1 Kernel driver jc42 1 Kernel driver jc42
2 ================== 2 ==================
3 3
4 Supported chips: 4 Supported chips:
5 5
6 * Analog Devices ADT7408 6 * Analog Devices ADT7408
7 7
8 Datasheets: 8 Datasheets:
9 9
10 https://www.analog.com/static/imported 10 https://www.analog.com/static/imported-files/data_sheets/ADT7408.pdf
11 11
12 * Atmel AT30TS00, AT30TS002A/B, AT30TSE004A 12 * Atmel AT30TS00, AT30TS002A/B, AT30TSE004A
13 13
14 Datasheets: 14 Datasheets:
15 15
16 http://www.atmel.com/Images/doc8585.pd 16 http://www.atmel.com/Images/doc8585.pdf
17 17
18 http://www.atmel.com/Images/doc8711.pd 18 http://www.atmel.com/Images/doc8711.pdf
19 19
20 http://www.atmel.com/Images/Atmel-8852 20 http://www.atmel.com/Images/Atmel-8852-SEEPROM-AT30TSE002A-Datasheet.pdf
21 21
22 http://www.atmel.com/Images/Atmel-8868 22 http://www.atmel.com/Images/Atmel-8868-DTS-AT30TSE004A-Datasheet.pdf
23 23
24 * IDT TSE2002B3, TSE2002GB2, TSE2004GB2, TS3 24 * IDT TSE2002B3, TSE2002GB2, TSE2004GB2, TS3000B3, TS3000GB0, TS3000GB2,
25 25
26 TS3001GB2 26 TS3001GB2
27 27
28 Datasheets: 28 Datasheets:
29 29
30 Available from IDT web site 30 Available from IDT web site
31 31
32 * Maxim MAX6604 32 * Maxim MAX6604
33 33
34 Datasheets: 34 Datasheets:
35 35
36 http://datasheets.maxim-ic.com/en/ds/M 36 http://datasheets.maxim-ic.com/en/ds/MAX6604.pdf
37 37
38 * Microchip MCP9804, MCP9805, MCP9808, MCP98 38 * Microchip MCP9804, MCP9805, MCP9808, MCP98242, MCP98243, MCP98244, MCP9843
39 39
40 Datasheets: 40 Datasheets:
41 41
42 https://ww1.microchip.com/downloads/en 42 https://ww1.microchip.com/downloads/en/DeviceDoc/22203C.pdf
43 43
44 https://ww1.microchip.com/downloads/en 44 https://ww1.microchip.com/downloads/en/DeviceDoc/21977b.pdf
45 45
46 https://ww1.microchip.com/downloads/en 46 https://ww1.microchip.com/downloads/en/DeviceDoc/25095A.pdf
47 47
48 https://ww1.microchip.com/downloads/en 48 https://ww1.microchip.com/downloads/en/DeviceDoc/21996a.pdf
49 49
50 https://ww1.microchip.com/downloads/en 50 https://ww1.microchip.com/downloads/en/DeviceDoc/22153c.pdf
51 51
52 https://ww1.microchip.com/downloads/en 52 https://ww1.microchip.com/downloads/en/DeviceDoc/22327A.pdf
53 53
54 * NXP Semiconductors SE97, SE97B, SE98, SE98 54 * NXP Semiconductors SE97, SE97B, SE98, SE98A
55 55
56 Datasheets: 56 Datasheets:
57 57
58 https://www.nxp.com/documents/data_she 58 https://www.nxp.com/documents/data_sheet/SE97.pdf
59 59
60 https://www.nxp.com/documents/data_she 60 https://www.nxp.com/documents/data_sheet/SE97B.pdf
61 61
62 https://www.nxp.com/documents/data_she 62 https://www.nxp.com/documents/data_sheet/SE98.pdf
63 63
64 https://www.nxp.com/documents/data_she 64 https://www.nxp.com/documents/data_sheet/SE98A.pdf
65 65
66 * ON Semiconductor CAT34TS02, CAT6095 66 * ON Semiconductor CAT34TS02, CAT6095
67 67
68 Datasheet: 68 Datasheet:
69 69
70 https://www.onsemi.com/pub_link/Collat 70 https://www.onsemi.com/pub_link/Collateral/CAT34TS02-D.PDF
71 71
72 https://www.onsemi.com/pub/Collateral/ 72 https://www.onsemi.com/pub/Collateral/CAT6095-D.PDF
73 73
74 * ST Microelectronics STTS424, STTS424E02, S 74 * ST Microelectronics STTS424, STTS424E02, STTS2002, STTS2004, STTS3000
75 75
76 Datasheets: 76 Datasheets:
77 77
78 http://www.st.com/web/en/resource/tech 78 http://www.st.com/web/en/resource/technical/document/datasheet/CD00157556.pdf
79 79
80 http://www.st.com/web/en/resource/tech 80 http://www.st.com/web/en/resource/technical/document/datasheet/CD00157558.pdf
81 81
82 http://www.st.com/web/en/resource/tech 82 http://www.st.com/web/en/resource/technical/document/datasheet/CD00266638.pdf
83 83
84 http://www.st.com/web/en/resource/tech 84 http://www.st.com/web/en/resource/technical/document/datasheet/CD00225278.pdf
85 85
86 http://www.st.com/web/en/resource/tech 86 http://www.st.com/web/en/resource/technical/document/datasheet/DM00076709.pdf
87 87
88 * JEDEC JC 42.4 compliant temperature sensor 88 * JEDEC JC 42.4 compliant temperature sensor chips
89 89
90 Datasheet: 90 Datasheet:
91 91
92 http://www.jedec.org/sites/default/fil 92 http://www.jedec.org/sites/default/files/docs/4_01_04R19.pdf
93 93
94 94
95 Common for all chips: 95 Common for all chips:
96 96
97 Prefix: 'jc42' 97 Prefix: 'jc42'
98 98
99 Addresses scanned: I2C 0x18 - 0x1f 99 Addresses scanned: I2C 0x18 - 0x1f
100 100
101 Author: 101 Author:
102 Guenter Roeck <linux@roeck-us.net> 102 Guenter Roeck <linux@roeck-us.net>
103 103
104 104
105 Description 105 Description
106 ----------- 106 -----------
107 107
108 This driver implements support for JEDEC JC 42 108 This driver implements support for JEDEC JC 42.4 compliant temperature sensors,
109 which are used on many DDR3 memory modules for 109 which are used on many DDR3 memory modules for mobile devices and servers. Some
110 systems use the sensor to prevent memory overh 110 systems use the sensor to prevent memory overheating by automatically throttling
111 the memory controller. 111 the memory controller.
112 112
113 The driver auto-detects the chips listed above 113 The driver auto-detects the chips listed above, but can be manually instantiated
114 to support other JC 42.4 compliant chips. 114 to support other JC 42.4 compliant chips.
115 115
116 Example: the following will load the driver fo 116 Example: the following will load the driver for a generic JC 42.4 compliant
117 temperature sensor at address 0x18 on I2C bus 117 temperature sensor at address 0x18 on I2C bus #1::
118 118
119 # modprobe jc42 119 # modprobe jc42
120 # echo jc42 0x18 > /sys/bus/i2c/device 120 # echo jc42 0x18 > /sys/bus/i2c/devices/i2c-1/new_device
121 121
122 A JC 42.4 compliant chip supports a single tem 122 A JC 42.4 compliant chip supports a single temperature sensor. Minimum, maximum,
123 and critical temperature can be configured. Th 123 and critical temperature can be configured. There are alarms for high, low,
124 and critical thresholds. 124 and critical thresholds.
125 125
126 There is also an hysteresis to control the thr 126 There is also an hysteresis to control the thresholds for resetting alarms.
127 Per JC 42.4 specification, the hysteresis thre 127 Per JC 42.4 specification, the hysteresis threshold can be configured to 0, 1.5,
128 3.0, and 6.0 degrees C. Configured hysteresis 128 3.0, and 6.0 degrees C. Configured hysteresis values will be rounded to those
129 limits. The chip supports only a single regist 129 limits. The chip supports only a single register to configure the hysteresis,
130 which applies to all limits. This register can 130 which applies to all limits. This register can be written by writing into
131 temp1_crit_hyst. Other hysteresis attributes a 131 temp1_crit_hyst. Other hysteresis attributes are read-only.
132 132
133 If the BIOS has configured the sensor for auto 133 If the BIOS has configured the sensor for automatic temperature management, it
134 is likely that it has locked the registers, i. 134 is likely that it has locked the registers, i.e., that the temperature limits
135 cannot be changed. 135 cannot be changed.
136 136
137 Sysfs entries 137 Sysfs entries
138 ------------- 138 -------------
139 139
140 ======================= ====================== 140 ======================= ===========================================
141 temp1_input Temperature (RO) 141 temp1_input Temperature (RO)
142 temp1_min Minimum temperature (R 142 temp1_min Minimum temperature (RO or RW)
143 temp1_max Maximum temperature (R 143 temp1_max Maximum temperature (RO or RW)
144 temp1_crit Critical high temperat 144 temp1_crit Critical high temperature (RO or RW)
145 145
146 temp1_crit_hyst Critical hysteresis te 146 temp1_crit_hyst Critical hysteresis temperature (RO or RW)
147 temp1_max_hyst Maximum hysteresis tem 147 temp1_max_hyst Maximum hysteresis temperature (RO)
148 148
149 temp1_min_alarm Temperature low alarm 149 temp1_min_alarm Temperature low alarm
150 temp1_max_alarm Temperature high alarm 150 temp1_max_alarm Temperature high alarm
151 temp1_crit_alarm Temperature critical a 151 temp1_crit_alarm Temperature critical alarm
152 ======================= ====================== 152 ======================= ===========================================
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