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, AT30TS002A/B, AT30TSE004A
9    Datasheets:
10	http://www.atmel.com/Images/doc8585.pdf
11	http://www.atmel.com/Images/doc8711.pdf
12	http://www.atmel.com/Images/Atmel-8852-SEEPROM-AT30TSE002A-Datasheet.pdf
13	http://www.atmel.com/Images/Atmel-8868-DTS-AT30TSE004A-Datasheet.pdf
14  * IDT TSE2002B3, TSE2002GB2, TSE2004GB2, TS3000B3, TS3000GB0, TS3000GB2,
15	TS3001GB2
16    Datasheets:
17	Available from IDT web site
18  * Maxim MAX6604
19    Datasheets:
20	http://datasheets.maxim-ic.com/en/ds/MAX6604.pdf
21  * Microchip MCP9804, MCP9805, MCP98242, MCP98243, MCP98244, MCP9843
22    Datasheets:
23	http://ww1.microchip.com/downloads/en/DeviceDoc/22203C.pdf
24	http://ww1.microchip.com/downloads/en/DeviceDoc/21977b.pdf
25	http://ww1.microchip.com/downloads/en/DeviceDoc/21996a.pdf
26	http://ww1.microchip.com/downloads/en/DeviceDoc/22153c.pdf
27	http://ww1.microchip.com/downloads/en/DeviceDoc/22327A.pdf
28  * NXP Semiconductors SE97, SE97B, SE98, SE98A
29    Datasheets:
30	http://www.nxp.com/documents/data_sheet/SE97.pdf
31	http://www.nxp.com/documents/data_sheet/SE97B.pdf
32	http://www.nxp.com/documents/data_sheet/SE98.pdf
33	http://www.nxp.com/documents/data_sheet/SE98A.pdf
34  * ON Semiconductor CAT34TS02, CAT6095
35    Datasheet:
36	http://www.onsemi.com/pub_link/Collateral/CAT34TS02-D.PDF
37	http://www.onsemi.com/pub/Collateral/CAT6095-D.PDF
38  * ST Microelectronics STTS424, STTS424E02, STTS2002, STTS2004, STTS3000
39    Datasheets:
40	http://www.st.com/web/en/resource/technical/document/datasheet/CD00157556.pdf
41	http://www.st.com/web/en/resource/technical/document/datasheet/CD00157558.pdf
42	http://www.st.com/web/en/resource/technical/document/datasheet/CD00266638.pdf
43	http://www.st.com/web/en/resource/technical/document/datasheet/CD00225278.pdf
44	http://www.st.com/web/en/resource/technical/document/datasheet/DM00076709.pdf
45  * JEDEC JC 42.4 compliant temperature sensor chips
46    Datasheet:
47	http://www.jedec.org/sites/default/files/docs/4_01_04R19.pdf
48
49  Common for all chips:
50    Prefix: 'jc42'
51    Addresses scanned: I2C 0x18 - 0x1f
52
53Author:
54	Guenter Roeck <linux@roeck-us.net>
55
56
57Description
58-----------
59
60This driver implements support for JEDEC JC 42.4 compliant temperature sensors,
61which are used on many DDR3 memory modules for mobile devices and servers. Some
62systems use the sensor to prevent memory overheating by automatically throttling
63the memory controller.
64
65The driver auto-detects the chips listed above, but can be manually instantiated
66to support other JC 42.4 compliant chips.
67
68Example: the following will load the driver for a generic JC 42.4 compliant
69temperature sensor at address 0x18 on I2C bus #1:
70
71# modprobe jc42
72# echo jc42 0x18 > /sys/bus/i2c/devices/i2c-1/new_device
73
74A JC 42.4 compliant chip supports a single temperature sensor. Minimum, maximum,
75and critical temperature can be configured. There are alarms for high, low,
76and critical thresholds.
77
78There is also an hysteresis to control the thresholds for resetting alarms.
79Per JC 42.4 specification, the hysteresis threshold can be configured to 0, 1.5,
803.0, and 6.0 degrees C. Configured hysteresis values will be rounded to those
81limits. The chip supports only a single register to configure the hysteresis,
82which applies to all limits. This register can be written by writing into
83temp1_crit_hyst. Other hysteresis attributes are read-only.
84
85If the BIOS has configured the sensor for automatic temperature management, it
86is likely that it has locked the registers, i.e., that the temperature limits
87cannot be changed.
88
89Sysfs entries
90-------------
91
92temp1_input		Temperature (RO)
93temp1_min		Minimum temperature (RO or RW)
94temp1_max		Maximum temperature (RO or RW)
95temp1_crit		Critical high temperature (RO or RW)
96
97temp1_crit_hyst		Critical hysteresis temperature (RO or RW)
98temp1_max_hyst		Maximum hysteresis temperature (RO)
99
100temp1_min_alarm		Temperature low alarm
101temp1_max_alarm		Temperature high alarm
102temp1_crit_alarm	Temperature critical alarm
103