jc42 4.0 KB

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  1. Kernel driver jc42
  2. ==================
  3. Supported chips:
  4. * Analog Devices ADT7408
  5. Datasheets:
  6. http://www.analog.com/static/imported-files/data_sheets/ADT7408.pdf
  7. * Atmel AT30TS00, AT30TS002A/B, AT30TSE004A
  8. Datasheets:
  9. http://www.atmel.com/Images/doc8585.pdf
  10. http://www.atmel.com/Images/doc8711.pdf
  11. http://www.atmel.com/Images/Atmel-8852-SEEPROM-AT30TSE002A-Datasheet.pdf
  12. http://www.atmel.com/Images/Atmel-8868-DTS-AT30TSE004A-Datasheet.pdf
  13. * IDT TSE2002B3, TSE2002GB2, TSE2004GB2, TS3000B3, TS3000GB0, TS3000GB2,
  14. TS3001GB2
  15. Datasheets:
  16. Available from IDT web site
  17. * Maxim MAX6604
  18. Datasheets:
  19. http://datasheets.maxim-ic.com/en/ds/MAX6604.pdf
  20. * Microchip MCP9804, MCP9805, MCP98242, MCP98243, MCP98244, MCP9843
  21. Datasheets:
  22. http://ww1.microchip.com/downloads/en/DeviceDoc/22203C.pdf
  23. http://ww1.microchip.com/downloads/en/DeviceDoc/21977b.pdf
  24. http://ww1.microchip.com/downloads/en/DeviceDoc/21996a.pdf
  25. http://ww1.microchip.com/downloads/en/DeviceDoc/22153c.pdf
  26. http://ww1.microchip.com/downloads/en/DeviceDoc/22327A.pdf
  27. * NXP Semiconductors SE97, SE97B, SE98, SE98A
  28. Datasheets:
  29. http://www.nxp.com/documents/data_sheet/SE97.pdf
  30. http://www.nxp.com/documents/data_sheet/SE97B.pdf
  31. http://www.nxp.com/documents/data_sheet/SE98.pdf
  32. http://www.nxp.com/documents/data_sheet/SE98A.pdf
  33. * ON Semiconductor CAT34TS02, CAT6095
  34. Datasheet:
  35. http://www.onsemi.com/pub_link/Collateral/CAT34TS02-D.PDF
  36. http://www.onsemi.com/pub/Collateral/CAT6095-D.PDF
  37. * ST Microelectronics STTS424, STTS424E02, STTS2002, STTS2004, STTS3000
  38. Datasheets:
  39. http://www.st.com/web/en/resource/technical/document/datasheet/CD00157556.pdf
  40. http://www.st.com/web/en/resource/technical/document/datasheet/CD00157558.pdf
  41. http://www.st.com/web/en/resource/technical/document/datasheet/CD00266638.pdf
  42. http://www.st.com/web/en/resource/technical/document/datasheet/CD00225278.pdf
  43. http://www.st.com/web/en/resource/technical/document/datasheet/DM00076709.pdf
  44. * JEDEC JC 42.4 compliant temperature sensor chips
  45. Datasheet:
  46. http://www.jedec.org/sites/default/files/docs/4_01_04R19.pdf
  47. Common for all chips:
  48. Prefix: 'jc42'
  49. Addresses scanned: I2C 0x18 - 0x1f
  50. Author:
  51. Guenter Roeck <linux@roeck-us.net>
  52. Description
  53. -----------
  54. This driver implements support for JEDEC JC 42.4 compliant temperature sensors,
  55. which are used on many DDR3 memory modules for mobile devices and servers. Some
  56. systems use the sensor to prevent memory overheating by automatically throttling
  57. the memory controller.
  58. The driver auto-detects the chips listed above, but can be manually instantiated
  59. to support other JC 42.4 compliant chips.
  60. Example: the following will load the driver for a generic JC 42.4 compliant
  61. temperature sensor at address 0x18 on I2C bus #1:
  62. # modprobe jc42
  63. # echo jc42 0x18 > /sys/bus/i2c/devices/i2c-1/new_device
  64. A JC 42.4 compliant chip supports a single temperature sensor. Minimum, maximum,
  65. and critical temperature can be configured. There are alarms for high, low,
  66. and critical thresholds.
  67. There is also an hysteresis to control the thresholds for resetting alarms.
  68. Per JC 42.4 specification, the hysteresis threshold can be configured to 0, 1.5,
  69. 3.0, and 6.0 degrees C. Configured hysteresis values will be rounded to those
  70. limits. The chip supports only a single register to configure the hysteresis,
  71. which applies to all limits. This register can be written by writing into
  72. temp1_crit_hyst. Other hysteresis attributes are read-only.
  73. If the BIOS has configured the sensor for automatic temperature management, it
  74. is likely that it has locked the registers, i.e., that the temperature limits
  75. cannot be changed.
  76. Sysfs entries
  77. -------------
  78. temp1_input Temperature (RO)
  79. temp1_min Minimum temperature (RO or RW)
  80. temp1_max Maximum temperature (RO or RW)
  81. temp1_crit Critical high temperature (RO or RW)
  82. temp1_crit_hyst Critical hysteresis temperature (RO or RW)
  83. temp1_max_hyst Maximum hysteresis temperature (RO)
  84. temp1_min_alarm Temperature low alarm
  85. temp1_max_alarm Temperature high alarm
  86. temp1_crit_alarm Temperature critical alarm