zephyr/drivers/sensor/lm77/lm77.c

425 lines
9.9 KiB
C

/*
* Copyright (c) 2021 Vestas Wind Systems A/S
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT lm77
#include <zephyr/device.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/drivers/sensor.h>
#include <zephyr/logging/log.h>
#include <zephyr/pm/device.h>
#include <zephyr/sys/byteorder.h>
LOG_MODULE_REGISTER(lm77, CONFIG_SENSOR_LOG_LEVEL);
/*
* Only compile in trigger support if enabled in Kconfig and at least one
* enabled lm77 devicetree node has the int-gpios property.
*/
#define LM77_TRIGGER_SUPPORT_INST(inst) DT_INST_NODE_HAS_PROP(inst, int_gpios) ||
#define LM77_TRIGGER_SUPPORT \
(CONFIG_LM77_TRIGGER && (DT_INST_FOREACH_STATUS_OKAY(LM77_TRIGGER_SUPPORT_INST) 0))
/* LM77 registers */
#define LM77_REG_TEMP 0x00U
#define LM77_REG_CONFIG 0x01U
#define LM77_REG_THYST 0x02U
#define LM77_REG_TCRIT 0x03U
#define LM77_REG_TLOW 0x04U
#define LM77_REG_THIGH 0x05U
/* LM77 configuration register bits */
union lm77_reg_config {
uint8_t reg;
struct {
uint8_t shutdown : 1;
uint8_t int_mode : 1;
uint8_t tcrita_pol : 1;
uint8_t int_pol : 1;
uint8_t fault_queue : 1;
uint8_t reserved : 3;
} __packed;
};
struct lm77_config {
struct i2c_dt_spec i2c;
union lm77_reg_config config_dt;
#if LM77_TRIGGER_SUPPORT
struct gpio_dt_spec int_gpio;
#endif /* LM77_TRIGGER_SUPPORT */
};
struct lm77_data {
int16_t temp;
#if LM77_TRIGGER_SUPPORT
const struct device *dev;
struct k_work_q workq;
struct k_work work;
struct gpio_callback int_gpio_cb;
const struct sensor_trigger *trigger;
sensor_trigger_handler_t trigger_handler;
K_KERNEL_STACK_MEMBER(stack, CONFIG_LM77_TRIGGER_THREAD_STACK_SIZE);
#endif /* LM77_TRIGGER_SUPPORT */
};
static int lm77_write_config(const struct device *dev, uint8_t value)
{
const struct lm77_config *config = dev->config;
uint8_t buf[2] = { LM77_REG_CONFIG, value };
return i2c_write_dt(&config->i2c, buf, sizeof(buf));
}
static int lm77_read_temp(const struct device *dev, uint8_t reg, int16_t *value)
{
const struct lm77_config *config = dev->config;
uint8_t buf[2];
int err;
err = i2c_write_read_dt(&config->i2c, &reg, sizeof(reg), &buf, sizeof(buf));
if (err < 0) {
LOG_ERR("failed to read temperature register 0x%02x (err %d)", reg, err);
return err;
}
*value = sys_get_be16(buf);
return 0;
}
static int lm77_write_temp(const struct device *dev, uint8_t reg, int16_t value)
{
const struct lm77_config *config = dev->config;
uint8_t buf[3] = { reg, value >> 8, value };
return i2c_write_dt(&config->i2c, buf, sizeof(buf));
}
static void lm77_sensor_value_to_temp(const struct sensor_value *val, int16_t *temp)
{
/* Integer part in degrees Celsius (LSB = 0.5 degrees Celsius) */
*temp = val->val1 << 1;
/* Fractional part in micro degrees Celsius */
*temp += (val->val2 * 2) / 1000000;
/* Shift up to include "status" bits */
*temp <<= 3;
}
static void lm77_temp_to_sensor_value(int16_t temp, struct sensor_value *val)
{
/* Shift down to remove "status" bits (LSB = 0.5 degrees Celsius) */
temp = (temp >> 3) * 5;
/* Integer part in degrees Celsius */
val->val1 = temp / 10;
/* Fractional part in micro degrees Celsius */
val->val2 = temp % 10;
val->val2 *= 100000;
}
static int lm77_attr_set(const struct device *dev, enum sensor_channel chan,
enum sensor_attribute attr, const struct sensor_value *val)
{
int16_t temp = 0;
uint8_t reg;
int err;
__ASSERT_NO_MSG(val != NULL);
if (chan != SENSOR_CHAN_AMBIENT_TEMP) {
return -ENOTSUP;
}
switch (attr) {
case SENSOR_ATTR_LOWER_THRESH:
reg = LM77_REG_TLOW;
break;
case SENSOR_ATTR_UPPER_THRESH:
reg = LM77_REG_THIGH;
break;
case SENSOR_ATTR_ALERT:
reg = LM77_REG_TCRIT;
break;
case SENSOR_ATTR_HYSTERESIS:
reg = LM77_REG_THYST;
break;
default:
return -ENOTSUP;
}
lm77_sensor_value_to_temp(val, &temp);
err = lm77_write_temp(dev, reg, temp);
if (err < 0) {
LOG_ERR("failed to write register 0x%02x (err %d)", reg, err);
return err;
}
return 0;
}
static int lm77_attr_get(const struct device *dev, enum sensor_channel chan,
enum sensor_attribute attr, struct sensor_value *val)
{
int16_t temp;
uint8_t reg;
int err;
__ASSERT_NO_MSG(val != NULL);
if (chan != SENSOR_CHAN_AMBIENT_TEMP) {
return -ENOTSUP;
}
switch (attr) {
case SENSOR_ATTR_LOWER_THRESH:
reg = LM77_REG_TLOW;
break;
case SENSOR_ATTR_UPPER_THRESH:
reg = LM77_REG_THIGH;
break;
case SENSOR_ATTR_ALERT:
reg = LM77_REG_TCRIT;
break;
case SENSOR_ATTR_HYSTERESIS:
reg = LM77_REG_THYST;
break;
default:
return -ENOTSUP;
}
err = lm77_read_temp(dev, reg, &temp);
if (err < 0) {
LOG_ERR("failed to read register 0x%02x (err %d)", reg, err);
return err;
}
lm77_temp_to_sensor_value(temp, val);
return 0;
}
#if LM77_TRIGGER_SUPPORT
static int lm77_trigger_set(const struct device *dev, const struct sensor_trigger *trig,
sensor_trigger_handler_t handler)
{
const struct lm77_config *config = dev->config;
struct lm77_data *data = dev->data;
gpio_flags_t flags;
int err;
__ASSERT_NO_MSG(trig != NULL);
if (trig->type != SENSOR_TRIG_THRESHOLD || trig->chan != SENSOR_CHAN_AMBIENT_TEMP ||
config->int_gpio.port == NULL) {
return -ENOTSUP;
}
if (handler != NULL) {
flags = GPIO_INT_EDGE_TO_ACTIVE;
} else {
flags = GPIO_INT_DISABLE;
}
err = gpio_pin_interrupt_configure_dt(&config->int_gpio, flags);
if (err < 0) {
LOG_ERR("failed to configure INT GPIO IRQ (err %d)", err);
return err;
}
data->trigger = trig;
data->trigger_handler = handler;
return 0;
}
static void lm77_trigger_work_handler(struct k_work *item)
{
struct lm77_data *data = CONTAINER_OF(item, struct lm77_data, work);
sensor_trigger_handler_t handler = data->trigger_handler;
if (handler != NULL) {
handler(data->dev, (struct sensor_trigger *)data->trigger);
}
}
static void lm77_int_gpio_callback_handler(const struct device *port,
struct gpio_callback *cb,
gpio_port_pins_t pins)
{
struct lm77_data *data = CONTAINER_OF(cb, struct lm77_data, int_gpio_cb);
ARG_UNUSED(port);
ARG_UNUSED(pins);
k_work_submit_to_queue(&data->workq, &data->work);
}
#endif /* LM77_TRIGGER_SUPPORT */
static int lm77_sample_fetch(const struct device *dev, enum sensor_channel chan)
{
struct lm77_data *data = dev->data;
int16_t temp;
int err;
if (chan != SENSOR_CHAN_ALL && chan != SENSOR_CHAN_AMBIENT_TEMP) {
return -ENOTSUP;
}
err = lm77_read_temp(dev, LM77_REG_TEMP, &temp);
if (err < 0) {
LOG_ERR("failed to read temperature (err %d)", err);
return err;
}
data->temp = temp;
return 0;
}
static int lm77_channel_get(const struct device *dev, enum sensor_channel chan,
struct sensor_value *val)
{
struct lm77_data *data = dev->data;
if (chan != SENSOR_CHAN_AMBIENT_TEMP) {
return -ENOTSUP;
}
lm77_temp_to_sensor_value(data->temp, val);
return 0;
}
static const struct sensor_driver_api lm77_driver_api = {
.attr_set = lm77_attr_set,
.attr_get = lm77_attr_get,
#if LM77_TRIGGER_SUPPORT
.trigger_set = lm77_trigger_set,
#endif /* LM77_TRIGGER_SUPPORT */
.sample_fetch = lm77_sample_fetch,
.channel_get = lm77_channel_get,
};
static int lm77_init(const struct device *dev)
{
const struct lm77_config *config = dev->config;
int err;
#if LM77_TRIGGER_SUPPORT
struct lm77_data *data = dev->data;
#endif /* LM77_TRIGGER_SUPPORT */
if (!device_is_ready(config->i2c.bus)) {
LOG_ERR("I2c bus not ready");
return -EINVAL;
}
err = lm77_write_config(dev, config->config_dt.reg);
if (err < 0) {
LOG_ERR("failed to write configuration (err %d)", err);
return err;
}
#if LM77_TRIGGER_SUPPORT
data->dev = dev;
k_work_queue_start(&data->workq, data->stack, K_THREAD_STACK_SIZEOF(data->stack),
CONFIG_LM77_TRIGGER_THREAD_PRIO, NULL);
k_thread_name_set(&data->workq.thread, "lm77_trigger");
k_work_init(&data->work, lm77_trigger_work_handler);
if (config->int_gpio.port != NULL) {
if (!device_is_ready(config->int_gpio.port)) {
LOG_ERR("INT GPIO not ready");
return -EINVAL;
}
err = gpio_pin_configure_dt(&config->int_gpio, GPIO_INPUT);
if (err < 0) {
LOG_ERR("failed to configure INT GPIO (err %d)", err);
return err;
}
gpio_init_callback(&data->int_gpio_cb, lm77_int_gpio_callback_handler,
BIT(config->int_gpio.pin));
err = gpio_add_callback(config->int_gpio.port, &data->int_gpio_cb);
if (err < 0) {
LOG_ERR("failed to add INT GPIO callback (err %d)", err);
return err;
}
}
#endif /* LM77_TRIGGER_SUPPORT */
return 0;
}
#ifdef CONFIG_PM_DEVICE
static int lm77_pm_action(const struct device *dev,
enum pm_device_action action)
{
const struct lm77_config *config = dev->config;
union lm77_reg_config creg = config->config_dt;
int err;
switch (action) {
case PM_DEVICE_ACTION_SUSPEND:
creg.shutdown = 1;
break;
case PM_DEVICE_ACTION_RESUME:
creg.shutdown = 0;
break;
default:
return -ENOTSUP;
}
err = lm77_write_config(dev, creg.reg);
if (err < 0) {
LOG_ERR("failed to write configuration (err %d)", err);
return err;
}
return 0;
}
#endif /* CONFIG_PM_DEVICE */
#if LM77_TRIGGER_SUPPORT
#define LM77_INT_GPIO_INIT(n) .int_gpio = GPIO_DT_SPEC_INST_GET_OR(n, int_gpios, { 0 })
#else /* LM77_TRIGGER_SUPPORT */
#define LM77_INT_GPIO_INIT(n)
#endif /* ! LM77_TRIGGER_SUPPORT */
#define LM77_INIT(n) \
static struct lm77_data lm77_data_##n; \
\
static const struct lm77_config lm77_config_##n = { \
.i2c = I2C_DT_SPEC_INST_GET(n), \
.config_dt = { \
.shutdown = 0, \
.int_mode = DT_INST_NODE_HAS_PROP(n, int_gpios), \
.tcrita_pol = DT_INST_PROP(n, tcrita_inverted), \
.int_pol = DT_INST_PROP(n, int_inverted), \
.fault_queue = DT_INST_PROP(n, enable_fault_queue), \
.reserved = 0, \
}, \
LM77_INT_GPIO_INIT(n) \
}; \
\
PM_DEVICE_DT_INST_DEFINE(n, lm77_pm_action); \
\
DEVICE_DT_INST_DEFINE(n, lm77_init, \
PM_DEVICE_DT_INST_GET(n), \
&lm77_data_##n, \
&lm77_config_##n, POST_KERNEL, \
CONFIG_SENSOR_INIT_PRIORITY, \
&lm77_driver_api);
DT_INST_FOREACH_STATUS_OKAY(LM77_INIT)