blob: 95b86f30d68a56ad5acb1d39e7291ded2d4a8f2e [file] [log] [blame]
/* LLTC LTC2451 ADC
*
* Copyright (c) 2023 Brill Power Ltd.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/device.h>
#include <zephyr/drivers/adc.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/logging/log.h>
#include <zephyr/sys/byteorder.h>
LOG_MODULE_REGISTER(ltc2451, CONFIG_ADC_LOG_LEVEL);
#define DT_DRV_COMPAT lltc_ltc2451
struct ltc2451_config {
struct i2c_dt_spec i2c;
uint8_t conversion_speed;
};
static int ltc2451_channel_setup(const struct device *dev,
const struct adc_channel_cfg *channel_cfg)
{
ARG_UNUSED(dev);
if (channel_cfg->channel_id != 0) {
LOG_ERR("Invalid channel id '%d'", channel_cfg->channel_id);
return -EINVAL;
}
return 0;
}
static int ltc2451_set_conversion_speed(const struct device *dev, uint8_t conversion_speed)
{
const struct ltc2451_config *config = dev->config;
uint8_t wr_buf[1];
int err;
if (conversion_speed == 60) {
wr_buf[0] = 0;
} else if (conversion_speed == 30) {
wr_buf[0] = 1;
} else {
LOG_ERR("Invalid conversion speed selected");
return -EINVAL;
}
err = i2c_write_dt(&config->i2c, wr_buf, sizeof(wr_buf));
if (err != 0) {
LOG_ERR("LTC write failed (err %d)", err);
}
return err;
}
static int ltc2451_read_latest_conversion(const struct device *dev,
const struct adc_sequence *sequence)
{
const struct ltc2451_config *config = dev->config;
uint8_t rd_buf[2];
uint16_t *value_buf;
int err = i2c_read_dt(&config->i2c, rd_buf, sizeof(rd_buf));
if (err == 0) {
value_buf = (uint16_t *)sequence->buffer;
value_buf[0] = sys_get_be16(rd_buf);
} else {
LOG_ERR("LTC read failed (err %d)", err);
}
return err;
}
static int ltc2451_init(const struct device *dev)
{
const struct ltc2451_config *config = dev->config;
if (!device_is_ready(config->i2c.bus)) {
LOG_ERR("I2C device not ready");
return -ENODEV;
}
return ltc2451_set_conversion_speed(dev, config->conversion_speed);
}
static const struct adc_driver_api ltc2451_api = {
.channel_setup = ltc2451_channel_setup,
.read = ltc2451_read_latest_conversion,
};
#define LTC2451_DEFINE(index) \
static const struct ltc2451_config ltc2451_cfg_##index = { \
.i2c = I2C_DT_SPEC_INST_GET(index), \
.conversion_speed = DT_INST_PROP(index, conversion_speed), \
}; \
\
DEVICE_DT_INST_DEFINE(index, &ltc2451_init, NULL, NULL, \
&ltc2451_cfg_##index, POST_KERNEL, CONFIG_ADC_INIT_PRIORITY, \
&ltc2451_api);
DT_INST_FOREACH_STATUS_OKAY(LTC2451_DEFINE)