linux-stable/drivers/iio/chemical/bme680.h
Mike Looijmans 73f3bc6da5 iio:chemical:bme680: Fix SPI read interface
The SPI interface implementation was completely broken.

When using the SPI interface, there are only 7 address bits, the upper bit
is controlled by a page select register. The core needs access to both
ranges, so implement register read/write for both regions. The regmap
paging functionality didn't agree with a register that needs to be read
and modified, so I implemented a custom paging algorithm.

This fixes that the device wouldn't even probe in SPI mode.

The SPI interface then isn't different from I2C, merged them into the core,
and the I2C/SPI named registers are no longer needed.

Implemented register value caching for the registers to reduce the I2C/SPI
data transfers considerably.

The calibration set reads as all zeroes until some undefined point in time,
and I couldn't determine what makes it valid. The datasheet mentions these
registers but does not provide any hints on when they become valid, and they
aren't even enumerated in the memory map. So check the calibration and
retry reading it from the device after each measurement until it provides
something valid.

Despite the size this is suitable for a stable backport given that
it seems the SPI support never worked.

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Fixes: 1b3bd85927 ("iio: chemical: Add support for Bosch BME680 sensor");
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-03-09 17:27:36 +00:00

91 lines
2.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef BME680_H_
#define BME680_H_
#define BME680_REG_CHIP_ID 0xD0
#define BME680_CHIP_ID_VAL 0x61
#define BME680_REG_SOFT_RESET 0xE0
#define BME680_CMD_SOFTRESET 0xB6
#define BME680_REG_STATUS 0x73
#define BME680_SPI_MEM_PAGE_BIT BIT(4)
#define BME680_SPI_MEM_PAGE_1_VAL 1
#define BME680_REG_TEMP_MSB 0x22
#define BME680_REG_PRESS_MSB 0x1F
#define BM6880_REG_HUMIDITY_MSB 0x25
#define BME680_REG_GAS_MSB 0x2A
#define BME680_REG_GAS_R_LSB 0x2B
#define BME680_GAS_STAB_BIT BIT(4)
#define BME680_GAS_RANGE_MASK GENMASK(3, 0)
#define BME680_REG_CTRL_HUMIDITY 0x72
#define BME680_OSRS_HUMIDITY_MASK GENMASK(2, 0)
#define BME680_REG_CTRL_MEAS 0x74
#define BME680_OSRS_TEMP_MASK GENMASK(7, 5)
#define BME680_OSRS_PRESS_MASK GENMASK(4, 2)
#define BME680_MODE_MASK GENMASK(1, 0)
#define BME680_MODE_FORCED 1
#define BME680_MODE_SLEEP 0
#define BME680_REG_CONFIG 0x75
#define BME680_FILTER_MASK GENMASK(4, 2)
#define BME680_FILTER_COEFF_VAL BIT(1)
/* TEMP/PRESS/HUMID reading skipped */
#define BME680_MEAS_SKIPPED 0x8000
#define BME680_MAX_OVERFLOW_VAL 0x40000000
#define BME680_HUM_REG_SHIFT_VAL 4
#define BME680_BIT_H1_DATA_MASK GENMASK(3, 0)
#define BME680_REG_RES_HEAT_RANGE 0x02
#define BME680_RHRANGE_MASK GENMASK(5, 4)
#define BME680_REG_RES_HEAT_VAL 0x00
#define BME680_REG_RANGE_SW_ERR 0x04
#define BME680_RSERROR_MASK GENMASK(7, 4)
#define BME680_REG_RES_HEAT_0 0x5A
#define BME680_REG_GAS_WAIT_0 0x64
#define BME680_ADC_GAS_RES_SHIFT 6
#define BME680_AMB_TEMP 25
#define BME680_REG_CTRL_GAS_1 0x71
#define BME680_RUN_GAS_MASK BIT(4)
#define BME680_NB_CONV_MASK GENMASK(3, 0)
#define BME680_REG_MEAS_STAT_0 0x1D
#define BME680_GAS_MEAS_BIT BIT(6)
/* Calibration Parameters */
#define BME680_T2_LSB_REG 0x8A
#define BME680_T3_REG 0x8C
#define BME680_P1_LSB_REG 0x8E
#define BME680_P2_LSB_REG 0x90
#define BME680_P3_REG 0x92
#define BME680_P4_LSB_REG 0x94
#define BME680_P5_LSB_REG 0x96
#define BME680_P7_REG 0x98
#define BME680_P6_REG 0x99
#define BME680_P8_LSB_REG 0x9C
#define BME680_P9_LSB_REG 0x9E
#define BME680_P10_REG 0xA0
#define BME680_H2_LSB_REG 0xE2
#define BME680_H2_MSB_REG 0xE1
#define BME680_H1_MSB_REG 0xE3
#define BME680_H1_LSB_REG 0xE2
#define BME680_H3_REG 0xE4
#define BME680_H4_REG 0xE5
#define BME680_H5_REG 0xE6
#define BME680_H6_REG 0xE7
#define BME680_H7_REG 0xE8
#define BME680_T1_LSB_REG 0xE9
#define BME680_GH2_LSB_REG 0xEB
#define BME680_GH1_REG 0xED
#define BME680_GH3_REG 0xEE
extern const struct regmap_config bme680_regmap_config;
int bme680_core_probe(struct device *dev, struct regmap *regmap,
const char *name);
#endif /* BME680_H_ */