ltc2947.rst 3.5 KB

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  1. Kernel drivers ltc2947-i2c and ltc2947-spi
  2. ==========================================
  3. Supported chips:
  4. * Analog Devices LTC2947
  5. Prefix: 'ltc2947'
  6. Addresses scanned: -
  7. Datasheet:
  8. https://www.analog.com/media/en/technical-documentation/data-sheets/LTC2947.pdf
  9. Author: Nuno Sá <nuno.sa@analog.com>
  10. Description
  11. ___________
  12. The LTC2947 is a high precision power and energy monitor that measures current,
  13. voltage, power, temperature, charge and energy. The device supports both SPI
  14. and I2C depending on the chip configuration.
  15. The device also measures accumulated quantities as energy. It has two banks of
  16. register's to read/set energy related values. These banks can be configured
  17. independently to have setups like: energy1 accumulates always and enrgy2 only
  18. accumulates if current is positive (to check battery charging efficiency for
  19. example). The device also supports a GPIO pin that can be configured as output
  20. to control a fan as a function of measured temperature. Then, the GPIO becomes
  21. active as soon as a temperature reading is higher than a defined threshold. The
  22. temp2 channel is used to control this thresholds and to read the respective
  23. alarms.
  24. Sysfs entries
  25. _____________
  26. The following attributes are supported. Limits are read-write, reset_history
  27. is write-only and all the other attributes are read-only.
  28. ======================= ==========================================
  29. in0_input VP-VM voltage (mV).
  30. in0_min Undervoltage threshold
  31. in0_max Overvoltage threshold
  32. in0_lowest Lowest measured voltage
  33. in0_highest Highest measured voltage
  34. in0_reset_history Write 1 to reset in1 history
  35. in0_min_alarm Undervoltage alarm
  36. in0_max_alarm Overvoltage alarm
  37. in0_label Channel label (VP-VM)
  38. in1_input DVCC voltage (mV)
  39. in1_min Undervoltage threshold
  40. in1_max Overvoltage threshold
  41. in1_lowest Lowest measured voltage
  42. in1_highest Highest measured voltage
  43. in1_reset_history Write 1 to reset in2 history
  44. in1_min_alarm Undervoltage alarm
  45. in1_max_alarm Overvoltage alarm
  46. in1_label Channel label (DVCC)
  47. curr1_input IP-IM Sense current (mA)
  48. curr1_min Undercurrent threshold
  49. curr1_max Overcurrent threshold
  50. curr1_lowest Lowest measured current
  51. curr1_highest Highest measured current
  52. curr1_reset_history Write 1 to reset curr1 history
  53. curr1_min_alarm Undercurrent alarm
  54. curr1_max_alarm Overcurrent alarm
  55. curr1_label Channel label (IP-IM)
  56. power1_input Power (in uW)
  57. power1_min Low power threshold
  58. power1_max High power threshold
  59. power1_input_lowest Historical minimum power use
  60. power1_input_highest Historical maximum power use
  61. power1_reset_history Write 1 to reset power1 history
  62. power1_min_alarm Low power alarm
  63. power1_max_alarm High power alarm
  64. power1_label Channel label (Power)
  65. temp1_input Chip Temperature (in milliC)
  66. temp1_min Low temperature threshold
  67. temp1_max High temperature threshold
  68. temp1_input_lowest Historical minimum temperature use
  69. temp1_input_highest Historical maximum temperature use
  70. temp1_reset_history Write 1 to reset temp1 history
  71. temp1_min_alarm Low temperature alarm
  72. temp1_max_alarm High temperature alarm
  73. temp1_label Channel label (Ambient)
  74. temp2_min Low temperature threshold for fan control
  75. temp2_max High temperature threshold for fan control
  76. temp2_min_alarm Low temperature fan control alarm
  77. temp2_max_alarm High temperature fan control alarm
  78. temp2_label Channel label (TEMPFAN)
  79. energy1_input Measured energy over time (in microJoule)
  80. energy2_input Measured energy over time (in microJoule)
  81. ======================= ==========================================