| /* |
| * 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; |
| } |