lkml.org 
[lkml]   [2018]   [Dec]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v4 2/3] iio: chemical: add support for Sensirion SPS30 sensor
On Fri, 14 Dec 2018 19:28:02 +0100
Tomasz Duszynski <tduszyns@gmail.com> wrote:

> Add support for Sensirion SPS30 particulate matter sensor.
>
> Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
One minor thing inline I'll fix whilst applying.
Please check I didn't mess it up though!

Thanks,

Jonathan

> ---
> drivers/iio/chemical/Kconfig | 11 +
> drivers/iio/chemical/Makefile | 1 +
> drivers/iio/chemical/sps30.c | 406 ++++++++++++++++++++++++++++++++++
> 3 files changed, 418 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..f1cea8699c78
> --- /dev/null
> +++ b/drivers/iio/chemical/sps30.c
> @@ -0,0 +1,406 @@
> +// 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 int 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, int *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, data[4 + 2]; /* PM1, PM2P5, PM4, PM10, timestamp */

Totally trivial and I'll fix it, but data should be a fixed
width data type, not an int. s32 will do nicely.


> +
> + 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");

\
 
 \ /
  Last update: 2018-12-16 14:15    [W:0.071 / U:0.544 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site