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linux-next/include/linux/i2c-mux-gpio.h

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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>
2011-01-11 05:11:23 +08:00
/*
i2c: Rename last mux driver to standard pattern Update the MAINTAINERS entry and all other references accordingly. Based on an original patch by Wolfram Sang. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Peter Korsgaard <peter.korsgaard@barco.com> [wsa: fixed merge conflict due to rework in i2c_add_mux_adapter()] Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-04-28 21:32:06 +08:00
* i2c-mux-gpio interface to platform code
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>
2011-01-11 05:11:23 +08:00
*
* 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.
*/
i2c: Rename last mux driver to standard pattern Update the MAINTAINERS entry and all other references accordingly. Based on an original patch by Wolfram Sang. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Peter Korsgaard <peter.korsgaard@barco.com> [wsa: fixed merge conflict due to rework in i2c_add_mux_adapter()] Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-04-28 21:32:06 +08:00
#ifndef _LINUX_I2C_MUX_GPIO_H
#define _LINUX_I2C_MUX_GPIO_H
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>
2011-01-11 05:11:23 +08:00
/* MUX has no specific idle mode */
i2c: Rename last mux driver to standard pattern Update the MAINTAINERS entry and all other references accordingly. Based on an original patch by Wolfram Sang. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Peter Korsgaard <peter.korsgaard@barco.com> [wsa: fixed merge conflict due to rework in i2c_add_mux_adapter()] Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-04-28 21:32:06 +08:00
#define I2C_MUX_GPIO_NO_IDLE ((unsigned)-1)
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>
2011-01-11 05:11:23 +08:00
/**
i2c: Rename last mux driver to standard pattern Update the MAINTAINERS entry and all other references accordingly. Based on an original patch by Wolfram Sang. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Peter Korsgaard <peter.korsgaard@barco.com> [wsa: fixed merge conflict due to rework in i2c_add_mux_adapter()] Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-04-28 21:32:06 +08:00
* struct i2c_mux_gpio_platform_data - Platform-dependent data for i2c-mux-gpio
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>
2011-01-11 05:11:23 +08:00
* @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)
i2c-mux: Add support for device auto-detection Let I2C bus segments behind multiplexers have a class. This allows for device auto-detection on these segments. As long as parent segments don't share the same class, it should be fine. I implemented support in drivers i2c-mux-gpio and i2c-mux-pca954x. I left i2c-mux-pca9541 and i2c-mux-pinctrl alone for the moment as I don't know if this feature makes sense for the use cases of these drivers. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Peter Korsgaard <peter.korsgaard@barco.com> Cc: David Daney <david.daney@cavium.com> Cc: Michael Lawnick <ml.lawnick@gmx.de> Cc: Rodolfo Giometti <giometti@linux.it>
2012-10-06 04:23:51 +08:00
* @classes: Optional I2C auto-detection classes
i2c-mux-gpio: Add support for dynamically allocated GPIO pins The code instantiating an i2c-mux-gpio platform device doesn't necessarily know in advance the GPIO pin numbers it wants to use. If pins are on a GPIO device which gets its base GPIO number assigned dynamically at run-time, the values can't be hard-coded. In that case, let the caller tell i2c-mux-gpio the name of the GPIO chip and the (relative) GPIO pin numbers to use. At probe time, the i2c-mux-gpio driver will look for the chip and apply the proper offset to turn relative GPIO pin numbers to absolute GPIO pin numbers. The same could be (and was so far) done on the caller's end, however doing it in i2c-mux-gpio has two benefits: * It avoids duplicating the code on every caller's side (about 30 lines of code.) * It allows for deferred probing for the muxed part of the I2C bus only. If finding the GPIO chip is the caller's responsibility, then deferred probing (if the GPIO chip isn't there yet) will not only affect the mux and the I2C bus segments behind it, but also the I2C bus trunk. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Peter Korsgaard <peter.korsgaard@barco.com>
2012-10-06 04:23:54 +08:00
* @gpio_chip: Optional GPIO chip name; if set, GPIO pin numbers are given
* relative to the base GPIO number of that chip
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>
2011-01-11 05:11:23 +08:00
* @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
*/
i2c: Rename last mux driver to standard pattern Update the MAINTAINERS entry and all other references accordingly. Based on an original patch by Wolfram Sang. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Peter Korsgaard <peter.korsgaard@barco.com> [wsa: fixed merge conflict due to rework in i2c_add_mux_adapter()] Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-04-28 21:32:06 +08:00
struct i2c_mux_gpio_platform_data {
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>
2011-01-11 05:11:23 +08:00
int parent;
int base_nr;
const unsigned *values;
int n_values;
i2c-mux: Add support for device auto-detection Let I2C bus segments behind multiplexers have a class. This allows for device auto-detection on these segments. As long as parent segments don't share the same class, it should be fine. I implemented support in drivers i2c-mux-gpio and i2c-mux-pca954x. I left i2c-mux-pca9541 and i2c-mux-pinctrl alone for the moment as I don't know if this feature makes sense for the use cases of these drivers. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Peter Korsgaard <peter.korsgaard@barco.com> Cc: David Daney <david.daney@cavium.com> Cc: Michael Lawnick <ml.lawnick@gmx.de> Cc: Rodolfo Giometti <giometti@linux.it>
2012-10-06 04:23:51 +08:00
const unsigned *classes;
i2c-mux-gpio: Add support for dynamically allocated GPIO pins The code instantiating an i2c-mux-gpio platform device doesn't necessarily know in advance the GPIO pin numbers it wants to use. If pins are on a GPIO device which gets its base GPIO number assigned dynamically at run-time, the values can't be hard-coded. In that case, let the caller tell i2c-mux-gpio the name of the GPIO chip and the (relative) GPIO pin numbers to use. At probe time, the i2c-mux-gpio driver will look for the chip and apply the proper offset to turn relative GPIO pin numbers to absolute GPIO pin numbers. The same could be (and was so far) done on the caller's end, however doing it in i2c-mux-gpio has two benefits: * It avoids duplicating the code on every caller's side (about 30 lines of code.) * It allows for deferred probing for the muxed part of the I2C bus only. If finding the GPIO chip is the caller's responsibility, then deferred probing (if the GPIO chip isn't there yet) will not only affect the mux and the I2C bus segments behind it, but also the I2C bus trunk. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Peter Korsgaard <peter.korsgaard@barco.com>
2012-10-06 04:23:54 +08:00
char *gpio_chip;
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>
2011-01-11 05:11:23 +08:00
const unsigned *gpios;
int n_gpios;
unsigned idle;
};
i2c: Rename last mux driver to standard pattern Update the MAINTAINERS entry and all other references accordingly. Based on an original patch by Wolfram Sang. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Peter Korsgaard <peter.korsgaard@barco.com> [wsa: fixed merge conflict due to rework in i2c_add_mux_adapter()] Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-04-28 21:32:06 +08:00
#endif /* _LINUX_I2C_MUX_GPIO_H */
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