfram Sang <wsa@the-dreams.de> 550a5ba87SWolfram SangDescription: 650a5ba87SWolfram Sang 750a5ba87SWolfram SangThis file selects the active I2C master for a demultiplexed bus. 850a5ba87SWolfram Sang 950a5ba87SWolfram SangWrite 0 there for the first master, 1 for the second etc. Reading the file will 1050a5ba87SWolfram Sanggive you a list with the active master marked. Example from a Renesas Lager 1150a5ba87SWolfram Sangboard: 1250a5ba87SWolfram Sang 1350a5ba87SWolfram Sangroot@Lager:~# cat /sys/devices/platform/i2c@8/cur_master 1450a5ba87SWolfram Sang* 0 - /i2c@9 1550a5ba87SWolfram Sang 1 - /i2c@e6520000 1650a5ba87SWolfram Sang 2 - /i2c@e6530000 1750a5ba87SWolfram Sang 1850a5ba87SWolfram Sangroot@Lager:~# echo 2 > /sys/devices/platform/i2c@8/cur_master 1950a5ba87SWolfram Sang 2050a5ba87SWolfram Sangroot@Lager:~# cat /sys/devices/platform/i2c@8/cur_master 2150a5ba87SWolfram Sang 0 - /i2c@9 2250a5ba87SWolfram Sang 1 - /i2c@e6520000 2350a5ba87SWolfram Sang* 2 - /i2c@e6530000 24