drivers/iio/chemical/pms7003.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Plantower PMS7003 particulate matter sensor driver
  *
  * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
  */

 #include <asm/unaligned.h>
 #include <linux/completion.h>
 #include <linux/device.h>
 #include <linux/errno.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/triggered_buffer.h>
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/serdev.h>

 #define PMS7003_DRIVER_NAME "pms7003"

 #define PMS7003_MAGIC 0x424d
 /* last 2 data bytes hold frame checksum */
 #define PMS7003_MAX_DATA_LENGTH 28
 #define PMS7003_CHECKSUM_LENGTH 2
 #define PMS7003_PM10_OFFSET 10
 #define PMS7003_PM2P5_OFFSET 8
 #define PMS7003_PM1_OFFSET 6

 #define PMS7003_TIMEOUT msecs_to_jiffies(6000)
 #define PMS7003_CMD_LENGTH 7
 #define PMS7003_PM_MAX 1000
 #define PMS7003_PM_MIN 0

 enum {
 	PM1,
 	PM2P5,
 	PM10,
 };

 enum pms7003_cmd {
 	CMD_WAKEUP,
 	CMD_ENTER_PASSIVE_MODE,
 	CMD_READ_PASSIVE,
 	CMD_SLEEP,
 };

 /*
  * commands have following format:
  *
  * +------+------+-----+------+-----+-----------+-----------+
  * | 0x42 | 0x4d | cmd | 0x00 | arg | cksum msb | cksum lsb |
  * +------+------+-----+------+-----+-----------+-----------+
  */
 static const u8 pms7003_cmd_tbl[][PMS7003_CMD_LENGTH] = {
 	[CMD_WAKEUP] = { 0x42, 0x4d, 0xe4, 0x00, 0x01, 0x01, 0x74 },
 	[CMD_ENTER_PASSIVE_MODE] = { 0x42, 0x4d, 0xe1, 0x00, 0x00, 0x01, 0x70 },
 	[CMD_READ_PASSIVE] = { 0x42, 0x4d, 0xe2, 0x00, 0x00, 0x01, 0x71 },
 	[CMD_SLEEP] = { 0x42, 0x4d, 0xe4, 0x00, 0x00, 0x01, 0x73 },
 };

 struct pms7003_frame {
 	u8 data[PMS7003_MAX_DATA_LENGTH];
 	u16 expected_length;
 	u16 length;
 };

 struct pms7003_state {
 	struct serdev_device *serdev;
 	struct pms7003_frame frame;
 	struct completion frame_ready;
 	struct mutex lock; /* must be held whenever state gets touched */
 };

 static int pms7003_do_cmd(struct pms7003_state *state, enum pms7003_cmd cmd)
 {
 	int ret;

 	ret = serdev_device_write(state->serdev, pms7003_cmd_tbl[cmd],
 				  PMS7003_CMD_LENGTH, PMS7003_TIMEOUT);
 	if (ret < PMS7003_CMD_LENGTH)
 		return ret < 0 ? ret : -EIO;

 	ret = wait_for_completion_interruptible_timeout(&state->frame_ready,
 							PMS7003_TIMEOUT);
 	if (!ret)
 		ret = -ETIMEDOUT;

 	return ret < 0 ? ret : 0;
 }

 static u16 pms7003_get_pm(const u8 *data)
 {
 	return clamp_val(get_unaligned_be16(data),
 			 PMS7003_PM_MIN, PMS7003_PM_MAX);
 }

 static irqreturn_t pms7003_trigger_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct pms7003_state *state = iio_priv(indio_dev);
 	struct pms7003_frame *frame = &state->frame;
 	u16 data[3 + 1 + 4]; /* PM1, PM2P5, PM10, padding, timestamp */
 	int ret;

 	mutex_lock(&state->lock);
 	ret = pms7003_do_cmd(state, CMD_READ_PASSIVE);
 	if (ret) {
 		mutex_unlock(&state->lock);
 		goto err;
 	}

 	data[PM1] = pms7003_get_pm(frame->data + PMS7003_PM1_OFFSET);
 	data[PM2P5] = pms7003_get_pm(frame->data + PMS7003_PM2P5_OFFSET);
 	data[PM10] = pms7003_get_pm(frame->data + PMS7003_PM10_OFFSET);
 	mutex_unlock(&state->lock);

 	iio_push_to_buffers_with_timestamp(indio_dev, data,
 					   iio_get_time_ns(indio_dev));
 err:
 	iio_trigger_notify_done(indio_dev->trig);

 	return IRQ_HANDLED;
 }

 static int pms7003_read_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
 			    int *val, int *val2, long mask)
 {
 	struct pms7003_state *state = iio_priv(indio_dev);
 	struct pms7003_frame *frame = &state->frame;
 	int ret;

 	switch (mask) {
 	case IIO_CHAN_INFO_PROCESSED:
 		switch (chan->type) {
 		case IIO_MASSCONCENTRATION:
 			mutex_lock(&state->lock);
 			ret = pms7003_do_cmd(state, CMD_READ_PASSIVE);
 			if (ret) {
 				mutex_unlock(&state->lock);
 				return ret;
 			}

 			*val = pms7003_get_pm(frame->data + chan->address);
 			mutex_unlock(&state->lock);

 			return IIO_VAL_INT;
 		default:
 			return -EINVAL;
 		}
 	}

 	return -EINVAL;
 }

 static const struct iio_info pms7003_info = {
 	.read_raw = pms7003_read_raw,
 };

 #define PMS7003_CHAN(_index, _mod, _addr) { \
 	.type = IIO_MASSCONCENTRATION, \
 	.modified = 1, \
 	.channel2 = IIO_MOD_ ## _mod, \
 	.address = _addr, \
 	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
 	.scan_index = _index, \
 	.scan_type = { \
 		.sign = 'u', \
 		.realbits = 10, \
 		.storagebits = 16, \
 		.endianness = IIO_CPU, \
 	}, \
 }

 static const struct iio_chan_spec pms7003_channels[] = {
 	PMS7003_CHAN(0, PM1, PMS7003_PM1_OFFSET),
 	PMS7003_CHAN(1, PM2P5, PMS7003_PM2P5_OFFSET),
 	PMS7003_CHAN(2, PM10, PMS7003_PM10_OFFSET),
 	IIO_CHAN_SOFT_TIMESTAMP(3),
 };

 static u16 pms7003_calc_checksum(struct pms7003_frame *frame)
 {
 	u16 checksum = (PMS7003_MAGIC >> 8) + (u8)(PMS7003_MAGIC & 0xff) +
 		       (frame->length >> 8) + (u8)frame->length;
 	int i;

 	for (i = 0; i < frame->length - PMS7003_CHECKSUM_LENGTH; i++)
 		checksum += frame->data[i];

 	return checksum;
 }

 static bool pms7003_frame_is_okay(struct pms7003_frame *frame)
 {
 	int offset = frame->length - PMS7003_CHECKSUM_LENGTH;
 	u16 checksum = get_unaligned_be16(frame->data + offset);

 	return checksum == pms7003_calc_checksum(frame);
 }

 static int pms7003_receive_buf(struct serdev_device *serdev,
 			       const unsigned char *buf, size_t size)
 {
 	struct iio_dev *indio_dev = serdev_device_get_drvdata(serdev);
 	struct pms7003_state *state = iio_priv(indio_dev);
 	struct pms7003_frame *frame = &state->frame;
 	int num;

 	if (!frame->expected_length) {
 		u16 magic;

 		/* wait for SOF and data length */
 		if (size < 4)
 			return 0;

 		magic = get_unaligned_be16(buf);
 		if (magic != PMS7003_MAGIC)
 			return 2;

 		num = get_unaligned_be16(buf + 2);
 		if (num <= PMS7003_MAX_DATA_LENGTH) {
 			frame->expected_length = num;
 			frame->length = 0;
 		}

 		return 4;
 	}

 	num = min(size, (size_t)(frame->expected_length - frame->length));
 	memcpy(frame->data + frame->length, buf, num);
 	frame->length += num;

 	if (frame->length == frame->expected_length) {
 		if (pms7003_frame_is_okay(frame))
 			complete(&state->frame_ready);

 		frame->expected_length = 0;
 	}

 	return num;
 }

 static const struct serdev_device_ops pms7003_serdev_ops = {
 	.receive_buf = pms7003_receive_buf,
 	.write_wakeup = serdev_device_write_wakeup,
 };

 static void pms7003_stop(void *data)
 {
 	struct pms7003_state *state = data;

 	pms7003_do_cmd(state, CMD_SLEEP);
 }

 static const unsigned long pms7003_scan_masks[] = { 0x07, 0x00 };

 static int pms7003_probe(struct serdev_device *serdev)
 {
 	struct pms7003_state *state;
 	struct iio_dev *indio_dev;
 	int ret;

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

 	state = iio_priv(indio_dev);
 	serdev_device_set_drvdata(serdev, indio_dev);
 	state->serdev = serdev;
 	indio_dev->dev.parent = &serdev->dev;
 	indio_dev->info = &pms7003_info;
 	indio_dev->name = PMS7003_DRIVER_NAME;
 	indio_dev->channels = pms7003_channels,
 	indio_dev->num_channels = ARRAY_SIZE(pms7003_channels);
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->available_scan_masks = pms7003_scan_masks;

 	mutex_init(&state->lock);
 	init_completion(&state->frame_ready);

 	serdev_device_set_client_ops(serdev, &pms7003_serdev_ops);
 	ret = devm_serdev_device_open(&serdev->dev, serdev);
 	if (ret)
 		return ret;

 	serdev_device_set_baudrate(serdev, 9600);
 	serdev_device_set_flow_control(serdev, false);

 	ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE);
 	if (ret)
 		return ret;

 	ret = pms7003_do_cmd(state, CMD_WAKEUP);
 	if (ret) {
 		dev_err(&serdev->dev, "failed to wakeup sensor\n");
 		return ret;
 	}

 	ret = pms7003_do_cmd(state, CMD_ENTER_PASSIVE_MODE);
 	if (ret) {
 		dev_err(&serdev->dev, "failed to enter passive mode\n");
 		return ret;
 	}

 	ret = devm_add_action_or_reset(&serdev->dev, pms7003_stop, state);
 	if (ret)
 		return ret;

 	ret = devm_iio_triggered_buffer_setup(&serdev->dev, indio_dev, NULL,
 					      pms7003_trigger_handler, NULL);
 	if (ret)
 		return ret;

 	return devm_iio_device_register(&serdev->dev, indio_dev);
 }

 static const struct of_device_id pms7003_of_match[] = {
 	{ .compatible = "plantower,pms7003" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, pms7003_of_match);

 static struct serdev_device_driver pms7003_driver = {
 	.driver = {
 		.name = PMS7003_DRIVER_NAME,
 		.of_match_table = pms7003_of_match,
 	},
 	.probe = pms7003_probe,
 };
 module_serdev_device_driver(pms7003_driver);

 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
 MODULE_DESCRIPTION("Plantower PMS7003 particulate matter sensor driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Plantower PMS7003 particulate matter sensor driver
	*
	* Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
	*/

	#include <asm/unaligned.h>
	#include <linux/completion.h>
	#include <linux/device.h>
	#include <linux/errno.h>
	#include <linux/iio/buffer.h>
	#include <linux/iio/iio.h>
	#include <linux/iio/trigger_consumer.h>
	#include <linux/iio/triggered_buffer.h>
	#include <linux/jiffies.h>
	#include <linux/kernel.h>
	#include <linux/mod_devicetable.h>
	#include <linux/module.h>
	#include <linux/mutex.h>
	#include <linux/serdev.h>

	#define PMS7003_DRIVER_NAME "pms7003"

	#define PMS7003_MAGIC 0x424d
	/* last 2 data bytes hold frame checksum */
	#define PMS7003_MAX_DATA_LENGTH 28
	#define PMS7003_CHECKSUM_LENGTH 2
	#define PMS7003_PM10_OFFSET 10
	#define PMS7003_PM2P5_OFFSET 8
	#define PMS7003_PM1_OFFSET 6

	#define PMS7003_TIMEOUT msecs_to_jiffies(6000)
	#define PMS7003_CMD_LENGTH 7
	#define PMS7003_PM_MAX 1000
	#define PMS7003_PM_MIN 0

	enum {
	PM1,
	PM2P5,
	PM10,
	};

	enum pms7003_cmd {
	CMD_WAKEUP,
	CMD_ENTER_PASSIVE_MODE,
	CMD_READ_PASSIVE,
	CMD_SLEEP,
	};

	/*
	* commands have following format:
	*
	* +------+------+-----+------+-----+-----------+-----------+
	* \| 0x42 \| 0x4d \| cmd \| 0x00 \| arg \| cksum msb \| cksum lsb \|
	* +------+------+-----+------+-----+-----------+-----------+
	*/
	static const u8 pms7003_cmd_tbl[][PMS7003_CMD_LENGTH] = {
	[CMD_WAKEUP] = { 0x42, 0x4d, 0xe4, 0x00, 0x01, 0x01, 0x74 },
	[CMD_ENTER_PASSIVE_MODE] = { 0x42, 0x4d, 0xe1, 0x00, 0x00, 0x01, 0x70 },
	[CMD_READ_PASSIVE] = { 0x42, 0x4d, 0xe2, 0x00, 0x00, 0x01, 0x71 },
	[CMD_SLEEP] = { 0x42, 0x4d, 0xe4, 0x00, 0x00, 0x01, 0x73 },
	};

	struct pms7003_frame {
	u8 data[PMS7003_MAX_DATA_LENGTH];
	u16 expected_length;
	u16 length;
	};

	struct pms7003_state {
	struct serdev_device *serdev;
	struct pms7003_frame frame;
	struct completion frame_ready;
	struct mutex lock; /* must be held whenever state gets touched */
	};

	static int pms7003_do_cmd(struct pms7003_state *state, enum pms7003_cmd cmd)
	{
	int ret;

	ret = serdev_device_write(state->serdev, pms7003_cmd_tbl[cmd],
	PMS7003_CMD_LENGTH, PMS7003_TIMEOUT);
	if (ret < PMS7003_CMD_LENGTH)
	return ret < 0 ? ret : -EIO;

	ret = wait_for_completion_interruptible_timeout(&state->frame_ready,
	PMS7003_TIMEOUT);
	if (!ret)
	ret = -ETIMEDOUT;

	return ret < 0 ? ret : 0;
	}

	static u16 pms7003_get_pm(const u8 *data)
	{
	return clamp_val(get_unaligned_be16(data),
	PMS7003_PM_MIN, PMS7003_PM_MAX);
	}

	static irqreturn_t pms7003_trigger_handler(int irq, void *p)
	{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct pms7003_state *state = iio_priv(indio_dev);
	struct pms7003_frame *frame = &state->frame;
	u16 data[3 + 1 + 4]; /* PM1, PM2P5, PM10, padding, timestamp */
	int ret;

	mutex_lock(&state->lock);
	ret = pms7003_do_cmd(state, CMD_READ_PASSIVE);
	if (ret) {
	mutex_unlock(&state->lock);
	goto err;
	}

	data[PM1] = pms7003_get_pm(frame->data + PMS7003_PM1_OFFSET);
	data[PM2P5] = pms7003_get_pm(frame->data + PMS7003_PM2P5_OFFSET);
	data[PM10] = pms7003_get_pm(frame->data + PMS7003_PM10_OFFSET);
	mutex_unlock(&state->lock);

	iio_push_to_buffers_with_timestamp(indio_dev, data,
	iio_get_time_ns(indio_dev));
	err:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
	}

	static int pms7003_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct pms7003_state *state = iio_priv(indio_dev);
	struct pms7003_frame *frame = &state->frame;
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_PROCESSED:
	switch (chan->type) {
	case IIO_MASSCONCENTRATION:
	mutex_lock(&state->lock);
	ret = pms7003_do_cmd(state, CMD_READ_PASSIVE);
	if (ret) {
	mutex_unlock(&state->lock);
	return ret;
	}

	*val = pms7003_get_pm(frame->data + chan->address);
	mutex_unlock(&state->lock);

	return IIO_VAL_INT;
	default:
	return -EINVAL;
	}
	}

	return -EINVAL;
	}

	static const struct iio_info pms7003_info = {
	.read_raw = pms7003_read_raw,
	};

	#define PMS7003_CHAN(_index, _mod, _addr) { \
	.type = IIO_MASSCONCENTRATION, \
	.modified = 1, \
	.channel2 = IIO_MOD_ ## _mod, \
	.address = _addr, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
	.scan_index = _index, \
	.scan_type = { \
	.sign = 'u', \
	.realbits = 10, \
	.storagebits = 16, \
	.endianness = IIO_CPU, \
	}, \
	}

	static const struct iio_chan_spec pms7003_channels[] = {
	PMS7003_CHAN(0, PM1, PMS7003_PM1_OFFSET),
	PMS7003_CHAN(1, PM2P5, PMS7003_PM2P5_OFFSET),
	PMS7003_CHAN(2, PM10, PMS7003_PM10_OFFSET),
	IIO_CHAN_SOFT_TIMESTAMP(3),
	};

	static u16 pms7003_calc_checksum(struct pms7003_frame *frame)
	{
	u16 checksum = (PMS7003_MAGIC >> 8) + (u8)(PMS7003_MAGIC & 0xff) +
	(frame->length >> 8) + (u8)frame->length;
	int i;

	for (i = 0; i < frame->length - PMS7003_CHECKSUM_LENGTH; i++)
	checksum += frame->data[i];

	return checksum;
	}

	static bool pms7003_frame_is_okay(struct pms7003_frame *frame)
	{
	int offset = frame->length - PMS7003_CHECKSUM_LENGTH;
	u16 checksum = get_unaligned_be16(frame->data + offset);

	return checksum == pms7003_calc_checksum(frame);
	}

	static int pms7003_receive_buf(struct serdev_device *serdev,
	const unsigned char *buf, size_t size)
	{
	struct iio_dev *indio_dev = serdev_device_get_drvdata(serdev);
	struct pms7003_state *state = iio_priv(indio_dev);
	struct pms7003_frame *frame = &state->frame;
	int num;

	if (!frame->expected_length) {
	u16 magic;

	/* wait for SOF and data length */
	if (size < 4)
	return 0;

	magic = get_unaligned_be16(buf);
	if (magic != PMS7003_MAGIC)
	return 2;

	num = get_unaligned_be16(buf + 2);
	if (num <= PMS7003_MAX_DATA_LENGTH) {
	frame->expected_length = num;
	frame->length = 0;
	}

	return 4;
	}

	num = min(size, (size_t)(frame->expected_length - frame->length));
	memcpy(frame->data + frame->length, buf, num);
	frame->length += num;

	if (frame->length == frame->expected_length) {
	if (pms7003_frame_is_okay(frame))
	complete(&state->frame_ready);

	frame->expected_length = 0;
	}

	return num;
	}

	static const struct serdev_device_ops pms7003_serdev_ops = {
	.receive_buf = pms7003_receive_buf,
	.write_wakeup = serdev_device_write_wakeup,
	};

	static void pms7003_stop(void *data)
	{
	struct pms7003_state *state = data;

	pms7003_do_cmd(state, CMD_SLEEP);
	}

	static const unsigned long pms7003_scan_masks[] = { 0x07, 0x00 };

	static int pms7003_probe(struct serdev_device *serdev)
	{
	struct pms7003_state *state;
	struct iio_dev *indio_dev;
	int ret;

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

	state = iio_priv(indio_dev);
	serdev_device_set_drvdata(serdev, indio_dev);
	state->serdev = serdev;
	indio_dev->dev.parent = &serdev->dev;
	indio_dev->info = &pms7003_info;
	indio_dev->name = PMS7003_DRIVER_NAME;
	indio_dev->channels = pms7003_channels,
	indio_dev->num_channels = ARRAY_SIZE(pms7003_channels);
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->available_scan_masks = pms7003_scan_masks;

	mutex_init(&state->lock);
	init_completion(&state->frame_ready);

	serdev_device_set_client_ops(serdev, &pms7003_serdev_ops);
	ret = devm_serdev_device_open(&serdev->dev, serdev);
	if (ret)
	return ret;

	serdev_device_set_baudrate(serdev, 9600);
	serdev_device_set_flow_control(serdev, false);

	ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE);
	if (ret)
	return ret;

	ret = pms7003_do_cmd(state, CMD_WAKEUP);
	if (ret) {
	dev_err(&serdev->dev, "failed to wakeup sensor\n");
	return ret;
	}

	ret = pms7003_do_cmd(state, CMD_ENTER_PASSIVE_MODE);
	if (ret) {
	dev_err(&serdev->dev, "failed to enter passive mode\n");
	return ret;
	}

	ret = devm_add_action_or_reset(&serdev->dev, pms7003_stop, state);
	if (ret)
	return ret;

	ret = devm_iio_triggered_buffer_setup(&serdev->dev, indio_dev, NULL,
	pms7003_trigger_handler, NULL);
	if (ret)
	return ret;

	return devm_iio_device_register(&serdev->dev, indio_dev);
	}

	static const struct of_device_id pms7003_of_match[] = {
	{ .compatible = "plantower,pms7003" },
	{ }
	};
	MODULE_DEVICE_TABLE(of, pms7003_of_match);

	static struct serdev_device_driver pms7003_driver = {
	.driver = {
	.name = PMS7003_DRIVER_NAME,
	.of_match_table = pms7003_of_match,
	},
	.probe = pms7003_probe,
	};
	module_serdev_device_driver(pms7003_driver);

	MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
	MODULE_DESCRIPTION("Plantower PMS7003 particulate matter sensor driver");
	MODULE_LICENSE("GPL v2");