emc2103.rst 1.2 KB

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  1. Kernel driver emc2103
  2. ======================
  3. Supported chips:
  4. * SMSC EMC2103
  5. Addresses scanned: I2C 0x2e
  6. Prefix: 'emc2103'
  7. Datasheet: Not public
  8. Authors:
  9. Steve Glendinning <steve.glendinning@smsc.com>
  10. Description
  11. -----------
  12. The Standard Microsystems Corporation (SMSC) EMC2103 chips
  13. contain up to 4 temperature sensors and a single fan controller.
  14. Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
  15. triggered if the rotation speed has dropped below a programmable limit. Fan
  16. readings can be divided by a programmable divider (1, 2, 4 or 8) to give
  17. the readings more range or accuracy. Not all RPM values can accurately be
  18. represented, so some rounding is done. With a divider of 1, the lowest
  19. representable value is 480 RPM.
  20. This driver supports RPM based control, to use this a fan target
  21. should be written to fan1_target and pwm1_enable should be set to 3.
  22. The 2103-2 and 2103-4 variants have a third temperature sensor, which can
  23. be connected to two anti-parallel diodes. These values can be read
  24. as temp3 and temp4. If only one diode is attached to this channel, temp4
  25. will show as "fault". The module parameter "apd=0" can be used to suppress
  26. this 4th channel when anti-parallel diodes are not fitted.