i2c: Add generic I2C multiplexer using GPIO API

Add an i2c mux driver providing access to i2c bus segments using a
hardware MUX sitting on a master bus and controlled through gpio pins.

E.G. something like:

  ----------              ----------  Bus segment 1   - - - - -
 |          | SCL/SDA    |          |-------------- |           |
 |          |------------|          |
 |          |            |          | Bus segment 2 |           |
 |  Linux   | GPIO 1..N  |   MUX    |---------------   Devices
 |          |------------|          |               |           |
 |          |            |          | Bus segment M
 |          |            |          |---------------|           |
  ----------              ----------                  - - - - -

SCL/SDA of the master I2C bus is multiplexed to bus segment 1..M
according to the settings of the GPIO pins 1..N.

Signed-off-by: Peter Korsgaard <peter.korsgaard@barco.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 23d04363a195..23a4765ab8d2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2608,6 +2608,14 @@ S:	Supported
 F:      drivers/i2c/busses/i2c-gpio.c
 F:      include/linux/i2c-gpio.h
 
+GENERIC GPIO I2C MULTIPLEXER DRIVER
+M:      Peter Korsgaard <peter.korsgaard@barco.com>
+L:      linux-i2c@vger.kernel.org
+S:      Supported
+F:      drivers/i2c/muxes/gpio-i2cmux.c
+F:      include/linux/gpio-i2cmux.h
+F:      Documentation/i2c/muxes/gpio-i2cmux
+
 GENERIC HDLC (WAN) DRIVERS
 M:      Krzysztof Halasa <khc@pm.waw.pl>
 W:      http://www.kernel.org/pub/linux/utils/net/hdlc/