zephyr/drivers/sensor/mcp9808/mcp9808.c

146 lines
3.6 KiB
C

/*
* Copyright (c) 2019 Peter Bigot Consulting, LLC
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT microchip_mcp9808
#include <errno.h>
#include <kernel.h>
#include <drivers/i2c.h>
#include <init.h>
#include <sys/byteorder.h>
#include <sys/__assert.h>
#include <logging/log.h>
#include "mcp9808.h"
LOG_MODULE_REGISTER(MCP9808, CONFIG_SENSOR_LOG_LEVEL);
int mcp9808_reg_read(const struct device *dev, uint8_t reg, uint16_t *val)
{
struct mcp9808_data *data = dev->data;
const struct mcp9808_config *cfg = dev->config;
int rc = i2c_write_read(data->i2c_master, cfg->i2c_addr,
&reg, sizeof(reg),
val, sizeof(*val));
if (rc == 0) {
*val = sys_be16_to_cpu(*val);
}
return rc;
}
int mcp9808_reg_write_16bit(const struct device *dev, uint8_t reg,
uint16_t val)
{
struct mcp9808_data *data = dev->data;
const struct mcp9808_config *cfg = dev->config;
uint8_t buf[3];
buf[0] = reg;
sys_put_be16(val, &buf[1]);
return i2c_write(data->i2c_master, buf, sizeof(buf), cfg->i2c_addr);
}
int mcp9808_reg_write_8bit(const struct device *dev, uint8_t reg,
uint8_t val)
{
struct mcp9808_data *data = dev->data;
const struct mcp9808_config *cfg = dev->config;
uint8_t buf[2] = {
reg,
val,
};
return i2c_write(data->i2c_master, buf, sizeof(buf), cfg->i2c_addr);
}
static int mcp9808_set_temperature_resolution(const struct device *dev,
uint8_t resolution)
{
return mcp9808_reg_write_8bit(dev, MCP9808_REG_RESOLUTION, resolution);
}
static int mcp9808_sample_fetch(const struct device *dev,
enum sensor_channel chan)
{
struct mcp9808_data *data = dev->data;
__ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL || chan == SENSOR_CHAN_AMBIENT_TEMP);
return mcp9808_reg_read(dev, MCP9808_REG_TEMP_AMB, &data->reg_val);
}
static int mcp9808_channel_get(const struct device *dev,
enum sensor_channel chan,
struct sensor_value *val)
{
const struct mcp9808_data *data = dev->data;
int temp = mcp9808_temp_signed_from_reg(data->reg_val);
__ASSERT_NO_MSG(chan == SENSOR_CHAN_AMBIENT_TEMP);
val->val1 = temp / MCP9808_TEMP_SCALE_CEL;
temp -= val->val1 * MCP9808_TEMP_SCALE_CEL;
val->val2 = (temp * 1000000) / MCP9808_TEMP_SCALE_CEL;
return 0;
}
static const struct sensor_driver_api mcp9808_api_funcs = {
.sample_fetch = mcp9808_sample_fetch,
.channel_get = mcp9808_channel_get,
#ifdef CONFIG_MCP9808_TRIGGER
.attr_set = mcp9808_attr_set,
.trigger_set = mcp9808_trigger_set,
#endif /* CONFIG_MCP9808_TRIGGER */
};
int mcp9808_init(const struct device *dev)
{
struct mcp9808_data *data = dev->data;
const struct mcp9808_config *cfg = dev->config;
int rc = 0;
data->i2c_master = device_get_binding(cfg->i2c_bus);
if (!data->i2c_master) {
LOG_ERR("mcp9808: i2c master not found: %s", cfg->i2c_bus);
return -EINVAL;
}
rc = mcp9808_set_temperature_resolution(dev, cfg->resolution);
if (rc) {
LOG_ERR("Could not set the resolution of mcp9808 module");
return rc;
}
#ifdef CONFIG_MCP9808_TRIGGER
rc = mcp9808_setup_interrupt(dev);
#endif /* CONFIG_MCP9808_TRIGGER */
return rc;
}
static struct mcp9808_data mcp9808_data;
static const struct mcp9808_config mcp9808_cfg = {
.i2c_bus = DT_INST_BUS_LABEL(0),
.i2c_addr = DT_INST_REG_ADDR(0),
.resolution = DT_INST_PROP(0, resolution),
#ifdef CONFIG_MCP9808_TRIGGER
.alert_pin = DT_INST_GPIO_PIN(0, int_gpios),
.alert_flags = DT_INST_GPIO_FLAGS(0, int_gpios),
.alert_controller = DT_INST_GPIO_LABEL(0, int_gpios),
#endif /* CONFIG_MCP9808_TRIGGER */
};
DEVICE_DT_INST_DEFINE(0, mcp9808_init, NULL,
&mcp9808_data, &mcp9808_cfg, POST_KERNEL,
CONFIG_SENSOR_INIT_PRIORITY, &mcp9808_api_funcs);