--- /dev/null
+From 232e0f6ddeaee104d64675fe7d0cc142cf955f35 Mon Sep 17 00:00:00 2001
+From: Tomasz Duszynski <tduszyns@gmail.com>
+Date: Fri, 14 Dec 2018 19:28:02 +0100
+Subject: [PATCH] iio: chemical: add support for Sensirion SPS30 sensor
+
+Add support for Sensirion SPS30 particulate matter sensor.
+
+Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
+Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
+---
+ drivers/iio/chemical/Kconfig | 11 +
+ drivers/iio/chemical/Makefile | 1 +
+ drivers/iio/chemical/sps30.c | 407 ++++++++++++++++++++++++++++++++++
+ 3 files changed, 419 insertions(+)
+ create mode 100644 drivers/iio/chemical/sps30.c
+
+diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
+index b8e005be4f87..57832b4360e9 100644
+--- a/drivers/iio/chemical/Kconfig
++++ b/drivers/iio/chemical/Kconfig
+@@ -61,6 +61,17 @@ config IAQCORE
+ iAQ-Core Continuous/Pulsed VOC (Volatile Organic Compounds)
+ sensors
+
++config SPS30
++ tristate "SPS30 particulate matter sensor"
++ depends on I2C
++ select CRC8
++ help
++ Say Y here to build support for the Sensirion SPS30 particulate
++ matter sensor.
++
++ To compile this driver as a module, choose M here: the module will
++ be called sps30.
++
+ config VZ89X
+ tristate "SGX Sensortech MiCS VZ89X VOC sensor"
+ depends on I2C
+diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
+index 2f4c4ba4d781..9f42f4252151 100644
+--- a/drivers/iio/chemical/Makefile
++++ b/drivers/iio/chemical/Makefile
+@@ -9,4 +9,5 @@ obj-$(CONFIG_BME680_I2C) += bme680_i2c.o
+ obj-$(CONFIG_BME680_SPI) += bme680_spi.o
+ obj-$(CONFIG_CCS811) += ccs811.o
+ obj-$(CONFIG_IAQCORE) += ams-iaq-core.o
++obj-$(CONFIG_SPS30) += sps30.o
+ obj-$(CONFIG_VZ89X) += vz89x.o
+diff --git a/drivers/iio/chemical/sps30.c b/drivers/iio/chemical/sps30.c
+new file mode 100644
+index 000000000000..fa3cd409b90b
+--- /dev/null
++++ b/drivers/iio/chemical/sps30.c
+@@ -0,0 +1,407 @@
++// SPDX-License-Identifier: GPL-2.0
++/*
++ * Sensirion SPS30 particulate matter sensor driver
++ *
++ * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
++ *
++ * I2C slave address: 0x69
++ *
++ * TODO:
++ * - support for turning on fan cleaning
++ * - support for reading/setting auto cleaning interval
++ */
++
++#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
++
++#include <asm/unaligned.h>
++#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/module.h>
++
++#define SPS30_CRC8_POLYNOMIAL 0x31
++/* max number of bytes needed to store PM measurements or serial string */
++#define SPS30_MAX_READ_SIZE 48
++/* sensor measures reliably up to 3000 ug / m3 */
++#define SPS30_MAX_PM 3000
++
++/* SPS30 commands */
++#define SPS30_START_MEAS 0x0010
++#define SPS30_STOP_MEAS 0x0104
++#define SPS30_RESET 0xd304
++#define SPS30_READ_DATA_READY_FLAG 0x0202
++#define SPS30_READ_DATA 0x0300
++#define SPS30_READ_SERIAL 0xd033
++
++enum {
++ PM1,
++ PM2P5,
++ PM4,
++ PM10,
++};
++
++struct sps30_state {
++ struct i2c_client *client;
++ /*
++ * Guards against concurrent access to sensor registers.
++ * Must be held whenever sequence of commands is to be executed.
++ */
++ struct mutex lock;
++};
++
++DECLARE_CRC8_TABLE(sps30_crc8_table);
++
++static int sps30_write_then_read(struct sps30_state *state, u8 *txbuf,
++ int txsize, u8 *rxbuf, int rxsize)
++{
++ int ret;
++
++ /*
++ * Sensor does not support repeated start so instead of
++ * sending two i2c messages in a row we just send one by one.
++ */
++ ret = i2c_master_send(state->client, txbuf, txsize);
++ if (ret != txsize)
++ return ret < 0 ? ret : -EIO;
++
++ if (!rxbuf)
++ return 0;
++
++ ret = i2c_master_recv(state->client, rxbuf, rxsize);
++ if (ret != rxsize)
++ return ret < 0 ? ret : -EIO;
++
++ return 0;
++}
++
++static int sps30_do_cmd(struct sps30_state *state, u16 cmd, u8 *data, int size)
++{
++ /*
++ * Internally sensor stores measurements in a following manner:
++ *
++ * PM1: upper two bytes, crc8, lower two bytes, crc8
++ * PM2P5: upper two bytes, crc8, lower two bytes, crc8
++ * PM4: upper two bytes, crc8, lower two bytes, crc8
++ * PM10: upper two bytes, crc8, lower two bytes, crc8
++ *
++ * What follows next are number concentration measurements and
++ * typical particle size measurement which we omit.
++ */
++ u8 buf[SPS30_MAX_READ_SIZE] = { cmd >> 8, cmd };
++ int i, ret = 0;
++
++ switch (cmd) {
++ case SPS30_START_MEAS:
++ buf[2] = 0x03;
++ buf[3] = 0x00;
++ buf[4] = crc8(sps30_crc8_table, &buf[2], 2, CRC8_INIT_VALUE);
++ ret = sps30_write_then_read(state, buf, 5, NULL, 0);
++ break;
++ case SPS30_STOP_MEAS:
++ case SPS30_RESET:
++ ret = sps30_write_then_read(state, buf, 2, NULL, 0);
++ break;
++ case SPS30_READ_DATA_READY_FLAG:
++ case SPS30_READ_DATA:
++ case SPS30_READ_SERIAL:
++ /* every two data bytes are checksummed */
++ size += size / 2;
++ ret = sps30_write_then_read(state, buf, 2, buf, size);
++ break;
++ }
++
++ if (ret)
++ return ret;
++
++ /* validate received data and strip off crc bytes */
++ for (i = 0; i < size; i += 3) {
++ u8 crc = crc8(sps30_crc8_table, &buf[i], 2, CRC8_INIT_VALUE);
++
++ if (crc != buf[i + 2]) {
++ dev_err(&state->client->dev,
++ "data integrity check failed\n");
++ return -EIO;
++ }
++
++ *data++ = buf[i];
++ *data++ = buf[i + 1];
++ }
++
++ return 0;
++}
++
++static s32 sps30_float_to_int_clamped(const u8 *fp)
++{
++ int val = get_unaligned_be32(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, tries = 5;
++ u8 tmp[16];
++
++ while (tries--) {
++ ret = sps30_do_cmd(state, SPS30_READ_DATA_READY_FLAG, tmp, 2);
++ if (ret)
++ return -EIO;
++
++ /* new measurements ready to be read */
++ if (tmp[1] == 1)
++ break;
++
++ msleep_interruptible(300);
++ }
++
++ if (!tries)
++ return -ETIMEDOUT;
++
++ ret = sps30_do_cmd(state, SPS30_READ_DATA, tmp, sizeof(int) * size);
++ if (ret)
++ return ret;
++
++ for (i = 0; i < size; i++)
++ data[i] = sps30_float_to_int_clamped(&tmp[4 * i]);
++
++ 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;
++ s32 data[4 + 2]; /* PM1, PM2P5, PM4, PM10, timestamp */
++
++ mutex_lock(&state->lock);
++ ret = sps30_do_meas(state, data, 4);
++ mutex_unlock(&state->lock);
++ if (ret)
++ goto err;
++
++ 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 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;
++ }
++ }
++
++ return -EINVAL;
++}
++
++static const struct iio_info sps30_info = {
++ .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_stop_meas(void *data)
++{
++ struct sps30_state *state = data;
++
++ sps30_do_cmd(state, SPS30_STOP_MEAS, NULL, 0);
++}
++
++static const unsigned long sps30_scan_masks[] = { 0x0f, 0x00 };
++
++static int sps30_probe(struct i2c_client *client)
++{
++ struct iio_dev *indio_dev;
++ struct sps30_state *state;
++ u8 buf[32];
++ int ret;
++
++ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
++ return -EOPNOTSUPP;
++
++ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*state));
++ if (!indio_dev)
++ return -ENOMEM;
++
++ state = iio_priv(indio_dev);
++ i2c_set_clientdata(client, indio_dev);
++ state->client = client;
++ indio_dev->dev.parent = &client->dev;
++ indio_dev->info = &sps30_info;
++ indio_dev->name = client->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;
++
++ mutex_init(&state->lock);
++ crc8_populate_msb(sps30_crc8_table, SPS30_CRC8_POLYNOMIAL);
++
++ ret = sps30_do_cmd(state, SPS30_RESET, NULL, 0);
++ if (ret) {
++ dev_err(&client->dev, "failed to reset device\n");
++ return ret;
++ }
++ msleep(300);
++ /*
++ * Power-on-reset causes sensor to produce some glitch on i2c bus and
++ * some controllers end up in error state. Recover simply by placing
++ * some data on the bus, for example STOP_MEAS command, which
++ * is NOP in this case.
++ */
++ sps30_do_cmd(state, SPS30_STOP_MEAS, NULL, 0);
++
++ ret = sps30_do_cmd(state, SPS30_READ_SERIAL, buf, sizeof(buf));
++ if (ret) {
++ dev_err(&client->dev, "failed to read serial number\n");
++ return ret;
++ }
++ /* returned serial number is already NUL terminated */
++ dev_info(&client->dev, "serial number: %s\n", buf);
++
++ ret = sps30_do_cmd(state, SPS30_START_MEAS, NULL, 0);
++ if (ret) {
++ dev_err(&client->dev, "failed to start measurement\n");
++ return ret;
++ }
++
++ ret = devm_add_action_or_reset(&client->dev, sps30_stop_meas, state);
++ if (ret)
++ return ret;
++
++ ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
++ sps30_trigger_handler, NULL);
++ if (ret)
++ return ret;
++
++ return devm_iio_device_register(&client->dev, indio_dev);
++}
++
++static const struct i2c_device_id sps30_id[] = {
++ { "sps30" },
++ { }
++};
++MODULE_DEVICE_TABLE(i2c, sps30_id);
++
++static const struct of_device_id sps30_of_match[] = {
++ { .compatible = "sensirion,sps30" },
++ { }
++};
++MODULE_DEVICE_TABLE(of, sps30_of_match);
++
++static struct i2c_driver sps30_driver = {
++ .driver = {
++ .name = "sps30",
++ .of_match_table = sps30_of_match,
++ },
++ .id_table = sps30_id,
++ .probe_new = sps30_probe,
++};
++module_i2c_driver(sps30_driver);
++
++MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
++MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor driver");
++MODULE_LICENSE("GPL v2");
projects / openwrt / staging / ynezz.git / blobdiff