drivers/iio/pressure/mpl3115.c - linux - Git at Google

 // 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,
  * interrupts, user offset correction, raw mode
  */

 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/triggered_buffer.h>
 #include <linux/delay.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_CTRL_REG1 0x26

 #define MPL3115_DEVICE_ID 0xc4

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

 #define MPL3115_CTRL_RESET BIT(2) /* software reset */
 #define MPL3115_CTRL_OST BIT(1) /* initiate measurement */
 #define MPL3115_CTRL_ACTIVE BIT(0) /* continuous measurement */
 #define MPL3115_CTRL_OS_258MS (BIT(5) | BIT(4)) /* 64x oversampling */

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

 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_CTRL_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_CTRL_OST))
 			break;
 		msleep(20);
 	}

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

 	return 0;
 }

 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:
 		ret = iio_device_claim_direct_mode(indio_dev);
 		if (ret)
 			return ret;

 		switch (chan->type) {
 		case IIO_PRESSURE: { /* in 0.25 pascal / LSB */
 			__be32 tmp = 0;

 			mutex_lock(&data->lock);
 			ret = mpl3115_request(data);
 			if (ret < 0) {
 				mutex_unlock(&data->lock);
 				break;
 			}
 			ret = i2c_smbus_read_i2c_block_data(data->client,
 				MPL3115_OUT_PRESS, 3, (u8 *) &tmp);
 			mutex_unlock(&data->lock);
 			if (ret < 0)
 				break;
 			*val = be32_to_cpu(tmp) >> chan->scan_type.shift;
 			ret = IIO_VAL_INT;
 			break;
 		}
 		case IIO_TEMP: { /* in 0.0625 celsius / LSB */
 			__be16 tmp;

 			mutex_lock(&data->lock);
 			ret = mpl3115_request(data);
 			if (ret < 0) {
 				mutex_unlock(&data->lock);
 				break;
 			}
 			ret = i2c_smbus_read_i2c_block_data(data->client,
 				MPL3115_OUT_TEMP, 2, (u8 *) &tmp);
 			mutex_unlock(&data->lock);
 			if (ret < 0)
 				break;
 			*val = sign_extend32(be16_to_cpu(tmp) >> chan->scan_type.shift,
 					     chan->scan_type.realbits - 1);
 			ret = IIO_VAL_INT;
 			break;
 		}
 		default:
 			ret = -EINVAL;
 			break;
 		}

 		iio_device_release_direct_mode(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;
 		}
 	}
 	return -EINVAL;
 }

 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, pos = 0;

 	mutex_lock(&data->lock);
 	ret = mpl3115_request(data);
 	if (ret < 0) {
 		mutex_unlock(&data->lock);
 		goto done;
 	}

 	memset(buffer, 0, sizeof(buffer));
 	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) {
 			mutex_unlock(&data->lock);
 			goto done;
 		}
 		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) {
 			mutex_unlock(&data->lock);
 			goto done;
 		}
 	}
 	mutex_unlock(&data->lock);

 	iio_push_to_buffers_with_timestamp(indio_dev, buffer,
 		iio_get_time_ns(indio_dev));

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

 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),
 		.scan_index = 0,
 		.scan_type = {
 			.sign = 'u',
 			.realbits = 20,
 			.storagebits = 32,
 			.shift = 12,
 			.endianness = IIO_BE,
 		}
 	},
 	{
 		.type = IIO_TEMP,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
 		.scan_index = 1,
 		.scan_type = {
 			.sign = 's',
 			.realbits = 12,
 			.storagebits = 16,
 			.shift = 4,
 			.endianness = IIO_BE,
 		}
 	},
 	IIO_CHAN_SOFT_TIMESTAMP(2),
 };

 static const struct iio_info mpl3115_info = {
 	.read_raw = &mpl3115_read_raw,
 };

 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_CTRL_RESET);
 	msleep(50);

 	data->ctrl_reg1 = MPL3115_CTRL_OS_258MS;
 	ret = i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
 		data->ctrl_reg1);
 	if (ret < 0)
 		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_CTRL_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");
	// 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,
	* interrupts, user offset correction, raw mode
	*/

	#include <linux/module.h>
	#include <linux/i2c.h>
	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>
	#include <linux/iio/trigger_consumer.h>
	#include <linux/iio/buffer.h>
	#include <linux/iio/triggered_buffer.h>
	#include <linux/delay.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_CTRL_REG1 0x26

	#define MPL3115_DEVICE_ID 0xc4

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

	#define MPL3115_CTRL_RESET BIT(2) /* software reset */
	#define MPL3115_CTRL_OST BIT(1) /* initiate measurement */
	#define MPL3115_CTRL_ACTIVE BIT(0) /* continuous measurement */
	#define MPL3115_CTRL_OS_258MS (BIT(5) \| BIT(4)) /* 64x oversampling */

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

	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_CTRL_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_CTRL_OST))
	break;
	msleep(20);
	}

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

	return 0;
	}

	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:
	ret = iio_device_claim_direct_mode(indio_dev);
	if (ret)
	return ret;

	switch (chan->type) {
	case IIO_PRESSURE: { /* in 0.25 pascal / LSB */
	__be32 tmp = 0;

	mutex_lock(&data->lock);
	ret = mpl3115_request(data);
	if (ret < 0) {
	mutex_unlock(&data->lock);
	break;
	}
	ret = i2c_smbus_read_i2c_block_data(data->client,
	MPL3115_OUT_PRESS, 3, (u8 *) &tmp);
	mutex_unlock(&data->lock);
	if (ret < 0)
	break;
	*val = be32_to_cpu(tmp) >> chan->scan_type.shift;
	ret = IIO_VAL_INT;
	break;
	}
	case IIO_TEMP: { /* in 0.0625 celsius / LSB */
	__be16 tmp;

	mutex_lock(&data->lock);
	ret = mpl3115_request(data);
	if (ret < 0) {
	mutex_unlock(&data->lock);
	break;
	}
	ret = i2c_smbus_read_i2c_block_data(data->client,
	MPL3115_OUT_TEMP, 2, (u8 *) &tmp);
	mutex_unlock(&data->lock);
	if (ret < 0)
	break;
	*val = sign_extend32(be16_to_cpu(tmp) >> chan->scan_type.shift,
	chan->scan_type.realbits - 1);
	ret = IIO_VAL_INT;
	break;
	}
	default:
	ret = -EINVAL;
	break;
	}

	iio_device_release_direct_mode(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;
	}
	}
	return -EINVAL;
	}

	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, pos = 0;

	mutex_lock(&data->lock);
	ret = mpl3115_request(data);
	if (ret < 0) {
	mutex_unlock(&data->lock);
	goto done;
	}

	memset(buffer, 0, sizeof(buffer));
	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) {
	mutex_unlock(&data->lock);
	goto done;
	}
	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) {
	mutex_unlock(&data->lock);
	goto done;
	}
	}
	mutex_unlock(&data->lock);

	iio_push_to_buffers_with_timestamp(indio_dev, buffer,
	iio_get_time_ns(indio_dev));

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

	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),
	.scan_index = 0,
	.scan_type = {
	.sign = 'u',
	.realbits = 20,
	.storagebits = 32,
	.shift = 12,
	.endianness = IIO_BE,
	}
	},
	{
	.type = IIO_TEMP,
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
	.scan_index = 1,
	.scan_type = {
	.sign = 's',
	.realbits = 12,
	.storagebits = 16,
	.shift = 4,
	.endianness = IIO_BE,
	}
	},
	IIO_CHAN_SOFT_TIMESTAMP(2),
	};

	static const struct iio_info mpl3115_info = {
	.read_raw = &mpl3115_read_raw,
	};

	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_CTRL_RESET);
	msleep(50);

	data->ctrl_reg1 = MPL3115_CTRL_OS_258MS;
	ret = i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
	data->ctrl_reg1);
	if (ret < 0)
	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_CTRL_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");