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
   7
   8                 - "reset"
   9                                 The UG bit from the TIMx_EGR register is
  10                                 used as trigger output (TRGO).
  11                 - "enable"
  12                                 The Counter Enable signal CNT_EN is used
  13                                 as trigger output.
  14                 - "update"
  15                                 The update event is selected as trigger output.
  16                                 For instance a master timer can then be used
  17                                 as a prescaler for a slave timer.
  18                 - "compare_pulse"
  19                                 The trigger output send a positive pulse
  20                                 when the CC1IF flag is to be set.
  21                 - "OC1REF"
  22                                 OC1REF signal is used as trigger output.
  23                 - "OC2REF"
  24                                 OC2REF signal is used as trigger output.
  25                 - "OC3REF"
  26                                 OC3REF signal is used as trigger output.
  27                 - "OC4REF"
  28                                 OC4REF signal is used as trigger output.
  29
  30                 Additional modes (on TRGO2 only):
  31
  32                 - "OC5REF"
  33                                 OC5REF signal is used as trigger output.
  34                 - "OC6REF"
  35                                 OC6REF signal is used as trigger output.
  36                 - "compare_pulse_OC4REF":
  37                                 OC4REF rising or falling edges generate pulses.
  38                 - "compare_pulse_OC6REF":
  39                                 OC6REF rising or falling edges generate pulses.
  40                 - "compare_pulse_OC4REF_r_or_OC6REF_r":
  41                                 OC4REF or OC6REF rising edges generate pulses.
  42                 - "compare_pulse_OC4REF_r_or_OC6REF_f":
  43                                 OC4REF rising or OC6REF falling edges generate
  44                                 pulses.
  45                 - "compare_pulse_OC5REF_r_or_OC6REF_r":
  46                                 OC5REF or OC6REF rising edges generate pulses.
  47                 - "compare_pulse_OC5REF_r_or_OC6REF_f":
  48                                 OC5REF rising or OC6REF falling edges generate
  49                                 pulses.
  50
  51                 ::
  52
  53                   +-----------+   +-------------+            +---------+
  54                   | Prescaler +-> | Counter     |        +-> | Master  | TRGO(2)
  55                   +-----------+   +--+--------+-+        |-> | Control +-->
  56                                      |        |          ||  +---------+
  57                                   +--v--------+-+ OCxREF ||  +---------+
  58                                   | Chx compare +----------> | Output  | ChX
  59                                   +-----------+-+         |  | Control +-->
  60                                         .     |           |  +---------+
  61                                         .     |           |    .
  62                                   +-----------v-+ OC6REF  |    .
  63                                   | Ch6 compare +---------+>
  64                                   +-------------+
  65
  66                 Example with: "compare_pulse_OC4REF_r_or_OC6REF_r"::
  67
  68                                   X
  69                                 X   X
  70                               X .   . X
  71                             X   .   .   X
  72                           X     .   .     X
  73                   count X .     .   .     . X
  74                           .     .   .     .
  75                           .     .   .     .
  76                           +---------------+
  77                   OC4REF  |     .   .     |
  78                         +-+     .   .     +-+
  79                           .     +---+     .
  80                   OC6REF  .     |   |     .
  81                         +-------+   +-------+
  82                           +-+   +-+
  83                   TRGO2   | |   | |
  84                         +-+ +---+ +---------+
  85
  86 What:           /sys/bus/iio/devices/triggerX/master_mode
  87 KernelVersion:  4.11
  88 Contact:        benjamin.gaignard@st.com
  89 Description:
  90                 Reading returns the current master modes.
  91                 Writing set the master mode
  92
  93 What:           /sys/bus/iio/devices/triggerX/sampling_frequency
  94 KernelVersion:  4.11
  95 Contact:        benjamin.gaignard@st.com
  96 Description:
  97                 Reading returns the current sampling frequency.
  98                 Writing an value different of 0 set and start sampling.
  99                 Writing 0 stop sampling.
 100
 101 What:           /sys/bus/iio/devices/iio:deviceX/in_count0_preset
 102 KernelVersion:  4.12
 103 Contact:        benjamin.gaignard@st.com
 104 Description:
 105                 Reading returns the current preset value.
 106                 Writing sets the preset value.
 107                 When counting up the counter starts from 0 and fires an
 108                 event when reach preset value.
 109                 When counting down the counter start from preset value
 110                 and fire event when reach 0.
 111
 112 What:           /sys/bus/iio/devices/iio:deviceX/in_count_enable_mode_available
 113 KernelVersion:  4.12
 114 Contact:        benjamin.gaignard@st.com
 115 Description:
 116                 Reading returns the list possible enable modes.
 117
 118 What:           /sys/bus/iio/devices/iio:deviceX/in_count0_enable_mode
 119 KernelVersion:  4.12
 120 Contact:        benjamin.gaignard@st.com
 121 Description:
 122                 Configure the device counter enable modes, in all case
 123                 counting direction is set by in_count0_count_direction
 124                 attribute and the counter is clocked by the internal clock.
 125
 126                 always:
 127                         Counter is always ON.
 128
 129                 gated:
 130                         Counting is enabled when connected trigger signal
 131                         level is high else counting is disabled.
 132
 133                 triggered:
 134                         Counting is enabled on rising edge of the connected
 135                         trigger, and remains enabled for the duration of this
 136                         selected mode.
 137
 138 What:           /sys/bus/iio/devices/iio:deviceX/in_count_trigger_mode_available
 139 KernelVersion:  4.13
 140 Contact:        benjamin.gaignard@st.com
 141 Description:
 142                 Reading returns the list possible trigger modes.
 143
 144 What:           /sys/bus/iio/devices/iio:deviceX/in_count0_trigger_mode
 145 KernelVersion:  4.13
 146 Contact:        benjamin.gaignard@st.com
 147 Description:
 148                 Configure the device counter trigger mode
 149                 counting direction is set by in_count0_count_direction
 150                 attribute and the counter is clocked by the connected trigger
 151                 rising edges.