blob: abd67559e451547b5620bcec40d0f10a2968c646 [file] [log] [blame]
// 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_GPL(sps30_probe);
MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor driver");
MODULE_LICENSE("GPL v2");