Documentation/ABI/testing/sysfs-bus-iio-counter-104-quad-8

   1 What:           /sys/bus/iio/devices/iio:deviceX/in_count_count_direction_available
   2 What:           /sys/bus/iio/devices/iio:deviceX/in_count_count_mode_available
   3 What:           /sys/bus/iio/devices/iio:deviceX/in_count_noise_error_available
   4 What:           /sys/bus/iio/devices/iio:deviceX/in_count_quadrature_mode_available
   5 What:           /sys/bus/iio/devices/iio:deviceX/in_index_index_polarity_available
   6 What:           /sys/bus/iio/devices/iio:deviceX/in_index_synchronous_mode_available
   7 KernelVersion:  4.9
   8 Contact:        linux-iio@vger.kernel.org
   9 Description:
  10                 Discrete set of available values for the respective counter
  11                 configuration are listed in this file.
  12
  13 What:           /sys/bus/iio/devices/iio:deviceX/in_countY_count_direction
  14 KernelVersion:  4.9
  15 Contact:        linux-iio@vger.kernel.org
  16 Description:
  17                 Read-only attribute that indicates whether the counter for
  18                 channel Y is counting up or down.
  19
  20 What:           /sys/bus/iio/devices/iio:deviceX/in_countY_count_mode
  21 KernelVersion:  4.9
  22 Contact:        linux-iio@vger.kernel.org
  23 Description:
  24                 Count mode for channel Y. Four count modes are available:
  25                 normal, range limit, non-recycle, and modulo-n. The preset value
  26                 for channel Y is used by the count mode where required.
  27
  28                 Normal:
  29                         Counting is continuous in either direction.
  30
  31                 Range Limit:
  32                         An upper or lower limit is set, mimicking limit switches
  33                         in the mechanical counterpart. The upper limit is set to
  34                         the preset value, while the lower limit is set to 0. The
  35                         counter freezes at count = preset when counting up, and
  36                         at count = 0 when counting down. At either of these
  37                         limits, the counting is resumed only when the count
  38                         direction is reversed.
  39
  40                 Non-recycle:
  41                         Counter is disabled whenever a 24-bit count overflow or
  42                         underflow takes place. The counter is re-enabled when a
  43                         new count value is loaded to the counter via a preset
  44                         operation or write to raw.
  45
  46                 Modulo-N:
  47                         A count boundary is set between 0 and the preset value.
  48                         The counter is reset to 0 at count = preset when
  49                         counting up, while the counter is set to the preset
  50                         value at count = 0 when counting down; the counter does
  51                         not freeze at the bundary points, but counts
  52                         continuously throughout.
  53
  54 What:           /sys/bus/iio/devices/iio:deviceX/in_countY_noise_error
  55 KernelVersion:  4.9
  56 Contact:        linux-iio@vger.kernel.org
  57 Description:
  58                 Read-only attribute that indicates whether excessive noise is
  59                 present at the channel Y count inputs in quadrature clock mode;
  60                 irrelevant in non-quadrature clock mode.
  61
  62 What:           /sys/bus/iio/devices/iio:deviceX/in_countY_preset
  63 KernelVersion:  4.9
  64 Contact:        linux-iio@vger.kernel.org
  65 Description:
  66                 If the counter device supports preset registers, the preset
  67                 count for channel Y is provided by this attribute.
  68
  69 What:           /sys/bus/iio/devices/iio:deviceX/in_countY_quadrature_mode
  70 KernelVersion:  4.9
  71 Contact:        linux-iio@vger.kernel.org
  72 Description:
  73                 Configure channel Y counter for non-quadrature or quadrature
  74                 clock mode. Selecting non-quadrature clock mode will disable
  75                 synchronous load mode. In quadrature clock mode, the channel Y
  76                 scale attribute selects the encoder phase division (scale of 1
  77                 selects full-cycle, scale of 0.5 selects half-cycle, scale of
  78                 0.25 selects quarter-cycle) processed by the channel Y counter.
  79
  80                 Non-quadrature:
  81                         The filter and decoder circuit are bypassed. Encoder A
  82                         input serves as the count input and B as the UP/DOWN
  83                         direction control input, with B = 1 selecting UP Count
  84                         mode and B = 0 selecting Down Count mode.
  85
  86                 Quadrature:
  87                         Encoder A and B inputs are digitally filtered and
  88                         decoded for UP/DN clock.
  89
  90 What:           /sys/bus/iio/devices/iio:deviceX/in_countY_set_to_preset_on_index
  91 KernelVersion:  4.9
  92 Contact:        linux-iio@vger.kernel.org
  93 Description:
  94                 Whether to set channel Y counter with channel Y preset value
  95                 when channel Y index input is active, or continuously count.
  96                 Valid attribute values are boolean.
  97
  98 What:           /sys/bus/iio/devices/iio:deviceX/in_indexY_index_polarity
  99 KernelVersion:  4.9
 100 Contact:        linux-iio@vger.kernel.org
 101 Description:
 102                 Active level of channel Y index input; irrelevant in
 103                 non-synchronous load mode.
 104
 105 What:           /sys/bus/iio/devices/iio:deviceX/in_indexY_synchronous_mode
 106 KernelVersion:  4.9
 107 Contact:        linux-iio@vger.kernel.org
 108 Description:
 109                 Configure channel Y counter for non-synchronous or synchronous
 110                 load mode. Synchronous load mode cannot be selected in
 111                 non-quadrature clock mode.
 112
 113                 Non-synchronous:
 114                         A logic low level is the active level at this index
 115                         input. The index function (as enabled via
 116                         set_to_preset_on_index) is performed directly on the
 117                         active level of the index input.
 118
 119                 Synchronous:
 120                         Intended for interfacing with encoder Index output in
 121                         quadrature clock mode. The active level is configured
 122                         via index_polarity. The index function (as enabled via
 123                         set_to_preset_on_index) is performed synchronously with
 124                         the quadrature clock on the active level of the index
 125                         input.