[deliverable/linux.git] / drivers / iio / pressure / bmp280.c

/*
 * 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_TEMP_START	0x88
#define BMP280_COMP_TEMP_REG_COUNT	6

#define BMP280_REG_COMP_PRESS_START	0x8E
#define BMP280_COMP_PRESS_REG_COUNT	18

#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;
};

/*
 * These enums are used for indexing into the array of compensation
 * parameters.
 */
enum { T1, T2, T3 };
enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };

static const struct iio_chan_spec bmp280_channels[] = {
	{
		.type = IIO_PRESSURE,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
	},
	{
		.type = IIO_TEMP,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
	},
};

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)
{
	int ret;
	s32 var1, var2;
	__le16 buf[BMP280_COMP_TEMP_REG_COUNT / 2];

	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START,
			       buf, BMP280_COMP_TEMP_REG_COUNT);
	if (ret < 0) {
		dev_err(&data->client->dev,
			"failed to read temperature calibration parameters\n");
		return ret;
	}

	/*
	 * The double casts are necessary because le16_to_cpu returns an
	 * unsigned 16-bit value.  Casting that value directly to a
	 * signed 32-bit will not do proper sign extension.
	 *
	 * Conversely, T1 and P1 are unsigned values, so they can be
	 * cast straight to the larger type.
	 */
	var1 = (((adc_temp >> 3) - ((s32)le16_to_cpu(buf[T1]) << 1)) *
		((s32)(s16)le16_to_cpu(buf[T2]))) >> 11;
	var2 = (((((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1]))) *
		  ((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1])))) >> 12) *
		((s32)(s16)le16_to_cpu(buf[T3]))) >> 14;
	data->t_fine = var1 + var2;

	return (data->t_fine * 5 + 128) >> 8;
}

/*
 * 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)
{
	int ret;
	s64 var1, var2, p;
	__le16 buf[BMP280_COMP_PRESS_REG_COUNT / 2];

	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_PRESS_START,
			       buf, BMP280_COMP_PRESS_REG_COUNT);
	if (ret < 0) {
		dev_err(&data->client->dev,
			"failed to read pressure calibration parameters\n");
		return ret;
	}

	var1 = ((s64)data->t_fine) - 128000;
	var2 = var1 * var1 * (s64)(s16)le16_to_cpu(buf[P6]);
	var2 += (var1 * (s64)(s16)le16_to_cpu(buf[P5])) << 17;
	var2 += ((s64)(s16)le16_to_cpu(buf[P4])) << 35;
	var1 = ((var1 * var1 * (s64)(s16)le16_to_cpu(buf[P3])) >> 8) +
		((var1 * (s64)(s16)le16_to_cpu(buf[P2])) << 12);
	var1 = ((((s64)1) << 47) + var1) * ((s64)le16_to_cpu(buf[P1])) >> 33;

	if (var1 == 0)
		return 0;

	p = ((((s64)1048576 - adc_press) << 31) - var2) * 3125;
	p = div64_s64(p, var1);
	var1 = (((s64)(s16)le16_to_cpu(buf[P9])) * (p >> 13) * (p >> 13)) >> 25;
	var2 = (((s64)(s16)le16_to_cpu(buf[P8])) * p) >> 19;
	p = ((p + var1 + var2) >> 8) + (((s64)(s16)le16_to_cpu(buf[P7])) << 4);

	return (u32)p;
}

static int bmp280_read_temp(struct bmp280_data *data,
			    int *val)
{
	int ret;
	__be32 tmp = 0;
	s32 adc_temp, comp_temp;

	ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB,
			       (u8 *) &tmp, 3);
	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 * 10;
		return IIO_VAL_INT;
	}

	return 0;
}

static int bmp280_read_press(struct bmp280_data *data,
			     int *val, int *val2)
{
	int ret;
	__be32 tmp = 0;
	s32 adc_press;
	u32 comp_press;

	/* Read and compensate temperature so we get a reading of t_fine. */
	ret = bmp280_read_temp(data, NULL);
	if (ret < 0)
		return ret;

	ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB,
			       (u8 *) &tmp, 3);
	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);

	*val = comp_press;
	*val2 = 256000;

	return IIO_VAL_FRACTIONAL;
}

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);

	switch (mask) {
	case IIO_CHAN_INFO_PROCESSED:
		switch (chan->type) {
		case IIO_PRESSURE:
			ret = bmp280_read_press(data, val, val2);
			break;
		case IIO_TEMP:
			ret = bmp280_read_temp(data, val);
			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_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 ctrl_meas 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;
	unsigned int chip_id;

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	if (!indio_dev)
		return -ENOMEM;

	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);
	}

	ret = regmap_read(data->regmap, BMP280_REG_ID, &chip_id);
	if (ret < 0)
		return ret;
	if (chip_id != BMP280_CHIP_ID) {
		dev_err(&client->dev, "bad chip id.  expected %x got %x\n",
			BMP280_CHIP_ID, chip_id);
		return -EINVAL;
	}

	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@intel.com>");
MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP280 pressure and temperature sensor");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
d5c94568 VD	1	/*
	2	* Copyright (c) 2014 Intel Corporation
	3	*
	4	* Driver for Bosch Sensortec BMP280 digital pressure sensor.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	*/
	11
	12	#define pr_fmt(fmt) "bmp280: " fmt
	13
	14	#include <linux/module.h>
	15	#include <linux/i2c.h>
	16	#include <linux/acpi.h>
	17	#include <linux/regmap.h>
	18	#include <linux/iio/iio.h>
	19	#include <linux/iio/sysfs.h>
	20
	21	#define BMP280_REG_TEMP_XLSB 0xFC
	22	#define BMP280_REG_TEMP_LSB 0xFB
	23	#define BMP280_REG_TEMP_MSB 0xFA
	24	#define BMP280_REG_PRESS_XLSB 0xF9
	25	#define BMP280_REG_PRESS_LSB 0xF8
	26	#define BMP280_REG_PRESS_MSB 0xF7
	27
	28	#define BMP280_REG_CONFIG 0xF5
	29	#define BMP280_REG_CTRL_MEAS 0xF4
	30	#define BMP280_REG_STATUS 0xF3
	31	#define BMP280_REG_RESET 0xE0
	32	#define BMP280_REG_ID 0xD0
	33
	34	#define BMP280_REG_COMP_TEMP_START 0x88
	35	#define BMP280_COMP_TEMP_REG_COUNT 6
	36
	37	#define BMP280_REG_COMP_PRESS_START 0x8E
	38	#define BMP280_COMP_PRESS_REG_COUNT 18
	39
	40	#define BMP280_FILTER_MASK (BIT(4) \| BIT(3) \| BIT(2))
	41	#define BMP280_FILTER_OFF 0
	42	#define BMP280_FILTER_2X BIT(2)
	43	#define BMP280_FILTER_4X BIT(3)
	44	#define BMP280_FILTER_8X (BIT(3) \| BIT(2))
	45	#define BMP280_FILTER_16X BIT(4)
	46
	47	#define BMP280_OSRS_TEMP_MASK (BIT(7) \| BIT(6) \| BIT(5))
	48	#define BMP280_OSRS_TEMP_SKIP 0
	49	#define BMP280_OSRS_TEMP_1X BIT(5)
	50	#define BMP280_OSRS_TEMP_2X BIT(6)
	51	#define BMP280_OSRS_TEMP_4X (BIT(6) \| BIT(5))
	52	#define BMP280_OSRS_TEMP_8X BIT(7)
	53	#define BMP280_OSRS_TEMP_16X (BIT(7) \| BIT(5))
	54
	55	#define BMP280_OSRS_PRESS_MASK (BIT(4) \| BIT(3) \| BIT(2))
	56	#define BMP280_OSRS_PRESS_SKIP 0
	57	#define BMP280_OSRS_PRESS_1X BIT(2)
	58	#define BMP280_OSRS_PRESS_2X BIT(3)
	59	#define BMP280_OSRS_PRESS_4X (BIT(3) \| BIT(2))
	60	#define BMP280_OSRS_PRESS_8X BIT(4)
	61	#define BMP280_OSRS_PRESS_16X (BIT(4) \| BIT(2))
	62
	63	#define BMP280_MODE_MASK (BIT(1) \| BIT(0))
	64	#define BMP280_MODE_SLEEP 0
65	#define BMP280_MODE_FORCED BIT(0)
66	#define BMP280_MODE_NORMAL (BIT(1) \| BIT(0))
67
68	#define BMP280_CHIP_ID 0x58
69	#define BMP280_SOFT_RESET_VAL 0xB6
70
71	struct bmp280_data {
72	struct i2c_client *client;
73	struct mutex lock;
74	struct regmap *regmap;
75
76	/*
77	* Carryover value from temperature conversion, used in pressure
78	* calculation.
79	*/
80	s32 t_fine;
81	};
82
0f8994b1 VD	83	/*
	84	* These enums are used for indexing into the array of compensation
	85	* parameters.
	86	*/
	87	enum { T1, T2, T3 };
	88	enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
d5c94568 VD	89
	90	static const struct iio_chan_spec bmp280_channels[] = {
	91	{
	92	.type = IIO_PRESSURE,
	93	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
	94	},
	95	{
	96	.type = IIO_TEMP,
	97	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
	98	},
	99	};
	100
	101	static bool bmp280_is_writeable_reg(struct device *dev, unsigned int reg)
	102	{
	103	switch (reg) {
	104	case BMP280_REG_CONFIG:
	105	case BMP280_REG_CTRL_MEAS:
	106	case BMP280_REG_RESET:
	107	return true;
	108	default:
	109	return false;
	110	};
	111	}
	112
	113	static bool bmp280_is_volatile_reg(struct device *dev, unsigned int reg)
	114	{
	115	switch (reg) {
	116	case BMP280_REG_TEMP_XLSB:
	117	case BMP280_REG_TEMP_LSB:
	118	case BMP280_REG_TEMP_MSB:
	119	case BMP280_REG_PRESS_XLSB:
	120	case BMP280_REG_PRESS_LSB:
	121	case BMP280_REG_PRESS_MSB:
	122	case BMP280_REG_STATUS:
	123	return true;
	124	default:
	125	return false;
	126	}
	127	}
	128
	129	static const struct regmap_config bmp280_regmap_config = {
	130	.reg_bits = 8,
	131	.val_bits = 8,
	132
	133	.max_register = BMP280_REG_TEMP_XLSB,
	134	.cache_type = REGCACHE_RBTREE,
	135
	136	.writeable_reg = bmp280_is_writeable_reg,
	137	.volatile_reg = bmp280_is_volatile_reg,
	138	};
	139
d5c94568 VD	140	/*
	141	* Returns temperature in DegC, resolution is 0.01 DegC. Output value of
	142	* "5123" equals 51.23 DegC. t_fine carries fine temperature as global
	143	* value.
	144	*
	145	* Taken from datasheet, Section 3.11.3, "Compensation formula".
	146	*/
	147	static s32 bmp280_compensate_temp(struct bmp280_data *data,
d5c94568 VD	148	s32 adc_temp)
d5c94568 VD	149	{
0f8994b1	150	int ret;
44cf3798	151	s32 var1, var2;
0f8994b1 VD	152	__le16 buf[BMP280_COMP_TEMP_REG_COUNT / 2];
	153
	154	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START,
	155	buf, BMP280_COMP_TEMP_REG_COUNT);
	156	if (ret < 0) {
	157	dev_err(&data->client->dev,
	158	"failed to read temperature calibration parameters\n");
	159	return ret;
	160	}
d5c94568	161
0f8994b1 VD	162	/*
	163	* The double casts are necessary because le16_to_cpu returns an
	164	* unsigned 16-bit value. Casting that value directly to a
	165	* signed 32-bit will not do proper sign extension.
	166	*
	167	* Conversely, T1 and P1 are unsigned values, so they can be
	168	* cast straight to the larger type.
	169	*/
	170	var1 = (((adc_temp >> 3) - ((s32)le16_to_cpu(buf[T1]) << 1)) *
	171	((s32)(s16)le16_to_cpu(buf[T2]))) >> 11;
	172	var2 = (((((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1]))) *
	173	((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1])))) >> 12) *
	174	((s32)(s16)le16_to_cpu(buf[T3]))) >> 14;
abad3983	175	data->t_fine = var1 + var2;
d5c94568	176
44cf3798	177	return (data->t_fine * 5 + 128) >> 8;
d5c94568 VD	178	}
	179
	180	/*
	181	* Returns pressure in Pa as unsigned 32 bit integer in Q24.8 format (24
	182	* integer bits and 8 fractional bits). Output value of "24674867"
	183	* represents 24674867/256 = 96386.2 Pa = 963.862 hPa
	184	*
	185	* Taken from datasheet, Section 3.11.3, "Compensation formula".
	186	*/
	187	static u32 bmp280_compensate_press(struct bmp280_data *data,
d5c94568 VD	188	s32 adc_press)
d5c94568 VD	189	{
0f8994b1	190	int ret;
d5c94568	191	s64 var1, var2, p;
0f8994b1 VD	192	__le16 buf[BMP280_COMP_PRESS_REG_COUNT / 2];
	193
	194	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_PRESS_START,
	195	buf, BMP280_COMP_PRESS_REG_COUNT);
	196	if (ret < 0) {
	197	dev_err(&data->client->dev,
	198	"failed to read pressure calibration parameters\n");
	199	return ret;
	200	}
d5c94568	201
0f8994b1 VD	202	var1 = ((s64)data->t_fine) - 128000;
0f8994b1 VD	203	var2 = var1 * var1 * (s64)(s16)le16_to_cpu(buf[P6]);
44cf3798 HK	204	var2 += (var1 * (s64)(s16)le16_to_cpu(buf[P5])) << 17;
44cf3798 HK	205	var2 += ((s64)(s16)le16_to_cpu(buf[P4])) << 35;
0f8994b1 VD	206	var1 = ((var1 * var1 * (s64)(s16)le16_to_cpu(buf[P3])) >> 8) +
	207	((var1 * (s64)(s16)le16_to_cpu(buf[P2])) << 12);
	208	var1 = ((((s64)1) << 47) + var1) * ((s64)le16_to_cpu(buf[P1])) >> 33;
d5c94568 VD	209
	210	if (var1 == 0)
	211	return 0;
	212
0f8994b1	213	p = ((((s64)1048576 - adc_press) << 31) - var2) * 3125;
46ee98a2	214	p = div64_s64(p, var1);
0f8994b1 VD	215	var1 = (((s64)(s16)le16_to_cpu(buf[P9])) * (p >> 13) * (p >> 13)) >> 25;
	216	var2 = (((s64)(s16)le16_to_cpu(buf[P8])) * p) >> 19;
	217	p = ((p + var1 + var2) >> 8) + (((s64)(s16)le16_to_cpu(buf[P7])) << 4);
d5c94568	218
44cf3798	219	return (u32)p;
d5c94568 VD	220	}
	221
	222	static int bmp280_read_temp(struct bmp280_data *data,
	223	int *val)
	224	{
	225	int ret;
	226	__be32 tmp = 0;
	227	s32 adc_temp, comp_temp;
d5c94568 VD	228
	229	ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB,
	230	(u8 *) &tmp, 3);
	231	if (ret < 0) {
	232	dev_err(&data->client->dev, "failed to read temperature\n");
	233	return ret;
	234	}
	235
	236	adc_temp = be32_to_cpu(tmp) >> 12;
0f8994b1	237	comp_temp = bmp280_compensate_temp(data, adc_temp);
d5c94568 VD	238
	239	/*
	240	* val might be NULL if we're called by the read_press routine,
	241	* who only cares about the carry over t_fine value.
	242	*/
	243	if (val) {
	244	val = comp_temp 10;
	245	return IIO_VAL_INT;
	246	}
	247
	248	return 0;
	249	}
	250
	251	static int bmp280_read_press(struct bmp280_data *data,
	252	int val, int val2)
	253	{
	254	int ret;
	255	__be32 tmp = 0;
	256	s32 adc_press;
	257	u32 comp_press;
d5c94568 VD	258
	259	/* Read and compensate temperature so we get a reading of t_fine. */
	260	ret = bmp280_read_temp(data, NULL);
	261	if (ret < 0)
	262	return ret;
	263
	264	ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB,
	265	(u8 *) &tmp, 3);
	266	if (ret < 0) {
	267	dev_err(&data->client->dev, "failed to read pressure\n");
	268	return ret;
	269	}
	270
	271	adc_press = be32_to_cpu(tmp) >> 12;
0f8994b1	272	comp_press = bmp280_compensate_press(data, adc_press);
d5c94568	273
81ebe850 HK	274	*val = comp_press;
81ebe850 HK	275	*val2 = 256000;
d5c94568	276
81ebe850	277	return IIO_VAL_FRACTIONAL;
d5c94568 VD	278	}
	279
	280	static int bmp280_read_raw(struct iio_dev *indio_dev,
	281	struct iio_chan_spec const *chan,
	282	int val, int val2, long mask)
	283	{
	284	int ret;
	285	struct bmp280_data *data = iio_priv(indio_dev);
	286
	287	mutex_lock(&data->lock);
	288
	289	switch (mask) {
	290	case IIO_CHAN_INFO_PROCESSED:
	291	switch (chan->type) {
	292	case IIO_PRESSURE:
	293	ret = bmp280_read_press(data, val, val2);
	294	break;
	295	case IIO_TEMP:
	296	ret = bmp280_read_temp(data, val);
	297	break;
	298	default:
	299	ret = -EINVAL;
	300	break;
	301	}
	302	break;
	303	default:
	304	ret = -EINVAL;
	305	break;
	306	}
	307
	308	mutex_unlock(&data->lock);
	309
	310	return ret;
	311	}
	312
	313	static const struct iio_info bmp280_info = {
	314	.driver_module = THIS_MODULE,
	315	.read_raw = &bmp280_read_raw,
	316	};
	317
	318	static int bmp280_chip_init(struct bmp280_data *data)
	319	{
	320	int ret;
	321
	322	ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS,
	323	BMP280_OSRS_TEMP_MASK \|
	324	BMP280_OSRS_PRESS_MASK \|
	325	BMP280_MODE_MASK,
	326	BMP280_OSRS_TEMP_2X \|
	327	BMP280_OSRS_PRESS_16X \|
	328	BMP280_MODE_NORMAL);
	329	if (ret < 0) {
	330	dev_err(&data->client->dev,
44cf3798	331	"failed to write ctrl_meas register\n");
d5c94568 VD	332	return ret;
	333	}
	334
	335	ret = regmap_update_bits(data->regmap, BMP280_REG_CONFIG,
	336	BMP280_FILTER_MASK,
	337	BMP280_FILTER_4X);
	338	if (ret < 0) {
	339	dev_err(&data->client->dev,
	340	"failed to write config register\n");
	341	return ret;
	342	}
	343
	344	return ret;
	345	}
	346
	347	static int bmp280_probe(struct i2c_client *client,
	348	const struct i2c_device_id *id)
	349	{
	350	int ret;
	351	struct iio_dev *indio_dev;
	352	struct bmp280_data *data;
	353	unsigned int chip_id;
	354
	355	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	356	if (!indio_dev)
	357	return -ENOMEM;
	358
d5c94568 VD	359	data = iio_priv(indio_dev);
	360	mutex_init(&data->lock);
	361	data->client = client;
	362
	363	indio_dev->dev.parent = &client->dev;
	364	indio_dev->name = id->name;
	365	indio_dev->channels = bmp280_channels;
	366	indio_dev->num_channels = ARRAY_SIZE(bmp280_channels);
	367	indio_dev->info = &bmp280_info;
	368	indio_dev->modes = INDIO_DIRECT_MODE;
	369
	370	data->regmap = devm_regmap_init_i2c(client, &bmp280_regmap_config);
	371	if (IS_ERR(data->regmap)) {
	372	dev_err(&client->dev, "failed to allocate register map\n");
	373	return PTR_ERR(data->regmap);
	374	}
	375
	376	ret = regmap_read(data->regmap, BMP280_REG_ID, &chip_id);
	377	if (ret < 0)
	378	return ret;
	379	if (chip_id != BMP280_CHIP_ID) {
	380	dev_err(&client->dev, "bad chip id. expected %x got %x\n",
	381	BMP280_CHIP_ID, chip_id);
	382	return -EINVAL;
	383	}
	384
	385	ret = bmp280_chip_init(data);
	386	if (ret < 0)
	387	return ret;
	388
	389	return devm_iio_device_register(&client->dev, indio_dev);
	390	}
	391
	392	static const struct acpi_device_id bmp280_acpi_match[] = {
	393	{"BMP0280", 0},
	394	{ },
	395	};
	396	MODULE_DEVICE_TABLE(acpi, bmp280_acpi_match);
	397
	398	static const struct i2c_device_id bmp280_id[] = {
	399	{"bmp280", 0},
	400	{ },
	401	};
	402	MODULE_DEVICE_TABLE(i2c, bmp280_id);
	403
	404	static struct i2c_driver bmp280_driver = {
	405	.driver = {
	406	.name = "bmp280",
	407	.acpi_match_table = ACPI_PTR(bmp280_acpi_match),
	408	},
	409	.probe = bmp280_probe,
	410	.id_table = bmp280_id,
	411	};
	412	module_i2c_driver(bmp280_driver);
	413
	414	MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
	415	MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP280 pressure and temperature sensor");
	416	MODULE_LICENSE("GPL v2");