sysfs-class-pwm 2.5 KB

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  1. What: /sys/class/pwm/
  2. Date: May 2013
  3. KernelVersion: 3.11
  4. Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
  5. Description:
  6. The pwm/ class sub-directory belongs to the Generic PWM
  7. Framework and provides a sysfs interface for using PWM
  8. channels.
  9. What: /sys/class/pwm/pwmchipN/
  10. Date: May 2013
  11. KernelVersion: 3.11
  12. Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
  13. Description:
  14. A /sys/class/pwm/pwmchipN directory is created for each
  15. probed PWM controller/chip where N is the base of the
  16. PWM chip.
  17. What: /sys/class/pwm/pwmchipN/npwm
  18. Date: May 2013
  19. KernelVersion: 3.11
  20. Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
  21. Description:
  22. The number of PWM channels supported by the PWM chip.
  23. What: /sys/class/pwm/pwmchipN/export
  24. Date: May 2013
  25. KernelVersion: 3.11
  26. Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
  27. Description:
  28. Exports a PWM channel from the PWM chip for sysfs control.
  29. Value is between 0 and /sys/class/pwm/pwmchipN/npwm - 1.
  30. What: /sys/class/pwm/pwmchipN/unexport
  31. Date: May 2013
  32. KernelVersion: 3.11
  33. Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
  34. Description:
  35. Unexports a PWM channel.
  36. What: /sys/class/pwm/pwmchipN/pwmX
  37. Date: May 2013
  38. KernelVersion: 3.11
  39. Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
  40. Description:
  41. A /sys/class/pwm/pwmchipN/pwmX directory is created for
  42. each exported PWM channel where X is the exported PWM
  43. channel number.
  44. What: /sys/class/pwm/pwmchipN/pwmX/period
  45. Date: May 2013
  46. KernelVersion: 3.11
  47. Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
  48. Description:
  49. Sets the PWM signal period in nanoseconds.
  50. What: /sys/class/pwm/pwmchipN/pwmX/duty_cycle
  51. Date: May 2013
  52. KernelVersion: 3.11
  53. Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
  54. Description:
  55. Sets the PWM signal duty cycle in nanoseconds.
  56. What: /sys/class/pwm/pwmchipN/pwmX/polarity
  57. Date: May 2013
  58. KernelVersion: 3.11
  59. Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
  60. Description:
  61. Sets the output polarity of the PWM signal to "normal" or
  62. "inversed".
  63. What: /sys/class/pwm/pwmchipN/pwmX/enable
  64. Date: May 2013
  65. KernelVersion: 3.11
  66. Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
  67. Description:
  68. Enable/disable the PWM signal.
  69. 0 is disabled
  70. 1 is enabled
  71. What: /sys/class/pwm/pwmchipN/pwmX/capture
  72. Date: June 2016
  73. KernelVersion: 4.8
  74. Contact: Lee Jones <lee.jones@linaro.org>
  75. Description:
  76. Capture information about a PWM signal. The output format is a
  77. pair unsigned integers (period and duty cycle), separated by a
  78. single space.