max6650 1.8 KB

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  1. Kernel driver max6650
  2. =====================
  3. Supported chips:
  4. * Maxim 6650 / 6651
  5. Prefix: 'max6650'
  6. Addresses scanned: I2C 0x1b, 0x1f, 0x48, 0x4b
  7. Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
  8. Authors:
  9. Hans J. Koch <hjk@linutronix.de>
  10. John Morris <john.morris@spirentcom.com>
  11. Claus Gindhart <claus.gindhart@kontron.com>
  12. Description
  13. -----------
  14. This driver implements support for the Maxim 6650/6651
  15. The 2 devices are very similar, but the Maxim 6550 has a reduced feature
  16. set, e.g. only one fan-input, instead of 4 for the 6651.
  17. The driver is not able to distinguish between the 2 devices.
  18. The driver provides the following sensor accesses in sysfs:
  19. fan1_input ro fan tachometer speed in RPM
  20. fan2_input ro "
  21. fan3_input ro "
  22. fan4_input ro "
  23. fan1_target rw desired fan speed in RPM (closed loop mode only)
  24. pwm1_enable rw regulator mode, 0=full on, 1=open loop, 2=closed loop
  25. pwm1 rw relative speed (0-255), 255=max. speed.
  26. Used in open loop mode only.
  27. fan1_div rw sets the speed range the inputs can handle. Legal
  28. values are 1, 2, 4, and 8. Use lower values for
  29. faster fans.
  30. Module parameters
  31. -----------------
  32. If your board has a BIOS that initializes the MAX6650/6651 correctly, you can
  33. simply load your module without parameters. It won't touch the configuration
  34. registers then. If your board BIOS doesn't initialize the chip, or you want
  35. different settings, you can set the following parameters:
  36. voltage_12V: 5=5V fan, 12=12V fan, 0=don't change
  37. prescaler: Possible values are 1,2,4,8,16, or 0 for don't change
  38. clock: The clock frequency in Hz of the chip the driver should assume [254000]
  39. Please have a look at the MAX6650/6651 data sheet and make sure that you fully
  40. understand the meaning of these parameters before you attempt to change them.