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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.
*/
#include <common.h>
#include <asm/gpio.h>
#include <asm/io.h>
#include <errno.h>
#include <i2c.h>
#include <gpio_exp.h>
#define MAX7310_REG_INPUT_PORT 0x00
#define MAX7310_REG_OUTPUT_PORT 0x01
#define MAX7310_REG_POLARITY 0x02
#define MAX7310_REG_CONFIGURATION 0x03
#define MAX7310_REG_TIMEOUT 0x04
enum max7310_gpio_direction {
MAX7310_GPIO_DIRECTION_IN,
MAX7310_GPIO_DIRECTION_OUT,
};
struct max7310_config_struct {
int i2c_slave_addr;
int i2c_bus_id;
};
static struct max7310_config_struct max7310_configs[CONFIG_IOEXP_DEVICES_NUM];
static int max7310_gpio_direction(unsigned int gpio,
enum max7310_gpio_direction direction)
{
unsigned int dev = IOEXP_GPIO_TO_DEVICE(gpio);
unsigned int pin = IOEXP_GPIO_TO_PIN(gpio);
unsigned char value, val2, val3;
unsigned char chip;
if (dev >= CONFIG_IOEXP_DEVICES_NUM)
return -EPERM;
chip = max7310_configs[dev].i2c_slave_addr;
i2c_set_bus_num(max7310_configs[dev].i2c_bus_id);
if (i2c_probe(chip))
return -ENXIO;
i2c_read(chip, MAX7310_REG_CONFIGURATION, 1, &value, 1);
switch (direction) {
case MAX7310_GPIO_DIRECTION_OUT:
value &= ~(1 << pin);
i2c_write(chip, MAX7310_REG_CONFIGURATION, 1, &value, 1);
break;
case MAX7310_GPIO_DIRECTION_IN:
i2c_read(chip, MAX7310_REG_POLARITY, 1, &val2, 1);
i2c_read(chip, MAX7310_REG_OUTPUT_PORT, 1, &val3, 1);
value |= (1 << pin);
val2 &= ~(1 << pin);
val3 &= ~(1 << pin);
i2c_write(chip, MAX7310_REG_POLARITY, 1, &val2, 1);
i2c_write(chip, MAX7310_REG_CONFIGURATION, 1, &value, 1);
i2c_write(chip, MAX7310_REG_OUTPUT_PORT, 1, &val3, 1);
break;
}
return 0;
}
static int max7310_gpio_set_value(unsigned gpio, int value)
{
unsigned int dev = IOEXP_GPIO_TO_DEVICE(gpio);
unsigned int pin = IOEXP_GPIO_TO_PIN(gpio);
unsigned char reg_val;
unsigned char chip;
if (dev >= CONFIG_IOEXP_DEVICES_NUM)
return -EPERM;
chip = max7310_configs[dev].i2c_slave_addr;
i2c_set_bus_num(max7310_configs[dev].i2c_bus_id);
if (i2c_probe(chip))
return -ENXIO;
i2c_read(chip, MAX7310_REG_OUTPUT_PORT, 1, ®_val, 1);
if (value)
reg_val |= 1 << pin;
else
reg_val &= ~(1 << pin);
i2c_write(chip, MAX7310_REG_OUTPUT_PORT, 1, ®_val, 1);
return 0;
}
static int max7310_gpio_get_value(unsigned gpio)
{
unsigned int dev = IOEXP_GPIO_TO_DEVICE(gpio);
unsigned int pin = IOEXP_GPIO_TO_PIN(gpio);
unsigned char reg_val;
unsigned char chip;
if (dev >= CONFIG_IOEXP_DEVICES_NUM)
return -EPERM;
chip = max7310_configs[dev].i2c_slave_addr;
i2c_set_bus_num(max7310_configs[dev].i2c_bus_id);
if (i2c_probe(chip))
return -ENXIO;
i2c_read(chip, MAX7310_REG_INPUT_PORT, 1, ®_val, 1);
reg_val = (reg_val >> pin) & 0x01;
return reg_val;
}
int gpio_exp_direction_input(unsigned gpio)
{
int ret = max7310_gpio_direction(gpio, MAX7310_GPIO_DIRECTION_IN);
if (ret < 0)
return ret;
return max7310_gpio_get_value(gpio);
}
int gpio_exp_direction_output(unsigned gpio, int value)
{
int ret = max7310_gpio_direction(gpio, MAX7310_GPIO_DIRECTION_OUT);
if (ret < 0)
return ret;
return max7310_gpio_set_value(gpio, value);
}
int gpio_exp_setup_port(int port, int i2c_bus_id, int i2c_slave_addr)
{
if (port > CONFIG_IOEXP_DEVICES_NUM || port <= 0)
return -EPERM;
max7310_configs[port-1].i2c_bus_id = i2c_bus_id;
max7310_configs[port-1].i2c_slave_addr = i2c_slave_addr;
return 0;
}
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