This adds support for the BMP180 to the bmp280 iio driver. The BMP180 has already been supported by misc/bmp085 driver but it doesn't use iio framework. This change adds the kconfig dependency not to be selected both of them in order to avoid any issues. Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx> Cc: Vlad Dogaru <vlad.dogaru@xxxxxxxxx> Cc: Christoph Mair <christoph.mair@xxxxxxxxx> Cc: Jonathan Cameron <jic23@xxxxxxxxxx> Cc: Hartmut Knaack <knaack.h@xxxxxx> Cc: Lars-Peter Clausen <lars@xxxxxxxxxx> Cc: Peter Meerwald <pmeerw@xxxxxxxxxx> --- * v3 - use single line comment style where possible suggested by Jonathan Cameron - remove double casts for calibration coefficients by using adequate data types, suggested by Jonathan Cameron drivers/iio/pressure/Kconfig | 5 +- drivers/iio/pressure/bmp280.c | 367 ++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 356 insertions(+), 16 deletions(-) diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig index e8f60db..31e5d36 100644 --- a/drivers/iio/pressure/Kconfig +++ b/drivers/iio/pressure/Kconfig @@ -6,11 +6,12 @@ menu "Pressure sensors" config BMP280 - tristate "Bosch Sensortec BMP280 pressure sensor driver" + tristate "Bosch Sensortec BMP180 and BMP280 pressure sensor driver" depends on I2C + depends on !(BMP085_I2C=y || BMP085_I2C=m) select REGMAP_I2C help - Say yes here to build support for Bosch Sensortec BMP280 + Say yes here to build support for Bosch Sensortec BMP180 and BMP280 pressure and temperature sensor. To compile this driver as a module, choose M here: the module diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c index a2602d8..dcf3b0a 100644 --- a/drivers/iio/pressure/bmp280.c +++ b/drivers/iio/pressure/bmp280.c @@ -1,12 +1,15 @@ /* * Copyright (c) 2014 Intel Corporation * - * Driver for Bosch Sensortec BMP280 digital pressure sensor. + * Driver for Bosch Sensortec BMP180 and BMP280 digital pressure sensor. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * + * Datasheet: + * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP180-DS000-121.pdf + * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP280-DS001-12.pdf */ #define pr_fmt(fmt) "bmp280: " fmt @@ -15,9 +18,11 @@ #include <linux/i2c.h> #include <linux/acpi.h> #include <linux/regmap.h> +#include <linux/delay.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> +/* BMP280 specific registers */ #define BMP280_REG_TEMP_XLSB 0xFC #define BMP280_REG_TEMP_LSB 0xFB #define BMP280_REG_TEMP_MSB 0xFA @@ -26,10 +31,7 @@ #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_RESET 0xE0 -#define BMP280_REG_ID 0xD0 #define BMP280_REG_COMP_TEMP_START 0x88 #define BMP280_COMP_TEMP_REG_COUNT 6 @@ -65,6 +67,28 @@ #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 BMP280_SOFT_RESET_VAL 0xB6 @@ -72,6 +96,7 @@ struct bmp280_data { struct i2c_client *client; struct mutex lock; struct regmap *regmap; + const struct bmp280_chip_info *chip_info; /* * Carryover value from temperature conversion, used in pressure @@ -80,9 +105,17 @@ struct bmp280_data { s32 t_fine; }; +struct bmp280_chip_info { + const struct regmap_config *regmap_config; + + int (*chip_config)(struct bmp280_data *); + int (*read_temp)(struct bmp280_data *, int *); + int (*read_press)(struct bmp280_data *, int *, int *); +}; + /* * These enums are used for indexing into the array of compensation - * parameters. + * parameters for BMP280. */ enum { T1, T2, T3 }; enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 }; @@ -290,10 +323,10 @@ static int bmp280_read_raw(struct iio_dev *indio_dev, case IIO_CHAN_INFO_PROCESSED: switch (chan->type) { case IIO_PRESSURE: - ret = bmp280_read_press(data, val, val2); + ret = data->chip_info->read_press(data, val, val2); break; case IIO_TEMP: - ret = bmp280_read_temp(data, val); + ret = data->chip_info->read_temp(data, val); break; default: ret = -EINVAL; @@ -315,7 +348,7 @@ static const struct iio_info bmp280_info = { .read_raw = &bmp280_read_raw, }; -static int bmp280_chip_init(struct bmp280_data *data) +static int bmp280_chip_config(struct bmp280_data *data) { int ret; @@ -344,6 +377,296 @@ static int bmp280_chip_init(struct bmp280_data *data) return ret; } +static const struct bmp280_chip_info bmp280_chip_info = { + .regmap_config = &bmp280_regmap_config, + .chip_config = bmp280_chip_config, + .read_temp = bmp280_read_temp, + .read_press = bmp280_read_press, +}; + +static bool bmp180_is_writeable_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case BMP280_REG_CTRL_MEAS: + case BMP280_REG_RESET: + return true; + default: + return false; + }; +} + +static bool bmp180_is_volatile_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case BMP180_REG_OUT_XLSB: + case BMP180_REG_OUT_LSB: + case BMP180_REG_OUT_MSB: + case BMP280_REG_CTRL_MEAS: + return true; + default: + return false; + } +} + +static const struct regmap_config bmp180_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + + .max_register = BMP180_REG_OUT_XLSB, + .cache_type = REGCACHE_RBTREE, + + .writeable_reg = bmp180_is_writeable_reg, + .volatile_reg = bmp180_is_volatile_reg, +}; + +static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas) +{ + int ret; + const int conversion_time_max[] = { 4500, 7500, 13500, 25500 }; + unsigned int delay_us; + unsigned int ctrl; + + ret = regmap_write(data->regmap, BMP280_REG_CTRL_MEAS, ctrl_meas); + if (ret) + return ret; + + if (ctrl_meas == BMP180_MEAS_TEMP) + delay_us = 4500; + else + delay_us = conversion_time_max[ilog2(8)]; + + usleep_range(delay_us, delay_us + 1000); + + ret = regmap_read(data->regmap, BMP280_REG_CTRL_MEAS, &ctrl); + if (ret) + return ret; + + /* The value of this bit reset to "0" after conversion is complete */ + if (ctrl & BMP180_MEAS_SCO) + return -EIO; + + return 0; +} + +static int bmp180_read_adc_temp(struct bmp280_data *data, int *val) +{ + int ret; + __be16 tmp = 0; + + ret = bmp180_measure(data, BMP180_MEAS_TEMP); + if (ret) + return ret; + + ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (u8 *)&tmp, 2); + if (ret) + return ret; + + *val = be16_to_cpu(tmp); + + return 0; +} + +/* + * These enums are used for indexing into the array of calibration + * coefficients for BMP180. + */ +enum { AC1, AC2, AC3, AC4, AC5, AC6, B1, B2, MB, MC, MD }; + +struct bmp180_calib { + s16 AC1; + s16 AC2; + s16 AC3; + u16 AC4; + u16 AC5; + u16 AC6; + s16 B1; + s16 B2; + s16 MB; + s16 MC; + s16 MD; +}; + +static int bmp180_read_calib(struct bmp280_data *data, + struct bmp180_calib *calib) +{ + int ret; + int i; + __be16 buf[BMP180_REG_CALIB_COUNT / 2]; + + ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START, buf, + sizeof(buf)); + + if (ret < 0) + return ret; + + /* None of the words has the value 0 or 0xFFFF */ + for (i = 0; i < ARRAY_SIZE(buf); i++) { + if (buf[i] == cpu_to_be16(0) || buf[i] == cpu_to_be16(0xffff)) + return -EIO; + } + + calib->AC1 = be16_to_cpu(buf[AC1]); + calib->AC2 = be16_to_cpu(buf[AC2]); + calib->AC3 = be16_to_cpu(buf[AC3]); + calib->AC4 = be16_to_cpu(buf[AC4]); + calib->AC5 = be16_to_cpu(buf[AC5]); + calib->AC6 = be16_to_cpu(buf[AC6]); + calib->B1 = be16_to_cpu(buf[B1]); + calib->B2 = be16_to_cpu(buf[B2]); + calib->MB = be16_to_cpu(buf[MB]); + calib->MC = be16_to_cpu(buf[MC]); + calib->MD = be16_to_cpu(buf[MD]); + + return 0; +} + +/* + * Returns temperature in DegC, resolution is 0.1 DegC. + * t_fine carries fine temperature as global value. + * + * Taken from datasheet, Section 3.5, "Calculating pressure and temperature". + */ +static s32 bmp180_compensate_temp(struct bmp280_data *data, s32 adc_temp) +{ + int ret; + s32 x1, x2; + struct bmp180_calib calib; + + ret = bmp180_read_calib(data, &calib); + if (ret < 0) { + dev_err(&data->client->dev, + "failed to read calibration coefficients\n"); + return ret; + } + + x1 = ((adc_temp - calib.AC6) * calib.AC5) >> 15; + x2 = (calib.MC << 11) / (x1 + calib.MD); + data->t_fine = x1 + x2; + + return (data->t_fine + 8) >> 4; +} + +static int bmp180_read_temp(struct bmp280_data *data, int *val) +{ + int ret; + s32 adc_temp, comp_temp; + + ret = bmp180_read_adc_temp(data, &adc_temp); + if (ret) + return ret; + + comp_temp = bmp180_compensate_temp(data, adc_temp); + + /* + * val might be NULL if we're called by the read_press routine, + * who only cares about the carry over t_fine value. + */ + if (val) { + *val = comp_temp * 100; + return IIO_VAL_INT; + } + + return 0; +} + +static int bmp180_read_adc_press(struct bmp280_data *data, int *val) +{ + int ret; + __be32 tmp = 0; + u8 oss = ilog2(8); + + ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss)); + if (ret) + return ret; + + ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (u8 *)&tmp, 3); + if (ret) + return ret; + + *val = (be32_to_cpu(tmp) >> 8) >> (8 - oss); + + return 0; +} + +/* + * Returns pressure in Pa, resolution is 1 Pa. + * + * Taken from datasheet, Section 3.5, "Calculating pressure and temperature". + */ +static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press) +{ + int ret; + s32 x1, x2, x3, p; + s32 b3, b6; + u32 b4, b7; + s32 oss = ilog2(8); + struct bmp180_calib calib; + + ret = bmp180_read_calib(data, &calib); + if (ret < 0) { + dev_err(&data->client->dev, + "failed to read calibration coefficients\n"); + return ret; + } + + b6 = data->t_fine - 4000; + x1 = (calib.B2 * (b6 * b6 >> 12)) >> 11; + x2 = calib.AC2 * b6 >> 11; + x3 = x1 + x2; + b3 = ((((s32)calib.AC1 * 4 + x3) << oss) + 2) / 4; + x1 = calib.AC3 * b6 >> 13; + x2 = (calib.B1 * ((b6 * b6) >> 12)) >> 16; + x3 = (x1 + x2 + 2) >> 2; + b4 = calib.AC4 * (u32)(x3 + 32768) >> 15; + b7 = ((u32)adc_press - b3) * (50000 >> oss); + if (b7 < 0x80000000) + p = (b7 * 2) / b4; + else + p = (b7 / b4) * 2; + + x1 = (p >> 8) * (p >> 8); + x1 = (x1 * 3038) >> 16; + x2 = (-7357 * p) >> 16; + + return p + ((x1 + x2 + 3791) >> 4); +} + +static int bmp180_read_press(struct bmp280_data *data, + int *val, int *val2) +{ + int ret; + s32 adc_press; + u32 comp_press; + + /* Read and compensate temperature so we get a reading of t_fine. */ + ret = bmp180_read_temp(data, NULL); + if (ret) + return ret; + + ret = bmp180_read_adc_press(data, &adc_press); + if (ret) + return ret; + + comp_press = bmp180_compensate_press(data, adc_press); + + *val = comp_press; + *val2 = 1000; + + return IIO_VAL_FRACTIONAL; +} + +static int bmp180_chip_config(struct bmp280_data *data) +{ + return 0; +} + +static const struct bmp280_chip_info bmp180_chip_info = { + .regmap_config = &bmp180_regmap_config, + .chip_config = bmp180_chip_config, + .read_temp = bmp180_read_temp, + .read_press = bmp180_read_press, +}; + static int bmp280_probe(struct i2c_client *client, const struct i2c_device_id *id) { @@ -367,7 +690,19 @@ static int bmp280_probe(struct i2c_client *client, indio_dev->info = &bmp280_info; indio_dev->modes = INDIO_DIRECT_MODE; - data->regmap = devm_regmap_init_i2c(client, &bmp280_regmap_config); + switch (id->driver_data) { + case BMP180_CHIP_ID: + data->chip_info = &bmp180_chip_info; + break; + case BMP280_CHIP_ID: + data->chip_info = &bmp280_chip_info; + break; + default: + return -EINVAL; + } + + data->regmap = devm_regmap_init_i2c(client, + data->chip_info->regmap_config); if (IS_ERR(data->regmap)) { dev_err(&client->dev, "failed to allocate register map\n"); return PTR_ERR(data->regmap); @@ -376,13 +711,13 @@ static int bmp280_probe(struct i2c_client *client, ret = regmap_read(data->regmap, BMP280_REG_ID, &chip_id); if (ret < 0) return ret; - if (chip_id != BMP280_CHIP_ID) { + if (chip_id != id->driver_data) { dev_err(&client->dev, "bad chip id. expected %x got %x\n", BMP280_CHIP_ID, chip_id); return -EINVAL; } - ret = bmp280_chip_init(data); + ret = data->chip_info->chip_config(data); if (ret < 0) return ret; @@ -390,13 +725,17 @@ static int bmp280_probe(struct i2c_client *client, } static const struct acpi_device_id bmp280_acpi_match[] = { - {"BMP0280", 0}, + {"BMP0280", BMP280_CHIP_ID }, + {"BMP0180", BMP180_CHIP_ID }, + {"BMP0085", BMP180_CHIP_ID }, { }, }; MODULE_DEVICE_TABLE(acpi, bmp280_acpi_match); static const struct i2c_device_id bmp280_id[] = { - {"bmp280", 0}, + {"bmp280", BMP280_CHIP_ID }, + {"bmp180", BMP180_CHIP_ID }, + {"bmp085", BMP180_CHIP_ID }, { }, }; MODULE_DEVICE_TABLE(i2c, bmp280_id); @@ -412,5 +751,5 @@ static struct i2c_driver bmp280_driver = { module_i2c_driver(bmp280_driver); MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@xxxxxxxxx>"); -MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP280 pressure and temperature sensor"); +MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP180/BMP280 pressure and temperature sensor"); MODULE_LICENSE("GPL v2"); -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
