zephyr/drivers/gpio/gpio_mcp23xxx.c

297 lines
6.3 KiB
C

/*
*
* Copyright (c) 2021 metraTec GmbH
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file Driver for MPC23xxx I2C/SPI-based GPIO driver.
*/
#include <errno.h>
#include <kernel.h>
#include <device.h>
#include <sys/byteorder.h>
#include <drivers/gpio.h>
#include "gpio_utils.h"
#include "gpio_mcp23xxx.h"
#define LOG_LEVEL CONFIG_GPIO_LOG_LEVEL
#include <logging/log.h>
LOG_MODULE_REGISTER(gpio_mcp23xxx);
/**
* @brief Reads given register from mcp23xxx.
*
* The registers of the mcp23x0x consist of one 8 bit port.
* The registers of the mcp23x1x consist of two 8 bit ports.
*
* @param dev The mcp23xxx device.
* @param reg The register to be read.
* @param buf The buffer to read data to.
* @return 0 if successful.
* Otherwise <0 will be returned.
*/
static int read_port_regs(const struct device *dev, uint8_t reg, uint16_t *buf)
{
const struct mcp23xxx_config *config = dev->config;
if (config->ngpios == 16U) {
reg *= 2;
}
return config->read_fn(dev, reg, buf);
}
/**
* @brief Writes registers of the mcp23xxx.
*
* On the mcp23x08 one 8 bit port will be written.
* On the mcp23x17 two 8 bit ports will be written.
*
* @param dev The mcp23xxx device.
* @param reg Register to be written.
* @param buf The new register value.
*
* @return 0 if successful. Otherwise <0 will be returned.
*/
static int write_port_regs(const struct device *dev, uint8_t reg, uint16_t value)
{
const struct mcp23xxx_config *config = dev->config;
if (config->ngpios == 16U) {
reg *= 2;
}
return config->write_fn(dev, reg, value);
}
/**
* @brief Setup the pin direction.
*
* @param dev The mcp23xxx device.
* @param pin The pin number.
* @param flags Flags of pin or port.
* @return 0 if successful. Otherwise <0 will be returned.
*/
static int setup_pin_dir(const struct device *dev, uint32_t pin, int flags)
{
struct mcp23xxx_drv_data *drv_data = dev->data;
uint16_t dir = drv_data->reg_cache.iodir;
uint16_t output = drv_data->reg_cache.gpio;
int ret;
if ((flags & GPIO_OUTPUT) != 0U) {
if ((flags & GPIO_OUTPUT_INIT_HIGH) != 0U) {
output |= BIT(pin);
} else if ((flags & GPIO_OUTPUT_INIT_LOW) != 0U) {
output &= ~BIT(pin);
}
dir &= ~BIT(pin);
} else {
dir |= BIT(pin);
}
ret = write_port_regs(dev, REG_GPIO, output);
if (ret != 0) {
return ret;
}
drv_data->reg_cache.gpio = output;
ret = write_port_regs(dev, REG_IODIR, dir);
if (ret == 0) {
drv_data->reg_cache.iodir = dir;
}
return ret;
}
/**
* @brief Setup pin pull up/pull down.
*
* @param dev The mcp23xxx device.
* @param pin The pin number.
* @param flags Flags of pin or port.
* @return 0 if successful. Otherwise <0 will be returned.
*/
static int setup_pin_pull(const struct device *dev, uint32_t pin, int flags)
{
struct mcp23xxx_drv_data *drv_data = dev->data;
uint16_t port;
int ret;
port = drv_data->reg_cache.gppu;
if ((flags & GPIO_PULL_DOWN) != 0U) {
return -ENOTSUP;
}
WRITE_BIT(port, pin, (flags & GPIO_PULL_UP) != 0);
ret = write_port_regs(dev, REG_GPPU, port);
if (ret == 0) {
drv_data->reg_cache.gppu = port;
}
return ret;
}
static int mcp23xxx_pin_cfg(const struct device *dev, gpio_pin_t pin, gpio_flags_t flags)
{
struct mcp23xxx_drv_data *drv_data = dev->data;
int ret;
if (k_is_in_isr()) {
return -EWOULDBLOCK;
}
k_sem_take(&drv_data->lock, K_FOREVER);
if ((flags & GPIO_SINGLE_ENDED) != 0U) {
ret = -ENOTSUP;
goto done;
}
ret = setup_pin_dir(dev, pin, flags);
if (ret < 0) {
LOG_ERR("Error setting pin direction (%d)", ret);
goto done;
}
ret = setup_pin_pull(dev, pin, flags);
if (ret < 0) {
LOG_ERR("Error setting pin pull up/pull down (%d)", ret);
goto done;
}
done:
k_sem_give(&drv_data->lock);
return ret;
}
static int mcp23xxx_port_get_raw(const struct device *dev, uint32_t *value)
{
struct mcp23xxx_drv_data *drv_data = dev->data;
uint16_t buf;
int ret;
if (k_is_in_isr()) {
return -EWOULDBLOCK;
}
k_sem_take(&drv_data->lock, K_FOREVER);
ret = read_port_regs(dev, REG_GPIO, &buf);
if (ret == 0) {
*value = buf;
}
k_sem_give(&drv_data->lock);
return ret;
}
static int mcp23xxx_port_set_masked_raw(const struct device *dev, uint32_t mask, uint32_t value)
{
struct mcp23xxx_drv_data *drv_data = dev->data;
uint16_t buf;
int ret;
if (k_is_in_isr()) {
return -EWOULDBLOCK;
}
k_sem_take(&drv_data->lock, K_FOREVER);
buf = drv_data->reg_cache.gpio;
buf = (buf & ~mask) | (mask & value);
ret = write_port_regs(dev, REG_GPIO, buf);
if (ret == 0) {
drv_data->reg_cache.gpio = buf;
}
k_sem_give(&drv_data->lock);
return ret;
}
static int mcp23xxx_port_set_bits_raw(const struct device *dev, uint32_t mask)
{
return mcp23xxx_port_set_masked_raw(dev, mask, mask);
}
static int mcp23xxx_port_clear_bits_raw(const struct device *dev, uint32_t mask)
{
return mcp23xxx_port_set_masked_raw(dev, mask, 0);
}
static int mcp23xxx_port_toggle_bits(const struct device *dev, uint32_t mask)
{
struct mcp23xxx_drv_data *drv_data = dev->data;
uint16_t buf;
int ret;
if (k_is_in_isr()) {
return -EWOULDBLOCK;
}
k_sem_take(&drv_data->lock, K_FOREVER);
buf = drv_data->reg_cache.gpio;
buf ^= mask;
ret = write_port_regs(dev, REG_GPIO, buf);
if (ret == 0) {
drv_data->reg_cache.gpio = buf;
}
k_sem_give(&drv_data->lock);
return ret;
}
static int mcp23xxx_pin_interrupt_configure(const struct device *dev, gpio_pin_t pin,
enum gpio_int_mode mode, enum gpio_int_trig trig)
{
return -ENOTSUP;
}
const struct gpio_driver_api gpio_mcp23xxx_api_table = {
.pin_configure = mcp23xxx_pin_cfg,
.port_get_raw = mcp23xxx_port_get_raw,
.port_set_masked_raw = mcp23xxx_port_set_masked_raw,
.port_set_bits_raw = mcp23xxx_port_set_bits_raw,
.port_clear_bits_raw = mcp23xxx_port_clear_bits_raw,
.port_toggle_bits = mcp23xxx_port_toggle_bits,
.pin_interrupt_configure = mcp23xxx_pin_interrupt_configure,
};
/**
* @brief Initialization function of MCP23XXX
*
* @param dev Device struct.
* @return 0 if successful. Otherwise <0 is returned.
*/
int gpio_mcp23xxx_init(const struct device *dev)
{
const struct mcp23xxx_config *config = dev->config;
struct mcp23xxx_drv_data *drv_data = dev->data;
int err;
if (config->ngpios != 8U && config->ngpios != 16U) {
LOG_ERR("Invalid value ngpios=%u. Expected 8 or 16!", config->ngpios);
return -EINVAL;
}
err = config->bus_fn(dev);
if (err < 0) {
return err;
}
k_sem_init(&drv_data->lock, 1, 1);
return 0;
}