/*
* 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
#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
#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
#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
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
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 };
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;
.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;
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)
{
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);
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;
}
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);
module_i2c_driver(bmp280_driver);
MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
-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");
projects / mirror_ubuntu-artful-kernel.git / commitdiff