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1// SPDX-License-Identifier: GPL-2.02/*3 * Sensirion SPS30 particulate matter sensor driver4 *5 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>6 */7 8#include <linux/crc8.h>9#include <linux/delay.h>10#include <linux/i2c.h>11#include <linux/iio/buffer.h>12#include <linux/iio/iio.h>13#include <linux/iio/sysfs.h>14#include <linux/iio/trigger_consumer.h>15#include <linux/iio/triggered_buffer.h>16#include <linux/kernel.h>17#include <linux/module.h>18 19#include "sps30.h"20 21/* sensor measures reliably up to 3000 ug / m3 */22#define SPS30_MAX_PM 300023/* minimum and maximum self cleaning periods in seconds */24#define SPS30_AUTO_CLEANING_PERIOD_MIN 025#define SPS30_AUTO_CLEANING_PERIOD_MAX 60480026 27enum {28 PM1,29 PM2P5,30 PM4,31 PM10,32};33 34enum {35 RESET,36 MEASURING,37};38 39static s32 sps30_float_to_int_clamped(__be32 *fp)40{41 int val = be32_to_cpup(fp);42 int mantissa = val & GENMASK(22, 0);43 /* this is fine since passed float is always non-negative */44 int exp = val >> 23;45 int fraction, shift;46 47 /* special case 0 */48 if (!exp && !mantissa)49 return 0;50 51 exp -= 127;52 if (exp < 0) {53 /* return values ranging from 1 to 99 */54 return ((((1 << 23) + mantissa) * 100) >> 23) >> (-exp);55 }56 57 /* return values ranging from 100 to 300000 */58 shift = 23 - exp;59 val = (1 << exp) + (mantissa >> shift);60 if (val >= SPS30_MAX_PM)61 return SPS30_MAX_PM * 100;62 63 fraction = mantissa & GENMASK(shift - 1, 0);64 65 return val * 100 + ((fraction * 100) >> shift);66}67 68static int sps30_do_meas(struct sps30_state *state, s32 *data, int size)69{70 int i, ret;71 72 if (state->state == RESET) {73 ret = state->ops->start_meas(state);74 if (ret)75 return ret;76 77 state->state = MEASURING;78 }79 80 ret = state->ops->read_meas(state, (__be32 *)data, size);81 if (ret)82 return ret;83 84 for (i = 0; i < size; i++)85 data[i] = sps30_float_to_int_clamped((__be32 *)&data[i]);86 87 return 0;88}89 90static int sps30_do_reset(struct sps30_state *state)91{92 int ret;93 94 ret = state->ops->reset(state);95 if (ret)96 return ret;97 98 state->state = RESET;99 100 return 0;101}102 103static irqreturn_t sps30_trigger_handler(int irq, void *p)104{105 struct iio_poll_func *pf = p;106 struct iio_dev *indio_dev = pf->indio_dev;107 struct sps30_state *state = iio_priv(indio_dev);108 int ret;109 struct {110 s32 data[4]; /* PM1, PM2P5, PM4, PM10 */111 s64 ts;112 } scan;113 114 mutex_lock(&state->lock);115 ret = sps30_do_meas(state, scan.data, ARRAY_SIZE(scan.data));116 mutex_unlock(&state->lock);117 if (ret)118 goto err;119 120 iio_push_to_buffers_with_timestamp(indio_dev, &scan,121 iio_get_time_ns(indio_dev));122err:123 iio_trigger_notify_done(indio_dev->trig);124 125 return IRQ_HANDLED;126}127 128static int sps30_read_raw(struct iio_dev *indio_dev,129 struct iio_chan_spec const *chan,130 int *val, int *val2, long mask)131{132 struct sps30_state *state = iio_priv(indio_dev);133 int data[4], ret = -EINVAL;134 135 switch (mask) {136 case IIO_CHAN_INFO_PROCESSED:137 switch (chan->type) {138 case IIO_MASSCONCENTRATION:139 mutex_lock(&state->lock);140 /* read up to the number of bytes actually needed */141 switch (chan->channel2) {142 case IIO_MOD_PM1:143 ret = sps30_do_meas(state, data, 1);144 break;145 case IIO_MOD_PM2P5:146 ret = sps30_do_meas(state, data, 2);147 break;148 case IIO_MOD_PM4:149 ret = sps30_do_meas(state, data, 3);150 break;151 case IIO_MOD_PM10:152 ret = sps30_do_meas(state, data, 4);153 break;154 }155 mutex_unlock(&state->lock);156 if (ret)157 return ret;158 159 *val = data[chan->address] / 100;160 *val2 = (data[chan->address] % 100) * 10000;161 162 return IIO_VAL_INT_PLUS_MICRO;163 default:164 return -EINVAL;165 }166 case IIO_CHAN_INFO_SCALE:167 switch (chan->type) {168 case IIO_MASSCONCENTRATION:169 switch (chan->channel2) {170 case IIO_MOD_PM1:171 case IIO_MOD_PM2P5:172 case IIO_MOD_PM4:173 case IIO_MOD_PM10:174 *val = 0;175 *val2 = 10000;176 177 return IIO_VAL_INT_PLUS_MICRO;178 default:179 return -EINVAL;180 }181 default:182 return -EINVAL;183 }184 }185 186 return -EINVAL;187}188 189static ssize_t start_cleaning_store(struct device *dev,190 struct device_attribute *attr,191 const char *buf, size_t len)192{193 struct iio_dev *indio_dev = dev_to_iio_dev(dev);194 struct sps30_state *state = iio_priv(indio_dev);195 int val, ret;196 197 if (kstrtoint(buf, 0, &val) || val != 1)198 return -EINVAL;199 200 mutex_lock(&state->lock);201 ret = state->ops->clean_fan(state);202 mutex_unlock(&state->lock);203 if (ret)204 return ret;205 206 return len;207}208 209static ssize_t cleaning_period_show(struct device *dev,210 struct device_attribute *attr,211 char *buf)212{213 struct iio_dev *indio_dev = dev_to_iio_dev(dev);214 struct sps30_state *state = iio_priv(indio_dev);215 __be32 val;216 int ret;217 218 mutex_lock(&state->lock);219 ret = state->ops->read_cleaning_period(state, &val);220 mutex_unlock(&state->lock);221 if (ret)222 return ret;223 224 return sysfs_emit(buf, "%d\n", be32_to_cpu(val));225}226 227static ssize_t cleaning_period_store(struct device *dev, struct device_attribute *attr,228 const char *buf, size_t len)229{230 struct iio_dev *indio_dev = dev_to_iio_dev(dev);231 struct sps30_state *state = iio_priv(indio_dev);232 int val, ret;233 234 if (kstrtoint(buf, 0, &val))235 return -EINVAL;236 237 if ((val < SPS30_AUTO_CLEANING_PERIOD_MIN) ||238 (val > SPS30_AUTO_CLEANING_PERIOD_MAX))239 return -EINVAL;240 241 mutex_lock(&state->lock);242 ret = state->ops->write_cleaning_period(state, cpu_to_be32(val));243 if (ret) {244 mutex_unlock(&state->lock);245 return ret;246 }247 248 msleep(20);249 250 /*251 * sensor requires reset in order to return up to date self cleaning252 * period253 */254 ret = sps30_do_reset(state);255 if (ret)256 dev_warn(dev,257 "period changed but reads will return the old value\n");258 259 mutex_unlock(&state->lock);260 261 return len;262}263 264static ssize_t cleaning_period_available_show(struct device *dev,265 struct device_attribute *attr,266 char *buf)267{268 return sysfs_emit(buf, "[%d %d %d]\n",269 SPS30_AUTO_CLEANING_PERIOD_MIN, 1,270 SPS30_AUTO_CLEANING_PERIOD_MAX);271}272 273static IIO_DEVICE_ATTR_WO(start_cleaning, 0);274static IIO_DEVICE_ATTR_RW(cleaning_period, 0);275static IIO_DEVICE_ATTR_RO(cleaning_period_available, 0);276 277static struct attribute *sps30_attrs[] = {278 &iio_dev_attr_start_cleaning.dev_attr.attr,279 &iio_dev_attr_cleaning_period.dev_attr.attr,280 &iio_dev_attr_cleaning_period_available.dev_attr.attr,281 NULL282};283 284static const struct attribute_group sps30_attr_group = {285 .attrs = sps30_attrs,286};287 288static const struct iio_info sps30_info = {289 .attrs = &sps30_attr_group,290 .read_raw = sps30_read_raw,291};292 293#define SPS30_CHAN(_index, _mod) { \294 .type = IIO_MASSCONCENTRATION, \295 .modified = 1, \296 .channel2 = IIO_MOD_ ## _mod, \297 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \298 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \299 .address = _mod, \300 .scan_index = _index, \301 .scan_type = { \302 .sign = 'u', \303 .realbits = 19, \304 .storagebits = 32, \305 .endianness = IIO_CPU, \306 }, \307}308 309static const struct iio_chan_spec sps30_channels[] = {310 SPS30_CHAN(0, PM1),311 SPS30_CHAN(1, PM2P5),312 SPS30_CHAN(2, PM4),313 SPS30_CHAN(3, PM10),314 IIO_CHAN_SOFT_TIMESTAMP(4),315};316 317static void sps30_devm_stop_meas(void *data)318{319 struct sps30_state *state = data;320 321 if (state->state == MEASURING)322 state->ops->stop_meas(state);323}324 325static const unsigned long sps30_scan_masks[] = { 0x0f, 0x00 };326 327int sps30_probe(struct device *dev, const char *name, void *priv, const struct sps30_ops *ops)328{329 struct iio_dev *indio_dev;330 struct sps30_state *state;331 int ret;332 333 indio_dev = devm_iio_device_alloc(dev, sizeof(*state));334 if (!indio_dev)335 return -ENOMEM;336 337 dev_set_drvdata(dev, indio_dev);338 339 state = iio_priv(indio_dev);340 state->dev = dev;341 state->priv = priv;342 state->ops = ops;343 mutex_init(&state->lock);344 345 indio_dev->info = &sps30_info;346 indio_dev->name = name;347 indio_dev->channels = sps30_channels;348 indio_dev->num_channels = ARRAY_SIZE(sps30_channels);349 indio_dev->modes = INDIO_DIRECT_MODE;350 indio_dev->available_scan_masks = sps30_scan_masks;351 352 ret = sps30_do_reset(state);353 if (ret) {354 dev_err(dev, "failed to reset device\n");355 return ret;356 }357 358 ret = state->ops->show_info(state);359 if (ret) {360 dev_err(dev, "failed to read device info\n");361 return ret;362 }363 364 ret = devm_add_action_or_reset(dev, sps30_devm_stop_meas, state);365 if (ret)366 return ret;367 368 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,369 sps30_trigger_handler, NULL);370 if (ret)371 return ret;372 373 return devm_iio_device_register(dev, indio_dev);374}375EXPORT_SYMBOL_NS_GPL(sps30_probe, IIO_SPS30);376 377MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");378MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor driver");379MODULE_LICENSE("GPL v2");380