1Kernel driver jc42 2================== 3 4Supported chips: 5 * Analog Devices ADT7408 6 Datasheets: 7 http://www.analog.com/static/imported-files/data_sheets/ADT7408.pdf 8 * Atmel AT30TS00 9 Datasheets: 10 http://www.atmel.com/Images/doc8585.pdf 11 * IDT TSE2002B3, TSE2002GB2, TS3000B3, TS3000GB2 12 Datasheets: 13 http://www.idt.com/sites/default/files/documents/IDT_TSE2002B3C_DST_20100512_120303152056.pdf 14 http://www.idt.com/sites/default/files/documents/IDT_TSE2002GB2A1_DST_20111107_120303145914.pdf 15 http://www.idt.com/sites/default/files/documents/IDT_TS3000B3A_DST_20101129_120303152013.pdf 16 http://www.idt.com/sites/default/files/documents/IDT_TS3000GB2A1_DST_20111104_120303151012.pdf 17 * Maxim MAX6604 18 Datasheets: 19 http://datasheets.maxim-ic.com/en/ds/MAX6604.pdf 20 * Microchip MCP9804, MCP9805, MCP98242, MCP98243, 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 * NXP Semiconductors SE97, SE97B, SE98, SE98A 27 Datasheets: 28 http://www.nxp.com/documents/data_sheet/SE97.pdf 29 http://www.nxp.com/documents/data_sheet/SE97B.pdf 30 http://www.nxp.com/documents/data_sheet/SE98.pdf 31 http://www.nxp.com/documents/data_sheet/SE98A.pdf 32 * ON Semiconductor CAT34TS02, CAT6095 33 Datasheet: 34 http://www.onsemi.com/pub_link/Collateral/CAT34TS02-D.PDF 35 http://www.onsemi.com/pub/Collateral/CAT6095-D.PDF 36 * ST Microelectronics STTS424, STTS424E02, STTS2002, STTS3000 37 Datasheets: 38 http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00157556.pdf 39 http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00157558.pdf 40 http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00225278.pdf 41 http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATA_BRIEF/CD00270920.pdf 42 * JEDEC JC 42.4 compliant temperature sensor chips 43 Datasheet: 44 http://www.jedec.org/sites/default/files/docs/4_01_04R19.pdf 45 46 Common for all chips: 47 Prefix: 'jc42' 48 Addresses scanned: I2C 0x18 - 0x1f 49 50Author: 51 Guenter Roeck <guenter.roeck@ericsson.com> 52 53 54Description 55----------- 56 57This driver implements support for JEDEC JC 42.4 compliant temperature sensors, 58which are used on many DDR3 memory modules for mobile devices and servers. Some 59systems use the sensor to prevent memory overheating by automatically throttling 60the memory controller. 61 62The driver auto-detects the chips listed above, but can be manually instantiated 63to support other JC 42.4 compliant chips. 64 65Example: the following will load the driver for a generic JC 42.4 compliant 66temperature sensor at address 0x18 on I2C bus #1: 67 68# modprobe jc42 69# echo jc42 0x18 > /sys/bus/i2c/devices/i2c-1/new_device 70 71A JC 42.4 compliant chip supports a single temperature sensor. Minimum, maximum, 72and critical temperature can be configured. There are alarms for high, low, 73and critical thresholds. 74 75There is also an hysteresis to control the thresholds for resetting alarms. 76Per JC 42.4 specification, the hysteresis threshold can be configured to 0, 1.5, 773.0, and 6.0 degrees C. Configured hysteresis values will be rounded to those 78limits. The chip supports only a single register to configure the hysteresis, 79which applies to all limits. This register can be written by writing into 80temp1_crit_hyst. Other hysteresis attributes are read-only. 81 82If the BIOS has configured the sensor for automatic temperature management, it 83is likely that it has locked the registers, i.e., that the temperature limits 84cannot be changed. 85 86Sysfs entries 87------------- 88 89temp1_input Temperature (RO) 90temp1_min Minimum temperature (RO or RW) 91temp1_max Maximum temperature (RO or RW) 92temp1_crit Critical high temperature (RO or RW) 93 94temp1_crit_hyst Critical hysteresis temperature (RO or RW) 95temp1_max_hyst Maximum hysteresis temperature (RO) 96 97temp1_min_alarm Temperature low alarm 98temp1_max_alarm Temperature high alarm 99temp1_crit_alarm Temperature critical alarm 100