cubelinux-kernel/drivers/iio/pressure/mpl3115.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * mpl3115.c - Support for Freescale MPL3115A2 pressure/temperature sensor
 *
 * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
 *
 * (7-bit I2C slave address 0x60)
 *
 * TODO: FIFO buffer, altimeter mode, oversampling, continuous mode,
 * user offset correction, raw mode
 */

#include <linux/bitfield.h>
#include <linux/cleanup.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/limits.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/unaligned.h>

#include <linux/iio/buffer.h>
#include <linux/iio/events.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/trigger.h>

#define MPL3115_STATUS 0x00
#define MPL3115_OUT_PRESS 0x01 /* MSB first, 20 bit */
#define MPL3115_OUT_TEMP 0x04 /* MSB first, 12 bit */
#define MPL3115_WHO_AM_I 0x0c
#define MPL3115_INT_SOURCE 0x12
#define MPL3115_PT_DATA_CFG 0x13
#define MPL3115_PRESS_TGT 0x16 /* MSB first, 16 bit */
#define MPL3115_TEMP_TGT 0x18
#define MPL3115_CTRL_REG1 0x26
#define MPL3115_CTRL_REG2 0x27
#define MPL3115_CTRL_REG3 0x28
#define MPL3115_CTRL_REG4 0x29
#define MPL3115_CTRL_REG5 0x2a

#define MPL3115_DEVICE_ID 0xc4

#define MPL3115_STATUS_PRESS_RDY BIT(2)
#define MPL3115_STATUS_TEMP_RDY BIT(1)

#define MPL3115_INT_SRC_DRDY BIT(7)
#define MPL3115_INT_SRC_PTH BIT(3)
#define MPL3115_INT_SRC_TTH BIT(2)

#define MPL3115_PT_DATA_EVENT_ALL GENMASK(2, 0)

#define MPL3115_CTRL1_RESET BIT(2) /* software reset */
#define MPL3115_CTRL1_OST BIT(1) /* initiate measurement */
#define MPL3115_CTRL1_ACTIVE BIT(0) /* continuous measurement */
#define MPL3115_CTRL1_OS_258MS GENMASK(5, 4) /* 64x oversampling */

#define MPL3115_CTRL2_ST GENMASK(3, 0)

#define MPL3115_CTRL3_IPOL1 BIT(5)
#define MPL3115_CTRL3_IPOL2 BIT(1)

#define MPL3115_CTRL4_INT_EN_DRDY BIT(7)
#define MPL3115_CTRL4_INT_EN_PTH BIT(3)
#define MPL3115_CTRL4_INT_EN_TTH BIT(2)

#define MPL3115_CTRL5_INT_CFG_DRDY BIT(7)

static const unsigned int mpl3115_samp_freq_table[][2] = {
	{ 1,      0 },
	{ 0, 500000 },
	{ 0, 250000 },
	{ 0, 125000 },
	{ 0,  62500 },
	{ 0,  31250 },
	{ 0,  15625 },
	{ 0,   7812 },
	{ 0,   3906 },
	{ 0,   1953 },
	{ 0,    976 },
	{ 0,    488 },
	{ 0,    244 },
	{ 0,    122 },
	{ 0,     61 },
	{ 0,     30 },
};

struct mpl3115_data {
	struct i2c_client *client;
	struct iio_trigger *drdy_trig;
	struct mutex lock;
	u8 ctrl_reg1;
	u8 ctrl_reg4;
};

enum mpl3115_irq_pin {
	MPL3115_IRQ_INT1,
	MPL3115_IRQ_INT2,
};

static int mpl3115_request(struct mpl3115_data *data)
{
	int ret, tries = 15;

	/* trigger measurement */
	ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
		data->ctrl_reg1 | MPL3115_CTRL1_OST);
	if (ret < 0)
		return ret;

	while (tries-- > 0) {
		ret = i2c_smbus_read_byte_data(data->client, MPL3115_CTRL_REG1);
		if (ret < 0)
			return ret;
		/* wait for data ready, i.e. OST cleared */
		if (!(ret & MPL3115_CTRL1_OST))
			break;
		msleep(20);
	}

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

	return 0;
}

static int mpl3115_read_info_raw(struct mpl3115_data *data,
				 struct iio_chan_spec const *chan, int *val)
{
	int ret;

	switch (chan->type) {
	case IIO_PRESSURE: { /* in 0.25 pascal / LSB */
		u8 press_be24[3];

		guard(mutex)(&data->lock);
		ret = mpl3115_request(data);
		if (ret < 0)
			return ret;

		ret = i2c_smbus_read_i2c_block_data(data->client,
						    MPL3115_OUT_PRESS,
						    sizeof(press_be24),
						    press_be24);
		if (ret < 0)
			return ret;

		/*
		 * The pressure channel shift is applied in the case where the
		 * data (24-bit big endian) is read into a 32-bit buffer. Here
		 * the data is stored in a 24-bit buffer, so the shift is 4.
		 */
		*val = get_unaligned_be24(press_be24) >> 4;
		return IIO_VAL_INT;
	}
	case IIO_TEMP: { /* in 0.0625 celsius / LSB */
		__be16 tmp;

		guard(mutex)(&data->lock);
		ret = mpl3115_request(data);
		if (ret < 0)
			return ret;

		ret = i2c_smbus_read_i2c_block_data(data->client,
						    MPL3115_OUT_TEMP,
						    2, (u8 *) &tmp);
		if (ret < 0)
			return ret;

		*val = sign_extend32(be16_to_cpu(tmp) >> chan->scan_type.shift,
				     chan->scan_type.realbits - 1);
		return IIO_VAL_INT;
	}
	default:
		return -EINVAL;
	}
}

static int mpl3115_read_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int *val, int *val2, long mask)
{
	struct mpl3115_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		if (!iio_device_claim_direct(indio_dev))
			return -EBUSY;

		ret = mpl3115_read_info_raw(data, chan, val);
		iio_device_release_direct(indio_dev);
		return ret;

	case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_PRESSURE:
			*val = 0;
			*val2 = 250; /* want kilopascal */
			return IIO_VAL_INT_PLUS_MICRO;
		case IIO_TEMP:
			*val = 0;
			*val2 = 62500;
			return IIO_VAL_INT_PLUS_MICRO;
		default:
			return -EINVAL;
		}
	case IIO_CHAN_INFO_SAMP_FREQ:
		ret = i2c_smbus_read_byte_data(data->client, MPL3115_CTRL_REG2);
		if (ret < 0)
			return ret;

		ret = FIELD_GET(MPL3115_CTRL2_ST, ret);

		*val = mpl3115_samp_freq_table[ret][0];
		*val2 = mpl3115_samp_freq_table[ret][1];
		return IIO_VAL_INT_PLUS_MICRO;
	}
	return -EINVAL;
}

static int mpl3115_read_avail(struct iio_dev *indio_dev,
			      struct iio_chan_spec const *chan,
			      const int **vals, int *type, int *length,
			      long mask)
{
	if (mask != IIO_CHAN_INFO_SAMP_FREQ)
		return -EINVAL;

	*type = IIO_VAL_INT_PLUS_MICRO;
	*length = ARRAY_SIZE(mpl3115_samp_freq_table) * 2;
	*vals = (int *)mpl3115_samp_freq_table;
	return IIO_AVAIL_LIST;
}

static int mpl3115_write_raw(struct iio_dev *indio_dev,
			     const struct iio_chan_spec *chan,
			     int val, int val2, long mask)
{
	struct mpl3115_data *data = iio_priv(indio_dev);
	int i, ret;

	if (mask != IIO_CHAN_INFO_SAMP_FREQ)
		return -EINVAL;

	for (i = 0; i < ARRAY_SIZE(mpl3115_samp_freq_table); i++)
		if (val == mpl3115_samp_freq_table[i][0] &&
		    val2 == mpl3115_samp_freq_table[i][1])
			break;

	if (i == ARRAY_SIZE(mpl3115_samp_freq_table))
		return -EINVAL;

	if (!iio_device_claim_direct(indio_dev))
		return -EBUSY;

	ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG2,
					FIELD_PREP(MPL3115_CTRL2_ST, i));
	iio_device_release_direct(indio_dev);
	return ret;
}

static int mpl3115_fill_trig_buffer(struct iio_dev *indio_dev, u8 *buffer)
{
	struct mpl3115_data *data = iio_priv(indio_dev);
	int ret, pos = 0;

	if (!(data->ctrl_reg1 & MPL3115_CTRL1_ACTIVE)) {
		ret = mpl3115_request(data);
		if (ret < 0)
			return ret;
	}

	if (test_bit(0, indio_dev->active_scan_mask)) {
		ret = i2c_smbus_read_i2c_block_data(data->client,
			MPL3115_OUT_PRESS, 3, &buffer[pos]);
		if (ret < 0)
			return ret;
		pos += 4;
	}

	if (test_bit(1, indio_dev->active_scan_mask)) {
		ret = i2c_smbus_read_i2c_block_data(data->client,
			MPL3115_OUT_TEMP, 2, &buffer[pos]);
		if (ret < 0)
			return ret;
	}

	return 0;
}

static irqreturn_t mpl3115_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct mpl3115_data *data = iio_priv(indio_dev);
	/*
	 * 32-bit channel + 16-bit channel + padding + ts
	 * Note that it is possible for only one of the first 2
	 * channels to be enabled. If that happens, the first element
	 * of the buffer may be either 16 or 32-bits.  As such we cannot
	 * use a simple structure definition to express this data layout.
	 */
	u8 buffer[16] __aligned(8) = { };
	int ret;

	mutex_lock(&data->lock);
	ret = mpl3115_fill_trig_buffer(indio_dev, buffer);
	mutex_unlock(&data->lock);
	if (ret)
		goto done;

	iio_push_to_buffers_with_ts(indio_dev, buffer, sizeof(buffer),
				    iio_get_time_ns(indio_dev));

done:
	iio_trigger_notify_done(indio_dev->trig);
	return IRQ_HANDLED;
}

static const struct iio_event_spec mpl3115_temp_press_event[] = {
	{
		.type = IIO_EV_TYPE_THRESH,
		.dir = IIO_EV_DIR_RISING,
		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
				 BIT(IIO_EV_INFO_VALUE),
	},
};

static const struct iio_chan_spec mpl3115_channels[] = {
	{
		.type = IIO_PRESSURE,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
		.info_mask_shared_by_all_available =
			BIT(IIO_CHAN_INFO_SAMP_FREQ),
		.scan_index = 0,
		.scan_type = {
			.sign = 'u',
			.realbits = 20,
			.storagebits = 32,
			.shift = 12,
			.endianness = IIO_BE,
		},
		.event_spec = mpl3115_temp_press_event,
		.num_event_specs = ARRAY_SIZE(mpl3115_temp_press_event),
	},
	{
		.type = IIO_TEMP,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
		.info_mask_shared_by_all_available =
			BIT(IIO_CHAN_INFO_SAMP_FREQ),
		.scan_index = 1,
		.scan_type = {
			.sign = 's',
			.realbits = 12,
			.storagebits = 16,
			.shift = 4,
			.endianness = IIO_BE,
		},
		.event_spec = mpl3115_temp_press_event,
		.num_event_specs = ARRAY_SIZE(mpl3115_temp_press_event),
	},
	IIO_CHAN_SOFT_TIMESTAMP(2),
};

static irqreturn_t mpl3115_interrupt_handler(int irq, void *private)
{
	struct iio_dev *indio_dev = private;
	struct mpl3115_data *data = iio_priv(indio_dev);
	int ret;
	u8 val_press[3];
	__be16 val_temp;

	ret = i2c_smbus_read_byte_data(data->client, MPL3115_INT_SOURCE);
	if (ret < 0)
		return IRQ_HANDLED;

	if (!(ret & (MPL3115_INT_SRC_TTH | MPL3115_INT_SRC_PTH |
		     MPL3115_INT_SRC_DRDY)))
		return IRQ_NONE;

	if (ret & MPL3115_INT_SRC_DRDY)
		iio_trigger_poll_nested(data->drdy_trig);

	if (ret & MPL3115_INT_SRC_PTH) {
		iio_push_event(indio_dev,
			       IIO_UNMOD_EVENT_CODE(IIO_PRESSURE, 0,
						    IIO_EV_TYPE_THRESH,
						    IIO_EV_DIR_RISING),
						    iio_get_time_ns(indio_dev));

		/* Reset the SRC_PTH bit in INT_SOURCE */
		i2c_smbus_read_i2c_block_data(data->client,
					      MPL3115_OUT_PRESS,
					      sizeof(val_press), val_press);
	}

	if (ret & MPL3115_INT_SRC_TTH) {
		iio_push_event(indio_dev,
			       IIO_UNMOD_EVENT_CODE(IIO_TEMP, 0,
						    IIO_EV_TYPE_THRESH,
						    IIO_EV_DIR_RISING),
						    iio_get_time_ns(indio_dev));

		/* Reset the SRC_TTH bit in INT_SOURCE */
		i2c_smbus_read_i2c_block_data(data->client,
					      MPL3115_OUT_TEMP,
					      sizeof(val_temp),
					      (u8 *)&val_temp);
	}

	return IRQ_HANDLED;
}

static int mpl3115_config_interrupt(struct mpl3115_data *data,
				    u8 ctrl_reg1, u8 ctrl_reg4)
{
	int ret;

	ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
					ctrl_reg1);
	if (ret < 0)
		return ret;

	ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG4,
					ctrl_reg4);
	if (ret < 0)
		goto reg1_cleanup;

	data->ctrl_reg1 = ctrl_reg1;
	data->ctrl_reg4 = ctrl_reg4;

	return 0;

reg1_cleanup:
	i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
				  data->ctrl_reg1);
	return ret;
}

static int mpl3115_set_trigger_state(struct iio_trigger *trig, bool state)
{
	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
	struct mpl3115_data *data = iio_priv(indio_dev);
	u8 ctrl_reg1, ctrl_reg4;

	guard(mutex)(&data->lock);

	ctrl_reg1 = data->ctrl_reg1;
	ctrl_reg4 = data->ctrl_reg4;

	if (state) {
		ctrl_reg1 |= MPL3115_CTRL1_ACTIVE;
		ctrl_reg4 |= MPL3115_CTRL4_INT_EN_DRDY;
	} else {
		ctrl_reg4 &= ~MPL3115_CTRL4_INT_EN_DRDY;

		if (!ctrl_reg4)
			ctrl_reg1 &= ~MPL3115_CTRL1_ACTIVE;
	}

	return mpl3115_config_interrupt(data, ctrl_reg1, ctrl_reg4);
}

static const struct iio_trigger_ops mpl3115_trigger_ops = {
	.set_trigger_state = mpl3115_set_trigger_state,
};

static int mpl3115_read_event_config(struct iio_dev *indio_dev,
				     const struct iio_chan_spec *chan,
				     enum iio_event_type type,
				     enum iio_event_direction dir)
{
	struct mpl3115_data *data = iio_priv(indio_dev);

	if (chan->type == IIO_PRESSURE)
		return !!(data->ctrl_reg4 & MPL3115_CTRL4_INT_EN_PTH);

	if (chan->type == IIO_TEMP)
		return !!(data->ctrl_reg4 & MPL3115_CTRL4_INT_EN_TTH);

	return -EINVAL;
}

static int mpl3115_write_event_config(struct iio_dev *indio_dev,
				      const struct iio_chan_spec *chan,
				      enum iio_event_type type,
				      enum iio_event_direction dir,
				      bool state)
{
	struct mpl3115_data *data = iio_priv(indio_dev);
	u8 int_en_mask;
	u8 ctrl_reg1, ctrl_reg4;

	switch (chan->type) {
	case IIO_PRESSURE:
		int_en_mask = MPL3115_CTRL4_INT_EN_PTH;
		break;
	case IIO_TEMP:
		int_en_mask = MPL3115_CTRL4_INT_EN_TTH;
		break;
	default:
		return -EINVAL;
	}

	guard(mutex)(&data->lock);

	ctrl_reg1 = data->ctrl_reg1;
	ctrl_reg4 = data->ctrl_reg4;

	if (state) {
		ctrl_reg1 |= MPL3115_CTRL1_ACTIVE;
		ctrl_reg4 |= int_en_mask;
	} else {
		ctrl_reg4 &= ~int_en_mask;

		if (!ctrl_reg4)
			ctrl_reg1 &= ~MPL3115_CTRL1_ACTIVE;
	}

	return mpl3115_config_interrupt(data, ctrl_reg1, ctrl_reg4);
}

static int mpl3115_read_thresh(struct iio_dev *indio_dev,
			       const struct iio_chan_spec *chan,
			       enum iio_event_type type,
			       enum iio_event_direction dir,
			       enum iio_event_info info,
			       int *val, int *val2)
{
	struct mpl3115_data *data = iio_priv(indio_dev);
	int ret;
	__be16 press_tgt;

	if (info != IIO_EV_INFO_VALUE)
		return -EINVAL;

	switch (chan->type) {
	case IIO_PRESSURE:
		ret = i2c_smbus_read_i2c_block_data(data->client,
						    MPL3115_PRESS_TGT,
						    sizeof(press_tgt),
						    (u8 *)&press_tgt);
		if (ret < 0)
			return ret;

		/*
		 * Target value for the pressure is 16-bit unsigned value,
		 * expressed in 2 Pa units
		 */
		*val = be16_to_cpu(press_tgt) << 1;

		return IIO_VAL_INT;
	case IIO_TEMP:
		ret = i2c_smbus_read_byte_data(data->client, MPL3115_TEMP_TGT);
		if (ret < 0)
			return ret;

		/* Target value for the temperature is 8-bit 2's complement */
		*val = sign_extend32(ret, 7);

		return IIO_VAL_INT;
	default:
		return -EINVAL;
	}
}

static int mpl3115_write_thresh(struct iio_dev *indio_dev,
				const struct iio_chan_spec *chan,
				enum iio_event_type type,
				enum iio_event_direction dir,
				enum iio_event_info info,
				int val, int val2)
{
	struct mpl3115_data *data = iio_priv(indio_dev);
	__be16 press_tgt;

	if (info != IIO_EV_INFO_VALUE)
		return -EINVAL;

	switch (chan->type) {
	case IIO_PRESSURE:
		val >>= 1;

		if (val < 0 || val > U16_MAX)
			return -EINVAL;

		press_tgt = cpu_to_be16(val);

		return i2c_smbus_write_i2c_block_data(data->client,
						      MPL3115_PRESS_TGT,
						      sizeof(press_tgt),
						      (u8 *)&press_tgt);
	case IIO_TEMP:
		if (val < S8_MIN || val > S8_MAX)
			return -EINVAL;

		return i2c_smbus_write_byte_data(data->client,
						 MPL3115_TEMP_TGT, val);
	default:
		return -EINVAL;
	}
}

static const struct iio_info mpl3115_info = {
	.read_raw = &mpl3115_read_raw,
	.read_avail = &mpl3115_read_avail,
	.write_raw = &mpl3115_write_raw,
	.read_event_config = mpl3115_read_event_config,
	.write_event_config = mpl3115_write_event_config,
	.read_event_value = mpl3115_read_thresh,
	.write_event_value = mpl3115_write_thresh,
};

static int mpl3115_trigger_probe(struct mpl3115_data *data,
				 struct iio_dev *indio_dev)
{
	struct fwnode_handle *fwnode = dev_fwnode(&data->client->dev);
	int ret, irq, irq_type, irq_pin = MPL3115_IRQ_INT1;

	irq = fwnode_irq_get_byname(fwnode, "INT1");
	if (irq < 0) {
		irq = fwnode_irq_get_byname(fwnode, "INT2");
		if (irq < 0)
			return 0;

		irq_pin = MPL3115_IRQ_INT2;
	}

	irq_type = irq_get_trigger_type(irq);
	if (irq_type != IRQF_TRIGGER_RISING && irq_type != IRQF_TRIGGER_FALLING)
		return -EINVAL;

	ret = i2c_smbus_write_byte_data(data->client, MPL3115_PT_DATA_CFG,
					MPL3115_PT_DATA_EVENT_ALL);
	if (ret < 0)
		return ret;

	if (irq_pin == MPL3115_IRQ_INT1) {
		ret = i2c_smbus_write_byte_data(data->client,
						MPL3115_CTRL_REG5,
						MPL3115_CTRL5_INT_CFG_DRDY);
		if (ret)
			return ret;

		if (irq_type == IRQF_TRIGGER_RISING) {
			ret = i2c_smbus_write_byte_data(data->client,
							MPL3115_CTRL_REG3,
							MPL3115_CTRL3_IPOL1);
			if (ret)
				return ret;
		}
	} else if (irq_type == IRQF_TRIGGER_RISING) {
		ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG3,
						MPL3115_CTRL3_IPOL2);
		if (ret)
			return ret;
	}

	data->drdy_trig = devm_iio_trigger_alloc(&data->client->dev,
						 "%s-dev%d",
						 indio_dev->name,
						 iio_device_id(indio_dev));
	if (!data->drdy_trig)
		return -ENOMEM;

	data->drdy_trig->ops = &mpl3115_trigger_ops;
	iio_trigger_set_drvdata(data->drdy_trig, indio_dev);

	ret = devm_request_threaded_irq(&data->client->dev, irq, NULL,
					mpl3115_interrupt_handler,
					IRQF_ONESHOT,
					"mpl3115_irq", indio_dev);
	if (ret)
		return ret;

	ret = devm_iio_trigger_register(&data->client->dev, data->drdy_trig);
	if (ret)
		return ret;

	indio_dev->trig = iio_trigger_get(data->drdy_trig);

	return 0;
}

static int mpl3115_probe(struct i2c_client *client)
{
	const struct i2c_device_id *id = i2c_client_get_device_id(client);
	struct mpl3115_data *data;
	struct iio_dev *indio_dev;
	int ret;

	ret = i2c_smbus_read_byte_data(client, MPL3115_WHO_AM_I);
	if (ret < 0)
		return ret;
	if (ret != MPL3115_DEVICE_ID)
		return -ENODEV;

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

	data = iio_priv(indio_dev);
	data->client = client;
	mutex_init(&data->lock);

	i2c_set_clientdata(client, indio_dev);
	indio_dev->info = &mpl3115_info;
	indio_dev->name = id->name;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = mpl3115_channels;
	indio_dev->num_channels = ARRAY_SIZE(mpl3115_channels);

	/* software reset, I2C transfer is aborted (fails) */
	i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
		MPL3115_CTRL1_RESET);
	msleep(50);

	data->ctrl_reg1 = MPL3115_CTRL1_OS_258MS;
	ret = i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
		data->ctrl_reg1);
	if (ret < 0)
		return ret;

	ret = mpl3115_trigger_probe(data, indio_dev);
	if (ret)
		return ret;

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
		mpl3115_trigger_handler, NULL);
	if (ret < 0)
		return ret;

	ret = iio_device_register(indio_dev);
	if (ret < 0)
		goto buffer_cleanup;
	return 0;

buffer_cleanup:
	iio_triggered_buffer_cleanup(indio_dev);
	return ret;
}

static int mpl3115_standby(struct mpl3115_data *data)
{
	return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
		data->ctrl_reg1 & ~MPL3115_CTRL1_ACTIVE);
}

static void mpl3115_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);
	mpl3115_standby(iio_priv(indio_dev));
}

static int mpl3115_suspend(struct device *dev)
{
	return mpl3115_standby(iio_priv(i2c_get_clientdata(
		to_i2c_client(dev))));
}

static int mpl3115_resume(struct device *dev)
{
	struct mpl3115_data *data = iio_priv(i2c_get_clientdata(
		to_i2c_client(dev)));

	return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
		data->ctrl_reg1);
}

static DEFINE_SIMPLE_DEV_PM_OPS(mpl3115_pm_ops, mpl3115_suspend,
				mpl3115_resume);

static const struct i2c_device_id mpl3115_id[] = {
	{ "mpl3115" },
	{ }
};
MODULE_DEVICE_TABLE(i2c, mpl3115_id);

static const struct of_device_id mpl3115_of_match[] = {
	{ .compatible = "fsl,mpl3115" },
	{ }
};
MODULE_DEVICE_TABLE(of, mpl3115_of_match);

static struct i2c_driver mpl3115_driver = {
	.driver = {
		.name	= "mpl3115",
		.of_match_table = mpl3115_of_match,
		.pm	= pm_sleep_ptr(&mpl3115_pm_ops),
	},
	.probe = mpl3115_probe,
	.remove = mpl3115_remove,
	.id_table = mpl3115_id,
};
module_i2c_driver(mpl3115_driver);

MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("Freescale MPL3115 pressure/temperature driver");
MODULE_LICENSE("GPL");