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zephyr/drivers/gpio/gpio_tca6424a.c

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/*
* Copyright (c) 2022 Chromium OS Authors
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT ti_tca6424a
#include <zephyr/drivers/gpio/gpio_utils.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/logging/log.h>
#include <zephyr/sys/byteorder.h>
#include <zephyr/sys/util.h>
LOG_MODULE_REGISTER(gpio_tca6424a, CONFIG_GPIO_LOG_LEVEL);
/* TCA6424A auto increment register addresses */
#define TCA6424A_REG_INPUT 0x80
#define TCA6424A_REG_OUTPUT 0x84
#define TCA6424A_REG_POLARITY_INVERSION 0x88
#define TCA6424A_REG_CONFIGURATION 0x8C
/** Cache of the output configuration and data of the pins. */
struct tca6424a_pins_state {
uint32_t input;
uint32_t output;
uint32_t config;
};
struct tca6424a_irq_state {
uint32_t rising;
uint32_t falling;
};
/** Configuration data */
struct tca6424a_drv_cfg {
/* gpio_driver_config needs to be first */
struct gpio_driver_config common;
struct i2c_dt_spec i2c_spec;
struct gpio_dt_spec int_gpio;
struct gpio_dt_spec reset_gpio;
};
/** Runtime driver data */
struct tca6424a_drv_data {
/* gpio_driver_data needs to be first */
struct gpio_driver_data common;
sys_slist_t callbacks;
struct k_sem lock;
struct k_work work;
const struct device *dev;
struct gpio_callback int_gpio_cb;
struct tca6424a_pins_state pins_state;
struct tca6424a_irq_state irq_state;
};
/**
* @brief Gets the state of a specified block of 3 registers from the TCA6424A
* and stores it in specified cache and buffer variables.
*
* @param dev Pointer to the device structure for the driver instance.
* @param reg Address of the first of 3 registers to be read.
* @param cache Pointer to the location to cache the pins states.
* @param buf Pointer to the buffer to output the register.
*
* @retval 0 if successful.
* @retval Negative value for error code.
*/
static int read_port_regs(const struct device *dev, uint8_t reg, uint32_t *buf)
{
const struct tca6424a_drv_cfg *const config = dev->config;
uint32_t port_data, value;
int ret;
ret = i2c_burst_read_dt(&config->i2c_spec, reg, (uint8_t *)&port_data, 3);
if (ret != 0) {
LOG_ERR("%s: error reading register 0x%X (%d)", dev->name,
reg, ret);
return ret;
}
value = sys_le24_to_cpu(port_data);
*buf = value;
LOG_DBG("%s: Read: REG[0x%X] = 0x%X, REG[0x%X] = 0x%X, "
"REG[0x%X] = 0x%X",
dev->name, reg, (*buf & 0xFF), (reg + 1), ((*buf >> 8) & 0xFF),
(reg + 2), ((*buf >> 16) & 0xFF));
return 0;
}
/**
* @brief writes to a specified block of 3 registers from the TCA6424A
* and stores it in a specified cache variable.
*
* @param dev Pointer to the device structure for the driver instance.
* @param reg Address of the first of 3 registers to be written.
* @param cache Pointer to the location to cache the pins states.
* @param value The pin value to be written into the registers.
*
* @retval 0 if successful.
* @retval Negative value for error code.
*/
static int write_port_regs(const struct device *dev, uint8_t reg, uint32_t value)
{
const struct tca6424a_drv_cfg *const config = dev->config;
uint8_t buf[4];
int ret;
LOG_DBG("%s: Write: REG[0x%X] = 0x%X, REG[0x%X] = 0x%X, "
"REG[0x%X] = 0x%X",
dev->name, reg, (value & 0xFF), (reg + 1), ((value >> 8) & 0xFF),
(reg + 2), ((value >> 16) & 0xFF));
buf[0] = reg;
sys_put_le24(value, &buf[1]);
ret = i2c_write_dt(&config->i2c_spec, buf, sizeof(buf));
if (ret != 0) {
LOG_ERR("%s: error writing to register 0x%X "
"(%d)",
dev->name, reg, ret);
}
return ret;
}
static inline int update_input_regs(const struct device *dev, uint32_t *buf)
{
int ret;
struct tca6424a_drv_data *const drv_data = dev->data;
ret = read_port_regs(dev, TCA6424A_REG_INPUT, buf);
if (ret == 0) {
drv_data->pins_state.input = *buf;
}
return ret;
}
static inline int update_output_regs(const struct device *dev, uint32_t value)
{
int ret;
struct tca6424a_drv_data *const drv_data = dev->data;
ret = write_port_regs(dev, TCA6424A_REG_OUTPUT, value);
if (ret == 0) {
drv_data->pins_state.output = value;
}
return ret;
}
static inline int update_invers_regs(const struct device *dev, uint32_t value)
{
return write_port_regs(dev, TCA6424A_REG_POLARITY_INVERSION, value);
}
static inline int update_config_regs(const struct device *dev, uint32_t value)
{
int ret;
struct tca6424a_drv_data *const drv_data = dev->data;
ret = write_port_regs(dev, TCA6424A_REG_CONFIGURATION, value);
if (ret == 0) {
drv_data->pins_state.config = value;
}
return ret;
}
/**
* @brief Handles interrupt triggered by the interrupt pin of TCA6424A.
*
* If int_gpios is configured in device tree then this will be triggered each
* time a gpio configured as an input changes state. The gpio input states are
* read in this function which clears the interrupt.
*
* @param dev Pointer to the device structure for the driver instance.
*/
static void tca6424a_handle_interrupt(const struct device *dev)
{
struct tca6424a_drv_data *drv_data = dev->data;
struct tca6424a_irq_state *irq_state = &drv_data->irq_state;
int ret;
uint32_t previous_state;
uint32_t current_state;
uint32_t transitioned_pins;
uint32_t interrupt_status;
k_sem_take(&drv_data->lock, K_FOREVER);
/* Any interrupts enabled? */
if (!irq_state->rising && !irq_state->falling) {
k_sem_give(&drv_data->lock);
return;
}
/* Store previous input state then read new value */
previous_state = drv_data->pins_state.input;
ret = update_input_regs(dev, &current_state);
if (ret != 0) {
k_sem_give(&drv_data->lock);
return;
}
/* Find out which input pins have changed state */
transitioned_pins = previous_state ^ current_state;
/* Mask gpio transactions with rising/falling edge interrupt config */
interrupt_status = (irq_state->rising & transitioned_pins & current_state);
interrupt_status |= (irq_state->falling & transitioned_pins & previous_state);
k_sem_give(&drv_data->lock);
if (interrupt_status) {
gpio_fire_callbacks(&drv_data->callbacks, dev, interrupt_status);
}
}
/**
* @brief Work handler for TCA6424A interrupt
*
* @param work Work struct that contains pointer to interrupt handler function
*/
static void tca6424a_work_handler(struct k_work *work)
{
struct tca6424a_drv_data *drv_data = CONTAINER_OF(work, struct tca6424a_drv_data, work);
tca6424a_handle_interrupt(drv_data->dev);
}
/**
* @brief ISR for interrupt pin of TCA6424A
*
* @param dev Pointer to the device structure for the driver instance.
* @param gpio_cb Pointer to callback function struct
* @param pins Bitmask of pins that triggered interrupt
*/
static void tca6424a_int_gpio_handler(const struct device *dev, struct gpio_callback *gpio_cb,
uint32_t pins)
{
ARG_UNUSED(dev);
ARG_UNUSED(pins);
struct tca6424a_drv_data *drv_data =
CONTAINER_OF(gpio_cb, struct tca6424a_drv_data, int_gpio_cb);
k_work_submit(&drv_data->work);
}
static int tca6424a_setup_pin(const struct device *dev, gpio_pin_t pin, gpio_flags_t flags)
{
struct tca6424a_drv_data *const drv_data = dev->data;
uint32_t reg_cfg = drv_data->pins_state.config;
uint32_t reg_out = drv_data->pins_state.output;
int ret;
/* For each pin, 0 == output, 1 == input */
if ((flags & GPIO_OUTPUT) != 0) {
if ((flags & GPIO_OUTPUT_INIT_HIGH) != 0) {
reg_out |= BIT(pin);
} else if ((flags & GPIO_OUTPUT_INIT_LOW) != 0) {
reg_out &= ~BIT(pin);
}
ret = update_output_regs(dev, reg_out);
if (ret != 0) {
return ret;
}
reg_cfg &= ~BIT(pin);
} else {
reg_cfg |= BIT(pin);
}
ret = update_config_regs(dev, reg_cfg);
return ret;
}
static int tca6424a_pin_config(const struct device *dev, gpio_pin_t pin, gpio_flags_t flags)
{
int ret;
struct tca6424a_drv_data *const drv_data = dev->data;
/* Does not support disconnected pin */
if ((flags & (GPIO_INPUT | GPIO_OUTPUT)) == GPIO_DISCONNECTED) {
return -ENOTSUP;
}
/* Single Ended lines (Open drain and open source) not supported */
if ((flags & GPIO_SINGLE_ENDED) != 0) {
return -ENOTSUP;
}
/* The TCA6424A has no internal pull up support */
if (((flags & GPIO_PULL_UP) != 0) || ((flags & GPIO_PULL_DOWN) != 0)) {
return -ENOTSUP;
}
/* Simultaneous input & output mode not supported */
if (((flags & GPIO_INPUT) != 0) && ((flags & GPIO_OUTPUT) != 0)) {
return -ENOTSUP;
}
/* Can't do I2C bus operations from an ISR */
if (k_is_in_isr()) {
return -EWOULDBLOCK;
}
k_sem_take(&drv_data->lock, K_FOREVER);
ret = tca6424a_setup_pin(dev, pin, flags);
if (ret != 0) {
LOG_ERR("%s: error setting pin direction (%d)", dev->name, ret);
}
k_sem_give(&drv_data->lock);
return ret;
}
static int tca6424a_port_get_raw(const struct device *dev, gpio_port_value_t *value)
{
struct tca6424a_drv_data *const drv_data = dev->data;
uint32_t buf;
int ret;
/* Can't do I2C bus operations from an ISR */
if (k_is_in_isr()) {
return -EWOULDBLOCK;
}
k_sem_take(&drv_data->lock, K_FOREVER);
ret = update_input_regs(dev, &buf);
if (ret == 0) {
*value = buf;
}
k_sem_give(&drv_data->lock);
return ret;
}
static int tca6424a_port_set_masked_raw(const struct device *dev, gpio_port_pins_t mask,
gpio_port_value_t value)
{
struct tca6424a_drv_data *const drv_data = dev->data;
uint32_t reg_out;
int ret;
/* Can't do I2C bus operations from an ISR */
if (k_is_in_isr()) {
return -EWOULDBLOCK;
}
k_sem_take(&drv_data->lock, K_FOREVER);
reg_out = drv_data->pins_state.output;
reg_out = (reg_out & ~mask) | (mask & value);
ret = update_output_regs(dev, reg_out);
k_sem_give(&drv_data->lock);
return ret;
}
static int tca6424a_port_set_bits_raw(const struct device *dev, gpio_port_pins_t mask)
{
return tca6424a_port_set_masked_raw(dev, mask, mask);
}
static int tca6424a_port_clear_bits_raw(const struct device *dev, gpio_port_pins_t mask)
{
return tca6424a_port_set_masked_raw(dev, mask, 0);
}
static int tca6424a_port_toggle_bits(const struct device *dev, gpio_port_pins_t mask)
{
struct tca6424a_drv_data *const drv_data = dev->data;
uint32_t reg_out;
int ret;
/* Can't do I2C bus operations from an ISR */
if (k_is_in_isr()) {
return -EWOULDBLOCK;
}
k_sem_take(&drv_data->lock, K_FOREVER);
reg_out = drv_data->pins_state.output;
reg_out ^= mask;
ret = update_output_regs(dev, reg_out);
k_sem_give(&drv_data->lock);
return ret;
}
static int tca6424a_pin_interrupt_configure(const struct device *dev, gpio_pin_t pin,
enum gpio_int_mode mode, enum gpio_int_trig trig)
{
struct tca6424a_drv_data *drv_data = dev->data;
struct tca6424a_irq_state *irq = &drv_data->irq_state;
/* Device does not support level-triggered interrupts. */
if (mode == GPIO_INT_MODE_LEVEL) {
return -ENOTSUP;
}
k_sem_take(&drv_data->lock, K_FOREVER);
if (mode == GPIO_INT_MODE_DISABLED) {
irq->falling &= ~BIT(pin);
irq->rising &= ~BIT(pin);
} else { /* GPIO_INT_MODE_EDGE */
if (trig == GPIO_INT_TRIG_BOTH) {
irq->falling |= BIT(pin);
irq->rising |= BIT(pin);
} else if (trig == GPIO_INT_TRIG_LOW) {
irq->falling |= BIT(pin);
irq->rising &= ~BIT(pin);
} else if (trig == GPIO_INT_TRIG_HIGH) {
irq->falling &= ~BIT(pin);
irq->rising |= BIT(pin);
}
}
k_sem_give(&drv_data->lock);
return 0;
}
static int tca6424a_manage_callback(const struct device *dev, struct gpio_callback *callback,
bool set)
{
struct tca6424a_drv_data *drv_data = dev->data;
return gpio_manage_callback(&drv_data->callbacks, callback, set);
}
static const struct gpio_driver_api tca6424a_drv_api = {
.pin_configure = tca6424a_pin_config,
.port_get_raw = tca6424a_port_get_raw,
.port_set_masked_raw = tca6424a_port_set_masked_raw,
.port_set_bits_raw = tca6424a_port_set_bits_raw,
.port_clear_bits_raw = tca6424a_port_clear_bits_raw,
.port_toggle_bits = tca6424a_port_toggle_bits,
.pin_interrupt_configure = tca6424a_pin_interrupt_configure,
.manage_callback = tca6424a_manage_callback,
};
/**
* @brief Initialization function of TCA6424A
*
* This sets initial input/output configuration and output states.
* The interrupt is configured if it is enabled.
*
* @param dev Device struct
*
* @retval 0 if successful.
* @retval Negative value for error code.
*/
static int tca6424a_init(const struct device *dev)
{
const struct tca6424a_drv_cfg *drv_cfg = dev->config;
struct tca6424a_drv_data *drv_data = dev->data;
int ret;
if (!device_is_ready(drv_cfg->i2c_spec.bus)) {
LOG_ERR("I2C device not found");
return -ENODEV;
}
/* If the RESET line is available, use it to reset the expander.
* Otherwise, write reset values to registers that are not used by
* this driver.
*/
if (drv_cfg->reset_gpio.port) {
if (!gpio_is_ready_dt(&drv_cfg->reset_gpio)) {
LOG_ERR("%s is not ready", drv_cfg->reset_gpio.port->name);
return -ENODEV;
}
ret = gpio_pin_configure_dt(&drv_cfg->reset_gpio, GPIO_OUTPUT_ACTIVE);
if (ret != 0) {
LOG_ERR("%s: failed to configure RESET line: %d", dev->name, ret);
return ret;
}
/* RESET signal needs to be active for a minimum of 30 ns. */
k_busy_wait(1);
ret = gpio_pin_set_dt(&drv_cfg->reset_gpio, 0);
if (ret != 0) {
LOG_ERR("%s: failed to deactivate RESET line: %d", dev->name, ret);
return ret;
}
/* Give the expander at least 200 ns to recover after reset. */
k_busy_wait(1);
} else {
ret = update_invers_regs(dev, 0x0);
if (ret != 0) {
LOG_ERR("%s: failed to reset inversion register: %d", dev->name, ret);
return ret;
}
}
/* Set initial configuration of the pins. */
ret = update_config_regs(dev, 0xFFFFFF);
if (ret != 0) {
return ret;
}
ret = update_output_regs(dev, 0x0);
if (ret != 0) {
return ret;
}
/* Read initial state of the input port register. */
ret = update_input_regs(dev, &drv_data->pins_state.input);
if (ret != 0) {
LOG_ERR("%s: failed to initially read input port: %d", dev->name, ret);
return ret;
}
/* If the INT line is available, configure the callback for it. */
if (drv_cfg->int_gpio.port) {
if (!gpio_is_ready_dt(&drv_cfg->int_gpio)) {
LOG_ERR("Cannot get pointer to gpio interrupt device "
"%s init failed", dev->name);
return -EINVAL;
}
drv_data->dev = dev;
k_work_init(&drv_data->work, tca6424a_work_handler);
ret = gpio_pin_configure_dt(&drv_cfg->int_gpio, GPIO_INPUT);
if (ret != 0) {
LOG_ERR("%s init failed: %d", dev->name, ret);
return ret;
}
ret = gpio_pin_interrupt_configure_dt(&drv_cfg->int_gpio, GPIO_INT_EDGE_TO_ACTIVE);
if (ret != 0) {
LOG_ERR("%s init failed: %d", dev->name, ret);
return ret;
}
gpio_init_callback(&drv_data->int_gpio_cb, tca6424a_int_gpio_handler,
BIT(drv_cfg->int_gpio.pin));
ret = gpio_add_callback(drv_cfg->int_gpio.port, &drv_data->int_gpio_cb);
if (ret != 0) {
LOG_ERR("%s init failed: %d", dev->name, ret);
return ret;
}
}
LOG_DBG("%s init ok", dev->name);
return ret;
}
#define TCA6424A_INST(idx) \
static const struct tca6424a_drv_cfg tca6424a_cfg##idx = { \
.common = { \
.port_pin_mask = GPIO_PORT_PIN_MASK_FROM_DT_INST(idx), \
}, \
.i2c_spec = I2C_DT_SPEC_INST_GET(idx), \
.int_gpio = GPIO_DT_SPEC_INST_GET_OR(idx, int_gpios, {0}), \
.reset_gpio = GPIO_DT_SPEC_INST_GET_OR(idx, reset_gpios, {0}), \
}; \
static struct tca6424a_drv_data tca6424a_data##idx = { \
.lock = Z_SEM_INITIALIZER(tca6424a_data##idx.lock, 1, 1), \
.work = Z_WORK_INITIALIZER(tca6424a_work_handler), \
.dev = DEVICE_DT_INST_GET(idx), \
}; \
DEVICE_DT_INST_DEFINE(idx, tca6424a_init, NULL, &tca6424a_data##idx, &tca6424a_cfg##idx, \
POST_KERNEL, CONFIG_GPIO_TCA6424A_INIT_PRIORITY, &tca6424a_drv_api);
DT_INST_FOREACH_STATUS_OKAY(TCA6424A_INST)
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