| /* |
| * Copyright (c) 2023 Google LLC |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #include <zephyr/drivers/adc.h> |
| #include <zephyr/drivers/sensor.h> |
| #include <zephyr/logging/log.h> |
| #include "ntc_thermistor.h" |
| |
| LOG_MODULE_REGISTER(NTC_THERMISTOR, CONFIG_SENSOR_LOG_LEVEL); |
| |
| struct ntc_thermistor_data { |
| struct k_mutex mutex; |
| int16_t raw; |
| int16_t sample_val; |
| }; |
| |
| struct ntc_thermistor_config { |
| const struct adc_dt_spec adc_channel; |
| const struct ntc_config ntc_cfg; |
| }; |
| |
| static int ntc_thermistor_sample_fetch(const struct device *dev, enum sensor_channel chan) |
| { |
| struct ntc_thermistor_data *data = dev->data; |
| const struct ntc_thermistor_config *cfg = dev->config; |
| int32_t val_mv; |
| int res; |
| struct adc_sequence sequence = { |
| .options = NULL, |
| .buffer = &data->raw, |
| .buffer_size = sizeof(data->raw), |
| .calibrate = false, |
| }; |
| |
| k_mutex_lock(&data->mutex, K_FOREVER); |
| |
| adc_sequence_init_dt(&cfg->adc_channel, &sequence); |
| res = adc_read(cfg->adc_channel.dev, &sequence); |
| if (res) { |
| val_mv = data->raw; |
| res = adc_raw_to_millivolts_dt(&cfg->adc_channel, &val_mv); |
| data->sample_val = val_mv; |
| } |
| |
| k_mutex_unlock(&data->mutex); |
| |
| return res; |
| } |
| |
| static int ntc_thermistor_channel_get(const struct device *dev, enum sensor_channel chan, |
| struct sensor_value *val) |
| { |
| struct ntc_thermistor_data *data = dev->data; |
| const struct ntc_thermistor_config *cfg = dev->config; |
| uint32_t ohm, max_adc; |
| int32_t temp; |
| |
| switch (chan) { |
| case SENSOR_CHAN_AMBIENT_TEMP: |
| max_adc = (1 << (cfg->adc_channel.resolution - 1)) - 1; |
| ohm = ntc_get_ohm_of_thermistor(&cfg->ntc_cfg, max_adc, data->raw); |
| temp = ntc_get_temp_mc(&cfg->ntc_cfg.type, ohm); |
| val->val1 = temp / 1000; |
| val->val2 = (temp % 1000) * 1000; |
| LOG_INF("ntc temp says %u", val->val1); |
| break; |
| default: |
| return -ENOTSUP; |
| } |
| return 0; |
| } |
| |
| static const struct sensor_driver_api ntc_thermistor_driver_api = { |
| .sample_fetch = ntc_thermistor_sample_fetch, |
| .channel_get = ntc_thermistor_channel_get, |
| }; |
| |
| static int ntc_thermistor_init(const struct device *dev) |
| { |
| const struct ntc_thermistor_config *cfg = dev->config; |
| int err; |
| |
| if (!device_is_ready(cfg->adc_channel.dev)) { |
| LOG_ERR("ADC controller device is not ready\n"); |
| return -ENODEV; |
| } |
| |
| err = adc_channel_setup_dt(&cfg->adc_channel); |
| if (err < 0) { |
| LOG_ERR("Could not setup channel err(%d)\n", err); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| #define NTC_THERMISTOR_DEFINE(inst, id, comp_table) \ |
| BUILD_ASSERT(ARRAY_SIZE(comp_table) % 2 == 0, "Compensation table needs to be even size"); \ |
| \ |
| static int compare_ohm_##id##inst(const void *key, const void *element); \ |
| \ |
| static struct ntc_thermistor_data ntc_thermistor_driver_##id##inst; \ |
| \ |
| static const struct ntc_thermistor_config ntc_thermistor_cfg_##id##inst = { \ |
| .adc_channel = ADC_DT_SPEC_INST_GET(inst), \ |
| .ntc_cfg = \ |
| { \ |
| .r25_ohm = DT_INST_PROP(inst, r25_ohm), \ |
| .pullup_uv = DT_INST_PROP(inst, pullup_uv), \ |
| .pullup_ohm = DT_INST_PROP(inst, pullup_ohm), \ |
| .pulldown_ohm = DT_INST_PROP(inst, pulldown_ohm), \ |
| .connected_positive = DT_INST_PROP(inst, connected_positive), \ |
| .type = { \ |
| .comp = (const struct ntc_compensation *)comp_table, \ |
| .n_comp = ARRAY_SIZE(comp_table), \ |
| .ohm_cmp = compare_ohm_##id##inst, \ |
| }, \ |
| }, \ |
| }; \ |
| \ |
| static int compare_ohm_##id##inst(const void *key, const void *element) \ |
| { \ |
| return ntc_compensation_compare_ohm( \ |
| &ntc_thermistor_cfg_##id##inst.ntc_cfg.type, key, element); \ |
| } \ |
| \ |
| SENSOR_DEVICE_DT_INST_DEFINE( \ |
| inst, ntc_thermistor_init, NULL, &ntc_thermistor_driver_##id##inst, \ |
| &ntc_thermistor_cfg_##id##inst, POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY, \ |
| &ntc_thermistor_driver_api); |
| |
| /* ntc-thermistor-generic */ |
| #define DT_DRV_COMPAT ntc_thermistor_generic |
| |
| #define NTC_THERMISTOR_GENERIC_DEFINE(inst) \ |
| static const uint32_t comp_##inst[] = DT_INST_PROP(inst, zephyr_compensation_table); \ |
| NTC_THERMISTOR_DEFINE(inst, DT_DRV_COMPAT, comp_##inst) |
| |
| DT_INST_FOREACH_STATUS_OKAY(NTC_THERMISTOR_GENERIC_DEFINE) |
| |
| /* epcos,b57861s0103a039 */ |
| #undef DT_DRV_COMPAT |
| #define DT_DRV_COMPAT epcos_b57861s0103a039 |
| |
| static __unused const struct ntc_compensation comp_epcos_b57861s0103a039[] = { |
| { -25, 146676 }, |
| { -15, 78875 }, |
| { -5, 44424 }, |
| { 5, 26075 }, |
| { 15, 15881 }, |
| { 25, 10000 }, |
| { 35, 6488 }, |
| { 45, 4326 }, |
| { 55, 2956 }, |
| { 65, 2066 }, |
| { 75, 1474 }, |
| { 85, 1072 }, |
| { 95, 793 }, |
| { 105, 596 }, |
| { 115, 454 }, |
| { 125, 351 }, |
| }; |
| |
| DT_INST_FOREACH_STATUS_OKAY_VARGS(NTC_THERMISTOR_DEFINE, DT_DRV_COMPAT, |
| comp_epcos_b57861s0103a039) |