| /* 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 <errno.h> |
| #include <kernel.h> |
| #include <sys/__assert.h> |
| #include <drivers/sensor.h> |
| #include <drivers/i2c.h> |
| #include <sys/byteorder.h> |
| #include <init.h> |
| #include <logging/log.h> |
| #include "mpr.h" |
| #include "mpr_configuration.h" |
| |
| LOG_MODULE_REGISTER(MPR, CONFIG_SENSOR_LOG_LEVEL); |
| |
| static int mpr_init(const struct device *dev) |
| { |
| struct mpr_data *data = dev->data; |
| const struct mpr_config *cfg = dev->config; |
| |
| data->i2c_master = device_get_binding(cfg->i2c_bus); |
| if (!data->i2c_master) { |
| LOG_ERR("mpr: i2c master not found: %s", cfg->i2c_bus); |
| return -EINVAL; |
| } |
| 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(data->i2c_master, write_buf, sizeof(write_buf), |
| cfg->i2c_addr); |
| |
| 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(data->i2c_master, read_buf, sizeof(read_buf), |
| cfg->i2c_addr); |
| 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, |
| }; |
| |
| static struct mpr_data mpr_data; |
| static const struct mpr_config mpr_cfg = { |
| .i2c_bus = DT_INST_BUS_LABEL(0), |
| .i2c_addr = DT_INST_REG_ADDR(0), |
| }; |
| |
| DEVICE_DT_INST_DEFINE(0, mpr_init, NULL, &mpr_data, |
| &mpr_cfg, POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY, |
| &mpr_api_funcs); |