da4e3e713b
Adds support for the Linear Technologies LTC2451 ADC. Signed-off-by: Ethan Duckett <ethan.duckett@brillpower.com>
106 lines
2.4 KiB
C
106 lines
2.4 KiB
C
/* LLTC LTC2451 ADC
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*
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* Copyright (c) 2023 Brill Power Ltd.
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <zephyr/device.h>
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#include <zephyr/drivers/adc.h>
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#include <zephyr/drivers/i2c.h>
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#include <zephyr/logging/log.h>
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#include <zephyr/sys/byteorder.h>
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LOG_MODULE_REGISTER(ltc2451, CONFIG_ADC_LOG_LEVEL);
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#define DT_DRV_COMPAT lltc_ltc2451
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struct ltc2451_config {
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struct i2c_dt_spec i2c;
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uint8_t conversion_speed;
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};
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static int ltc2451_channel_setup(const struct device *dev,
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const struct adc_channel_cfg *channel_cfg)
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{
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ARG_UNUSED(dev);
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if (channel_cfg->channel_id != 0) {
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LOG_ERR("Invalid channel id '%d'", channel_cfg->channel_id);
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return -EINVAL;
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}
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return 0;
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}
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static int ltc2451_set_conversion_speed(const struct device *dev, uint8_t conversion_speed)
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{
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const struct ltc2451_config *config = dev->config;
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uint8_t wr_buf[1];
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int err;
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if (conversion_speed == 60) {
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wr_buf[0] = 0;
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} else if (conversion_speed == 30) {
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wr_buf[0] = 1;
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} else {
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LOG_ERR("Invalid conversion speed selected");
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return -EINVAL;
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}
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err = i2c_write_dt(&config->i2c, wr_buf, sizeof(wr_buf));
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if (err != 0) {
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LOG_ERR("LTC write failed (err %d)", err);
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}
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return err;
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}
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static int ltc2451_read_latest_conversion(const struct device *dev,
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const struct adc_sequence *sequence)
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{
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const struct ltc2451_config *config = dev->config;
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uint8_t rd_buf[2];
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uint16_t *value_buf;
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int err = i2c_read_dt(&config->i2c, rd_buf, sizeof(rd_buf));
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if (err == 0) {
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value_buf = (uint16_t *)sequence->buffer;
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value_buf[0] = sys_get_be16(rd_buf);
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} else {
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LOG_ERR("LTC read failed (err %d)", err);
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}
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return err;
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}
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static int ltc2451_init(const struct device *dev)
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{
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const struct ltc2451_config *config = dev->config;
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if (!device_is_ready(config->i2c.bus)) {
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LOG_ERR("I2C device not ready");
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return -ENODEV;
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}
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return ltc2451_set_conversion_speed(dev, config->conversion_speed);
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}
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static const struct adc_driver_api ltc2451_api = {
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.channel_setup = ltc2451_channel_setup,
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.read = ltc2451_read_latest_conversion,
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};
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#define LTC2451_DEFINE(index) \
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static const struct ltc2451_config ltc2451_cfg_##index = { \
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.i2c = I2C_DT_SPEC_INST_GET(index), \
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.conversion_speed = DT_INST_PROP(index, conversion_speed), \
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}; \
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\
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DEVICE_DT_INST_DEFINE(index, <c2451_init, NULL, NULL, \
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<c2451_cfg_##index, POST_KERNEL, CONFIG_ADC_INIT_PRIORITY, \
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<c2451_api);
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DT_INST_FOREACH_STATUS_OKAY(LTC2451_DEFINE)
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