drivers/iio/proximity/pulsedlight-lidar-lite-v2.c - kernel/bruno - Git at Google

 /*
  * pulsedlight-lidar-lite-v2.c - Support for PulsedLight LIDAR sensor
  *
  * Copyright (C) 2015 Matt Ranostay <mranostay@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * TODO: runtime pm, interrupt mode, and signal strength reporting
  */

 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/trigger.h>
 #include <linux/iio/triggered_buffer.h>
 #include <linux/iio/trigger_consumer.h>

 #define LIDAR_REG_CONTROL		0x00
 #define LIDAR_REG_CONTROL_ACQUIRE	BIT(2)

 #define LIDAR_REG_STATUS		0x01
 #define LIDAR_REG_STATUS_INVALID	BIT(3)
 #define LIDAR_REG_STATUS_READY		BIT(0)

 #define LIDAR_REG_DATA_HBYTE	0x0f
 #define LIDAR_REG_DATA_LBYTE	0x10

 #define LIDAR_DRV_NAME "lidar"

 struct lidar_data {
 	struct iio_dev *indio_dev;
 	struct i2c_client *client;

 	u16 buffer[8]; /* 2 byte distance + 8 byte timestamp */
 };

 static const struct iio_chan_spec lidar_channels[] = {
 	{
 		.type = IIO_DISTANCE,
 		.info_mask_separate =
 			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
 		.scan_index = 0,
 		.scan_type = {
 			.sign = 'u',
 			.realbits = 16,
 			.storagebits = 16,
 		},
 	},
 	IIO_CHAN_SOFT_TIMESTAMP(1),
 };

 static int lidar_read_byte(struct lidar_data *data, int reg)
 {
 	struct i2c_client *client = data->client;
 	int ret;

 	/*
 	 * Device needs a STOP condition between address write, and data read
 	 * so in turn i2c_smbus_read_byte_data cannot be used
 	 */

 	ret = i2c_smbus_write_byte(client, reg);
 	if (ret < 0) {
 		dev_err(&client->dev, "cannot write addr value");
 		return ret;
 	}

 	ret = i2c_smbus_read_byte(client);
 	if (ret < 0)
 		dev_err(&client->dev, "cannot read data value");

 	return ret;
 }

 static inline int lidar_write_control(struct lidar_data *data, int val)
 {
 	return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL, val);
 }

 static int lidar_read_measurement(struct lidar_data *data, u16 *reg)
 {
 	int ret;
 	int val;

 	ret = lidar_read_byte(data, LIDAR_REG_DATA_HBYTE);
 	if (ret < 0)
 		return ret;
 	val = ret << 8;

 	ret = lidar_read_byte(data, LIDAR_REG_DATA_LBYTE);
 	if (ret < 0)
 		return ret;

 	val |= ret;
 	*reg = val;

 	return 0;
 }

 static int lidar_get_measurement(struct lidar_data *data, u16 *reg)
 {
 	struct i2c_client *client = data->client;
 	int tries = 10;
 	int ret;

 	/* start sample */
 	ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE);
 	if (ret < 0) {
 		dev_err(&client->dev, "cannot send start measurement command");
 		return ret;
 	}

 	while (tries--) {
 		usleep_range(1000, 2000);

 		ret = lidar_read_byte(data, LIDAR_REG_STATUS);
 		if (ret < 0)
 			break;

 		/* return -EINVAL since laser is likely pointed out of range */
 		if (ret & LIDAR_REG_STATUS_INVALID) {
 			*reg = 0;
 			ret = -EINVAL;
 			break;
 		}

 		/* sample ready to read */
 		if (!(ret & LIDAR_REG_STATUS_READY)) {
 			ret = lidar_read_measurement(data, reg);
 			break;
 		}
 		ret = -EIO;
 	}

 	return ret;
 }

 static int lidar_read_raw(struct iio_dev *indio_dev,
 			  struct iio_chan_spec const *chan,
 			  int *val, int *val2, long mask)
 {
 	struct lidar_data *data = iio_priv(indio_dev);
 	int ret = -EINVAL;

 	mutex_lock(&indio_dev->mlock);

 	if (iio_buffer_enabled(indio_dev) && mask == IIO_CHAN_INFO_RAW) {
 		ret = -EBUSY;
 		goto error_busy;
 	}

 	switch (mask) {
 	case IIO_CHAN_INFO_RAW: {
 		u16 reg;

 		ret = lidar_get_measurement(data, &reg);
 		if (!ret) {
 			*val = reg;
 			ret = IIO_VAL_INT;
 		}
 		break;
 	}
 	case IIO_CHAN_INFO_SCALE:
 		*val = 0;
 		*val2 = 10000;
 		ret = IIO_VAL_INT_PLUS_MICRO;
 		break;
 	}

 error_busy:
 	mutex_unlock(&indio_dev->mlock);

 	return ret;
 }

 static irqreturn_t lidar_trigger_handler(int irq, void *private)
 {
 	struct iio_poll_func *pf = private;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct lidar_data *data = iio_priv(indio_dev);
 	int ret;

 	ret = lidar_get_measurement(data, data->buffer);
 	if (!ret) {
 		iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
 						   iio_get_time_ns());
 	} else if (ret != -EINVAL) {
 		dev_err(&data->client->dev, "cannot read LIDAR measurement");
 	}

 	iio_trigger_notify_done(indio_dev->trig);

 	return IRQ_HANDLED;
 }

 static const struct iio_info lidar_info = {
 	.driver_module = THIS_MODULE,
 	.read_raw = lidar_read_raw,
 };

 static int lidar_probe(struct i2c_client *client,
 		       const struct i2c_device_id *id)
 {
 	struct lidar_data *data;
 	struct iio_dev *indio_dev;
 	int ret;

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

 	indio_dev->info = &lidar_info;
 	indio_dev->name = LIDAR_DRV_NAME;
 	indio_dev->channels = lidar_channels;
 	indio_dev->num_channels = ARRAY_SIZE(lidar_channels);
 	indio_dev->modes = INDIO_DIRECT_MODE;

 	data = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);

 	data->client = client;
 	data->indio_dev = indio_dev;

 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
 					 lidar_trigger_handler, NULL);
 	if (ret)
 		return ret;

 	ret = iio_device_register(indio_dev);
 	if (ret)
 		goto error_unreg_buffer;

 	return 0;

 error_unreg_buffer:
 	iio_triggered_buffer_cleanup(indio_dev);

 	return ret;
 }

 static int lidar_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);

 	return 0;
 }

 static const struct i2c_device_id lidar_id[] = {
 	{"lidar-lite-v2", 0},
 	{ },
 };
 MODULE_DEVICE_TABLE(i2c, lidar_id);

 static const struct of_device_id lidar_dt_ids[] = {
 	{ .compatible = "pulsedlight,lidar-lite-v2" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, lidar_dt_ids);

 static struct i2c_driver lidar_driver = {
 	.driver = {
 		.name	= LIDAR_DRV_NAME,
 		.of_match_table	= of_match_ptr(lidar_dt_ids),
 	},
 	.probe		= lidar_probe,
 	.remove		= lidar_remove,
 	.id_table	= lidar_id,
 };
 module_i2c_driver(lidar_driver);

 MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
 MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
 MODULE_LICENSE("GPL");
	/*
	* pulsedlight-lidar-lite-v2.c - Support for PulsedLight LIDAR sensor
	*
	* Copyright (C) 2015 Matt Ranostay <mranostay@gmail.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* TODO: runtime pm, interrupt mode, and signal strength reporting
	*/

	#include <linux/err.h>
	#include <linux/init.h>
	#include <linux/i2c.h>
	#include <linux/delay.h>
	#include <linux/module.h>
	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>
	#include <linux/iio/buffer.h>
	#include <linux/iio/trigger.h>
	#include <linux/iio/triggered_buffer.h>
	#include <linux/iio/trigger_consumer.h>

	#define LIDAR_REG_CONTROL 0x00
	#define LIDAR_REG_CONTROL_ACQUIRE BIT(2)

	#define LIDAR_REG_STATUS 0x01
	#define LIDAR_REG_STATUS_INVALID BIT(3)
	#define LIDAR_REG_STATUS_READY BIT(0)

	#define LIDAR_REG_DATA_HBYTE 0x0f
	#define LIDAR_REG_DATA_LBYTE 0x10

	#define LIDAR_DRV_NAME "lidar"

	struct lidar_data {
	struct iio_dev *indio_dev;
	struct i2c_client *client;

	u16 buffer[8]; /* 2 byte distance + 8 byte timestamp */
	};

	static const struct iio_chan_spec lidar_channels[] = {
	{
	.type = IIO_DISTANCE,
	.info_mask_separate =
	BIT(IIO_CHAN_INFO_RAW) \| BIT(IIO_CHAN_INFO_SCALE),
	.scan_index = 0,
	.scan_type = {
	.sign = 'u',
	.realbits = 16,
	.storagebits = 16,
	},
	},
	IIO_CHAN_SOFT_TIMESTAMP(1),
	};

	static int lidar_read_byte(struct lidar_data *data, int reg)
	{
	struct i2c_client *client = data->client;
	int ret;

	/*
	* Device needs a STOP condition between address write, and data read
	* so in turn i2c_smbus_read_byte_data cannot be used
	*/

	ret = i2c_smbus_write_byte(client, reg);
	if (ret < 0) {
	dev_err(&client->dev, "cannot write addr value");
	return ret;
	}

	ret = i2c_smbus_read_byte(client);
	if (ret < 0)
	dev_err(&client->dev, "cannot read data value");

	return ret;
	}

	static inline int lidar_write_control(struct lidar_data *data, int val)
	{
	return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL, val);
	}

	static int lidar_read_measurement(struct lidar_data data, u16 reg)
	{
	int ret;
	int val;

	ret = lidar_read_byte(data, LIDAR_REG_DATA_HBYTE);
	if (ret < 0)
	return ret;
	val = ret << 8;

	ret = lidar_read_byte(data, LIDAR_REG_DATA_LBYTE);
	if (ret < 0)
	return ret;

	val \|= ret;
	*reg = val;

	return 0;
	}

	static int lidar_get_measurement(struct lidar_data data, u16 reg)
	{
	struct i2c_client *client = data->client;
	int tries = 10;
	int ret;

	/* start sample */
	ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE);
	if (ret < 0) {
	dev_err(&client->dev, "cannot send start measurement command");
	return ret;
	}

	while (tries--) {
	usleep_range(1000, 2000);

	ret = lidar_read_byte(data, LIDAR_REG_STATUS);
	if (ret < 0)
	break;

	/* return -EINVAL since laser is likely pointed out of range */
	if (ret & LIDAR_REG_STATUS_INVALID) {
	*reg = 0;
	ret = -EINVAL;
	break;
	}

	/* sample ready to read */
	if (!(ret & LIDAR_REG_STATUS_READY)) {
	ret = lidar_read_measurement(data, reg);
	break;
	}
	ret = -EIO;
	}

	return ret;
	}

	static int lidar_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct lidar_data *data = iio_priv(indio_dev);
	int ret = -EINVAL;

	mutex_lock(&indio_dev->mlock);

	if (iio_buffer_enabled(indio_dev) && mask == IIO_CHAN_INFO_RAW) {
	ret = -EBUSY;
	goto error_busy;
	}

	switch (mask) {
	case IIO_CHAN_INFO_RAW: {
	u16 reg;

	ret = lidar_get_measurement(data, &reg);
	if (!ret) {
	*val = reg;
	ret = IIO_VAL_INT;
	}
	break;
	}
	case IIO_CHAN_INFO_SCALE:
	*val = 0;
	*val2 = 10000;
	ret = IIO_VAL_INT_PLUS_MICRO;
	break;
	}

	error_busy:
	mutex_unlock(&indio_dev->mlock);

	return ret;
	}

	static irqreturn_t lidar_trigger_handler(int irq, void *private)
	{
	struct iio_poll_func *pf = private;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct lidar_data *data = iio_priv(indio_dev);
	int ret;

	ret = lidar_get_measurement(data, data->buffer);
	if (!ret) {
	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
	iio_get_time_ns());
	} else if (ret != -EINVAL) {
	dev_err(&data->client->dev, "cannot read LIDAR measurement");
	}

	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
	}

	static const struct iio_info lidar_info = {
	.driver_module = THIS_MODULE,
	.read_raw = lidar_read_raw,
	};

	static int lidar_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct lidar_data *data;
	struct iio_dev *indio_dev;
	int ret;

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

	indio_dev->info = &lidar_info;
	indio_dev->name = LIDAR_DRV_NAME;
	indio_dev->channels = lidar_channels;
	indio_dev->num_channels = ARRAY_SIZE(lidar_channels);
	indio_dev->modes = INDIO_DIRECT_MODE;

	data = iio_priv(indio_dev);
	i2c_set_clientdata(client, indio_dev);

	data->client = client;
	data->indio_dev = indio_dev;

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
	lidar_trigger_handler, NULL);
	if (ret)
	return ret;

	ret = iio_device_register(indio_dev);
	if (ret)
	goto error_unreg_buffer;

	return 0;

	error_unreg_buffer:
	iio_triggered_buffer_cleanup(indio_dev);

	return ret;
	}

	static int lidar_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);

	return 0;
	}

	static const struct i2c_device_id lidar_id[] = {
	{"lidar-lite-v2", 0},
	{ },
	};
	MODULE_DEVICE_TABLE(i2c, lidar_id);

	static const struct of_device_id lidar_dt_ids[] = {
	{ .compatible = "pulsedlight,lidar-lite-v2" },
	{ }
	};
	MODULE_DEVICE_TABLE(of, lidar_dt_ids);

	static struct i2c_driver lidar_driver = {
	.driver = {
	.name = LIDAR_DRV_NAME,
	.of_match_table = of_match_ptr(lidar_dt_ids),
	},
	.probe = lidar_probe,
	.remove = lidar_remove,
	.id_table = lidar_id,
	};
	module_i2c_driver(lidar_driver);

	MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
	MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
	MODULE_LICENSE("GPL");