| Guenter Roeck | 4453d73 | 2010-08-09 17:21:08 -0700 | [diff] [blame] | 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 |
| Guenter Roeck | 1bd612a | 2012-03-05 11:13:52 -0800 | [diff] [blame^] | 10 | * Atmel AT30TS00 |
| 11 | Prefix: 'at30ts00' |
| Guenter Roeck | 4453d73 | 2010-08-09 17:21:08 -0700 | [diff] [blame] | 12 | Addresses scanned: I2C 0x18 - 0x1f |
| 13 | Datasheets: |
| Guenter Roeck | 1bd612a | 2012-03-05 11:13:52 -0800 | [diff] [blame^] | 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 |
| Guenter Roeck | 4453d73 | 2010-08-09 17:21:08 -0700 | [diff] [blame] | 23 | * Maxim MAX6604 |
| 24 | Prefix: 'max6604' |
| 25 | Addresses scanned: I2C 0x18 - 0x1f |
| 26 | Datasheets: |
| 27 | http://datasheets.maxim-ic.com/en/ds/MAX6604.pdf |
| Guenter Roeck | 1bd612a | 2012-03-05 11:13:52 -0800 | [diff] [blame^] | 28 | * Microchip MCP9804, MCP9805, MCP98242, MCP98243, MCP9843 |
| 29 | Prefixes: 'mcp9804', 'mcp9805', 'mcp98242', 'mcp98243', 'mcp9843' |
| Guenter Roeck | 4453d73 | 2010-08-09 17:21:08 -0700 | [diff] [blame] | 30 | Addresses scanned: I2C 0x18 - 0x1f |
| 31 | Datasheets: |
| Guenter Roeck | 1bd612a | 2012-03-05 11:13:52 -0800 | [diff] [blame^] | 32 | http://ww1.microchip.com/downloads/en/DeviceDoc/22203C.pdf |
| Guenter Roeck | 4453d73 | 2010-08-09 17:21:08 -0700 | [diff] [blame] | 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 |
| Jean Delvare | 4de8612 | 2012-03-05 08:32:00 -0500 | [diff] [blame] | 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 |
| Guenter Roeck | 4453d73 | 2010-08-09 17:21:08 -0700 | [diff] [blame] | 65 | * JEDEC JC 42.4 compliant temperature sensor chips |
| 66 | Prefix: 'jc42' |
| 67 | Addresses scanned: I2C 0x18 - 0x1f |
| Clemens Ladisch | d5622f5 | 2011-02-16 08:02:08 -0500 | [diff] [blame] | 68 | Datasheet: |
| 69 | http://www.jedec.org/sites/default/files/docs/4_01_04R19.pdf |
| Guenter Roeck | 4453d73 | 2010-08-09 17:21:08 -0700 | [diff] [blame] | 70 | |
| 71 | Author: |
| 72 | Guenter Roeck <guenter.roeck@ericsson.com> |
| 73 | |
| 74 | |
| 75 | Description |
| 76 | ----------- |
| 77 | |
| Clemens Ladisch | d5622f5 | 2011-02-16 08:02:08 -0500 | [diff] [blame] | 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 | |
| Guenter Roeck | 4453d73 | 2010-08-09 17:21:08 -0700 | [diff] [blame] | 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 | |
| Clemens Ladisch | 2c6315d | 2011-02-16 08:02:38 -0500 | [diff] [blame] | 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 | |
| Guenter Roeck | 4453d73 | 2010-08-09 17:21:08 -0700 | [diff] [blame] | 107 | Sysfs entries |
| 108 | ------------- |
| 109 | |
| 110 | temp1_input Temperature (RO) |
| Clemens Ladisch | 2c6315d | 2011-02-16 08:02:38 -0500 | [diff] [blame] | 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) |
| Guenter Roeck | 4453d73 | 2010-08-09 17:21:08 -0700 | [diff] [blame] | 114 | |
| Clemens Ladisch | 2c6315d | 2011-02-16 08:02:38 -0500 | [diff] [blame] | 115 | temp1_crit_hyst Critical hysteresis temperature (RO or RW) |
| Guenter Roeck | 4453d73 | 2010-08-09 17:21:08 -0700 | [diff] [blame] | 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 |