Documentation/ABI/testing/sysfs-bus-counter

   1 What:           /sys/bus/counter/devices/counterX/cascade_counts_enable
   2 KernelVersion:  6.4
   3 Contact:        linux-iio@vger.kernel.org
   4 Description:
   5                 Indicates the cascading of Counts on Counter X.
   6
   7                 Valid attribute values are boolean.
   8
   9 What:           /sys/bus/counter/devices/counterX/external_input_phase_clock_select
  10 KernelVersion:  6.4
  11 Contact:        linux-iio@vger.kernel.org
  12 Description:
  13                 Selects the external clock pin for phase counting mode of
  14                 Counter X.
  15
  16                 MTCLKA-MTCLKB:
  17                         MTCLKA and MTCLKB pins are selected for the external
  18                         phase clock.
  19
  20                 MTCLKC-MTCLKD:
  21                         MTCLKC and MTCLKD pins are selected for the external
  22                         phase clock.
  23
  24 What:           /sys/bus/counter/devices/counterX/external_input_phase_clock_select_available
  25 KernelVersion:  6.4
  26 Contact:        linux-iio@vger.kernel.org
  27 Description:
  28                 Discrete set of available values for the respective device
  29                 configuration are listed in this file.
  30
  31 What:           /sys/bus/counter/devices/counterX/countY/count
  32 KernelVersion:  5.2
  33 Contact:        linux-iio@vger.kernel.org
  34 Description:
  35                 Count data of Count Y represented as a string.
  36
  37 What:           /sys/bus/counter/devices/counterX/countY/capture
  38 KernelVersion:  6.1
  39 Contact:        linux-iio@vger.kernel.org
  40 Description:
  41                 Historical capture of the Count Y count data.
  42
  43 What:           /sys/bus/counter/devices/counterX/countY/ceiling
  44 KernelVersion:  5.2
  45 Contact:        linux-iio@vger.kernel.org
  46 Description:
  47                 Count value ceiling for Count Y. This is the upper limit for the
  48                 respective counter.
  49
  50 What:           /sys/bus/counter/devices/counterX/countY/floor
  51 KernelVersion:  5.2
  52 Contact:        linux-iio@vger.kernel.org
  53 Description:
  54                 Count value floor for Count Y. This is the lower limit for the
  55                 respective counter.
  56
  57 What:           /sys/bus/counter/devices/counterX/countY/count_mode
  58 KernelVersion:  5.2
  59 Contact:        linux-iio@vger.kernel.org
  60 Description:
  61                 Count mode for channel Y. The ceiling and floor values for
  62                 Count Y are used by the count mode where required. The following
  63                 count modes are available:
  64
  65                 normal:
  66                         Counting is continuous in either direction.
  67
  68                 range limit:
  69                         An upper or lower limit is set, mimicking limit switches
  70                         in the mechanical counterpart. The upper limit is set to
  71                         the Count Y ceiling value, while the lower limit is set
  72                         to the Count Y floor value. The counter freezes at
  73                         count = ceiling when counting up, and at count = floor
  74                         when counting down. At either of these limits, the
  75                         counting is resumed only when the count direction is
  76                         reversed.
  77
  78                 non-recycle:
  79                         The counter is disabled whenever a counter overflow or
  80                         underflow takes place. The counter is re-enabled when a
  81                         new count value is loaded to the counter via a preset
  82                         operation or direct write.
  83
  84                 modulo-n:
  85                         A count value boundary is set between the Count Y floor
  86                         value and the Count Y ceiling value. The counter is
  87                         reset to the Count Y floor value at count = ceiling when
  88                         counting up, while the counter is set to the Count Y
  89                         ceiling value at count = floor when counting down; the
  90                         counter does not freeze at the boundary points, but
  91                         counts continuously throughout.
  92
  93                 interrupt on terminal count:
  94                         The output signal is initially low, and will remain low
  95                         until the counter reaches zero. The output signal then
  96                         goes high and remains high until a new preset value is
  97                         set.
  98
  99                 hardware retriggerable one-shot:
 100                         The output signal is initially high. The output signal
 101                         will go low by a trigger input signal, and will remain
 102                         low until the counter reaches zero. The output will then
 103                         go high and remain high until the next trigger. A
 104                         trigger results in loading the counter to the preset
 105                         value and setting the output signal low, thus starting
 106                         the one-shot pulse.
 107
 108                 rate generator:
 109                         The output signal is initially high. When the counter
 110                         has decremented to 1, the output signal goes low for one
 111                         clock pulse. The output signal then goes high again, the
 112                         counter is reloaded to the preset value, and the process
 113                         repeats in a periodic manner as such.
 114
 115                 square wave mode:
 116                         The output signal is initially high.
 117
 118                         If the initial count is even, the counter is decremented
 119                         by two on succeeding clock pulses. When the count
 120                         expires, the output signal changes value and the
 121                         counter is reloaded to the preset value. The process
 122                         repeats in periodic manner as such.
 123
 124                         If the initial count is odd, the initial count minus one
 125                         (an even number) is loaded and then is decremented by
 126                         two on succeeding clock pulses. One clock pulse after
 127                         the count expires, the output signal goes low and the
 128                         counter is reloaded to the preset value minus one.
 129                         Succeeding clock pulses decrement the count by two. When
 130                         the count expires, the output goes high again and the
 131                         counter is reloaded to the preset value minus one. The
 132                         process repeats in a periodic manner as such.
 133
 134                 software triggered strobe:
 135                         The output signal is initially high. When the count
 136                         expires, the output will go low for one clock pulse and
 137                         then go high again. The counting sequence is "triggered"
 138                         by setting the preset value.
 139
 140                 hardware triggered strobe:
 141                         The output signal is initially high. Counting is started
 142                         by a trigger input signal. When the count expires, the
 143                         output signal will go low for one clock pulse and then
 144                         go high again. A trigger results in loading the counter
 145                         to the preset value.
 146
 147 What:           /sys/bus/counter/devices/counterX/countY/count_mode_available
 148 What:           /sys/bus/counter/devices/counterX/countY/error_noise_available
 149 What:           /sys/bus/counter/devices/counterX/countY/function_available
 150 What:           /sys/bus/counter/devices/counterX/countY/prescaler_available
 151 What:           /sys/bus/counter/devices/counterX/countY/signalZ_action_available
 152 KernelVersion:  5.2
 153 Contact:        linux-iio@vger.kernel.org
 154 Description:
 155                 Discrete set of available values for the respective Count Y
 156                 configuration are listed in this file. Values are delimited by
 157                 newline characters.
 158
 159 What:           /sys/bus/counter/devices/counterX/countY/direction
 160 KernelVersion:  5.2
 161 Contact:        linux-iio@vger.kernel.org
 162 Description:
 163                 Read-only attribute that indicates the count direction of Count
 164                 Y. Two count directions are available: forward and backward.
 165
 166                 Some counter devices are able to determine the direction of
 167                 their counting. For example, quadrature encoding counters can
 168                 determine the direction of movement by evaluating the leading
 169                 phase of the respective A and B quadrature encoding signals.
 170                 This attribute exposes such count directions.
 171
 172 What:           /sys/bus/counter/devices/counterX/countY/enable
 173 KernelVersion:  5.2
 174 Contact:        linux-iio@vger.kernel.org
 175 Description:
 176                 Whether channel Y counter is enabled. Valid attribute values are
 177                 boolean.
 178
 179                 This attribute is intended to serve as a pause/unpause mechanism
 180                 for Count Y. Suppose a counter device is used to count the total
 181                 movement of a conveyor belt: this attribute allows an operator
 182                 to temporarily pause the counter, service the conveyor belt,
 183                 and then finally unpause the counter to continue where it had
 184                 left off.
 185
 186 What:           /sys/bus/counter/devices/counterX/countY/error_noise
 187 KernelVersion:  5.2
 188 Contact:        linux-iio@vger.kernel.org
 189 Description:
 190                 Read-only attribute that indicates whether excessive noise is
 191                 present at the channel Y counter inputs.
 192
 193 What:           /sys/bus/counter/devices/counterX/countY/function
 194 KernelVersion:  5.2
 195 Contact:        linux-iio@vger.kernel.org
 196 Description:
 197                 Count function mode of Count Y; count function evaluation is
 198                 triggered by conditions specified by the Count Y signalZ_action
 199                 attributes. The following count functions are available:
 200
 201                 increase:
 202                         Accumulated count is incremented.
 203
 204                 decrease:
 205                         Accumulated count is decremented.
 206
 207                 pulse-direction:
 208                         Rising edges on signal A updates the respective count.
 209                         The input level of signal B determines direction.
 210
 211                 quadrature x1 a:
 212                         If direction is forward, rising edges on quadrature pair
 213                         signal A updates the respective count; if the direction
 214                         is backward, falling edges on quadrature pair signal A
 215                         updates the respective count. Quadrature encoding
 216                         determines the direction.
 217
 218                 quadrature x1 b:
 219                         If direction is forward, rising edges on quadrature pair
 220                         signal B updates the respective count; if the direction
 221                         is backward, falling edges on quadrature pair signal B
 222                         updates the respective count. Quadrature encoding
 223                         determines the direction.
 224
 225                 quadrature x2 a:
 226                         Any state transition on quadrature pair signal A updates
 227                         the respective count. Quadrature encoding determines the
 228                         direction.
 229
 230                 quadrature x2 b:
 231                         Any state transition on quadrature pair signal B updates
 232                         the respective count. Quadrature encoding determines the
 233                         direction.
 234
 235                 quadrature x4:
 236                         Any state transition on either quadrature pair signals
 237                         updates the respective count. Quadrature encoding
 238                         determines the direction.
 239
 240 What:           /sys/bus/counter/devices/counterX/countY/name
 241 KernelVersion:  5.2
 242 Contact:        linux-iio@vger.kernel.org
 243 Description:
 244                 Read-only attribute that indicates the device-specific name of
 245                 Count Y. If possible, this should match the name of the
 246                 respective channel as it appears in the device datasheet.
 247
 248 What:           /sys/bus/counter/devices/counterX/countY/prescaler
 249 KernelVersion:  5.2
 250 Contact:        linux-iio@vger.kernel.org
 251 Description:
 252                 Configure the prescaler value associated with Count Y.
 253                 On the FlexTimer, the counter clock source passes through a
 254                 prescaler (i.e. a counter). This acts like a clock
 255                 divider.
 256
 257 What:           /sys/bus/counter/devices/counterX/countY/preset
 258 KernelVersion:  5.2
 259 Contact:        linux-iio@vger.kernel.org
 260 Description:
 261                 If the counter device supports preset registers -- registers
 262                 used to load counter channels to a set count upon device-defined
 263                 preset operation trigger events -- the preset count for channel
 264                 Y is provided by this attribute.
 265
 266 What:           /sys/bus/counter/devices/counterX/countY/preset_enable
 267 KernelVersion:  5.2
 268 Contact:        linux-iio@vger.kernel.org
 269 Description:
 270                 Whether channel Y counter preset operation is enabled. Valid
 271                 attribute values are boolean.
 272
 273 What:           /sys/bus/counter/devices/counterX/countY/signalZ_action
 274 KernelVersion:  5.2
 275 Contact:        linux-iio@vger.kernel.org
 276 Description:
 277                 Action mode of Count Y for Signal Z. This attribute indicates
 278                 the condition of Signal Z that triggers the count function
 279                 evaluation for Count Y. The following action modes are
 280                 available:
 281
 282                 none:
 283                         Signal does not trigger the count function. In
 284                         Pulse-Direction count function mode, this Signal is
 285                         evaluated as Direction.
 286
 287                 rising edge:
 288                         Low state transitions to high state.
 289
 290                 falling edge:
 291                         High state transitions to low state.
 292
 293                 both edges:
 294                         Any state transition.
 295
 296 What:           /sys/bus/counter/devices/counterX/countY/num_overflows
 297 KernelVersion:  6.1
 298 Contact:        linux-iio@vger.kernel.org
 299 Description:
 300                 This attribute indicates the number of overflows of count Y.
 301
 302 What:           /sys/bus/counter/devices/counterX/cascade_counts_enable_component_id
 303 What:           /sys/bus/counter/devices/counterX/external_input_phase_clock_select_component_id
 304 What:           /sys/bus/counter/devices/counterX/countY/capture_component_id
 305 What:           /sys/bus/counter/devices/counterX/countY/ceiling_component_id
 306 What:           /sys/bus/counter/devices/counterX/countY/floor_component_id
 307 What:           /sys/bus/counter/devices/counterX/countY/count_mode_component_id
 308 What:           /sys/bus/counter/devices/counterX/countY/direction_component_id
 309 What:           /sys/bus/counter/devices/counterX/countY/enable_component_id
 310 What:           /sys/bus/counter/devices/counterX/countY/error_noise_component_id
 311 What:           /sys/bus/counter/devices/counterX/countY/prescaler_component_id
 312 What:           /sys/bus/counter/devices/counterX/countY/preset_component_id
 313 What:           /sys/bus/counter/devices/counterX/countY/preset_enable_component_id
 314 What:           /sys/bus/counter/devices/counterX/countY/signalZ_action_component_id
 315 What:           /sys/bus/counter/devices/counterX/countY/num_overflows_component_id
 316 What:           /sys/bus/counter/devices/counterX/signalY/cable_fault_component_id
 317 What:           /sys/bus/counter/devices/counterX/signalY/cable_fault_enable_component_id
 318 What:           /sys/bus/counter/devices/counterX/signalY/filter_clock_prescaler_component_id
 319 What:           /sys/bus/counter/devices/counterX/signalY/index_polarity_component_id
 320 What:           /sys/bus/counter/devices/counterX/signalY/polarity_component_id
 321 What:           /sys/bus/counter/devices/counterX/signalY/synchronous_mode_component_id
 322 What:           /sys/bus/counter/devices/counterX/signalY/frequency_component_id
 323 KernelVersion:  5.16
 324 Contact:        linux-iio@vger.kernel.org
 325 Description:
 326                 Read-only attribute that indicates the component ID of the
 327                 respective extension or Synapse.
 328
 329 What:           /sys/bus/counter/devices/counterX/countY/spike_filter_ns
 330 KernelVersion:  5.14
 331 Contact:        linux-iio@vger.kernel.org
 332 Description:
 333                 If the counter device supports programmable spike filter this
 334                 attribute indicates the value in nanoseconds where noise pulses
 335                 shorter or equal to configured value are ignored. Value 0 means
 336                 filter is disabled.
 337
 338 What:           /sys/bus/counter/devices/counterX/events_queue_size
 339 KernelVersion:  5.16
 340 Contact:        linux-iio@vger.kernel.org
 341 Description:
 342                 Size of the Counter events queue in number of struct
 343                 counter_event data structures. The number of elements will be
 344                 rounded-up to a power of 2.
 345
 346 What:           /sys/bus/counter/devices/counterX/name
 347 KernelVersion:  5.2
 348 Contact:        linux-iio@vger.kernel.org
 349 Description:
 350                 Read-only attribute that indicates the device-specific name of
 351                 the Counter. This should match the name of the device as it
 352                 appears in its respective datasheet.
 353
 354 What:           /sys/bus/counter/devices/counterX/num_counts
 355 KernelVersion:  5.2
 356 Contact:        linux-iio@vger.kernel.org
 357 Description:
 358                 Read-only attribute that indicates the total number of Counts
 359                 belonging to the Counter.
 360
 361 What:           /sys/bus/counter/devices/counterX/num_signals
 362 KernelVersion:  5.2
 363 Contact:        linux-iio@vger.kernel.org
 364 Description:
 365                 Read-only attribute that indicates the total number of Signals
 366                 belonging to the Counter.
 367
 368 What:           /sys/bus/counter/devices/counterX/signalY/cable_fault
 369 KernelVersion:  5.7
 370 Contact:        linux-iio@vger.kernel.org
 371 Description:
 372                 Read-only attribute that indicates whether a differential
 373                 encoder cable fault (not connected or loose wires) is detected
 374                 for the respective channel of Signal Y. Valid attribute values
 375                 are boolean. Detection must first be enabled via the
 376                 corresponding cable_fault_enable attribute.
 377
 378 What:           /sys/bus/counter/devices/counterX/signalY/cable_fault_enable
 379 KernelVersion:  5.7
 380 Contact:        linux-iio@vger.kernel.org
 381 Description:
 382                 Whether detection of differential encoder cable faults for the
 383                 respective channel of Signal Y is enabled. Valid attribute
 384                 values are boolean.
 385
 386 What:           /sys/bus/counter/devices/counterX/signalY/filter_clock_prescaler
 387 KernelVersion:  5.7
 388 Contact:        linux-iio@vger.kernel.org
 389 Description:
 390                 Filter clock factor for input Signal Y. This prescaler value
 391                 affects the inputs of both quadrature pair signals.
 392
 393 What:           /sys/bus/counter/devices/counterX/signalY/index_polarity
 394 KernelVersion:  5.2
 395 Contact:        linux-iio@vger.kernel.org
 396 Description:
 397                 Active level of index input Signal Y; irrelevant in
 398                 non-synchronous load mode.
 399
 400 What:           /sys/bus/counter/devices/counterX/signalY/index_polarity_available
 401 What:           /sys/bus/counter/devices/counterX/signalY/synchronous_mode_available
 402 KernelVersion:  5.2
 403 Contact:        linux-iio@vger.kernel.org
 404 Description:
 405                 Discrete set of available values for the respective Signal Y
 406                 configuration are listed in this file.
 407
 408 What:           /sys/bus/counter/devices/counterX/signalY/polarity
 409 KernelVersion:  6.1
 410 Contact:        linux-iio@vger.kernel.org
 411 Description:
 412                 Active level of Signal Y. The following polarity values are
 413                 available:
 414
 415                 positive:
 416                         Signal high state considered active level (rising edge).
 417
 418                 negative:
 419                         Signal low state considered active level (falling edge).
 420
 421 What:           /sys/bus/counter/devices/counterX/signalY/name
 422 KernelVersion:  5.2
 423 Contact:        linux-iio@vger.kernel.org
 424 Description:
 425                 Read-only attribute that indicates the device-specific name of
 426                 Signal Y. If possible, this should match the name of the
 427                 respective signal as it appears in the device datasheet.
 428
 429 What:           /sys/bus/counter/devices/counterX/signalY/signal
 430 KernelVersion:  5.2
 431 Contact:        linux-iio@vger.kernel.org
 432 Description:
 433                 Signal level state of Signal Y. The following signal level
 434                 states are available:
 435
 436                 low:
 437                         Low level state.
 438
 439                 high:
 440                         High level state.
 441
 442 What:           /sys/bus/counter/devices/counterX/signalY/synchronous_mode
 443 KernelVersion:  5.2
 444 Contact:        linux-iio@vger.kernel.org
 445 Description:
 446                 Configure the counter associated with Signal Y for
 447                 non-synchronous or synchronous load mode. Synchronous load mode
 448                 cannot be selected in non-quadrature (Pulse-Direction) clock
 449                 mode.
 450
 451                 non-synchronous:
 452                         A logic low level is the active level at this index
 453                         input. The index function (as enabled via preset_enable)
 454                         is performed directly on the active level of the index
 455                         input.
 456
 457                 synchronous:
 458                         Intended for interfacing with encoder Index output in
 459                         quadrature clock mode. The active level is configured
 460                         via index_polarity. The index function (as enabled via
 461                         preset_enable) is performed synchronously with the
 462                         quadrature clock on the active level of the index input.
 463
 464 What:           /sys/bus/counter/devices/counterX/signalY/frequency
 465 KernelVersion:  6.1
 466 Contact:        linux-iio@vger.kernel.org
 467 Description:
 468                 Read-only attribute that indicates the signal Y frequency, in Hz.