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