Documentation/ABI/testing/sysfs-bus-iio-lptimer-stm32

   1 What:           /sys/bus/iio/devices/iio:deviceX/in_count0_preset
   2 KernelVersion:  4.13
   3 Contact:        fabrice.gasnier@st.com
   4 Description:
   5                 Reading returns the current preset value. Writing sets the
   6                 preset value. Encoder counts continuously from 0 to preset
   7                 value, depending on direction (up/down).
   8
   9 What:           /sys/bus/iio/devices/iio:deviceX/in_count_quadrature_mode_available
  10 KernelVersion:  4.13
  11 Contact:        fabrice.gasnier@st.com
  12 Description:
  13                 Reading returns the list possible quadrature modes.
  14
  15 What:           /sys/bus/iio/devices/iio:deviceX/in_count0_quadrature_mode
  16 KernelVersion:  4.13
  17 Contact:        fabrice.gasnier@st.com
  18 Description:
  19                 Configure the device counter quadrature modes:
  20
  21                 - non-quadrature:
  22                         Encoder IN1 input servers as the count input (up
  23                         direction).
  24
  25                 - quadrature:
  26                         Encoder IN1 and IN2 inputs are mixed to get direction
  27                         and count.
  28
  29 What:           /sys/bus/iio/devices/iio:deviceX/in_count_polarity_available
  30 KernelVersion:  4.13
  31 Contact:        fabrice.gasnier@st.com
  32 Description:
  33                 Reading returns the list possible active edges.
  34
  35 What:           /sys/bus/iio/devices/iio:deviceX/in_count0_polarity
  36 KernelVersion:  4.13
  37 Contact:        fabrice.gasnier@st.com
  38 Description:
  39                 Configure the device encoder/counter active edge:
  40
  41                 - rising-edge
  42                 - falling-edge
  43                 - both-edges
  44
  45                 In non-quadrature mode, device counts up on active edge.
  46
  47                 In quadrature mode, encoder counting scenarios are as follows:
  48
  49                 +---------+----------+--------------------+--------------------+
  50                 | Active  | Level on |      IN1 signal    |     IN2 signal     |
  51                 | edge    | opposite +----------+---------+----------+---------+
  52                 |         | signal   |  Rising  | Falling |  Rising  | Falling |
  53                 +---------+----------+----------+---------+----------+---------+
  54                 | Rising  | High ->  |   Down   |    -    |   Up     |    -    |
  55                 | edge    | Low  ->  |   Up     |    -    |   Down   |    -    |
  56                 +---------+----------+----------+---------+----------+---------+
  57                 | Falling | High ->  |    -     |   Up    |    -     |   Down  |
  58                 | edge    | Low  ->  |    -     |   Down  |    -     |   Up    |
  59                 +---------+----------+----------+---------+----------+---------+
  60                 | Both    | High ->  |   Down   |   Up    |   Up     |   Down  |
  61                 | edges   | Low  ->  |   Up     |   Down  |   Down   |   Up    |
  62                 +---------+----------+----------+---------+----------+---------+