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iio: chemical: bme680: Modify startup procedure

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Modify the startup procedure to reflect the procedure of the Bosch BME68x
Sensor API. The initial readings and configuration of the sensor need to
happen in the following order:

1) Read calibration data [1,2]
2) Chip general configuration [3]
3) Gas configuration [4]

After the chip configuration it is necessary to ensure that the sensor is
in sleeping mode, in order to apply the gas configuration settings [5].

Also, after the soft reset, it is advised to wait for 5ms [6].

Link: https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/bme68x.c#L162 # [1]
Link: https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/examples/forced_mode/forced_mode.c#L44 # [2]
Link: https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/examples/forced_mode/forced_mode.c#L53 # [3]
Link: https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/examples/forced_mode/forced_mode.c#L60 # [4]
Link: https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/bme68x.c#L640 # [5]
Link: https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/bme68x.c#L294 # [6]
Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
Link: https://patch.msgid.link/20240609233826.330516-12-vassilisamir@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Vasileios Amoiridis 2024-06-10 01:38:22 +02:00 committed by Jonathan Cameron
parent 8bc1f428ba
commit fe358e57af
2 changed files with 16 additions and 7 deletions
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2
drivers/iio/chemical/bme680.h
View File

@ -63,6 +63,8 @@
#define BME680_MEAS_TRIM_MASK GENMASK(24, 4) #define BME680_MEAS_TRIM_MASK GENMASK(24, 4)
#define BME680_STARTUP_TIME_US 5000
/* Calibration Parameters */ /* Calibration Parameters */
#define BME680_T2_LSB_REG 0x8A #define BME680_T2_LSB_REG 0x8A
#define BME680_H2_MSB_REG 0xE1 #define BME680_H2_MSB_REG 0xE1

21
drivers/iio/chemical/bme680_core.c
View File

@ -531,6 +531,11 @@ static int bme680_gas_config(struct bme680_data *data)
int ret; int ret;
u8 heatr_res, heatr_dur; u8 heatr_res, heatr_dur;
/* Go to sleep */
ret = bme680_set_mode(data, false);
if (ret < 0)
return ret;
heatr_res = bme680_calc_heater_res(data, data->heater_temp); heatr_res = bme680_calc_heater_res(data, data->heater_temp);
/* set target heater temperature */ /* set target heater temperature */
@ -866,6 +871,8 @@ int bme680_core_probe(struct device *dev, struct regmap *regmap,
return ret; return ret;
} }
usleep_range(BME680_STARTUP_TIME_US, BME680_STARTUP_TIME_US + 1000);
ret = regmap_read(regmap, BME680_REG_CHIP_ID, &data->check); ret = regmap_read(regmap, BME680_REG_CHIP_ID, &data->check);
if (ret < 0) { if (ret < 0) {
dev_err(dev, "Error reading chip ID\n"); dev_err(dev, "Error reading chip ID\n");
@ -878,6 +885,13 @@ int bme680_core_probe(struct device *dev, struct regmap *regmap,
return -ENODEV; return -ENODEV;
} }
ret = bme680_read_calib(data, &data->bme680);
if (ret < 0) {
dev_err(dev,
"failed to read calibration coefficients at probe\n");
return ret;
}
ret = bme680_chip_config(data); ret = bme680_chip_config(data);
if (ret < 0) { if (ret < 0) {
dev_err(dev, "failed to set chip_config data\n"); dev_err(dev, "failed to set chip_config data\n");
@ -890,13 +904,6 @@ int bme680_core_probe(struct device *dev, struct regmap *regmap,
return ret; return ret;
} }
ret = bme680_read_calib(data, &data->bme680);
if (ret < 0) {
dev_err(dev,
"failed to read calibration coefficients at probe\n");
return ret;
}
return devm_iio_device_register(dev, indio_dev); return devm_iio_device_register(dev, indio_dev);
} }
EXPORT_SYMBOL_NS_GPL(bme680_core_probe, IIO_BME680); EXPORT_SYMBOL_NS_GPL(bme680_core_probe, IIO_BME680);