[deliverable/linux.git] / drivers / iio / magnetometer / mmc35240.c

/*
 * MMC35240 - MEMSIC 3-axis Magnetic Sensor
 *
 * Copyright (c) 2015, Intel Corporation.
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 *
 * IIO driver for MMC35240 (7-bit I2C slave address 0x30).
 *
 * TODO: offset, ACPI, continuous measurement mode, PM
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/regmap.h>
#include <linux/acpi.h>
#include <linux/pm.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>

#define MMC35240_DRV_NAME "mmc35240"
#define MMC35240_REGMAP_NAME "mmc35240_regmap"

#define MMC35240_REG_XOUT_L	0x00
#define MMC35240_REG_XOUT_H	0x01
#define MMC35240_REG_YOUT_L	0x02
#define MMC35240_REG_YOUT_H	0x03
#define MMC35240_REG_ZOUT_L	0x04
#define MMC35240_REG_ZOUT_H	0x05

#define MMC35240_REG_STATUS	0x06
#define MMC35240_REG_CTRL0	0x07
#define MMC35240_REG_CTRL1	0x08

#define MMC35240_REG_ID		0x20

#define MMC35240_STATUS_MEAS_DONE_BIT	BIT(0)

#define MMC35240_CTRL0_REFILL_BIT	BIT(7)
#define MMC35240_CTRL0_RESET_BIT	BIT(6)
#define MMC35240_CTRL0_SET_BIT		BIT(5)
#define MMC35240_CTRL0_CMM_BIT		BIT(1)
#define MMC35240_CTRL0_TM_BIT		BIT(0)

/* output resolution bits */
#define MMC35240_CTRL1_BW0_BIT		BIT(0)
#define MMC35240_CTRL1_BW1_BIT		BIT(1)

#define MMC35240_CTRL1_BW_MASK	 (MMC35240_CTRL1_BW0_BIT | \
		 MMC35240_CTRL1_BW1_BIT)
#define MMC35240_CTRL1_BW_SHIFT		0

#define MMC35240_WAIT_CHARGE_PUMP	50000	/* us */
#define MMC53240_WAIT_SET_RESET		1000	/* us */

enum mmc35240_resolution {
	MMC35240_16_BITS_SLOW = 0, /* 100 Hz */
	MMC35240_16_BITS_FAST,     /* 200 Hz */
	MMC35240_14_BITS,          /* 333 Hz */
	MMC35240_12_BITS,          /* 666 Hz */
};

enum mmc35240_axis {
	AXIS_X = 0,
	AXIS_Y,
	AXIS_Z,
};

static const struct {
	int sens[3]; /* sensitivity per X, Y, Z axis */
	int nfo; /* null field output */
} mmc35240_props_table[] = {
	/* 16 bits, 100Hz ODR */
	{
		{1024, 1024, 770},
		32768,
	},
	/* 16 bits, 200Hz ODR */
	{
		{1024, 1024, 770},
		32768,
	},
	/* 14 bits, 333Hz ODR */
	{
		{256, 256, 193},
		8192,
	},
	/* 12 bits, 666Hz ODR */
	{
		{64, 64, 48},
		2048,
	},
};

struct mmc35240_data {
	struct i2c_client *client;
	struct mutex mutex;
	struct regmap *regmap;
	enum mmc35240_resolution res;
};

static const int mmc35240_samp_freq[] = {100, 200, 333, 666};

static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("100 200 333 666");

#define MMC35240_CHANNEL(_axis) { \
	.type = IIO_MAGN, \
	.modified = 1, \
	.channel2 = IIO_MOD_ ## _axis, \
	.address = AXIS_ ## _axis, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
			BIT(IIO_CHAN_INFO_SCALE), \
}

static const struct iio_chan_spec mmc35240_channels[] = {
	MMC35240_CHANNEL(X),
	MMC35240_CHANNEL(Y),
	MMC35240_CHANNEL(Z),
};

static struct attribute *mmc35240_attributes[] = {
	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
	NULL
};

static const struct attribute_group mmc35240_attribute_group = {
	.attrs = mmc35240_attributes,
};

static int mmc35240_get_samp_freq_index(struct mmc35240_data *data,
					int val, int val2)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(mmc35240_samp_freq); i++)
		if (mmc35240_samp_freq[i] == val)
			return i;
	return -EINVAL;
}

static int mmc35240_hw_set(struct mmc35240_data *data, bool set)
{
	int ret;
	u8 coil_bit;

	/*
	 * Recharge the capacitor at VCAP pin, requested to be issued
	 * before a SET/RESET command.
	 */
	ret = regmap_update_bits(data->regmap, MMC35240_REG_CTRL0,
				 MMC35240_CTRL0_REFILL_BIT,
				 MMC35240_CTRL0_REFILL_BIT);
	if (ret < 0)
		return ret;
	usleep_range(MMC35240_WAIT_CHARGE_PUMP, MMC35240_WAIT_CHARGE_PUMP + 1);

	if (set)
		coil_bit = MMC35240_CTRL0_SET_BIT;
	else
		coil_bit = MMC35240_CTRL0_RESET_BIT;

	return regmap_update_bits(data->regmap, MMC35240_REG_CTRL0,
				  MMC35240_CTRL0_REFILL_BIT,
				  coil_bit);
}

static int mmc35240_init(struct mmc35240_data *data)
{
	int ret;
	unsigned int reg_id;

	ret = regmap_read(data->regmap, MMC35240_REG_ID, &reg_id);
	if (ret < 0) {
		dev_err(&data->client->dev, "Error reading product id\n");
		return ret;
	}

	dev_dbg(&data->client->dev, "MMC35240 chip id %x\n", reg_id);

	/*
	 * make sure we restore sensor characteristics, by doing
	 * a RESET/SET sequence
	 */
	ret = mmc35240_hw_set(data, false);
	if (ret < 0)
		return ret;
	usleep_range(MMC53240_WAIT_SET_RESET, MMC53240_WAIT_SET_RESET + 1);

	ret = mmc35240_hw_set(data, true);
	if (ret < 0)
		return ret;

	/* set default sampling frequency */
	return regmap_update_bits(data->regmap, MMC35240_REG_CTRL1,
				  MMC35240_CTRL1_BW_MASK,
				  data->res << MMC35240_CTRL1_BW_SHIFT);
}

static int mmc35240_take_measurement(struct mmc35240_data *data)
{
	int ret, tries = 100;
	unsigned int reg_status;

	ret = regmap_write(data->regmap, MMC35240_REG_CTRL0,
			   MMC35240_CTRL0_TM_BIT);
	if (ret < 0)
		return ret;

	while (tries-- > 0) {
		ret = regmap_read(data->regmap, MMC35240_REG_STATUS,
				  &reg_status);
		if (ret < 0)
			return ret;
		if (reg_status & MMC35240_STATUS_MEAS_DONE_BIT)
			break;
		/* minimum wait time to complete measurement is 10 ms */
		usleep_range(10000, 11000);
	}

	if (tries < 0) {
		dev_err(&data->client->dev, "data not ready\n");
		return -EIO;
	}

	return 0;
}

static int mmc35240_read_measurement(struct mmc35240_data *data, __le16 buf[3])
{
	int ret;

	ret = mmc35240_take_measurement(data);
	if (ret < 0)
		return ret;

	return regmap_bulk_read(data->regmap, MMC35240_REG_XOUT_L, (u8 *)buf,
				3 * sizeof(__le16));
}

/**
 * mmc35240_raw_to_mgauss - convert raw readings to milli gauss. Also apply
			    compensation for output value.
 *
 * @data: device private data
 * @index: axis index for which we want the conversion
 * @buf: raw data to be converted, 2 bytes in little endian format
 * @val: compensated output reading (unit is milli gauss)
 *
 * Returns: 0 in case of success, -EINVAL when @index is not valid
 */
static int mmc35240_raw_to_mgauss(struct mmc35240_data *data, int index,
				  __le16 buf[], int *val)
{
	int raw_x, raw_y, raw_z;
	int sens_x, sens_y, sens_z;
	int nfo;

	raw_x = le16_to_cpu(buf[AXIS_X]);
	raw_y = le16_to_cpu(buf[AXIS_Y]);
	raw_z = le16_to_cpu(buf[AXIS_Z]);

	sens_x = mmc35240_props_table[data->res].sens[AXIS_X];
	sens_y = mmc35240_props_table[data->res].sens[AXIS_Y];
	sens_z = mmc35240_props_table[data->res].sens[AXIS_Z];

	nfo = mmc35240_props_table[data->res].nfo;

	switch (index) {
	case AXIS_X:
		*val = (raw_x - nfo) * 1000 / sens_x;
		break;
	case AXIS_Y:
		*val = (raw_y - nfo) * 1000 / sens_y -
			(raw_z - nfo)  * 1000 / sens_z;
		break;
	case AXIS_Z:
		*val = (raw_y - nfo) * 1000 / sens_y +
			(raw_z - nfo) * 1000 / sens_z;
		break;
	default:
		return -EINVAL;
	}
	return 0;
}

static int mmc35240_read_raw(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan, int *val,
			     int *val2, long mask)
{
	struct mmc35240_data *data = iio_priv(indio_dev);
	int ret, i;
	unsigned int reg;
	__le16 buf[3];

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		mutex_lock(&data->mutex);
		ret = mmc35240_read_measurement(data, buf);
		mutex_unlock(&data->mutex);
		if (ret < 0)
			return ret;
		ret = mmc35240_raw_to_mgauss(data, chan->address, buf, val);
		if (ret < 0)
			return ret;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		*val = 0;
		*val2 = 1000;
		return IIO_VAL_INT_PLUS_MICRO;
	case IIO_CHAN_INFO_SAMP_FREQ:
		mutex_lock(&data->mutex);
		ret = regmap_read(data->regmap, MMC35240_REG_CTRL1, &reg);
		mutex_unlock(&data->mutex);
		if (ret < 0)
			return ret;

		i = (reg & MMC35240_CTRL1_BW_MASK) >> MMC35240_CTRL1_BW_SHIFT;
		if (i < 0 || i >= ARRAY_SIZE(mmc35240_samp_freq))
			return -EINVAL;

		*val = mmc35240_samp_freq[i];
		*val2 = 0;
		return IIO_VAL_INT;
	default:
		return -EINVAL;
	}
}

static int mmc35240_write_raw(struct iio_dev *indio_dev,
			      struct iio_chan_spec const *chan, int val,
			      int val2, long mask)
{
	struct mmc35240_data *data = iio_priv(indio_dev);
	int i, ret;

	switch (mask) {
	case IIO_CHAN_INFO_SAMP_FREQ:
		i = mmc35240_get_samp_freq_index(data, val, val2);
		if (i < 0)
			return -EINVAL;
		mutex_lock(&data->mutex);
		ret = regmap_update_bits(data->regmap, MMC35240_REG_CTRL1,
					 MMC35240_CTRL1_BW_MASK,
					 i << MMC35240_CTRL1_BW_SHIFT);
		mutex_unlock(&data->mutex);
		return ret;
	default:
		return -EINVAL;
	}
}

static const struct iio_info mmc35240_info = {
	.driver_module	= THIS_MODULE,
	.read_raw	= mmc35240_read_raw,
	.write_raw	= mmc35240_write_raw,
	.attrs		= &mmc35240_attribute_group,
};

static bool mmc35240_is_writeable_reg(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case MMC35240_REG_CTRL0:
	case MMC35240_REG_CTRL1:
		return true;
	default:
		return false;
	}
}

static bool mmc35240_is_readable_reg(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case MMC35240_REG_XOUT_L:
	case MMC35240_REG_XOUT_H:
	case MMC35240_REG_YOUT_L:
	case MMC35240_REG_YOUT_H:
	case MMC35240_REG_ZOUT_L:
	case MMC35240_REG_ZOUT_H:
	case MMC35240_REG_STATUS:
	case MMC35240_REG_ID:
		return true;
	default:
		return false;
	}
}

static bool mmc35240_is_volatile_reg(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case MMC35240_REG_CTRL0:
	case MMC35240_REG_CTRL1:
		return false;
	default:
		return true;
	}
}

static struct reg_default mmc35240_reg_defaults[] = {
	{ MMC35240_REG_CTRL0,  0x00 },
	{ MMC35240_REG_CTRL1,  0x00 },
};

static const struct regmap_config mmc35240_regmap_config = {
	.name = MMC35240_REGMAP_NAME,

	.reg_bits = 8,
	.val_bits = 8,

	.max_register = MMC35240_REG_ID,
	.cache_type = REGCACHE_FLAT,

	.writeable_reg = mmc35240_is_writeable_reg,
	.readable_reg = mmc35240_is_readable_reg,
	.volatile_reg = mmc35240_is_volatile_reg,

	.reg_defaults = mmc35240_reg_defaults,
	.num_reg_defaults = ARRAY_SIZE(mmc35240_reg_defaults),
};

static int mmc35240_probe(struct i2c_client *client,
			  const struct i2c_device_id *id)
{
	struct mmc35240_data *data;
	struct iio_dev *indio_dev;
	struct regmap *regmap;
	int ret;

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

	regmap = devm_regmap_init_i2c(client, &mmc35240_regmap_config);
	if (IS_ERR(regmap)) {
		dev_err(&client->dev, "regmap initialization failed\n");
		return PTR_ERR(regmap);
	}

	data = iio_priv(indio_dev);
	data->client = client;
	data->regmap = regmap;
	data->res = MMC35240_16_BITS_SLOW;

	mutex_init(&data->mutex);

	indio_dev->dev.parent = &client->dev;
	indio_dev->info = &mmc35240_info;
	indio_dev->name = MMC35240_DRV_NAME;
	indio_dev->channels = mmc35240_channels;
	indio_dev->num_channels = ARRAY_SIZE(mmc35240_channels);
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = mmc35240_init(data);
	if (ret < 0) {
		dev_err(&client->dev, "mmc35240 chip init failed\n");
		return ret;
	}
	return devm_iio_device_register(&client->dev, indio_dev);
}

#ifdef CONFIG_PM_SLEEP
static int mmc35240_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	struct mmc35240_data *data = iio_priv(indio_dev);

	regcache_cache_only(data->regmap, true);

	return 0;
}

static int mmc35240_resume(struct device *dev)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	struct mmc35240_data *data = iio_priv(indio_dev);
	int ret;

	regcache_mark_dirty(data->regmap);
	ret = regcache_sync_region(data->regmap, MMC35240_REG_CTRL0,
				   MMC35240_REG_CTRL1);
	if (ret < 0)
		dev_err(dev, "Failed to restore control registers\n");

	regcache_cache_only(data->regmap, false);

	return 0;
}
#endif

static const struct dev_pm_ops mmc35240_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(mmc35240_suspend, mmc35240_resume)
};

static const struct acpi_device_id mmc35240_acpi_match[] = {
	{"MMC35240", 0},
	{ },
};
MODULE_DEVICE_TABLE(acpi, mmc35240_acpi_match);

static const struct i2c_device_id mmc35240_id[] = {
	{"mmc35240", 0},
	{}
};
MODULE_DEVICE_TABLE(i2c, mmc35240_id);

static struct i2c_driver mmc35240_driver = {
	.driver = {
		.name = MMC35240_DRV_NAME,
		.pm = &mmc35240_pm_ops,
		.acpi_match_table = ACPI_PTR(mmc35240_acpi_match),
	},
	.probe		= mmc35240_probe,
	.id_table	= mmc35240_id,
};

module_i2c_driver(mmc35240_driver);

MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
MODULE_DESCRIPTION("MEMSIC MMC35240 magnetic sensor driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
abeb6b1e DB	1	/*
	2	* MMC35240 - MEMSIC 3-axis Magnetic Sensor
	3	*
	4	* Copyright (c) 2015, Intel Corporation.
	5	*
	6	* This file is subject to the terms and conditions of version 2 of
	7	* the GNU General Public License. See the file COPYING in the main
	8	* directory of this archive for more details.
	9	*
	10	* IIO driver for MMC35240 (7-bit I2C slave address 0x30).
	11	*
	12	* TODO: offset, ACPI, continuous measurement mode, PM
	13	*/
	14
	15	#include <linux/module.h>
	16	#include <linux/init.h>
	17	#include <linux/i2c.h>
	18	#include <linux/delay.h>
	19	#include <linux/regmap.h>
d11715f0	20	#include <linux/acpi.h>
553a776b	21	#include <linux/pm.h>
abeb6b1e DB	22
	23	#include <linux/iio/iio.h>
	24	#include <linux/iio/sysfs.h>
	25
	26	#define MMC35240_DRV_NAME "mmc35240"
	27	#define MMC35240_REGMAP_NAME "mmc35240_regmap"
	28
	29	#define MMC35240_REG_XOUT_L 0x00
	30	#define MMC35240_REG_XOUT_H 0x01
	31	#define MMC35240_REG_YOUT_L 0x02
	32	#define MMC35240_REG_YOUT_H 0x03
	33	#define MMC35240_REG_ZOUT_L 0x04
	34	#define MMC35240_REG_ZOUT_H 0x05
	35
	36	#define MMC35240_REG_STATUS 0x06
	37	#define MMC35240_REG_CTRL0 0x07
	38	#define MMC35240_REG_CTRL1 0x08
	39
	40	#define MMC35240_REG_ID 0x20
	41
	42	#define MMC35240_STATUS_MEAS_DONE_BIT BIT(0)
	43
	44	#define MMC35240_CTRL0_REFILL_BIT BIT(7)
	45	#define MMC35240_CTRL0_RESET_BIT BIT(6)
	46	#define MMC35240_CTRL0_SET_BIT BIT(5)
	47	#define MMC35240_CTRL0_CMM_BIT BIT(1)
	48	#define MMC35240_CTRL0_TM_BIT BIT(0)
	49
	50	/* output resolution bits */
	51	#define MMC35240_CTRL1_BW0_BIT BIT(0)
	52	#define MMC35240_CTRL1_BW1_BIT BIT(1)
	53
	54	#define MMC35240_CTRL1_BW_MASK (MMC35240_CTRL1_BW0_BIT \| \
	55	MMC35240_CTRL1_BW1_BIT)
	56	#define MMC35240_CTRL1_BW_SHIFT 0
	57
	58	#define MMC35240_WAIT_CHARGE_PUMP 50000 /* us */
	59	#define MMC53240_WAIT_SET_RESET 1000 /* us */
	60
	61	enum mmc35240_resolution {
	62	MMC35240_16_BITS_SLOW = 0, /* 100 Hz */
	63	MMC35240_16_BITS_FAST, /* 200 Hz */
	64	MMC35240_14_BITS, /* 333 Hz */
	65	MMC35240_12_BITS, /* 666 Hz */
	66	};
	67
	68	enum mmc35240_axis {
	69	AXIS_X = 0,
	70	AXIS_Y,
	71	AXIS_Z,
	72	};
	73
	74	static const struct {
	75	int sens[3]; /* sensitivity per X, Y, Z axis */
	76	int nfo; /* null field output */
	77	} mmc35240_props_table[] = {
	78	/* 16 bits, 100Hz ODR */
	79	{
	80	{1024, 1024, 770},
	81	32768,
	82	},
	83	/* 16 bits, 200Hz ODR */
	84	{
	85	{1024, 1024, 770},
86	32768,
87	},
88	/* 14 bits, 333Hz ODR */
89	{
90	{256, 256, 193},
91	8192,
92	},
93	/* 12 bits, 666Hz ODR */
94	{
95	{64, 64, 48},
96	2048,
97	},
98	};
99
100	struct mmc35240_data {
101	struct i2c_client *client;
102	struct mutex mutex;
103	struct regmap *regmap;
104	enum mmc35240_resolution res;
105	};
106
107	static const int mmc35240_samp_freq[] = {100, 200, 333, 666};
108
109	static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("100 200 333 666");
110
111	#define MMC35240_CHANNEL(_axis) { \
112	.type = IIO_MAGN, \
113	.modified = 1, \
114	.channel2 = IIO_MOD_ ## _axis, \
115	.address = AXIS_ ## _axis, \
c2890547 DB	116	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	117	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) \| \
	118	BIT(IIO_CHAN_INFO_SCALE), \
abeb6b1e DB	119	}
	120
	121	static const struct iio_chan_spec mmc35240_channels[] = {
	122	MMC35240_CHANNEL(X),
	123	MMC35240_CHANNEL(Y),
	124	MMC35240_CHANNEL(Z),
	125	};
	126
	127	static struct attribute *mmc35240_attributes[] = {
	128	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
bd35a214	129	NULL
abeb6b1e DB	130	};
	131
	132	static const struct attribute_group mmc35240_attribute_group = {
	133	.attrs = mmc35240_attributes,
	134	};
	135
	136	static int mmc35240_get_samp_freq_index(struct mmc35240_data *data,
	137	int val, int val2)
	138	{
	139	int i;
	140
	141	for (i = 0; i < ARRAY_SIZE(mmc35240_samp_freq); i++)
	142	if (mmc35240_samp_freq[i] == val)
	143	return i;
	144	return -EINVAL;
	145	}
	146
	147	static int mmc35240_hw_set(struct mmc35240_data *data, bool set)
	148	{
	149	int ret;
	150	u8 coil_bit;
	151
	152	/*
	153	* Recharge the capacitor at VCAP pin, requested to be issued
	154	* before a SET/RESET command.
	155	*/
	156	ret = regmap_update_bits(data->regmap, MMC35240_REG_CTRL0,
	157	MMC35240_CTRL0_REFILL_BIT,
	158	MMC35240_CTRL0_REFILL_BIT);
	159	if (ret < 0)
	160	return ret;
	161	usleep_range(MMC35240_WAIT_CHARGE_PUMP, MMC35240_WAIT_CHARGE_PUMP + 1);
	162
	163	if (set)
	164	coil_bit = MMC35240_CTRL0_SET_BIT;
	165	else
	166	coil_bit = MMC35240_CTRL0_RESET_BIT;
	167
	168	return regmap_update_bits(data->regmap, MMC35240_REG_CTRL0,
	169	MMC35240_CTRL0_REFILL_BIT,
	170	coil_bit);
	171	}
	172
	173	static int mmc35240_init(struct mmc35240_data *data)
	174	{
	175	int ret;
	176	unsigned int reg_id;
	177
	178	ret = regmap_read(data->regmap, MMC35240_REG_ID, &reg_id);
	179	if (ret < 0) {
	180	dev_err(&data->client->dev, "Error reading product id\n");
	181	return ret;
	182	}
	183
	184	dev_dbg(&data->client->dev, "MMC35240 chip id %x\n", reg_id);
	185
	186	/*
	187	* make sure we restore sensor characteristics, by doing
	188	* a RESET/SET sequence
	189	*/
	190	ret = mmc35240_hw_set(data, false);
	191	if (ret < 0)
	192	return ret;
	193	usleep_range(MMC53240_WAIT_SET_RESET, MMC53240_WAIT_SET_RESET + 1);
194
195	ret = mmc35240_hw_set(data, true);
196	if (ret < 0)
197	return ret;
198
199	/* set default sampling frequency */
200	return regmap_update_bits(data->regmap, MMC35240_REG_CTRL1,
201	MMC35240_CTRL1_BW_MASK,
202	data->res << MMC35240_CTRL1_BW_SHIFT);
203	}
204
205	static int mmc35240_take_measurement(struct mmc35240_data *data)
206	{
207	int ret, tries = 100;
208	unsigned int reg_status;
209
210	ret = regmap_write(data->regmap, MMC35240_REG_CTRL0,
211	MMC35240_CTRL0_TM_BIT);
212	if (ret < 0)
213	return ret;
214
215	while (tries-- > 0) {
216	ret = regmap_read(data->regmap, MMC35240_REG_STATUS,
217	&reg_status);
218	if (ret < 0)
219	return ret;
220	if (reg_status & MMC35240_STATUS_MEAS_DONE_BIT)
221	break;
787f55c4 DB	222	/* minimum wait time to complete measurement is 10 ms */
787f55c4 DB	223	usleep_range(10000, 11000);
abeb6b1e DB	224	}
	225
	226	if (tries < 0) {
	227	dev_err(&data->client->dev, "data not ready\n");
	228	return -EIO;
	229	}
	230
	231	return 0;
	232	}
	233
	234	static int mmc35240_read_measurement(struct mmc35240_data *data, __le16 buf[3])
	235	{
	236	int ret;
	237
	238	ret = mmc35240_take_measurement(data);
	239	if (ret < 0)
	240	return ret;
	241
	242	return regmap_bulk_read(data->regmap, MMC35240_REG_XOUT_L, (u8 *)buf,
	243	3 * sizeof(__le16));
	244	}
	245
c2890547 DB	246	/**
	247	* mmc35240_raw_to_mgauss - convert raw readings to milli gauss. Also apply
	248	compensation for output value.
	249	*
	250	* @data: device private data
	251	* @index: axis index for which we want the conversion
	252	* @buf: raw data to be converted, 2 bytes in little endian format
	253	* @val: compensated output reading (unit is milli gauss)
	254	*
	255	* Returns: 0 in case of success, -EINVAL when @index is not valid
	256	*/
	257	static int mmc35240_raw_to_mgauss(struct mmc35240_data *data, int index,
	258	__le16 buf[], int *val)
abeb6b1e DB	259	{
	260	int raw_x, raw_y, raw_z;
	261	int sens_x, sens_y, sens_z;
	262	int nfo;
	263
	264	raw_x = le16_to_cpu(buf[AXIS_X]);
	265	raw_y = le16_to_cpu(buf[AXIS_Y]);
	266	raw_z = le16_to_cpu(buf[AXIS_Z]);
	267
	268	sens_x = mmc35240_props_table[data->res].sens[AXIS_X];
	269	sens_y = mmc35240_props_table[data->res].sens[AXIS_Y];
	270	sens_z = mmc35240_props_table[data->res].sens[AXIS_Z];
	271
	272	nfo = mmc35240_props_table[data->res].nfo;
	273
	274	switch (index) {
	275	case AXIS_X:
c2890547	276	val = (raw_x - nfo) 1000 / sens_x;
abeb6b1e DB	277	break;
abeb6b1e DB	278	case AXIS_Y:
c2890547 DB	279	val = (raw_y - nfo) 1000 / sens_y -
c2890547 DB	280	(raw_z - nfo) * 1000 / sens_z;
abeb6b1e DB	281	break;
abeb6b1e DB	282	case AXIS_Z:
c2890547 DB	283	val = (raw_y - nfo) 1000 / sens_y +
c2890547 DB	284	(raw_z - nfo) * 1000 / sens_z;
abeb6b1e DB	285	break;
	286	default:
	287	return -EINVAL;
	288	}
	289	return 0;
	290	}
	291
	292	static int mmc35240_read_raw(struct iio_dev *indio_dev,
	293	struct iio_chan_spec const chan, int val,
	294	int *val2, long mask)
	295	{
	296	struct mmc35240_data *data = iio_priv(indio_dev);
	297	int ret, i;
	298	unsigned int reg;
	299	__le16 buf[3];
	300
	301	switch (mask) {
c2890547	302	case IIO_CHAN_INFO_RAW:
abeb6b1e DB	303	mutex_lock(&data->mutex);
	304	ret = mmc35240_read_measurement(data, buf);
	305	mutex_unlock(&data->mutex);
	306	if (ret < 0)
	307	return ret;
c2890547	308	ret = mmc35240_raw_to_mgauss(data, chan->address, buf, val);
abeb6b1e DB	309	if (ret < 0)
abeb6b1e DB	310	return ret;
c2890547 DB	311	return IIO_VAL_INT;
	312	case IIO_CHAN_INFO_SCALE:
	313	*val = 0;
	314	*val2 = 1000;
abeb6b1e DB	315	return IIO_VAL_INT_PLUS_MICRO;
	316	case IIO_CHAN_INFO_SAMP_FREQ:
	317	mutex_lock(&data->mutex);
	318	ret = regmap_read(data->regmap, MMC35240_REG_CTRL1, &reg);
	319	mutex_unlock(&data->mutex);
	320	if (ret < 0)
	321	return ret;
	322
	323	i = (reg & MMC35240_CTRL1_BW_MASK) >> MMC35240_CTRL1_BW_SHIFT;
5517547b	324	if (i < 0 \|\| i >= ARRAY_SIZE(mmc35240_samp_freq))
abeb6b1e DB	325	return -EINVAL;
	326
	327	*val = mmc35240_samp_freq[i];
	328	*val2 = 0;
	329	return IIO_VAL_INT;
	330	default:
	331	return -EINVAL;
	332	}
	333	}
	334
	335	static int mmc35240_write_raw(struct iio_dev *indio_dev,
	336	struct iio_chan_spec const *chan, int val,
	337	int val2, long mask)
	338	{
	339	struct mmc35240_data *data = iio_priv(indio_dev);
	340	int i, ret;
	341
	342	switch (mask) {
	343	case IIO_CHAN_INFO_SAMP_FREQ:
	344	i = mmc35240_get_samp_freq_index(data, val, val2);
	345	if (i < 0)
	346	return -EINVAL;
	347	mutex_lock(&data->mutex);
	348	ret = regmap_update_bits(data->regmap, MMC35240_REG_CTRL1,
	349	MMC35240_CTRL1_BW_MASK,
	350	i << MMC35240_CTRL1_BW_SHIFT);
	351	mutex_unlock(&data->mutex);
	352	return ret;
	353	default:
	354	return -EINVAL;
	355	}
	356	}
	357
	358	static const struct iio_info mmc35240_info = {
	359	.driver_module = THIS_MODULE,
	360	.read_raw = mmc35240_read_raw,
	361	.write_raw = mmc35240_write_raw,
	362	.attrs = &mmc35240_attribute_group,
	363	};
	364
	365	static bool mmc35240_is_writeable_reg(struct device *dev, unsigned int reg)
	366	{
	367	switch (reg) {
	368	case MMC35240_REG_CTRL0:
	369	case MMC35240_REG_CTRL1:
	370	return true;
	371	default:
	372	return false;
	373	}
	374	}
	375
	376	static bool mmc35240_is_readable_reg(struct device *dev, unsigned int reg)
	377	{
	378	switch (reg) {
	379	case MMC35240_REG_XOUT_L:
	380	case MMC35240_REG_XOUT_H:
	381	case MMC35240_REG_YOUT_L:
	382	case MMC35240_REG_YOUT_H:
	383	case MMC35240_REG_ZOUT_L:
	384	case MMC35240_REG_ZOUT_H:
	385	case MMC35240_REG_STATUS:
	386	case MMC35240_REG_ID:
	387	return true;
	388	default:
389	return false;
390	}
391	}
392
393	static bool mmc35240_is_volatile_reg(struct device *dev, unsigned int reg)
394	{
395	switch (reg) {
396	case MMC35240_REG_CTRL0:
397	case MMC35240_REG_CTRL1:
398	return false;
399	default:
400	return true;
401	}
402	}
403
404	static struct reg_default mmc35240_reg_defaults[] = {
405	{ MMC35240_REG_CTRL0, 0x00 },
406	{ MMC35240_REG_CTRL1, 0x00 },
407	};
408
409	static const struct regmap_config mmc35240_regmap_config = {
410	.name = MMC35240_REGMAP_NAME,
411
412	.reg_bits = 8,
413	.val_bits = 8,
414
415	.max_register = MMC35240_REG_ID,
416	.cache_type = REGCACHE_FLAT,
417
418	.writeable_reg = mmc35240_is_writeable_reg,
419	.readable_reg = mmc35240_is_readable_reg,
420	.volatile_reg = mmc35240_is_volatile_reg,
421
422	.reg_defaults = mmc35240_reg_defaults,
423	.num_reg_defaults = ARRAY_SIZE(mmc35240_reg_defaults),
424	};
425
426	static int mmc35240_probe(struct i2c_client *client,
427	const struct i2c_device_id *id)
428	{
429	struct mmc35240_data *data;
430	struct iio_dev *indio_dev;
431	struct regmap *regmap;
432	int ret;
433
434	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
435	if (!indio_dev)
436	return -ENOMEM;
437
438	regmap = devm_regmap_init_i2c(client, &mmc35240_regmap_config);
439	if (IS_ERR(regmap)) {
440	dev_err(&client->dev, "regmap initialization failed\n");
441	return PTR_ERR(regmap);
442	}
443
444	data = iio_priv(indio_dev);
445	data->client = client;
446	data->regmap = regmap;
447	data->res = MMC35240_16_BITS_SLOW;
448
449	mutex_init(&data->mutex);
450
451	indio_dev->dev.parent = &client->dev;
452	indio_dev->info = &mmc35240_info;
453	indio_dev->name = MMC35240_DRV_NAME;
454	indio_dev->channels = mmc35240_channels;
455	indio_dev->num_channels = ARRAY_SIZE(mmc35240_channels);
456	indio_dev->modes = INDIO_DIRECT_MODE;
457
458	ret = mmc35240_init(data);
459	if (ret < 0) {
460	dev_err(&client->dev, "mmc35240 chip init failed\n");
461	return ret;
462	}
463	return devm_iio_device_register(&client->dev, indio_dev);
464	}
465
553a776b DB	466	#ifdef CONFIG_PM_SLEEP
	467	static int mmc35240_suspend(struct device *dev)
	468	{
	469	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	470	struct mmc35240_data *data = iio_priv(indio_dev);
	471
	472	regcache_cache_only(data->regmap, true);
	473
	474	return 0;
	475	}
	476
	477	static int mmc35240_resume(struct device *dev)
	478	{
	479	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	480	struct mmc35240_data *data = iio_priv(indio_dev);
	481	int ret;
	482
	483	regcache_mark_dirty(data->regmap);
	484	ret = regcache_sync_region(data->regmap, MMC35240_REG_CTRL0,
	485	MMC35240_REG_CTRL1);
	486	if (ret < 0)
	487	dev_err(dev, "Failed to restore control registers\n");
	488
	489	regcache_cache_only(data->regmap, false);
	490
	491	return 0;
	492	}
	493	#endif
	494
	495	static const struct dev_pm_ops mmc35240_pm_ops = {
	496	SET_SYSTEM_SLEEP_PM_OPS(mmc35240_suspend, mmc35240_resume)
	497	};
	498
d11715f0 DB	499	static const struct acpi_device_id mmc35240_acpi_match[] = {
	500	{"MMC35240", 0},
	501	{ },
	502	};
	503	MODULE_DEVICE_TABLE(acpi, mmc35240_acpi_match);
	504
abeb6b1e	505	static const struct i2c_device_id mmc35240_id[] = {
a52ffebc	506	{"mmc35240", 0},
abeb6b1e DB	507	{}
	508	};
	509	MODULE_DEVICE_TABLE(i2c, mmc35240_id);
	510
	511	static struct i2c_driver mmc35240_driver = {
	512	.driver = {
	513	.name = MMC35240_DRV_NAME,
553a776b	514	.pm = &mmc35240_pm_ops,
d11715f0	515	.acpi_match_table = ACPI_PTR(mmc35240_acpi_match),
abeb6b1e DB	516	},
	517	.probe = mmc35240_probe,
	518	.id_table = mmc35240_id,
	519	};
	520
	521	module_i2c_driver(mmc35240_driver);
	522
	523	MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
	524	MODULE_DESCRIPTION("MEMSIC MMC35240 magnetic sensor driver");
	525	MODULE_LICENSE("GPL v2");