target/linux/generic/backport-4.19/501-v5.1-iio-chemical-sps30-add-support-for-self-cleaning.patch

   1 From c546d49656143855093c7b7fde60866e6e23a69d Mon Sep 17 00:00:00 2001
   2 From: Tomasz Duszynski <tduszyns@gmail.com>
   3 Date: Tue, 18 Dec 2018 21:28:09 +0100
   4 Subject: [PATCH] iio: chemical: sps30: add support for self cleaning
   5
   6 Self cleaning is especially useful in cases where sensor undergoes
   7 frequent power on/off cycles. In such scenarios it is recommended to
   8 turn self cleaning at least once per week in order to maintain reliable
   9 measurements.
  10
  11 Self cleaning is activated by writing 1 to a dedicated attribute.
  12 Internal fan accelerates to its maximum speed and keeps spinning
  13 for about 10 seconds blowing out accumulated dust.
  14
  15 Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
  16 Tested-by: Andreas Brauchli <andreas.brauchli@sensirion.com>
  17 Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
  18 ---
  19  Documentation/ABI/testing/sysfs-bus-iio-sps30 |  8 +++++
  20  drivers/iio/chemical/sps30.c                  | 35 ++++++++++++++++++-
  21  2 files changed, 42 insertions(+), 1 deletion(-)
  22  create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-sps30
  23
  24 diff --git a/Documentation/ABI/testing/sysfs-bus-iio-sps30 b/Documentation/ABI/testing/sysfs-bus-iio-sps30
  25 new file mode 100644
  26 index 000000000000..e7ce2c57635e
  27 --- /dev/null
  28 +++ b/Documentation/ABI/testing/sysfs-bus-iio-sps30
  29 @@ -0,0 +1,8 @@
  30 +What:          /sys/bus/iio/devices/iio:deviceX/start_cleaning
  31 +Date:          December 2018
  32 +KernelVersion: 4.22
  33 +Contact:       linux-iio@vger.kernel.org
  34 +Description:
  35 +               Writing 1 starts sensor self cleaning. Internal fan accelerates
  36 +               to its maximum speed and keeps spinning for about 10 seconds in
  37 +               order to blow out accumulated dust.
  38 diff --git a/drivers/iio/chemical/sps30.c b/drivers/iio/chemical/sps30.c
  39 index fa3cd409b90b..f3b4390c8f5c 100644
  40 --- a/drivers/iio/chemical/sps30.c
  41 +++ b/drivers/iio/chemical/sps30.c
  42 @@ -7,7 +7,6 @@
  43   * I2C slave address: 0x69
  44   *
  45   * TODO:
  46 - *  - support for turning on fan cleaning
  47   *  - support for reading/setting auto cleaning interval
  48   */
  49
  50 @@ -37,6 +36,7 @@
  51  #define SPS30_READ_DATA_READY_FLAG 0x0202
  52  #define SPS30_READ_DATA 0x0300
  53  #define SPS30_READ_SERIAL 0xd033
  54 +#define SPS30_START_FAN_CLEANING 0x5607
  55
  56  enum {
  57         PM1,
  58 @@ -104,6 +104,7 @@ static int sps30_do_cmd(struct sps30_state *state, u16 cmd, u8 *data, int size)
  59                 break;
  60         case SPS30_STOP_MEAS:
  61         case SPS30_RESET:
  62 +       case SPS30_START_FAN_CLEANING:
  63                 ret = sps30_write_then_read(state, buf, 2, NULL, 0);
  64                 break;
  65         case SPS30_READ_DATA_READY_FLAG:
  66 @@ -275,7 +276,39 @@ static int sps30_read_raw(struct iio_dev *indio_dev,
  67         return -EINVAL;
  68  }
  69
  70 +static ssize_t start_cleaning_store(struct device *dev,
  71 +                                   struct device_attribute *attr,
  72 +                                   const char *buf, size_t len)
  73 +{
  74 +       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
  75 +       struct sps30_state *state = iio_priv(indio_dev);
  76 +       int val, ret;
  77 +
  78 +       if (kstrtoint(buf, 0, &val) || val != 1)
  79 +               return -EINVAL;
  80 +
  81 +       mutex_lock(&state->lock);
  82 +       ret = sps30_do_cmd(state, SPS30_START_FAN_CLEANING, NULL, 0);
  83 +       mutex_unlock(&state->lock);
  84 +       if (ret)
  85 +               return ret;
  86 +
  87 +       return len;
  88 +}
  89 +
  90 +static IIO_DEVICE_ATTR_WO(start_cleaning, 0);
  91 +
  92 +static struct attribute *sps30_attrs[] = {
  93 +       &iio_dev_attr_start_cleaning.dev_attr.attr,
  94 +       NULL
  95 +};
  96 +
  97 +static const struct attribute_group sps30_attr_group = {
  98 +       .attrs = sps30_attrs,
  99 +};
 100 +
 101  static const struct iio_info sps30_info = {
 102 +       .attrs = &sps30_attr_group,
 103         .read_raw = sps30_read_raw,
 104  };
 105