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140 lines
3.6 KiB
140 lines
3.6 KiB
/* |
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* Copyright (c) 2023 FTP Technologies |
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* |
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* SPDX-License-Identifier: Apache-2.0 |
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*/ |
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#define DT_DRV_COMPAT microchip_mcp970x |
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#include <zephyr/drivers/adc.h> |
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#include <zephyr/drivers/sensor.h> |
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#include <zephyr/logging/log.h> |
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LOG_MODULE_REGISTER(mcp970x, CONFIG_SENSOR_LOG_LEVEL); |
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enum ic_family { |
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FAMILY_MCP9700_9700A, |
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FAMILY_MCP9701_9701A |
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}; |
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/* Milli degrees C per degree C */ |
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#define MC_PER_C 1000 |
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#define MV_AT_0C_MCP9700_9700A 500 |
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#define MV_AT_0C_MCP9701_9701A 400 |
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#define T_COEFF_MCP9700_9700A 10 |
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#define T_COEFF_MCP9701_9701A 19.5 |
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struct mcp970x_config { |
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struct adc_dt_spec adc; |
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enum ic_family family; |
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}; |
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struct mcp970x_data { |
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struct adc_sequence sequence; |
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int16_t raw; |
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}; |
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static int fetch(const struct device *dev, enum sensor_channel chan) |
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{ |
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const struct mcp970x_config *config = dev->config; |
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struct mcp970x_data *data = dev->data; |
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int ret; |
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if ((chan != SENSOR_CHAN_AMBIENT_TEMP) && (chan != SENSOR_CHAN_ALL)) { |
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return -ENOTSUP; |
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} |
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ret = adc_read_dt(&config->adc, &data->sequence); |
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if (ret != 0) { |
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LOG_ERR("adc_read: %d", ret); |
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} |
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return ret; |
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} |
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static int get(const struct device *dev, enum sensor_channel chan, struct sensor_value *val) |
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{ |
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const struct mcp970x_config *config = dev->config; |
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struct mcp970x_data *data = dev->data; |
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int32_t raw_val = data->raw; |
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int32_t t; |
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int ret; |
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__ASSERT_NO_MSG(val != NULL); |
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if (chan != SENSOR_CHAN_AMBIENT_TEMP) { |
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return -ENOTSUP; |
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} |
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ret = adc_raw_to_millivolts_dt(&config->adc, &raw_val); |
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if (ret != 0) { |
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LOG_ERR("to_mv: %d", ret); |
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return ret; |
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} |
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if (config->family == FAMILY_MCP9700_9700A) { |
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t = (MC_PER_C * (raw_val - MV_AT_0C_MCP9700_9700A)) / T_COEFF_MCP9700_9700A; |
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} else { |
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int32_t t_coeff = 10 * T_COEFF_MCP9701_9701A; /* float to int */ |
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t = (MC_PER_C * 10 * (raw_val - MV_AT_0C_MCP9701_9701A)) / t_coeff; |
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} |
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val->val1 = t / MC_PER_C; |
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val->val2 = 1000 * (t % MC_PER_C); |
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LOG_DBG("%d of %d, %dmV, %dmC", data->raw, (1 << data->sequence.resolution) - 1, raw_val, |
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t); |
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return 0; |
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} |
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static DEVICE_API(sensor, mcp970x_api) = { |
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.sample_fetch = fetch, |
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.channel_get = get, |
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}; |
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static int init(const struct device *dev) |
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{ |
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const struct mcp970x_config *config = dev->config; |
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struct mcp970x_data *data = dev->data; |
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int ret; |
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if (!adc_is_ready_dt(&config->adc)) { |
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LOG_ERR("ADC is not ready"); |
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return -ENODEV; |
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} |
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ret = adc_channel_setup_dt(&config->adc); |
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if (ret != 0) { |
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LOG_ERR("setup: %d", ret); |
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return ret; |
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} |
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ret = adc_sequence_init_dt(&config->adc, &data->sequence); |
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if (ret != 0) { |
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LOG_ERR("sequence: %d", ret); |
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return ret; |
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} |
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data->sequence.buffer = &data->raw; |
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data->sequence.buffer_size = sizeof(data->raw); |
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return 0; |
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} |
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#define MCP970X_INIT(inst) \ |
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static struct mcp970x_data mcp970x_##inst##_data = {0}; \ |
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\ |
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static const struct mcp970x_config mcp970x_##inst##_config = { \ |
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.adc = ADC_DT_SPEC_INST_GET(inst), \ |
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.family = DT_INST_ENUM_IDX(inst, family), \ |
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}; \ |
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\ |
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SENSOR_DEVICE_DT_INST_DEFINE(inst, &init, NULL, &mcp970x_##inst##_data, \ |
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&mcp970x_##inst##_config, POST_KERNEL, \ |
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CONFIG_SENSOR_INIT_PRIORITY, &mcp970x_api); |
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DT_INST_FOREACH_STATUS_OKAY(MCP970X_INIT)
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