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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * MMC35240 - MEMSIC 3-axis Magnetic Sensor
 *
 * Copyright (c) 2015, Intel Corporation.
 *
 * 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 MMC35240_WAIT_SET_RESET		1000	/* us */

/*
 * Memsic OTP process code piece is put here for reference:
 *
 * #define OTP_CONVERT(REG)  ((float)((REG) >=32 ? (32 - (REG)) : (REG)) * 0.006
 * 1) For X axis, the COEFFICIENT is always 1.
 * 2) For Y axis, the COEFFICIENT is as below:
 *    f_OTP_matrix[4] = OTP_CONVERT(((reg_data[1] & 0x03) << 4) |
 *                                   (reg_data[2] >> 4)) + 1.0;
 * 3) For Z axis, the COEFFICIENT is as below:
 *    f_OTP_matrix[8] = (OTP_CONVERT(reg_data[3] & 0x3f) + 1) * 1.35;
 * We implemented the OTP logic into driver.
 */

/* scale = 1000 here for Y otp */
#define MMC35240_OTP_CONVERT_Y(REG) (((REG) >= 32 ? (32 - (REG)) : (REG)) * 6)

/* 0.6 * 1.35 = 0.81, scale 10000 for Z otp */
#define MMC35240_OTP_CONVERT_Z(REG) (((REG) >= 32 ? (32 - (REG)) : (REG)) * 81)

#define MMC35240_X_COEFF(x)	(x)
#define MMC35240_Y_COEFF(y)	(y + 1000)
#define MMC35240_Z_COEFF(z)	(z + 13500)

#define MMC35240_OTP_START_ADDR		0x1B

enum mmc35240_resolution {
	MMC35240_16_BITS_SLOW = 0, /* 7.92 ms */
	MMC35240_16_BITS_FAST,     /* 4.08 ms */
	MMC35240_14_BITS,          /* 2.16 ms */
	MMC35240_12_BITS,          /* 1.20 ms */
};

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, 125Hz ODR */
	{
		{1024, 1024, 1024},
		32768,
	},
	/* 16 bits, 250Hz ODR */
	{
		{1024, 1024, 770},
		32768,
	},
	/* 14 bits, 450Hz ODR */
	{
		{256, 256, 193},
		8192,
	},
	/* 12 bits, 800Hz ODR */
	{
		{64, 64, 48},
		2048,
	},
};

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

	/* OTP compensation */
	int axis_coef[3];
	int axis_scale[3];
};

static const struct {
	int val;
	int val2;
} mmc35240_samp_freq[] = { {1, 500000},
			   {13, 0},
			   {25, 0},
			   {50, 0} };

static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("1.5 13 25 50");

#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 == val &&
		    mmc35240_samp_freq[i].val2 == val2)
			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,
				  coil_bit, coil_bit);

}

static int mmc35240_init(struct mmc35240_data *data)
{
	int ret, y_convert, z_convert;
	unsigned int reg_id;
	u8 otp_data[6];

	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 SET/RESET sequence, the axis polarity being naturally
	 * aligned after RESET
	 */
	ret = mmc35240_hw_set(data, true);
	if (ret < 0)
		return ret;
	usleep_range(MMC35240_WAIT_SET_RESET, MMC35240_WAIT_SET_RESET + 1);

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

	/* set default sampling frequency */
	ret = regmap_update_bits(data->regmap, MMC35240_REG_CTRL1,
				 MMC35240_CTRL1_BW_MASK,
				 data->res << MMC35240_CTRL1_BW_SHIFT);
	if (ret < 0)
		return ret;

	ret = regmap_bulk_read(data->regmap, MMC35240_OTP_START_ADDR,
			       otp_data, sizeof(otp_data));
	if (ret < 0)
		return ret;

	y_convert = MMC35240_OTP_CONVERT_Y(((otp_data[1] & 0x03) << 4) |
					   (otp_data[2] >> 4));
	z_convert = MMC35240_OTP_CONVERT_Z(otp_data[3] & 0x3f);

	data->axis_coef[0] = MMC35240_X_COEFF(1);
	data->axis_coef[1] = MMC35240_Y_COEFF(y_convert);
	data->axis_coef[2] = MMC35240_Z_COEFF(z_convert);

	data->axis_scale[0] = 1;
	data->axis_scale[1] = 1000;
	data->axis_scale[2] = 10000;

	return 0;
}

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, 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[3];
	int sens[3];
	int nfo;

	raw[AXIS_X] = le16_to_cpu(buf[AXIS_X]);
	raw[AXIS_Y] = le16_to_cpu(buf[AXIS_Y]);
	raw[AXIS_Z] = le16_to_cpu(buf[AXIS_Z]);

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

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

	switch (index) {
	case AXIS_X:
		*val = (raw[AXIS_X] - nfo) * 1000 / sens[AXIS_X];
		break;
	case AXIS_Y:
		*val = (raw[AXIS_Y] - nfo) * 1000 / sens[AXIS_Y] -
			(raw[AXIS_Z] - nfo)  * 1000 / sens[AXIS_Z];
		break;
	case AXIS_Z:
		*val = (raw[AXIS_Y] - nfo) * 1000 / sens[AXIS_Y] +
			(raw[AXIS_Z] - nfo) * 1000 / sens[AXIS_Z];
		break;
	default:
		return -EINVAL;
	}
	/* apply OTP compensation */
	*val = (*val) * data->axis_coef[index] / data->axis_scale[index];

	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].val;
		*val2 = mmc35240_samp_freq[i].val2;
		return IIO_VAL_INT_PLUS_MICRO;
	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 = {
	.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 const 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);
	i2c_set_clientdata(client, indio_dev);
	data->client = client;
	data->regmap = regmap;
	data->res = MMC35240_16_BITS_SLOW;

	mutex_init(&data->mutex);

	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);
}

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;
}

static DEFINE_SIMPLE_DEV_PM_OPS(mmc35240_pm_ops, mmc35240_suspend,
				mmc35240_resume);

static const struct of_device_id mmc35240_of_match[] = {
	{ .compatible = "memsic,mmc35240", },
	{ }
};
MODULE_DEVICE_TABLE(of, mmc35240_of_match);

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,
		.of_match_table = mmc35240_of_match,
		.pm = pm_sleep_ptr(&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 <[email protected]>");
MODULE_DESCRIPTION("MEMSIC MMC35240 magnetic sensor driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
36edc939	1	// SPDX-License-Identifier: GPL-2.0-only
abeb6b1e DB	2	/*
	3	* MMC35240 - MEMSIC 3-axis Magnetic Sensor
	4	*
	5	* Copyright (c) 2015, Intel Corporation.
	6	*
abeb6b1e DB	7	* IIO driver for MMC35240 (7-bit I2C slave address 0x30).
	8	*
	9	* TODO: offset, ACPI, continuous measurement mode, PM
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/init.h>
	14	#include <linux/i2c.h>
	15	#include <linux/delay.h>
	16	#include <linux/regmap.h>
d11715f0	17	#include <linux/acpi.h>
553a776b	18	#include <linux/pm.h>
abeb6b1e DB	19
	20	#include <linux/iio/iio.h>
	21	#include <linux/iio/sysfs.h>
	22
	23	#define MMC35240_DRV_NAME "mmc35240"
	24	#define MMC35240_REGMAP_NAME "mmc35240_regmap"
	25
	26	#define MMC35240_REG_XOUT_L 0x00
	27	#define MMC35240_REG_XOUT_H 0x01
	28	#define MMC35240_REG_YOUT_L 0x02
	29	#define MMC35240_REG_YOUT_H 0x03
	30	#define MMC35240_REG_ZOUT_L 0x04
	31	#define MMC35240_REG_ZOUT_H 0x05
	32
	33	#define MMC35240_REG_STATUS 0x06
	34	#define MMC35240_REG_CTRL0 0x07
	35	#define MMC35240_REG_CTRL1 0x08
	36
	37	#define MMC35240_REG_ID 0x20
	38
	39	#define MMC35240_STATUS_MEAS_DONE_BIT BIT(0)
	40
	41	#define MMC35240_CTRL0_REFILL_BIT BIT(7)
	42	#define MMC35240_CTRL0_RESET_BIT BIT(6)
	43	#define MMC35240_CTRL0_SET_BIT BIT(5)
	44	#define MMC35240_CTRL0_CMM_BIT BIT(1)
	45	#define MMC35240_CTRL0_TM_BIT BIT(0)
	46
	47	/* output resolution bits */
	48	#define MMC35240_CTRL1_BW0_BIT BIT(0)
	49	#define MMC35240_CTRL1_BW1_BIT BIT(1)
	50
	51	#define MMC35240_CTRL1_BW_MASK (MMC35240_CTRL1_BW0_BIT \| \
	52	MMC35240_CTRL1_BW1_BIT)
	53	#define MMC35240_CTRL1_BW_SHIFT 0
	54
	55	#define MMC35240_WAIT_CHARGE_PUMP 50000 /* us */
3f2cde74	56	#define MMC35240_WAIT_SET_RESET 1000 /* us */
abeb6b1e	57
4892688d DB	58	/*
	59	* Memsic OTP process code piece is put here for reference:
	60	*
	61	* #define OTP_CONVERT(REG) ((float)((REG) >=32 ? (32 - (REG)) : (REG)) * 0.006
	62	* 1) For X axis, the COEFFICIENT is always 1.
	63	* 2) For Y axis, the COEFFICIENT is as below:
	64	* f_OTP_matrix[4] = OTP_CONVERT(((reg_data[1] & 0x03) << 4) \|
	65	* (reg_data[2] >> 4)) + 1.0;
	66	* 3) For Z axis, the COEFFICIENT is as below:
	67	* f_OTP_matrix[8] = (OTP_CONVERT(reg_data[3] & 0x3f) + 1) * 1.35;
	68	* We implemented the OTP logic into driver.
	69	*/
	70
	71	/* scale = 1000 here for Y otp */
	72	#define MMC35240_OTP_CONVERT_Y(REG) (((REG) >= 32 ? (32 - (REG)) : (REG)) * 6)
	73
	74	/* 0.6 * 1.35 = 0.81, scale 10000 for Z otp */
	75	#define MMC35240_OTP_CONVERT_Z(REG) (((REG) >= 32 ? (32 - (REG)) : (REG)) * 81)
	76
	77	#define MMC35240_X_COEFF(x) (x)
	78	#define MMC35240_Y_COEFF(y) (y + 1000)
	79	#define MMC35240_Z_COEFF(z) (z + 13500)
	80
	81	#define MMC35240_OTP_START_ADDR 0x1B
	82
abeb6b1e	83	enum mmc35240_resolution {
c99389ad TB	84	MMC35240_16_BITS_SLOW = 0, /* 7.92 ms */
	85	MMC35240_16_BITS_FAST, /* 4.08 ms */
	86	MMC35240_14_BITS, /* 2.16 ms */
	87	MMC35240_12_BITS, /* 1.20 ms */
abeb6b1e DB	88	};
	89
	90	enum mmc35240_axis {
	91	AXIS_X = 0,
	92	AXIS_Y,
	93	AXIS_Z,
	94	};
	95
	96	static const struct {
	97	int sens[3]; /* sensitivity per X, Y, Z axis */
	98	int nfo; /* null field output */
	99	} mmc35240_props_table[] = {
c99389ad	100	/* 16 bits, 125Hz ODR */
abeb6b1e	101	{
6b90da4b	102	{1024, 1024, 1024},
abeb6b1e DB	103	32768,
abeb6b1e DB	104	},
c99389ad	105	/* 16 bits, 250Hz ODR */
abeb6b1e DB	106	{
	107	{1024, 1024, 770},
	108	32768,
	109	},
c99389ad	110	/* 14 bits, 450Hz ODR */
abeb6b1e DB	111	{
	112	{256, 256, 193},
	113	8192,
	114	},
c99389ad	115	/* 12 bits, 800Hz ODR */
abeb6b1e DB	116	{
	117	{64, 64, 48},
	118	2048,
	119	},
	120	};
	121
	122	struct mmc35240_data {
	123	struct i2c_client *client;
	124	struct mutex mutex;
	125	struct regmap *regmap;
	126	enum mmc35240_resolution res;
4892688d DB	127
	128	/* OTP compensation */
	129	int axis_coef[3];
	130	int axis_scale[3];
abeb6b1e DB	131	};
abeb6b1e DB	132
c99389ad TB	133	static const struct {
	134	int val;
	135	int val2;
	136	} mmc35240_samp_freq[] = { {1, 500000},
	137	{13, 0},
	138	{25, 0},
	139	{50, 0} };
abeb6b1e	140
c99389ad	141	static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("1.5 13 25 50");
abeb6b1e DB	142
	143	#define MMC35240_CHANNEL(_axis) { \
	144	.type = IIO_MAGN, \
	145	.modified = 1, \
	146	.channel2 = IIO_MOD_ ## _axis, \
	147	.address = AXIS_ ## _axis, \
c2890547 DB	148	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	149	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) \| \
	150	BIT(IIO_CHAN_INFO_SCALE), \
abeb6b1e DB	151	}
	152
	153	static const struct iio_chan_spec mmc35240_channels[] = {
	154	MMC35240_CHANNEL(X),
	155	MMC35240_CHANNEL(Y),
	156	MMC35240_CHANNEL(Z),
	157	};
	158
	159	static struct attribute *mmc35240_attributes[] = {
	160	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
bd35a214	161	NULL
abeb6b1e DB	162	};
	163
	164	static const struct attribute_group mmc35240_attribute_group = {
	165	.attrs = mmc35240_attributes,
	166	};
	167
	168	static int mmc35240_get_samp_freq_index(struct mmc35240_data *data,
	169	int val, int val2)
	170	{
	171	int i;
	172
	173	for (i = 0; i < ARRAY_SIZE(mmc35240_samp_freq); i++)
c99389ad TB	174	if (mmc35240_samp_freq[i].val == val &&
c99389ad TB	175	mmc35240_samp_freq[i].val2 == val2)
abeb6b1e DB	176	return i;
	177	return -EINVAL;
	178	}
	179
	180	static int mmc35240_hw_set(struct mmc35240_data *data, bool set)
	181	{
	182	int ret;
	183	u8 coil_bit;
	184
	185	/*
	186	* Recharge the capacitor at VCAP pin, requested to be issued
	187	* before a SET/RESET command.
	188	*/
	189	ret = regmap_update_bits(data->regmap, MMC35240_REG_CTRL0,
	190	MMC35240_CTRL0_REFILL_BIT,
	191	MMC35240_CTRL0_REFILL_BIT);
	192	if (ret < 0)
	193	return ret;
	194	usleep_range(MMC35240_WAIT_CHARGE_PUMP, MMC35240_WAIT_CHARGE_PUMP + 1);
	195
	196	if (set)
	197	coil_bit = MMC35240_CTRL0_SET_BIT;
	198	else
	199	coil_bit = MMC35240_CTRL0_RESET_BIT;
	200
	201	return regmap_update_bits(data->regmap, MMC35240_REG_CTRL0,
3ceaa2c2 DB	202	coil_bit, coil_bit);
3ceaa2c2 DB	203
abeb6b1e DB	204	}
	205
	206	static int mmc35240_init(struct mmc35240_data *data)
	207	{
4892688d	208	int ret, y_convert, z_convert;
abeb6b1e	209	unsigned int reg_id;
4892688d	210	u8 otp_data[6];
abeb6b1e DB	211
	212	ret = regmap_read(data->regmap, MMC35240_REG_ID, &reg_id);
	213	if (ret < 0) {
	214	dev_err(&data->client->dev, "Error reading product id\n");
	215	return ret;
	216	}
	217
	218	dev_dbg(&data->client->dev, "MMC35240 chip id %x\n", reg_id);
	219
	220	/*
	221	* make sure we restore sensor characteristics, by doing
354c879d VS	222	* a SET/RESET sequence, the axis polarity being naturally
354c879d VS	223	* aligned after RESET
abeb6b1e	224	*/
354c879d	225	ret = mmc35240_hw_set(data, true);
abeb6b1e DB	226	if (ret < 0)
abeb6b1e DB	227	return ret;
3f2cde74	228	usleep_range(MMC35240_WAIT_SET_RESET, MMC35240_WAIT_SET_RESET + 1);
abeb6b1e	229
354c879d	230	ret = mmc35240_hw_set(data, false);
abeb6b1e DB	231	if (ret < 0)
	232	return ret;
	233
	234	/* set default sampling frequency */
4892688d DB	235	ret = regmap_update_bits(data->regmap, MMC35240_REG_CTRL1,
	236	MMC35240_CTRL1_BW_MASK,
	237	data->res << MMC35240_CTRL1_BW_SHIFT);
	238	if (ret < 0)
	239	return ret;
	240
	241	ret = regmap_bulk_read(data->regmap, MMC35240_OTP_START_ADDR,
06c48260	242	otp_data, sizeof(otp_data));
4892688d DB	243	if (ret < 0)
	244	return ret;
	245
	246	y_convert = MMC35240_OTP_CONVERT_Y(((otp_data[1] & 0x03) << 4) \|
	247	(otp_data[2] >> 4));
	248	z_convert = MMC35240_OTP_CONVERT_Z(otp_data[3] & 0x3f);
	249
	250	data->axis_coef[0] = MMC35240_X_COEFF(1);
	251	data->axis_coef[1] = MMC35240_Y_COEFF(y_convert);
	252	data->axis_coef[2] = MMC35240_Z_COEFF(z_convert);
	253
	254	data->axis_scale[0] = 1;
	255	data->axis_scale[1] = 1000;
	256	data->axis_scale[2] = 10000;
	257
	258	return 0;
abeb6b1e DB	259	}
	260
	261	static int mmc35240_take_measurement(struct mmc35240_data *data)
	262	{
	263	int ret, tries = 100;
	264	unsigned int reg_status;
	265
	266	ret = regmap_write(data->regmap, MMC35240_REG_CTRL0,
	267	MMC35240_CTRL0_TM_BIT);
	268	if (ret < 0)
	269	return ret;
	270
	271	while (tries-- > 0) {
	272	ret = regmap_read(data->regmap, MMC35240_REG_STATUS,
	273	&reg_status);
	274	if (ret < 0)
	275	return ret;
	276	if (reg_status & MMC35240_STATUS_MEAS_DONE_BIT)
	277	break;
787f55c4 DB	278	/* minimum wait time to complete measurement is 10 ms */
787f55c4 DB	279	usleep_range(10000, 11000);
abeb6b1e DB	280	}
	281
	282	if (tries < 0) {
	283	dev_err(&data->client->dev, "data not ready\n");
	284	return -EIO;
	285	}
	286
	287	return 0;
	288	}
	289
	290	static int mmc35240_read_measurement(struct mmc35240_data *data, __le16 buf[3])
	291	{
	292	int ret;
	293
	294	ret = mmc35240_take_measurement(data);
	295	if (ret < 0)
	296	return ret;
	297
06c48260	298	return regmap_bulk_read(data->regmap, MMC35240_REG_XOUT_L, buf,
abeb6b1e DB	299	3 * sizeof(__le16));
	300	}
	301
c2890547 DB	302	/**
c2890547 DB	303	* mmc35240_raw_to_mgauss - convert raw readings to milli gauss. Also apply
faa4540e	304	* compensation for output value.
c2890547 DB	305	*
	306	* @data: device private data
	307	* @index: axis index for which we want the conversion
	308	* @buf: raw data to be converted, 2 bytes in little endian format
	309	* @val: compensated output reading (unit is milli gauss)
	310	*
	311	* Returns: 0 in case of success, -EINVAL when @index is not valid
	312	*/
	313	static int mmc35240_raw_to_mgauss(struct mmc35240_data *data, int index,
	314	__le16 buf[], int *val)
abeb6b1e	315	{
9e35d366 TB	316	int raw[3];
9e35d366 TB	317	int sens[3];
abeb6b1e DB	318	int nfo;
abeb6b1e DB	319
9e35d366 TB	320	raw[AXIS_X] = le16_to_cpu(buf[AXIS_X]);
	321	raw[AXIS_Y] = le16_to_cpu(buf[AXIS_Y]);
	322	raw[AXIS_Z] = le16_to_cpu(buf[AXIS_Z]);
abeb6b1e	323
9e35d366 TB	324	sens[AXIS_X] = mmc35240_props_table[data->res].sens[AXIS_X];
	325	sens[AXIS_Y] = mmc35240_props_table[data->res].sens[AXIS_Y];
	326	sens[AXIS_Z] = mmc35240_props_table[data->res].sens[AXIS_Z];
abeb6b1e DB	327
	328	nfo = mmc35240_props_table[data->res].nfo;
	329
	330	switch (index) {
	331	case AXIS_X:
9e35d366	332	val = (raw[AXIS_X] - nfo) 1000 / sens[AXIS_X];
abeb6b1e DB	333	break;
abeb6b1e DB	334	case AXIS_Y:
9e35d366 TB	335	val = (raw[AXIS_Y] - nfo) 1000 / sens[AXIS_Y] -
9e35d366 TB	336	(raw[AXIS_Z] - nfo) * 1000 / sens[AXIS_Z];
abeb6b1e DB	337	break;
abeb6b1e DB	338	case AXIS_Z:
9e35d366 TB	339	val = (raw[AXIS_Y] - nfo) 1000 / sens[AXIS_Y] +
9e35d366 TB	340	(raw[AXIS_Z] - nfo) * 1000 / sens[AXIS_Z];
abeb6b1e DB	341	break;
	342	default:
	343	return -EINVAL;
	344	}
4892688d DB	345	/* apply OTP compensation */
	346	val = (val) * data->axis_coef[index] / data->axis_scale[index];
	347
abeb6b1e DB	348	return 0;
	349	}
	350
	351	static int mmc35240_read_raw(struct iio_dev *indio_dev,
	352	struct iio_chan_spec const chan, int val,
	353	int *val2, long mask)
	354	{
	355	struct mmc35240_data *data = iio_priv(indio_dev);
	356	int ret, i;
	357	unsigned int reg;
	358	__le16 buf[3];
	359
	360	switch (mask) {
c2890547	361	case IIO_CHAN_INFO_RAW:
abeb6b1e DB	362	mutex_lock(&data->mutex);
	363	ret = mmc35240_read_measurement(data, buf);
	364	mutex_unlock(&data->mutex);
	365	if (ret < 0)
	366	return ret;
c2890547	367	ret = mmc35240_raw_to_mgauss(data, chan->address, buf, val);
abeb6b1e DB	368	if (ret < 0)
abeb6b1e DB	369	return ret;
c2890547 DB	370	return IIO_VAL_INT;
	371	case IIO_CHAN_INFO_SCALE:
	372	*val = 0;
	373	*val2 = 1000;
abeb6b1e DB	374	return IIO_VAL_INT_PLUS_MICRO;
	375	case IIO_CHAN_INFO_SAMP_FREQ:
	376	mutex_lock(&data->mutex);
	377	ret = regmap_read(data->regmap, MMC35240_REG_CTRL1, &reg);
	378	mutex_unlock(&data->mutex);
	379	if (ret < 0)
	380	return ret;
	381
	382	i = (reg & MMC35240_CTRL1_BW_MASK) >> MMC35240_CTRL1_BW_SHIFT;
5517547b	383	if (i < 0 \|\| i >= ARRAY_SIZE(mmc35240_samp_freq))
abeb6b1e DB	384	return -EINVAL;
abeb6b1e DB	385
c99389ad TB	386	*val = mmc35240_samp_freq[i].val;
	387	*val2 = mmc35240_samp_freq[i].val2;
	388	return IIO_VAL_INT_PLUS_MICRO;
abeb6b1e DB	389	default:
	390	return -EINVAL;
	391	}
	392	}
	393
	394	static int mmc35240_write_raw(struct iio_dev *indio_dev,
	395	struct iio_chan_spec const *chan, int val,
	396	int val2, long mask)
	397	{
	398	struct mmc35240_data *data = iio_priv(indio_dev);
	399	int i, ret;
	400
	401	switch (mask) {
	402	case IIO_CHAN_INFO_SAMP_FREQ:
	403	i = mmc35240_get_samp_freq_index(data, val, val2);
	404	if (i < 0)
	405	return -EINVAL;
	406	mutex_lock(&data->mutex);
	407	ret = regmap_update_bits(data->regmap, MMC35240_REG_CTRL1,
	408	MMC35240_CTRL1_BW_MASK,
	409	i << MMC35240_CTRL1_BW_SHIFT);
	410	mutex_unlock(&data->mutex);
	411	return ret;
	412	default:
	413	return -EINVAL;
	414	}
	415	}
	416
	417	static const struct iio_info mmc35240_info = {
abeb6b1e DB	418	.read_raw = mmc35240_read_raw,
	419	.write_raw = mmc35240_write_raw,
	420	.attrs = &mmc35240_attribute_group,
	421	};
	422
	423	static bool mmc35240_is_writeable_reg(struct device *dev, unsigned int reg)
	424	{
	425	switch (reg) {
	426	case MMC35240_REG_CTRL0:
	427	case MMC35240_REG_CTRL1:
	428	return true;
	429	default:
	430	return false;
	431	}
	432	}
	433
	434	static bool mmc35240_is_readable_reg(struct device *dev, unsigned int reg)
	435	{
	436	switch (reg) {
	437	case MMC35240_REG_XOUT_L:
	438	case MMC35240_REG_XOUT_H:
	439	case MMC35240_REG_YOUT_L:
	440	case MMC35240_REG_YOUT_H:
	441	case MMC35240_REG_ZOUT_L:
	442	case MMC35240_REG_ZOUT_H:
	443	case MMC35240_REG_STATUS:
	444	case MMC35240_REG_ID:
	445	return true;
	446	default:
	447	return false;
	448	}
	449	}
	450
	451	static bool mmc35240_is_volatile_reg(struct device *dev, unsigned int reg)
	452	{
	453	switch (reg) {
	454	case MMC35240_REG_CTRL0:
	455	case MMC35240_REG_CTRL1:
	456	return false;
	457	default:
	458	return true;
	459	}
	460	}
	461
c2c87809	462	static const struct reg_default mmc35240_reg_defaults[] = {
abeb6b1e DB	463	{ MMC35240_REG_CTRL0, 0x00 },
	464	{ MMC35240_REG_CTRL1, 0x00 },
	465	};
	466
	467	static const struct regmap_config mmc35240_regmap_config = {
	468	.name = MMC35240_REGMAP_NAME,
	469
	470	.reg_bits = 8,
	471	.val_bits = 8,
	472
	473	.max_register = MMC35240_REG_ID,
	474	.cache_type = REGCACHE_FLAT,
	475
	476	.writeable_reg = mmc35240_is_writeable_reg,
	477	.readable_reg = mmc35240_is_readable_reg,
	478	.volatile_reg = mmc35240_is_volatile_reg,
	479
	480	.reg_defaults = mmc35240_reg_defaults,
	481	.num_reg_defaults = ARRAY_SIZE(mmc35240_reg_defaults),
	482	};
	483
	484	static int mmc35240_probe(struct i2c_client *client,
	485	const struct i2c_device_id *id)
	486	{
	487	struct mmc35240_data *data;
	488	struct iio_dev *indio_dev;
	489	struct regmap *regmap;
	490	int ret;
	491
	492	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	493	if (!indio_dev)
	494	return -ENOMEM;
	495
	496	regmap = devm_regmap_init_i2c(client, &mmc35240_regmap_config);
	497	if (IS_ERR(regmap)) {
	498	dev_err(&client->dev, "regmap initialization failed\n");
	499	return PTR_ERR(regmap);
	500	}
	501
	502	data = iio_priv(indio_dev);
8b14821a	503	i2c_set_clientdata(client, indio_dev);
abeb6b1e DB	504	data->client = client;
	505	data->regmap = regmap;
	506	data->res = MMC35240_16_BITS_SLOW;
	507
	508	mutex_init(&data->mutex);
	509
abeb6b1e DB	510	indio_dev->info = &mmc35240_info;
	511	indio_dev->name = MMC35240_DRV_NAME;
	512	indio_dev->channels = mmc35240_channels;
	513	indio_dev->num_channels = ARRAY_SIZE(mmc35240_channels);
	514	indio_dev->modes = INDIO_DIRECT_MODE;
	515
	516	ret = mmc35240_init(data);
	517	if (ret < 0) {
	518	dev_err(&client->dev, "mmc35240 chip init failed\n");
	519	return ret;
	520	}
	521	return devm_iio_device_register(&client->dev, indio_dev);
	522	}
	523
553a776b DB	524	static int mmc35240_suspend(struct device *dev)
	525	{
	526	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	527	struct mmc35240_data *data = iio_priv(indio_dev);
	528
	529	regcache_cache_only(data->regmap, true);
	530
	531	return 0;
	532	}
	533
	534	static int mmc35240_resume(struct device *dev)
	535	{
	536	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	537	struct mmc35240_data *data = iio_priv(indio_dev);
	538	int ret;
	539
	540	regcache_mark_dirty(data->regmap);
	541	ret = regcache_sync_region(data->regmap, MMC35240_REG_CTRL0,
	542	MMC35240_REG_CTRL1);
	543	if (ret < 0)
	544	dev_err(dev, "Failed to restore control registers\n");
	545
	546	regcache_cache_only(data->regmap, false);
	547
	548	return 0;
	549	}
553a776b	550
c9f384b8 JC	551	static DEFINE_SIMPLE_DEV_PM_OPS(mmc35240_pm_ops, mmc35240_suspend,
c9f384b8 JC	552	mmc35240_resume);
553a776b	553
7dbf1ea8 JG	554	static const struct of_device_id mmc35240_of_match[] = {
	555	{ .compatible = "memsic,mmc35240", },
	556	{ }
	557	};
	558	MODULE_DEVICE_TABLE(of, mmc35240_of_match);
	559
d11715f0 DB	560	static const struct acpi_device_id mmc35240_acpi_match[] = {
	561	{"MMC35240", 0},
	562	{ },
	563	};
	564	MODULE_DEVICE_TABLE(acpi, mmc35240_acpi_match);
	565
abeb6b1e	566	static const struct i2c_device_id mmc35240_id[] = {
a52ffebc	567	{"mmc35240", 0},
abeb6b1e DB	568	{}
	569	};
	570	MODULE_DEVICE_TABLE(i2c, mmc35240_id);
	571
	572	static struct i2c_driver mmc35240_driver = {
	573	.driver = {
	574	.name = MMC35240_DRV_NAME,
7dbf1ea8	575	.of_match_table = mmc35240_of_match,
c9f384b8	576	.pm = pm_sleep_ptr(&mmc35240_pm_ops),
d11715f0	577	.acpi_match_table = ACPI_PTR(mmc35240_acpi_match),
abeb6b1e DB	578	},
	579	.probe = mmc35240_probe,
	580	.id_table = mmc35240_id,
	581	};
	582
	583	module_i2c_driver(mmc35240_driver);
	584
	585	MODULE_AUTHOR("Daniel Baluta <[email protected]>");
	586	MODULE_DESCRIPTION("MEMSIC MMC35240 magnetic sensor driver");
	587	MODULE_LICENSE("GPL v2");