gpio_exp.h
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/*
* Copyright (C) 2014 Freescale Semiconductor, Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef __GPIO_EXP_H
#define __GPIO_EXP_H
#ifndef CONFIG_IOEXP_DEV_PINS_NUM
#define CONFIG_IOEXP_DEV_PINS_NUM 8
#endif
#ifndef CONFIG_IOEXP_DEVICES_NUM
#define CONFIG_IOEXP_DEVICES_NUM 1
#endif
/*Define for building ioexp gpio, port starts from 1, index starts from 0*/
#define IOEXP_GPIO_NR(port, index) \
((((port)-1)*CONFIG_IOEXP_DEV_PINS_NUM)+ \
((index)&(CONFIG_IOEXP_DEV_PINS_NUM-1)))
/*Get the device number from a ioexp gpio*/
#define IOEXP_GPIO_TO_DEVICE(gpio_nr) \
(gpio_nr / CONFIG_IOEXP_DEV_PINS_NUM)
/*Get the port number from a ioexp gpio*/
#define IOEXP_GPIO_TO_PORT(gpio_nr) \
((gpio_nr / CONFIG_IOEXP_DEV_PINS_NUM) + 1)
/*Get the pin number from a ioexp gpio*/
#define IOEXP_GPIO_TO_PIN(gpio_nr) \
(gpio_nr % CONFIG_IOEXP_DEV_PINS_NUM)
/**
* Make a GPIO an input.
*
* @param gpio GPIO number
* @return 0 if ok, -1 on error
*/
int gpio_exp_direction_input(unsigned gpio);
/**
* Make a GPIO an output, and set its value.
*
* @param gpio GPIO number
* @param value GPIO value (0 for low or 1 for high)
* @return 0 if ok, -1 on error
*/
int gpio_exp_direction_output(unsigned gpio, int value);
/**
* Setup the io expander's port.
*
* @param port IO expander port , starts from 1
* @param i2c_bus_id i2c bus index, starts from 0
* @param i2c_slave_addr i2c address of the io expander port
* @return 0 if ok, -1 on error
*/
int gpio_exp_setup_port(int port, int i2c_bus_id, int i2c_slave_addr);
#endif /*__GPIO_EXP_H*/