drivers/iio/chemical/sps30.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Sensirion SPS30 particulate matter sensor driver
  *
  * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
  */

 #include <linux/crc8.h>
 #include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/triggered_buffer.h>
 #include <linux/kernel.h>
 #include <linux/module.h>

 #include "sps30.h"

 /* sensor measures reliably up to 3000 ug / m3 */
 #define SPS30_MAX_PM 3000
 /* minimum and maximum self cleaning periods in seconds */
 #define SPS30_AUTO_CLEANING_PERIOD_MIN 0
 #define SPS30_AUTO_CLEANING_PERIOD_MAX 604800

 enum {
 	PM1,
 	PM2P5,
 	PM4,
 	PM10,
 };

 enum {
 	RESET,
 	MEASURING,
 };

 static s32 sps30_float_to_int_clamped(__be32 *fp)
 {
 	int val = be32_to_cpup(fp);
 	int mantissa = val & GENMASK(22, 0);
 	/* this is fine since passed float is always non-negative */
 	int exp = val >> 23;
 	int fraction, shift;

 	/* special case 0 */
 	if (!exp && !mantissa)
 		return 0;

 	exp -= 127;
 	if (exp < 0) {
 		/* return values ranging from 1 to 99 */
 		return ((((1 << 23) + mantissa) * 100) >> 23) >> (-exp);
 	}

 	/* return values ranging from 100 to 300000 */
 	shift = 23 - exp;
 	val = (1 << exp) + (mantissa >> shift);
 	if (val >= SPS30_MAX_PM)
 		return SPS30_MAX_PM * 100;

 	fraction = mantissa & GENMASK(shift - 1, 0);

 	return val * 100 + ((fraction * 100) >> shift);
 }

 static int sps30_do_meas(struct sps30_state *state, s32 *data, int size)
 {
 	int i, ret;

 	if (state->state == RESET) {
 		ret = state->ops->start_meas(state);
 		if (ret)
 			return ret;

 		state->state = MEASURING;
 	}

 	ret = state->ops->read_meas(state, (__be32 *)data, size);
 	if (ret)
 		return ret;

 	for (i = 0; i < size; i++)
 		data[i] = sps30_float_to_int_clamped((__be32 *)&data[i]);

 	return 0;
 }

 static int sps30_do_reset(struct sps30_state *state)
 {
 	int ret;

 	ret = state->ops->reset(state);
 	if (ret)
 		return ret;

 	state->state = RESET;

 	return 0;
 }

 static irqreturn_t sps30_trigger_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct sps30_state *state = iio_priv(indio_dev);
 	int ret;
 	struct {
 		s32 data[4]; /* PM1, PM2P5, PM4, PM10 */
 		s64 ts;
 	} scan;

 	mutex_lock(&state->lock);
 	ret = sps30_do_meas(state, scan.data, ARRAY_SIZE(scan.data));
 	mutex_unlock(&state->lock);
 	if (ret)
 		goto err;

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

 	return IRQ_HANDLED;
 }

 static int sps30_read_raw(struct iio_dev *indio_dev,
 			  struct iio_chan_spec const *chan,
 			  int *val, int *val2, long mask)
 {
 	struct sps30_state *state = iio_priv(indio_dev);
 	int data[4], ret = -EINVAL;

 	switch (mask) {
 	case IIO_CHAN_INFO_PROCESSED:
 		switch (chan->type) {
 		case IIO_MASSCONCENTRATION:
 			mutex_lock(&state->lock);
 			/* read up to the number of bytes actually needed */
 			switch (chan->channel2) {
 			case IIO_MOD_PM1:
 				ret = sps30_do_meas(state, data, 1);
 				break;
 			case IIO_MOD_PM2P5:
 				ret = sps30_do_meas(state, data, 2);
 				break;
 			case IIO_MOD_PM4:
 				ret = sps30_do_meas(state, data, 3);
 				break;
 			case IIO_MOD_PM10:
 				ret = sps30_do_meas(state, data, 4);
 				break;
 			}
 			mutex_unlock(&state->lock);
 			if (ret)
 				return ret;

 			*val = data[chan->address] / 100;
 			*val2 = (data[chan->address] % 100) * 10000;

 			return IIO_VAL_INT_PLUS_MICRO;
 		default:
 			return -EINVAL;
 		}
 	case IIO_CHAN_INFO_SCALE:
 		switch (chan->type) {
 		case IIO_MASSCONCENTRATION:
 			switch (chan->channel2) {
 			case IIO_MOD_PM1:
 			case IIO_MOD_PM2P5:
 			case IIO_MOD_PM4:
 			case IIO_MOD_PM10:
 				*val = 0;
 				*val2 = 10000;

 				return IIO_VAL_INT_PLUS_MICRO;
 			default:
 				return -EINVAL;
 			}
 		default:
 			return -EINVAL;
 		}
 	}

 	return -EINVAL;
 }

 static ssize_t start_cleaning_store(struct device *dev,
 				    struct device_attribute *attr,
 				    const char *buf, size_t len)
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct sps30_state *state = iio_priv(indio_dev);
 	int val, ret;

 	if (kstrtoint(buf, 0, &val) || val != 1)
 		return -EINVAL;

 	mutex_lock(&state->lock);
 	ret = state->ops->clean_fan(state);
 	mutex_unlock(&state->lock);
 	if (ret)
 		return ret;

 	return len;
 }

 static ssize_t cleaning_period_show(struct device *dev,
 				    struct device_attribute *attr,
 				    char *buf)
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct sps30_state *state = iio_priv(indio_dev);
 	__be32 val;
 	int ret;

 	mutex_lock(&state->lock);
 	ret = state->ops->read_cleaning_period(state, &val);
 	mutex_unlock(&state->lock);
 	if (ret)
 		return ret;

 	return sprintf(buf, "%d\n", be32_to_cpu(val));
 }

 static ssize_t cleaning_period_store(struct device *dev, struct device_attribute *attr,
 				     const char *buf, size_t len)
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct sps30_state *state = iio_priv(indio_dev);
 	int val, ret;

 	if (kstrtoint(buf, 0, &val))
 		return -EINVAL;

 	if ((val < SPS30_AUTO_CLEANING_PERIOD_MIN) ||
 	    (val > SPS30_AUTO_CLEANING_PERIOD_MAX))
 		return -EINVAL;

 	mutex_lock(&state->lock);
 	ret = state->ops->write_cleaning_period(state, cpu_to_be32(val));
 	if (ret) {
 		mutex_unlock(&state->lock);
 		return ret;
 	}

 	msleep(20);

 	/*
 	 * sensor requires reset in order to return up to date self cleaning
 	 * period
 	 */
 	ret = sps30_do_reset(state);
 	if (ret)
 		dev_warn(dev,
 			 "period changed but reads will return the old value\n");

 	mutex_unlock(&state->lock);

 	return len;
 }

 static ssize_t cleaning_period_available_show(struct device *dev,
 					      struct device_attribute *attr,
 					      char *buf)
 {
 	return sysfs_emit(buf, "[%d %d %d]\n",
 			  SPS30_AUTO_CLEANING_PERIOD_MIN, 1,
 			  SPS30_AUTO_CLEANING_PERIOD_MAX);
 }

 static IIO_DEVICE_ATTR_WO(start_cleaning, 0);
 static IIO_DEVICE_ATTR_RW(cleaning_period, 0);
 static IIO_DEVICE_ATTR_RO(cleaning_period_available, 0);

 static struct attribute *sps30_attrs[] = {
 	&iio_dev_attr_start_cleaning.dev_attr.attr,
 	&iio_dev_attr_cleaning_period.dev_attr.attr,
 	&iio_dev_attr_cleaning_period_available.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group sps30_attr_group = {
 	.attrs = sps30_attrs,
 };

 static const struct iio_info sps30_info = {
 	.attrs = &sps30_attr_group,
 	.read_raw = sps30_read_raw,
 };

 #define SPS30_CHAN(_index, _mod) { \
 	.type = IIO_MASSCONCENTRATION, \
 	.modified = 1, \
 	.channel2 = IIO_MOD_ ## _mod, \
 	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
 	.address = _mod, \
 	.scan_index = _index, \
 	.scan_type = { \
 		.sign = 'u', \
 		.realbits = 19, \
 		.storagebits = 32, \
 		.endianness = IIO_CPU, \
 	}, \
 }

 static const struct iio_chan_spec sps30_channels[] = {
 	SPS30_CHAN(0, PM1),
 	SPS30_CHAN(1, PM2P5),
 	SPS30_CHAN(2, PM4),
 	SPS30_CHAN(3, PM10),
 	IIO_CHAN_SOFT_TIMESTAMP(4),
 };

 static void sps30_devm_stop_meas(void *data)
 {
 	struct sps30_state *state = data;

 	if (state->state == MEASURING)
 		state->ops->stop_meas(state);
 }

 static const unsigned long sps30_scan_masks[] = { 0x0f, 0x00 };

 int sps30_probe(struct device *dev, const char *name, void *priv, const struct sps30_ops *ops)
 {
 	struct iio_dev *indio_dev;
 	struct sps30_state *state;
 	int ret;

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

 	dev_set_drvdata(dev, indio_dev);

 	state = iio_priv(indio_dev);
 	state->dev = dev;
 	state->priv = priv;
 	state->ops = ops;
 	mutex_init(&state->lock);

 	indio_dev->info = &sps30_info;
 	indio_dev->name = name;
 	indio_dev->channels = sps30_channels;
 	indio_dev->num_channels = ARRAY_SIZE(sps30_channels);
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->available_scan_masks = sps30_scan_masks;

 	ret = sps30_do_reset(state);
 	if (ret) {
 		dev_err(dev, "failed to reset device\n");
 		return ret;
 	}

 	ret = state->ops->show_info(state);
 	if (ret) {
 		dev_err(dev, "failed to read device info\n");
 		return ret;
 	}

 	ret = devm_add_action_or_reset(dev, sps30_devm_stop_meas, state);
 	if (ret)
 		return ret;

 	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
 					      sps30_trigger_handler, NULL);
 	if (ret)
 		return ret;

 	return devm_iio_device_register(dev, indio_dev);
 }
 EXPORT_SYMBOL_GPL(sps30_probe);

 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
 MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Sensirion SPS30 particulate matter sensor driver
	*
	* Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
	*/

	#include <linux/crc8.h>
	#include <linux/delay.h>
	#include <linux/i2c.h>
	#include <linux/iio/buffer.h>
	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>
	#include <linux/iio/trigger_consumer.h>
	#include <linux/iio/triggered_buffer.h>
	#include <linux/kernel.h>
	#include <linux/module.h>

	#include "sps30.h"

	/* sensor measures reliably up to 3000 ug / m3 */
	#define SPS30_MAX_PM 3000
	/* minimum and maximum self cleaning periods in seconds */
	#define SPS30_AUTO_CLEANING_PERIOD_MIN 0
	#define SPS30_AUTO_CLEANING_PERIOD_MAX 604800

	enum {
	PM1,
	PM2P5,
	PM4,
	PM10,
	};

	enum {
	RESET,
	MEASURING,
	};

	static s32 sps30_float_to_int_clamped(__be32 *fp)
	{
	int val = be32_to_cpup(fp);
	int mantissa = val & GENMASK(22, 0);
	/* this is fine since passed float is always non-negative */
	int exp = val >> 23;
	int fraction, shift;

	/* special case 0 */
	if (!exp && !mantissa)
	return 0;

	exp -= 127;
	if (exp < 0) {
	/* return values ranging from 1 to 99 */
	return ((((1 << 23) + mantissa) * 100) >> 23) >> (-exp);
	}

	/* return values ranging from 100 to 300000 */
	shift = 23 - exp;
	val = (1 << exp) + (mantissa >> shift);
	if (val >= SPS30_MAX_PM)
	return SPS30_MAX_PM * 100;

	fraction = mantissa & GENMASK(shift - 1, 0);

	return val * 100 + ((fraction * 100) >> shift);
	}

	static int sps30_do_meas(struct sps30_state state, s32 data, int size)
	{
	int i, ret;

	if (state->state == RESET) {
	ret = state->ops->start_meas(state);
	if (ret)
	return ret;

	state->state = MEASURING;
	}

	ret = state->ops->read_meas(state, (__be32 *)data, size);
	if (ret)
	return ret;

	for (i = 0; i < size; i++)
	data[i] = sps30_float_to_int_clamped((__be32 *)&data[i]);

	return 0;
	}

	static int sps30_do_reset(struct sps30_state *state)
	{
	int ret;

	ret = state->ops->reset(state);
	if (ret)
	return ret;

	state->state = RESET;

	return 0;
	}

	static irqreturn_t sps30_trigger_handler(int irq, void *p)
	{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct sps30_state *state = iio_priv(indio_dev);
	int ret;
	struct {
	s32 data[4]; /* PM1, PM2P5, PM4, PM10 */
	s64 ts;
	} scan;

	mutex_lock(&state->lock);
	ret = sps30_do_meas(state, scan.data, ARRAY_SIZE(scan.data));
	mutex_unlock(&state->lock);
	if (ret)
	goto err;

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

	return IRQ_HANDLED;
	}

	static int sps30_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct sps30_state *state = iio_priv(indio_dev);
	int data[4], ret = -EINVAL;

	switch (mask) {
	case IIO_CHAN_INFO_PROCESSED:
	switch (chan->type) {
	case IIO_MASSCONCENTRATION:
	mutex_lock(&state->lock);
	/* read up to the number of bytes actually needed */
	switch (chan->channel2) {
	case IIO_MOD_PM1:
	ret = sps30_do_meas(state, data, 1);
	break;
	case IIO_MOD_PM2P5:
	ret = sps30_do_meas(state, data, 2);
	break;
	case IIO_MOD_PM4:
	ret = sps30_do_meas(state, data, 3);
	break;
	case IIO_MOD_PM10:
	ret = sps30_do_meas(state, data, 4);
	break;
	}
	mutex_unlock(&state->lock);
	if (ret)
	return ret;

	*val = data[chan->address] / 100;
	val2 = (data[chan->address] % 100) 10000;

	return IIO_VAL_INT_PLUS_MICRO;
	default:
	return -EINVAL;
	}
	case IIO_CHAN_INFO_SCALE:
	switch (chan->type) {
	case IIO_MASSCONCENTRATION:
	switch (chan->channel2) {
	case IIO_MOD_PM1:
	case IIO_MOD_PM2P5:
	case IIO_MOD_PM4:
	case IIO_MOD_PM10:
	*val = 0;
	*val2 = 10000;

	return IIO_VAL_INT_PLUS_MICRO;
	default:
	return -EINVAL;
	}
	default:
	return -EINVAL;
	}
	}

	return -EINVAL;
	}

	static ssize_t start_cleaning_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t len)
	{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct sps30_state *state = iio_priv(indio_dev);
	int val, ret;

	if (kstrtoint(buf, 0, &val) \|\| val != 1)
	return -EINVAL;

	mutex_lock(&state->lock);
	ret = state->ops->clean_fan(state);
	mutex_unlock(&state->lock);
	if (ret)
	return ret;

	return len;
	}

	static ssize_t cleaning_period_show(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct sps30_state *state = iio_priv(indio_dev);
	__be32 val;
	int ret;

	mutex_lock(&state->lock);
	ret = state->ops->read_cleaning_period(state, &val);
	mutex_unlock(&state->lock);
	if (ret)
	return ret;

	return sprintf(buf, "%d\n", be32_to_cpu(val));
	}

	static ssize_t cleaning_period_store(struct device dev, struct device_attribute attr,
	const char *buf, size_t len)
	{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct sps30_state *state = iio_priv(indio_dev);
	int val, ret;

	if (kstrtoint(buf, 0, &val))
	return -EINVAL;

	if ((val < SPS30_AUTO_CLEANING_PERIOD_MIN) \|\|
	(val > SPS30_AUTO_CLEANING_PERIOD_MAX))
	return -EINVAL;

	mutex_lock(&state->lock);
	ret = state->ops->write_cleaning_period(state, cpu_to_be32(val));
	if (ret) {
	mutex_unlock(&state->lock);
	return ret;
	}

	msleep(20);

	/*
	* sensor requires reset in order to return up to date self cleaning
	* period
	*/
	ret = sps30_do_reset(state);
	if (ret)
	dev_warn(dev,
	"period changed but reads will return the old value\n");

	mutex_unlock(&state->lock);

	return len;
	}

	static ssize_t cleaning_period_available_show(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	return sysfs_emit(buf, "[%d %d %d]\n",
	SPS30_AUTO_CLEANING_PERIOD_MIN, 1,
	SPS30_AUTO_CLEANING_PERIOD_MAX);
	}

	static IIO_DEVICE_ATTR_WO(start_cleaning, 0);
	static IIO_DEVICE_ATTR_RW(cleaning_period, 0);
	static IIO_DEVICE_ATTR_RO(cleaning_period_available, 0);

	static struct attribute *sps30_attrs[] = {
	&iio_dev_attr_start_cleaning.dev_attr.attr,
	&iio_dev_attr_cleaning_period.dev_attr.attr,
	&iio_dev_attr_cleaning_period_available.dev_attr.attr,
	NULL
	};

	static const struct attribute_group sps30_attr_group = {
	.attrs = sps30_attrs,
	};

	static const struct iio_info sps30_info = {
	.attrs = &sps30_attr_group,
	.read_raw = sps30_read_raw,
	};

	#define SPS30_CHAN(_index, _mod) { \
	.type = IIO_MASSCONCENTRATION, \
	.modified = 1, \
	.channel2 = IIO_MOD_ ## _mod, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
	.address = _mod, \
	.scan_index = _index, \
	.scan_type = { \
	.sign = 'u', \
	.realbits = 19, \
	.storagebits = 32, \
	.endianness = IIO_CPU, \
	}, \
	}

	static const struct iio_chan_spec sps30_channels[] = {
	SPS30_CHAN(0, PM1),
	SPS30_CHAN(1, PM2P5),
	SPS30_CHAN(2, PM4),
	SPS30_CHAN(3, PM10),
	IIO_CHAN_SOFT_TIMESTAMP(4),
	};

	static void sps30_devm_stop_meas(void *data)
	{
	struct sps30_state *state = data;

	if (state->state == MEASURING)
	state->ops->stop_meas(state);
	}

	static const unsigned long sps30_scan_masks[] = { 0x0f, 0x00 };

	int sps30_probe(struct device dev, const char name, void priv, const struct sps30_ops ops)
	{
	struct iio_dev *indio_dev;
	struct sps30_state *state;
	int ret;

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

	dev_set_drvdata(dev, indio_dev);

	state = iio_priv(indio_dev);
	state->dev = dev;
	state->priv = priv;
	state->ops = ops;
	mutex_init(&state->lock);

	indio_dev->info = &sps30_info;
	indio_dev->name = name;
	indio_dev->channels = sps30_channels;
	indio_dev->num_channels = ARRAY_SIZE(sps30_channels);
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->available_scan_masks = sps30_scan_masks;

	ret = sps30_do_reset(state);
	if (ret) {
	dev_err(dev, "failed to reset device\n");
	return ret;
	}

	ret = state->ops->show_info(state);
	if (ret) {
	dev_err(dev, "failed to read device info\n");
	return ret;
	}

	ret = devm_add_action_or_reset(dev, sps30_devm_stop_meas, state);
	if (ret)
	return ret;

	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
	sps30_trigger_handler, NULL);
	if (ret)
	return ret;

	return devm_iio_device_register(dev, indio_dev);
	}
	EXPORT_SYMBOL_GPL(sps30_probe);

	MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
	MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor driver");
	MODULE_LICENSE("GPL v2");