diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpio/Makefile | 1 | ||||
| -rw-r--r-- | drivers/gpio/max7310_ioexp.c | 167 |
2 files changed, 168 insertions, 0 deletions
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 9df1e26..e46fd0f 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -47,6 +47,7 @@ COBJS-$(CONFIG_OMAP_GPIO) += omap_gpio.o COBJS-$(CONFIG_DB8500_GPIO) += db8500_gpio.o COBJS-$(CONFIG_BCM2835_GPIO) += bcm2835_gpio.o COBJS-$(CONFIG_S3C2440_GPIO) += s3c2440_gpio.o +COBJS-$(CONFIG_MAX7310_IOEXP) += max7310_ioexp.o COBJS := $(COBJS-y) SRCS := $(COBJS:.o=.c) diff --git a/drivers/gpio/max7310_ioexp.c b/drivers/gpio/max7310_ioexp.c new file mode 100644 index 0000000..34c494f --- /dev/null +++ b/drivers/gpio/max7310_ioexp.c @@ -0,0 +1,167 @@ +/* + * 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; +} |