max31790.rst 1.4 KB

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  1. Kernel driver max31790
  2. ======================
  3. Supported chips:
  4. * Maxim MAX31790
  5. Prefix: 'max31790'
  6. Addresses scanned: -
  7. Datasheet: https://pdfserv.maximintegrated.com/en/ds/MAX31790.pdf
  8. Author: Il Han <corone.il.han@gmail.com>
  9. Description
  10. -----------
  11. This driver implements support for the Maxim MAX31790 chip.
  12. The MAX31790 controls the speeds of up to six fans using six independent
  13. PWM outputs. The desired fan speeds (or PWM duty cycles) are written
  14. through the I2C interface. The outputs drive "4-wire" fans directly,
  15. or can be used to modulate the fan's power terminals using an external
  16. pass transistor.
  17. Tachometer inputs monitor fan tachometer logic outputs for precise (+/-1%)
  18. monitoring and control of fan RPM as well as detection of fan failure.
  19. Six pins are dedicated tachometer inputs. Any of the six PWM outputs can
  20. also be configured to serve as tachometer inputs.
  21. Sysfs entries
  22. -------------
  23. ================== === =======================================================
  24. fan[1-12]_input RO fan tachometer speed in RPM
  25. fan[1-12]_fault RO fan experienced fault
  26. fan[1-6]_target RW desired fan speed in RPM
  27. pwm[1-6]_enable RW regulator mode, 0=disabled (duty cycle=0%), 1=manual mode, 2=rpm mode
  28. pwm[1-6] RW read: current pwm duty cycle,
  29. write: target pwm duty cycle (0-255)
  30. ================== === =======================================================