On Sun, Apr 24, 2016 at 6:52 AM, Akinobu Mita <akinobu.mita@xxxxxxxxx> wrote: > 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); BMP280_CHIP_ID should be id->driver_data as well > 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 -- 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
