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

   1 What:           /sys/bus/iio/devices/triggerX/master_mode_available
   2 KernelVersion:  4.11
   3 Contact:        benjamin.gaignard@st.com
   4 Description:
   5                 Reading returns the list possible master modes which are:
   6                 - "reset"     : The UG bit from the TIMx_EGR register is
   7                                 used as trigger output (TRGO).
   8                 - "enable"    : The Counter Enable signal CNT_EN is used
   9                                 as trigger output.
  10                 - "update"    : The update event is selected as trigger output.
  11                                 For instance a master timer can then be used
  12                                 as a prescaler for a slave timer.
  13                 - "compare_pulse" : The trigger output send a positive pulse
  14                                     when the CC1IF flag is to be set.
  15                 - "OC1REF"    : OC1REF signal is used as trigger output.
  16                 - "OC2REF"    : OC2REF signal is used as trigger output.
  17                 - "OC3REF"    : OC3REF signal is used as trigger output.
  18                 - "OC4REF"    : OC4REF signal is used as trigger output.
  19                 Additional modes (on TRGO2 only):
  20                 - "OC5REF"    : OC5REF signal is used as trigger output.
  21                 - "OC6REF"    : OC6REF signal is used as trigger output.
  22                 - "compare_pulse_OC4REF":
  23                   OC4REF rising or falling edges generate pulses.
  24                 - "compare_pulse_OC6REF":
  25                   OC6REF rising or falling edges generate pulses.
  26                 - "compare_pulse_OC4REF_r_or_OC6REF_r":
  27                   OC4REF or OC6REF rising edges generate pulses.
  28                 - "compare_pulse_OC4REF_r_or_OC6REF_f":
  29                   OC4REF rising or OC6REF falling edges generate pulses.
  30                 - "compare_pulse_OC5REF_r_or_OC6REF_r":
  31                   OC5REF or OC6REF rising edges generate pulses.
  32                 - "compare_pulse_OC5REF_r_or_OC6REF_f":
  33                   OC5REF rising or OC6REF falling edges generate pulses.
  34
  35                 +-----------+   +-------------+            +---------+
  36                 | Prescaler +-> | Counter     |        +-> | Master  | TRGO(2)
  37                 +-----------+   +--+--------+-+        |-> | Control +-->
  38                                    |        |          ||  +---------+
  39                                 +--v--------+-+ OCxREF ||  +---------+
  40                                 | Chx compare +----------> | Output  | ChX
  41                                 +-----------+-+         |  | Control +-->
  42                                       .     |           |  +---------+
  43                                       .     |           |    .
  44                                 +-----------v-+ OC6REF  |    .
  45                                 | Ch6 compare +---------+>
  46                                 +-------------+
  47
  48                 Example with: "compare_pulse_OC4REF_r_or_OC6REF_r":
  49
  50                                 X
  51                               X   X
  52                             X .   . X
  53                           X   .   .   X
  54                         X     .   .     X
  55                 count X .     .   .     . X
  56                         .     .   .     .
  57                         .     .   .     .
  58                         +---------------+
  59                 OC4REF  |     .   .     |
  60                       +-+     .   .     +-+
  61                         .     +---+     .
  62                 OC6REF  .     |   |     .
  63                       +-------+   +-------+
  64                         +-+   +-+
  65                 TRGO2   | |   | |
  66                       +-+ +---+ +---------+
  67
  68 What:           /sys/bus/iio/devices/triggerX/master_mode
  69 KernelVersion:  4.11
  70 Contact:        benjamin.gaignard@st.com
  71 Description:
  72                 Reading returns the current master modes.
  73                 Writing set the master mode
  74
  75 What:           /sys/bus/iio/devices/triggerX/sampling_frequency
  76 KernelVersion:  4.11
  77 Contact:        benjamin.gaignard@st.com
  78 Description:
  79                 Reading returns the current sampling frequency.
  80                 Writing an value different of 0 set and start sampling.
  81                 Writing 0 stop sampling.
  82
  83 What:           /sys/bus/iio/devices/iio:deviceX/in_count0_preset
  84 KernelVersion:  4.12
  85 Contact:        benjamin.gaignard@st.com
  86 Description:
  87                 Reading returns the current preset value.
  88                 Writing sets the preset value.
  89                 When counting up the counter starts from 0 and fires an
  90                 event when reach preset value.
  91                 When counting down the counter start from preset value
  92                 and fire event when reach 0.
  93
  94 What:           /sys/bus/iio/devices/iio:deviceX/in_count_enable_mode_available
  95 KernelVersion:  4.12
  96 Contact:        benjamin.gaignard@st.com
  97 Description:
  98                 Reading returns the list possible enable modes.
  99
 100 What:           /sys/bus/iio/devices/iio:deviceX/in_count0_enable_mode
 101 KernelVersion:  4.12
 102 Contact:        benjamin.gaignard@st.com
 103 Description:
 104                 Configure the device counter enable modes, in all case
 105                 counting direction is set by in_count0_count_direction
 106                 attribute and the counter is clocked by the internal clock.
 107                 always:
 108                         Counter is always ON.
 109
 110                 gated:
 111                         Counting is enabled when connected trigger signal
 112                         level is high else counting is disabled.
 113
 114                 triggered:
 115                         Counting is enabled on rising edge of the connected
 116                         trigger, and remains enabled for the duration of this
 117                         selected mode.
 118
 119 What:           /sys/bus/iio/devices/iio:deviceX/in_count_trigger_mode_available
 120 KernelVersion:  4.13
 121 Contact:        benjamin.gaignard@st.com
 122 Description:
 123                 Reading returns the list possible trigger modes.
 124
 125 What:           /sys/bus/iio/devices/iio:deviceX/in_count0_trigger_mode
 126 KernelVersion:  4.13
 127 Contact:        benjamin.gaignard@st.com
 128 Description:
 129                 Configure the device counter trigger mode
 130                 counting direction is set by in_count0_count_direction
 131                 attribute and the counter is clocked by the connected trigger
 132                 rising edges.