ltc2990.rst 1.8 KB

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  1. Kernel driver ltc2990
  2. =====================
  3. Supported chips:
  4. * Linear Technology LTC2990
  5. Prefix: 'ltc2990'
  6. Addresses scanned: -
  7. Datasheet: http://www.linear.com/product/ltc2990
  8. Author:
  9. - Mike Looijmans <mike.looijmans@topic.nl>
  10. - Tom Levens <tom.levens@cern.ch>
  11. Description
  12. -----------
  13. LTC2990 is a Quad I2C Voltage, Current and Temperature Monitor.
  14. The chip's inputs can measure 4 voltages, or two inputs together (1+2 and 3+4)
  15. can be combined to measure a differential voltage, which is typically used to
  16. measure current through a series resistor, or a temperature with an external
  17. diode.
  18. Usage Notes
  19. -----------
  20. This driver does not probe for PMBus devices. You will have to instantiate
  21. devices explicitly.
  22. Sysfs attributes
  23. ----------------
  24. ============= ==================================================
  25. in0_input Voltage at Vcc pin in millivolt (range 2.5V to 5V)
  26. temp1_input Internal chip temperature in millidegrees Celsius
  27. ============= ==================================================
  28. A subset of the following attributes are visible, depending on the measurement
  29. mode of the chip.
  30. ============= ==========================================================
  31. in[1-4]_input Voltage at V[1-4] pin in millivolt
  32. temp2_input External temperature sensor TR1 in millidegrees Celsius
  33. temp3_input External temperature sensor TR2 in millidegrees Celsius
  34. curr1_input Current in mA across V1-V2 assuming a 1mOhm sense resistor
  35. curr2_input Current in mA across V3-V4 assuming a 1mOhm sense resistor
  36. ============= ==========================================================
  37. The "curr*_input" measurements actually report the voltage drop across the
  38. input pins in microvolts. This is equivalent to the current through a 1mOhm
  39. sense resistor. Divide the reported value by the actual sense resistor value
  40. in mOhm to get the actual value.