linux_dsm_epyc7002/drivers/iio/pressure/bmp280.h
Andreas Klinger eb92b4183d iio: bmp280: properly initialize device for humidity reading
If the device is not initialized at least once it happens that the humidity
reading is skipped, which means the special value 0x8000 is delivered.

For omitting this case the oversampling of the humidity must be set before
the oversampling of the temperature und pressure is set as written in the
datasheet of the BME280.

Furthermore proper error detection is added in case a skipped value is read
from the device. This is done also for pressure and temperature reading.
Especially it don't make sense to compensate this value and treat it as
regular value.

Signed-off-by: Andreas Klinger <ak@it-klinger.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2017-07-30 14:41:12 +01:00

118 lines
3.9 KiB
C

#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/regmap.h>
/* BMP280 specific registers */
#define BMP280_REG_HUMIDITY_LSB 0xFE
#define BMP280_REG_HUMIDITY_MSB 0xFD
#define BMP280_REG_TEMP_XLSB 0xFC
#define BMP280_REG_TEMP_LSB 0xFB
#define BMP280_REG_TEMP_MSB 0xFA
#define BMP280_REG_PRESS_XLSB 0xF9
#define BMP280_REG_PRESS_LSB 0xF8
#define BMP280_REG_PRESS_MSB 0xF7
#define BMP280_REG_CONFIG 0xF5
#define BMP280_REG_CTRL_MEAS 0xF4
#define BMP280_REG_STATUS 0xF3
#define BMP280_REG_CTRL_HUMIDITY 0xF2
/* Due to non linear mapping, and data sizes we can't do a bulk read */
#define BMP280_REG_COMP_H1 0xA1
#define BMP280_REG_COMP_H2 0xE1
#define BMP280_REG_COMP_H3 0xE3
#define BMP280_REG_COMP_H4 0xE4
#define BMP280_REG_COMP_H5 0xE5
#define BMP280_REG_COMP_H6 0xE7
#define BMP280_REG_COMP_TEMP_START 0x88
#define BMP280_COMP_TEMP_REG_COUNT 6
#define BMP280_REG_COMP_PRESS_START 0x8E
#define BMP280_COMP_PRESS_REG_COUNT 18
#define BMP280_FILTER_MASK (BIT(4) | BIT(3) | BIT(2))
#define BMP280_FILTER_OFF 0
#define BMP280_FILTER_2X BIT(2)
#define BMP280_FILTER_4X BIT(3)
#define BMP280_FILTER_8X (BIT(3) | BIT(2))
#define BMP280_FILTER_16X BIT(4)
#define BMP280_OSRS_HUMIDITY_MASK (BIT(2) | BIT(1) | BIT(0))
#define BMP280_OSRS_HUMIDITIY_X(osrs_h) ((osrs_h) << 0)
#define BMP280_OSRS_HUMIDITY_SKIP 0
#define BMP280_OSRS_HUMIDITY_1X BMP280_OSRS_HUMIDITIY_X(1)
#define BMP280_OSRS_HUMIDITY_2X BMP280_OSRS_HUMIDITIY_X(2)
#define BMP280_OSRS_HUMIDITY_4X BMP280_OSRS_HUMIDITIY_X(3)
#define BMP280_OSRS_HUMIDITY_8X BMP280_OSRS_HUMIDITIY_X(4)
#define BMP280_OSRS_HUMIDITY_16X BMP280_OSRS_HUMIDITIY_X(5)
#define BMP280_OSRS_TEMP_MASK (BIT(7) | BIT(6) | BIT(5))
#define BMP280_OSRS_TEMP_SKIP 0
#define BMP280_OSRS_TEMP_X(osrs_t) ((osrs_t) << 5)
#define BMP280_OSRS_TEMP_1X BMP280_OSRS_TEMP_X(1)
#define BMP280_OSRS_TEMP_2X BMP280_OSRS_TEMP_X(2)
#define BMP280_OSRS_TEMP_4X BMP280_OSRS_TEMP_X(3)
#define BMP280_OSRS_TEMP_8X BMP280_OSRS_TEMP_X(4)
#define BMP280_OSRS_TEMP_16X BMP280_OSRS_TEMP_X(5)
#define BMP280_OSRS_PRESS_MASK (BIT(4) | BIT(3) | BIT(2))
#define BMP280_OSRS_PRESS_SKIP 0
#define BMP280_OSRS_PRESS_X(osrs_p) ((osrs_p) << 2)
#define BMP280_OSRS_PRESS_1X BMP280_OSRS_PRESS_X(1)
#define BMP280_OSRS_PRESS_2X BMP280_OSRS_PRESS_X(2)
#define BMP280_OSRS_PRESS_4X BMP280_OSRS_PRESS_X(3)
#define BMP280_OSRS_PRESS_8X BMP280_OSRS_PRESS_X(4)
#define BMP280_OSRS_PRESS_16X BMP280_OSRS_PRESS_X(5)
#define BMP280_MODE_MASK (BIT(1) | BIT(0))
#define BMP280_MODE_SLEEP 0
#define BMP280_MODE_FORCED BIT(0)
#define BMP280_MODE_NORMAL (BIT(1) | BIT(0))
/* BMP180 specific registers */
#define BMP180_REG_OUT_XLSB 0xF8
#define BMP180_REG_OUT_LSB 0xF7
#define BMP180_REG_OUT_MSB 0xF6
#define BMP180_REG_CALIB_START 0xAA
#define BMP180_REG_CALIB_COUNT 22
#define BMP180_MEAS_SCO BIT(5)
#define BMP180_MEAS_TEMP (0x0E | BMP180_MEAS_SCO)
#define BMP180_MEAS_PRESS_X(oss) ((oss) << 6 | 0x14 | BMP180_MEAS_SCO)
#define BMP180_MEAS_PRESS_1X BMP180_MEAS_PRESS_X(0)
#define BMP180_MEAS_PRESS_2X BMP180_MEAS_PRESS_X(1)
#define BMP180_MEAS_PRESS_4X BMP180_MEAS_PRESS_X(2)
#define BMP180_MEAS_PRESS_8X BMP180_MEAS_PRESS_X(3)
/* BMP180 and BMP280 common registers */
#define BMP280_REG_CTRL_MEAS 0xF4
#define BMP280_REG_RESET 0xE0
#define BMP280_REG_ID 0xD0
#define BMP180_CHIP_ID 0x55
#define BMP280_CHIP_ID 0x58
#define BME280_CHIP_ID 0x60
#define BMP280_SOFT_RESET_VAL 0xB6
/* BMP280 register skipped special values */
#define BMP280_TEMP_SKIPPED 0x80000
#define BMP280_PRESS_SKIPPED 0x80000
#define BMP280_HUMIDITY_SKIPPED 0x8000
/* Regmap configurations */
extern const struct regmap_config bmp180_regmap_config;
extern const struct regmap_config bmp280_regmap_config;
/* Probe called from different transports */
int bmp280_common_probe(struct device *dev,
struct regmap *regmap,
unsigned int chip,
const char *name,
int irq);
int bmp280_common_remove(struct device *dev);
/* PM ops */
extern const struct dev_pm_ops bmp280_dev_pm_ops;