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

   1 What:           /sys/bus/iio/devices/iio:deviceX/in_count_count_mode_available
   2 What:           /sys/bus/iio/devices/iio:deviceX/in_count_noise_error_available
   3 What:           /sys/bus/iio/devices/iio:deviceX/in_count_quadrature_mode_available
   4 What:           /sys/bus/iio/devices/iio:deviceX/in_index_index_polarity_available
   5 What:           /sys/bus/iio/devices/iio:deviceX/in_index_synchronous_mode_available
   6 KernelVersion:  4.10
   7 Contact:        linux-iio@vger.kernel.org
   8 Description:
   9                 Discrete set of available values for the respective counter
  10                 configuration are listed in this file.
  11
  12 What:           /sys/bus/iio/devices/iio:deviceX/in_countY_count_mode
  13 KernelVersion:  4.10
  14 Contact:        linux-iio@vger.kernel.org
  15 Description:
  16                 Count mode for channel Y. Four count modes are available:
  17                 normal, range limit, non-recycle, and modulo-n. The preset value
  18                 for channel Y is used by the count mode where required.
  19
  20                 Normal:
  21                         Counting is continuous in either direction.
  22
  23                 Range Limit:
  24                         An upper or lower limit is set, mimicking limit switches
  25                         in the mechanical counterpart. The upper limit is set to
  26                         the preset value, while the lower limit is set to 0. The
  27                         counter freezes at count = preset when counting up, and
  28                         at count = 0 when counting down. At either of these
  29                         limits, the counting is resumed only when the count
  30                         direction is reversed.
  31
  32                 Non-recycle:
  33                         Counter is disabled whenever a 24-bit count overflow or
  34                         underflow takes place. The counter is re-enabled when a
  35                         new count value is loaded to the counter via a preset
  36                         operation or write to raw.
  37
  38                 Modulo-N:
  39                         A count boundary is set between 0 and the preset value.
  40                         The counter is reset to 0 at count = preset when
  41                         counting up, while the counter is set to the preset
  42                         value at count = 0 when counting down; the counter does
  43                         not freeze at the bundary points, but counts
  44                         continuously throughout.
  45
  46 What:           /sys/bus/iio/devices/iio:deviceX/in_countY_noise_error
  47 KernelVersion:  4.10
  48 Contact:        linux-iio@vger.kernel.org
  49 Description:
  50                 Read-only attribute that indicates whether excessive noise is
  51                 present at the channel Y count inputs in quadrature clock mode;
  52                 irrelevant in non-quadrature clock mode.
  53
  54 What:           /sys/bus/iio/devices/iio:deviceX/in_countY_preset
  55 KernelVersion:  4.10
  56 Contact:        linux-iio@vger.kernel.org
  57 Description:
  58                 If the counter device supports preset registers, the preset
  59                 count for channel Y is provided by this attribute.
  60
  61 What:           /sys/bus/iio/devices/iio:deviceX/in_countY_quadrature_mode
  62 KernelVersion:  4.10
  63 Contact:        linux-iio@vger.kernel.org
  64 Description:
  65                 Configure channel Y counter for non-quadrature or quadrature
  66                 clock mode. Selecting non-quadrature clock mode will disable
  67                 synchronous load mode. In quadrature clock mode, the channel Y
  68                 scale attribute selects the encoder phase division (scale of 1
  69                 selects full-cycle, scale of 0.5 selects half-cycle, scale of
  70                 0.25 selects quarter-cycle) processed by the channel Y counter.
  71
  72                 Non-quadrature:
  73                         The filter and decoder circuit are bypassed. Encoder A
  74                         input serves as the count input and B as the UP/DOWN
  75                         direction control input, with B = 1 selecting UP Count
  76                         mode and B = 0 selecting Down Count mode.
  77
  78                 Quadrature:
  79                         Encoder A and B inputs are digitally filtered and
  80                         decoded for UP/DN clock.
  81
  82 What:           /sys/bus/iio/devices/iio:deviceX/in_countY_set_to_preset_on_index
  83 KernelVersion:  4.10
  84 Contact:        linux-iio@vger.kernel.org
  85 Description:
  86                 Whether to set channel Y counter with channel Y preset value
  87                 when channel Y index input is active, or continuously count.
  88                 Valid attribute values are boolean.
  89
  90 What:           /sys/bus/iio/devices/iio:deviceX/in_indexY_index_polarity
  91 KernelVersion:  4.10
  92 Contact:        linux-iio@vger.kernel.org
  93 Description:
  94                 Active level of channel Y index input; irrelevant in
  95                 non-synchronous load mode.
  96
  97 What:           /sys/bus/iio/devices/iio:deviceX/in_indexY_synchronous_mode
  98 KernelVersion:  4.10
  99 Contact:        linux-iio@vger.kernel.org
 100 Description:
 101                 Configure channel Y counter for non-synchronous or synchronous
 102                 load mode. Synchronous load mode cannot be selected in
 103                 non-quadrature clock mode.
 104
 105                 Non-synchronous:
 106                         A logic low level is the active level at this index
 107                         input. The index function (as enabled via
 108                         set_to_preset_on_index) is performed directly on the
 109                         active level of the index input.
 110
 111                 Synchronous:
 112                         Intended for interfacing with encoder Index output in
 113                         quadrature clock mode. The active level is configured
 114                         via index_polarity. The index function (as enabled via
 115                         set_to_preset_on_index) is performed synchronously with
 116                         the quadrature clock on the active level of the index
 117                         input.