> Minimal implementation, can read temperature and data using direct mode. > > Datasheet available at > <http://ae-bst.resource.bosch.com/media/products/dokumente/bmp280/BST-BMP280-DS001-09.pdf> minor comments below > Signed-off-by: Vlad Dogaru <vlad.dogaru@xxxxxxxxx> > --- > drivers/iio/pressure/Kconfig | 11 ++ > drivers/iio/pressure/Makefile | 1 + > drivers/iio/pressure/bmp280.c | 433 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 445 insertions(+) > create mode 100644 drivers/iio/pressure/bmp280.c > > diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig > index 15afbc9..27ab27e 100644 > --- a/drivers/iio/pressure/Kconfig > +++ b/drivers/iio/pressure/Kconfig > @@ -5,6 +5,17 @@ > > menu "Pressure sensors" > > +config BMP280 > + tristate "Bosch Sensortec BMP280 pressure sensor driver" > + depends on I2C > + select REGMAP_I2C > + help > + Say yes here to build support for Bosch Sensortec BMP28 BMP280 > + pressure and temperature sensor. > + > + To compile this driver as a module, choose M here: the module > + will be called bmp280. > + > config HID_SENSOR_PRESS > depends on HID_SENSOR_HUB > select IIO_BUFFER > diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile > index 90a37e8..88011f2 100644 > --- a/drivers/iio/pressure/Makefile > +++ b/drivers/iio/pressure/Makefile > @@ -3,6 +3,7 @@ > # > > # When adding new entries keep the list in alphabetical order > +obj-$(CONFIG_BMP280) += bmp280.o > obj-$(CONFIG_HID_SENSOR_PRESS) += hid-sensor-press.o > obj-$(CONFIG_MPL115) += mpl115.o > obj-$(CONFIG_MPL3115) += mpl3115.o > diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c > new file mode 100644 > index 0000000..f5764ee > --- /dev/null > +++ b/drivers/iio/pressure/bmp280.c > @@ -0,0 +1,433 @@ > +/* > + * Copyright (c) 2014 Intel Corporation > + * > + * Driver for Bosch Sensortec 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. > + * > + */ > + > +#define pr_fmt(fmt) "bmp280: " fmt > + > +#include <linux/module.h> > +#include <linux/i2c.h> > +#include <linux/acpi.h> > +#include <linux/regmap.h> > +#include <linux/iio/iio.h> > +#include <linux/iio/sysfs.h> > + > +#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_RESET 0xE0 > +#define BMP280_REG_ID 0xD0 > + > +#define BMP280_REG_COMP_START 0x88 > +#define BMP280_COMP_REG_COUNT 24 > + > +#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_TEMP_MASK (BIT(7) | BIT(6) | BIT(5)) > +#define BMP280_OSRS_TEMP_SKIP 0 > +#define BMP280_OSRS_TEMP_1X BIT(5) > +#define BMP280_OSRS_TEMP_2X BIT(6) > +#define BMP280_OSRS_TEMP_4X (BIT(6) | BIT(5)) > +#define BMP280_OSRS_TEMP_8X BIT(7) > +#define BMP280_OSRS_TEMP_16X (BIT(7) | BIT(5)) > + > +#define BMP280_OSRS_PRESS_MASK (BIT(4) | BIT(3) | BIT(2)) > +#define BMP280_OSRS_PRESS_SKIP 0 > +#define BMP280_OSRS_PRESS_1X BIT(2) > +#define BMP280_OSRS_PRESS_2X BIT(3) > +#define BMP280_OSRS_PRESS_4X (BIT(3) | BIT(2)) > +#define BMP280_OSRS_PRESS_8X BIT(4) > +#define BMP280_OSRS_PRESS_16X (BIT(4) | BIT(2)) > + > +#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)) > + > +#define BMP280_CHIP_ID 0x58 > +#define BMP280_SOFT_RESET_VAL 0xB6 > + > +struct bmp280_data { > + struct i2c_client *client; > + struct mutex lock; > + struct regmap *regmap; > + > + /* > + * Carryover value from temperature conversion, used in pressure > + * calculation. > + */ > + s32 t_fine; > + > + /* Compensation parameters. */ > + u16 dig_t1; > + s16 dig_t2, dig_t3; > + u16 dig_p1; > + s16 dig_p2, dig_p3, dig_p4, dig_p5, dig_p6, dig_p7, dig_p8, dig_p9; > +}; > + > +static const struct iio_chan_spec bmp280_channels[] = { > + { > + .type = IIO_PRESSURE, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > + BIT(IIO_CHAN_INFO_SCALE), > + }, > + { > + .type = IIO_TEMP, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > + BIT(IIO_CHAN_INFO_SCALE), should probably be _PROCESSED, not _RAW > + }, > +}; > + > +static bool bmp280_is_writeable_reg(struct device *dev, unsigned int reg) > +{ > + switch (reg) { > + case BMP280_REG_CONFIG: > + case BMP280_REG_CTRL_MEAS: > + case BMP280_REG_RESET: > + return true; > + default: > + return false; > + }; > +} > + > +static bool bmp280_is_volatile_reg(struct device *dev, unsigned int reg) > +{ > + switch (reg) { > + case BMP280_REG_TEMP_XLSB: > + case BMP280_REG_TEMP_LSB: > + case BMP280_REG_TEMP_MSB: > + case BMP280_REG_PRESS_XLSB: > + case BMP280_REG_PRESS_LSB: > + case BMP280_REG_PRESS_MSB: > + case BMP280_REG_STATUS: > + return true; > + default: > + return false; > + } > +} > + > +static const struct regmap_config bmp280_regmap_config = { > + .reg_bits = 8, > + .val_bits = 8, > + > + .max_register = BMP280_REG_TEMP_XLSB, > + .cache_type = REGCACHE_RBTREE, > + > + .writeable_reg = bmp280_is_writeable_reg, > + .volatile_reg = bmp280_is_volatile_reg, > +}; > + > +/* > + * Returns temperature in DegC, resolution is 0.01 DegC. Output value of > + * "5123" equals 51.23 DegC. t_fine carries fine temperature as global > + * value. > + * > + * Taken from datasheet, Section 3.11.3, "Compensation formula". > + */ > +static s32 bmp280_compensate_temp(struct bmp280_data *data, > + s32 adc_temp) > +{ > + s32 var1, var2, T; use lowercase t? > + > + var1 = (((adc_temp >> 3) - ((s32) data->dig_t1 << 1)) * > + ((s32) data->dig_t2)) >> 11; > + var2 = (((((adc_temp >> 4) - ((s32) data->dig_t1)) * > + ((adc_temp >> 4) - ((s32) data->dig_t1))) >> 12) * > + ((s32) data->dig_t3)) >> 14; > + > + data->t_fine = var1 + var2; > + T = (data->t_fine * 5 + 128) >> 8; > + > + return T; > +} > + > +/* > + * Returns pressure in Pa as unsigned 32 bit integer in Q24.8 format (24 > + * integer bits and 8 fractional bits). Output value of "24674867" > + * represents 24674867/256 = 96386.2 Pa = 963.862 hPa > + * > + * Taken from datasheet, Section 3.11.3, "Compensation formula". > + */ > +static u32 bmp280_compensate_press(struct bmp280_data *data, > + s32 adc_press) > +{ > + s64 var1, var2, p; > + > + var1 = ((s64) data->t_fine) - 128000; > + var2 = var1 * var1 * (s64) data->dig_p6; > + var2 = var2 + ((var1 * (s64) data->dig_p5) << 17); > + var2 = var2 + (((s64) data->dig_p4) << 35); > + var1 = ((var1 * var1 * (s64) data->dig_p3) >> 8) + > + ((var1 * (s64) data->dig_p2) << 12); > + var1 = (((((s64) 1) << 47) + var1)) * ((s64) data->dig_p1) >> 33; > + > + if (var1 == 0) > + return 0; > + > + p = 1048576 - adc_press; > + p = (((p << 31) - var2) * 3125) / var1; > + var1 = (((s64) data->dig_p9) * (p >> 13) * (p >> 13)) >> 25; > + var2 = (((s64) data->dig_p8) * p) >> 19; > + p = ((p + var1 + var2) >> 8) + (((s64) data->dig_p7) << 4); > + > + return (u32) p; > +} > + > +static int bmp280_read_temp(struct bmp280_data *data, > + int *val, int *val2) > +{ val2 is not used > + int ret; > + __be32 tmp; > + s32 adc_temp, comp_temp; > + > + ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB, > + (u8 *) &tmp, 3); tmp should be initialized, only 3 bytes out of 4 read > + if (ret < 0) { > + dev_err(&data->client->dev, "failed to read temperature\n"); > + return ret; > + } > + > + adc_temp = be32_to_cpu(tmp) >> 12; > + comp_temp = bmp280_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; > + return IIO_VAL_INT; > + } > + > + return 0; > +} > + > +static int bmp280_read_press(struct bmp280_data *data, > + int *val, int *val2) > +{ val2 is not used > + int ret; > + __be32 tmp; > + s32 adc_press; > + u32 comp_press; > + > + /* Read and compensate temperature so we get a reading of t_fine. */ > + ret = bmp280_read_temp(data, NULL, NULL); > + if (ret < 0) > + return ret; > + > + ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB, > + (u8 *) &tmp, 3); I think tmp should be initialized, only 3 bytes out of 4 are set here > + if (ret < 0) { > + dev_err(&data->client->dev, "failed to read pressure\n"); > + return ret; > + } > + > + adc_press = be32_to_cpu(tmp) >> 12; > + comp_press = bmp280_compensate_press(data, adc_press); variable comp_press could probably be saved > + *val = comp_press; > + > + return IIO_VAL_INT; > +} > + > +static int bmp280_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + int ret; > + struct bmp280_data *data = iio_priv(indio_dev); > + > + mutex_lock(&data->lock); locking is only needed for _RAW > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: I think this should be _PROCESSED, not _RAW; there is calibration and all kind of scaling done internally > + switch (chan->type) { > + case IIO_PRESSURE: > + ret = bmp280_read_press(data, val, val2); > + break; > + case IIO_TEMP: > + ret = bmp280_read_temp(data, val, val2); > + break; > + default: > + ret = -EINVAL; > + break; > + } > + break; > + case IIO_CHAN_INFO_SCALE: > + switch (chan->type) { > + case IIO_PRESSURE: > + /* Each LSB is 1/256 Pa. We need kPa. */ > + *val = 1; > + *val2 = 256000; > + ret = IIO_VAL_FRACTIONAL; > + break; > + case IIO_TEMP: > + /* Each LSB is 0.01 degC. We need milli degC. */ > + *val = 10; > + ret = IIO_VAL_INT; > + break; > + default: > + ret = -EINVAL; > + break; > + } > + break; > + default: > + ret = -EINVAL; > + break; > + } > + > + mutex_unlock(&data->lock); > + > + return ret; > +} > + > +static const struct iio_info bmp280_info = { > + .driver_module = THIS_MODULE, > + .read_raw = &bmp280_read_raw, > +}; > + > +static int bmp280_read_calibration_regs(struct iio_dev *indio_dev) > +{ > + struct bmp280_data *data = iio_priv(indio_dev); > + int ret; > + u8 buf[BMP280_COMP_REG_COUNT]; > + __le16 *buf16; > + > + ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_START, buf, > + BMP280_COMP_REG_COUNT); > + if (ret < 0) { > + dev_err(&data->client->dev, > + "failed to read calibration parameters\n"); > + return ret; > + } > + > + buf16 = (__le16 *) buf; > + > + data->dig_t1 = (u16) le16_to_cpu(buf16[0]); > + data->dig_t2 = (s16) le16_to_cpu(buf16[1]); > + data->dig_t3 = (s16) le16_to_cpu(buf16[2]); > + > + data->dig_p1 = (s16) le16_to_cpu(buf16[3]); > + data->dig_p2 = (u16) le16_to_cpu(buf16[4]); > + data->dig_p3 = (u16) le16_to_cpu(buf16[5]); > + data->dig_p4 = (u16) le16_to_cpu(buf16[6]); > + data->dig_p5 = (u16) le16_to_cpu(buf16[7]); > + data->dig_p6 = (u16) le16_to_cpu(buf16[8]); > + data->dig_p7 = (u16) le16_to_cpu(buf16[9]); > + data->dig_p8 = (u16) le16_to_cpu(buf16[10]); > + data->dig_p9 = (u16) le16_to_cpu(buf16[11]); > + > + return 0; > +} > + > +static int bmp280_chip_init(struct bmp280_data *data) > +{ > + int ret; > + > + ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS, > + BMP280_OSRS_TEMP_MASK | > + BMP280_OSRS_PRESS_MASK | > + BMP280_MODE_MASK, > + BMP280_OSRS_TEMP_2X | > + BMP280_OSRS_PRESS_16X | > + BMP280_MODE_NORMAL); > + if (ret < 0) { > + dev_err(&data->client->dev, > + "failed to write config register\n"); > + return ret; > + } > + > + ret = regmap_update_bits(data->regmap, BMP280_REG_CONFIG, > + BMP280_FILTER_MASK, > + BMP280_FILTER_4X); > + if (ret < 0) { > + dev_err(&data->client->dev, > + "failed to write config register\n"); > + return ret; > + } > + > + return ret; > +} > + > +static int bmp280_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + int ret; > + struct iio_dev *indio_dev; > + struct bmp280_data *data; > + > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > + if (!indio_dev) > + return -ENOMEM; > + > + i2c_set_clientdata(client, indio_dev); > + data = iio_priv(indio_dev); > + mutex_init(&data->lock); > + data->client = client; > + > + indio_dev->dev.parent = &client->dev; > + indio_dev->name = id->name; > + indio_dev->channels = bmp280_channels; > + indio_dev->num_channels = ARRAY_SIZE(bmp280_channels); > + indio_dev->info = &bmp280_info; > + indio_dev->modes = INDIO_DIRECT_MODE; > + > + data->regmap = devm_regmap_init_i2c(client, &bmp280_regmap_config); > + if (IS_ERR(data->regmap)) { > + dev_err(&client->dev, "failed to allocate register map\n"); > + return PTR_ERR(data->regmap); > + } > + the BMP280 has a nice CHIP_ID which is already #define, why not check it? > + ret = bmp280_read_calibration_regs(indio_dev); > + if (ret < 0) > + return ret; > + > + ret = bmp280_chip_init(data); > + if (ret < 0) > + return ret; > + > + return devm_iio_device_register(&client->dev, indio_dev); > +} > + > +static const struct acpi_device_id bmp280_acpi_match[] = { > + {"BMP0280", 0}, > + { }, > +}; > +MODULE_DEVICE_TABLE(acpi, bmp280_acpi_match); > + > +static const struct i2c_device_id bmp280_id[] = { > + {"bmp280", 0}, > + { }, > +}; > +MODULE_DEVICE_TABLE(i2c, bmp280_id); > + > +static struct i2c_driver bmp280_driver = { > + .driver = { > + .name = "bmp280", > + .acpi_match_table = ACPI_PTR(bmp280_acpi_match), > + }, > + .probe = bmp280_probe, > + .id_table = bmp280_id, > +}; > +module_i2c_driver(bmp280_driver); > + > +MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@xxxxxxxxx>"); > +MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP280 pressure and temperature sensor"); > +MODULE_LICENSE("GPL v2"); > -- Peter Meerwald +43-664-2444418 (mobile) -- 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
