mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-22 12:14:01 +08:00
92ed1a76ca
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>
39 lines
1.1 KiB
C
39 lines
1.1 KiB
C
/*
|
|
* gpio-i2cmux interface to platform code
|
|
*
|
|
* Peter Korsgaard <peter.korsgaard@barco.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#ifndef _LINUX_GPIO_I2CMUX_H
|
|
#define _LINUX_GPIO_I2CMUX_H
|
|
|
|
/* MUX has no specific idle mode */
|
|
#define GPIO_I2CMUX_NO_IDLE ((unsigned)-1)
|
|
|
|
/**
|
|
* struct gpio_i2cmux_platform_data - Platform-dependent data for gpio-i2cmux
|
|
* @parent: Parent I2C bus adapter number
|
|
* @base_nr: Base I2C bus number to number adapters from or zero for dynamic
|
|
* @values: Array of bitmasks of GPIO settings (low/high) for each
|
|
* position
|
|
* @n_values: Number of multiplexer positions (busses to instantiate)
|
|
* @gpios: Array of GPIO numbers used to control MUX
|
|
* @n_gpios: Number of GPIOs used to control MUX
|
|
* @idle: Bitmask to write to MUX when idle or GPIO_I2CMUX_NO_IDLE if not used
|
|
*/
|
|
struct gpio_i2cmux_platform_data {
|
|
int parent;
|
|
int base_nr;
|
|
const unsigned *values;
|
|
int n_values;
|
|
const unsigned *gpios;
|
|
int n_gpios;
|
|
unsigned idle;
|
|
};
|
|
|
|
#endif /* _LINUX_GPIO_I2CMUX_H */
|