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