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 --- /dev/null
  25 +++ b/Documentation/ABI/testing/sysfs-bus-iio-sps30
  26 @@ -0,0 +1,8 @@
  27 +What:          /sys/bus/iio/devices/iio:deviceX/start_cleaning
  28 +Date:          December 2018
  29 +KernelVersion: 4.22
  30 +Contact:       linux-iio@vger.kernel.org
  31 +Description:
  32 +               Writing 1 starts sensor self cleaning. Internal fan accelerates
  33 +               to its maximum speed and keeps spinning for about 10 seconds in
  34 +               order to blow out accumulated dust.
  35 --- a/drivers/iio/chemical/sps30.c
  36 +++ b/drivers/iio/chemical/sps30.c
  37 @@ -7,7 +7,6 @@
  38   * I2C slave address: 0x69
  39   *
  40   * TODO:
  41 - *  - support for turning on fan cleaning
  42   *  - support for reading/setting auto cleaning interval
  43   */
  44
  45 @@ -37,6 +36,7 @@
  46  #define SPS30_READ_DATA_READY_FLAG 0x0202
  47  #define SPS30_READ_DATA 0x0300
  48  #define SPS30_READ_SERIAL 0xd033
  49 +#define SPS30_START_FAN_CLEANING 0x5607
  50
  51  enum {
  52         PM1,
  53 @@ -104,6 +104,7 @@ static int sps30_do_cmd(struct sps30_sta
  54                 break;
  55         case SPS30_STOP_MEAS:
  56         case SPS30_RESET:
  57 +       case SPS30_START_FAN_CLEANING:
  58                 ret = sps30_write_then_read(state, buf, 2, NULL, 0);
  59                 break;
  60         case SPS30_READ_DATA_READY_FLAG:
  61 @@ -275,7 +276,39 @@ static int sps30_read_raw(struct iio_dev
  62         return -EINVAL;
  63  }
  64
  65 +static ssize_t start_cleaning_store(struct device *dev,
  66 +                                   struct device_attribute *attr,
  67 +                                   const char *buf, size_t len)
  68 +{
  69 +       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
  70 +       struct sps30_state *state = iio_priv(indio_dev);
  71 +       int val, ret;
  72 +
  73 +       if (kstrtoint(buf, 0, &val) || val != 1)
  74 +               return -EINVAL;
  75 +
  76 +       mutex_lock(&state->lock);
  77 +       ret = sps30_do_cmd(state, SPS30_START_FAN_CLEANING, NULL, 0);
  78 +       mutex_unlock(&state->lock);
  79 +       if (ret)
  80 +               return ret;
  81 +
  82 +       return len;
  83 +}
  84 +
  85 +static IIO_DEVICE_ATTR_WO(start_cleaning, 0);
  86 +
  87 +static struct attribute *sps30_attrs[] = {
  88 +       &iio_dev_attr_start_cleaning.dev_attr.attr,
  89 +       NULL
  90 +};
  91 +
  92 +static const struct attribute_group sps30_attr_group = {
  93 +       .attrs = sps30_attrs,
  94 +};
  95 +
  96  static const struct iio_info sps30_info = {
  97 +       .attrs = &sps30_attr_group,
  98         .read_raw = sps30_read_raw,
  99  };
 100