1 files changed, 379 insertions, 0 deletions
diff --git a/drivers/iio/chemical/sps30.c b/drivers/iio/chemical/sps30.c
new file mode 100644
index 000000000..814ce0aad
--- /dev/null
+++ b/drivers/iio/chemical/sps30.c
@@ -0,0 +1,379 @@
+// 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 sysfs_emit(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_NS_GPL(sps30_probe, IIO_SPS30);
+
+MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
+MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor driver");
+MODULE_LICENSE("GPL v2");