Documentation/hwmon/jc42

   1 Kernel driver jc42
   2 ==================
   3
   4 Supported chips:
   5   * Analog Devices ADT7408
   6     Prefix: 'adt7408'
   7     Addresses scanned: I2C 0x18 - 0x1f
   8     Datasheets:
   9         http://www.analog.com/static/imported-files/data_sheets/ADT7408.pdf
  10   * Atmel AT30TS00
  11     Prefix: 'at30ts00'
  12     Addresses scanned: I2C 0x18 - 0x1f
  13     Datasheets:
  14         http://www.atmel.com/Images/doc8585.pdf
  15   * IDT TSE2002B3, TSE2002GB2, TS3000B3, TS3000GB2
  16     Prefix: 'tse2002', 'ts3000'
  17     Addresses scanned: I2C 0x18 - 0x1f
  18     Datasheets:
  19         http://www.idt.com/sites/default/files/documents/IDT_TSE2002B3C_DST_20100512_120303152056.pdf
  20         http://www.idt.com/sites/default/files/documents/IDT_TSE2002GB2A1_DST_20111107_120303145914.pdf
  21         http://www.idt.com/sites/default/files/documents/IDT_TS3000B3A_DST_20101129_120303152013.pdf
  22         http://www.idt.com/sites/default/files/documents/IDT_TS3000GB2A1_DST_20111104_120303151012.pdf
  23   * Maxim MAX6604
  24     Prefix: 'max6604'
  25     Addresses scanned: I2C 0x18 - 0x1f
  26     Datasheets:
  27         http://datasheets.maxim-ic.com/en/ds/MAX6604.pdf
  28   * Microchip MCP9804, MCP9805, MCP98242, MCP98243, MCP9843
  29     Prefixes: 'mcp9804', 'mcp9805', 'mcp98242', 'mcp98243', 'mcp9843'
  30     Addresses scanned: I2C 0x18 - 0x1f
  31     Datasheets:
  32         http://ww1.microchip.com/downloads/en/DeviceDoc/22203C.pdf
  33         http://ww1.microchip.com/downloads/en/DeviceDoc/21977b.pdf
  34         http://ww1.microchip.com/downloads/en/DeviceDoc/21996a.pdf
  35         http://ww1.microchip.com/downloads/en/DeviceDoc/22153c.pdf
  36   * NXP Semiconductors SE97, SE97B
  37     Prefix: 'se97'
  38     Addresses scanned: I2C 0x18 - 0x1f
  39     Datasheets:
  40         http://www.nxp.com/documents/data_sheet/SE97.pdf
  41         http://www.nxp.com/documents/data_sheet/SE97B.pdf
  42   * NXP Semiconductors SE98
  43     Prefix: 'se98'
  44     Addresses scanned: I2C 0x18 - 0x1f
  45     Datasheets:
  46         http://www.nxp.com/documents/data_sheet/SE98.pdf
  47   * ON Semiconductor CAT34TS02, CAT6095
  48     Prefix: 'cat34ts02', 'cat6095'
  49     Addresses scanned: I2C 0x18 - 0x1f
  50     Datasheet:
  51         http://www.onsemi.com/pub_link/Collateral/CAT34TS02-D.PDF
  52         http://www.onsemi.com/pub/Collateral/CAT6095-D.PDF
  53   * ST Microelectronics STTS424, STTS424E02
  54     Prefix: 'stts424'
  55     Addresses scanned: I2C 0x18 - 0x1f
  56     Datasheets:
  57         http://www.st.com/stonline/products/literature/ds/13447/stts424.pdf
  58         http://www.st.com/stonline/products/literature/ds/13448/stts424e02.pdf
  59   * ST Microelectronics STTS2002, STTS3000
  60     Prefix: 'stts2002', 'stts3000'
  61     Addresses scanned: I2C 0x18 - 0x1f
  62     Datasheets:
  63         http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00225278.pdf
  64         http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATA_BRIEF/CD00270920.pdf
  65   * JEDEC JC 42.4 compliant temperature sensor chips
  66     Prefix: 'jc42'
  67     Addresses scanned: I2C 0x18 - 0x1f
  68     Datasheet:
  69         http://www.jedec.org/sites/default/files/docs/4_01_04R19.pdf
  70
  71 Author:
  72         Guenter Roeck <guenter.roeck@ericsson.com>
  73
  74
  75 Description
  76 -----------
  77
  78 This driver implements support for JEDEC JC 42.4 compliant temperature sensors,
  79 which are used on many DDR3 memory modules for mobile devices and servers. Some
  80 systems use the sensor to prevent memory overheating by automatically throttling
  81 the memory controller.
  82
  83 The driver auto-detects the chips listed above, but can be manually instantiated
  84 to support other JC 42.4 compliant chips.
  85
  86 Example: the following will load the driver for a generic JC 42.4 compliant
  87 temperature sensor at address 0x18 on I2C bus #1:
  88
  89 # modprobe jc42
  90 # echo jc42 0x18 > /sys/bus/i2c/devices/i2c-1/new_device
  91
  92 A JC 42.4 compliant chip supports a single temperature sensor. Minimum, maximum,
  93 and critical temperature can be configured. There are alarms for high, low,
  94 and critical thresholds.
  95
  96 There is also an hysteresis to control the thresholds for resetting alarms.
  97 Per JC 42.4 specification, the hysteresis threshold can be configured to 0, 1.5,
  98 3.0, and 6.0 degrees C. Configured hysteresis values will be rounded to those
  99 limits. The chip supports only a single register to configure the hysteresis,
 100 which applies to all limits. This register can be written by writing into
 101 temp1_crit_hyst. Other hysteresis attributes are read-only.
 102
 103 If the BIOS has configured the sensor for automatic temperature management, it
 104 is likely that it has locked the registers, i.e., that the temperature limits
 105 cannot be changed.
 106
 107 Sysfs entries
 108 -------------
 109
 110 temp1_input             Temperature (RO)
 111 temp1_min               Minimum temperature (RO or RW)
 112 temp1_max               Maximum temperature (RO or RW)
 113 temp1_crit              Critical high temperature (RO or RW)
 114
 115 temp1_crit_hyst         Critical hysteresis temperature (RO or RW)
 116 temp1_max_hyst          Maximum hysteresis temperature (RO)
 117
 118 temp1_min_alarm         Temperature low alarm
 119 temp1_max_alarm         Temperature high alarm
 120 temp1_crit_alarm        Temperature critical alarm