/* mpr.c - Driver for Honeywell MPR pressure sensor series */ /* * Copyright (c) 2020 Sven Herrmann * * SPDX-License-Identifier: Apache-2.0 */ #define DT_DRV_COMPAT honeywell_mpr #include #include #include #include #include #include #include #include #include "mpr.h" #include "mpr_configuration.h" LOG_MODULE_REGISTER(MPR, CONFIG_SENSOR_LOG_LEVEL); static int mpr_init(const struct device *dev) { const struct mpr_config *cfg = dev->config; if (!device_is_ready(cfg->i2c.bus)) { LOG_ERR("Bus device is not ready"); return -ENODEV; } return 0; } static int mpr_read_reg(const struct device *dev) { struct mpr_data *data = dev->data; const struct mpr_config *cfg = dev->config; uint8_t write_buf[] = { MPR_OUTPUT_MEASUREMENT_COMMAND, 0x00, 0x00 }; uint8_t read_buf[4] = { 0x0 }; int rc = i2c_write_dt(&cfg->i2c, write_buf, sizeof(write_buf)); if (rc < 0) { return rc; } uint8_t retries = MPR_REG_READ_MAX_RETRIES; for (; retries > 0; retries--) { k_sleep(K_MSEC(MPR_REG_READ_DATA_CONV_DELAY_MS)); rc = i2c_read_dt(&cfg->i2c, read_buf, sizeof(read_buf)); if (rc < 0) { return rc; } if (!(*read_buf & MPR_STATUS_MASK_POWER_ON) || (*read_buf & MPR_STATUS_MASK_INTEGRITY_TEST_FAILED) || (*read_buf & MPR_STATUS_MASK_MATH_SATURATION)) { return -EIO; } if (!(*read_buf & MPR_STATUS_MASK_BUSY)) { break; } } if (retries == 0) { return -EIO; } data->reg_val = (read_buf[1] << 16) | (read_buf[2] << 8) | read_buf[3]; return 0; } /* (reg_value - out_min) * (p_max - p_min) * pressure = --------------------------------------- + p_min * out_max - out_min * * returns pressure [kPa] * 10^6 */ static inline void mpr_convert_reg(const uint32_t *reg, uint64_t *value) { if (*reg > MPR_OUTPUT_MIN) { *value = (uint64_t)(*reg - MPR_OUTPUT_MIN) * (MPR_P_MAX - MPR_P_MIN); *value *= MPR_CONVERSION_FACTOR; *value /= MPR_OUTPUT_RANGE; *value += MPR_P_MIN; } else { *value = MPR_P_MIN; } } static int mpr_sample_fetch(const struct device *dev, enum sensor_channel chan) { __ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL || chan == SENSOR_CHAN_PRESS); return mpr_read_reg(dev); } static int mpr_channel_get(const struct device *dev, enum sensor_channel chan, struct sensor_value *val) { const struct mpr_data *data = dev->data; __ASSERT_NO_MSG(chan == SENSOR_CHAN_PRESS); uint64_t value; mpr_convert_reg(&data->reg_val, &value); val->val1 = value / 1000000; val->val2 = value % 1000000; return 0; } static const struct sensor_driver_api mpr_api_funcs = { .sample_fetch = mpr_sample_fetch, .channel_get = mpr_channel_get, }; #define MPR_DEFINE(inst) \ static struct mpr_data mpr_data_##inst; \ \ static const struct mpr_config mpr_config_##inst = { \ .i2c = I2C_DT_SPEC_INST_GET(inst), \ }; \ \ DEVICE_DT_INST_DEFINE(inst, mpr_init, NULL, \ &mpr_data_##inst, &mpr_config_##inst, POST_KERNEL, \ CONFIG_SENSOR_INIT_PRIORITY, &mpr_api_funcs); \ DT_INST_FOREACH_STATUS_OKAY(MPR_DEFINE)