1 Kernel driver lm63 1 Kernel driver lm63
2 ================== 2 ==================
3 3
4 Supported chips: 4 Supported chips:
5 5
6 * National Semiconductor LM63 6 * National Semiconductor LM63
7 7
8 Prefix: 'lm63' 8 Prefix: 'lm63'
9 9
10 Addresses scanned: I2C 0x4c 10 Addresses scanned: I2C 0x4c
11 11
12 Datasheet: Publicly available at the Natio 12 Datasheet: Publicly available at the National Semiconductor website
13 13
14 http://www.national.com/pf/LM/L 14 http://www.national.com/pf/LM/LM63.html
15 15
16 * National Semiconductor LM64 16 * National Semiconductor LM64
17 17
18 Prefix: 'lm64' 18 Prefix: 'lm64'
19 19
20 Addresses scanned: I2C 0x18 and 0x4e 20 Addresses scanned: I2C 0x18 and 0x4e
21 21
22 Datasheet: Publicly available at the Natio 22 Datasheet: Publicly available at the National Semiconductor website
23 23
24 http://www.national.com/pf/LM/L 24 http://www.national.com/pf/LM/LM64.html
25 25
26 * National Semiconductor LM96163 26 * National Semiconductor LM96163
27 27
28 Prefix: 'lm96163' 28 Prefix: 'lm96163'
29 29
30 Addresses scanned: I2C 0x4c 30 Addresses scanned: I2C 0x4c
31 31
32 Datasheet: Publicly available at the Natio 32 Datasheet: Publicly available at the National Semiconductor website
33 33
34 http://www.national.com/pf/LM/L 34 http://www.national.com/pf/LM/LM96163.html
35 35
36 36
37 Author: Jean Delvare <jdelvare@suse.de> 37 Author: Jean Delvare <jdelvare@suse.de>
38 38
39 Thanks go to Tyan and especially Alex Buckingh 39 Thanks go to Tyan and especially Alex Buckingham for setting up a remote
40 access to their S4882 test platform for this d 40 access to their S4882 test platform for this driver.
41 41
42 https://www.tyan.com/ 42 https://www.tyan.com/
43 43
44 Description 44 Description
45 ----------- 45 -----------
46 46
47 The LM63 is a digital temperature sensor with 47 The LM63 is a digital temperature sensor with integrated fan monitoring
48 and control. 48 and control.
49 49
50 The LM63 is basically an LM86 with fan speed m 50 The LM63 is basically an LM86 with fan speed monitoring and control
51 capabilities added. It misses some of the LM86 51 capabilities added. It misses some of the LM86 features though:
52 52
53 - No low limit for local temperature. 53 - No low limit for local temperature.
54 - No critical limit for local temperature. 54 - No critical limit for local temperature.
55 - Critical limit for remote temperature can b 55 - Critical limit for remote temperature can be changed only once. We
56 will consider that the critical limit is re 56 will consider that the critical limit is read-only.
57 57
58 The datasheet isn't very clear about what the 58 The datasheet isn't very clear about what the tachometer reading is.
59 59
60 An explanation from National Semiconductor: Th 60 An explanation from National Semiconductor: The two lower bits of the read
61 value have to be masked out. The value is stil 61 value have to be masked out. The value is still 16 bit in width.
62 62
63 All temperature values are given in degrees Ce 63 All temperature values are given in degrees Celsius. Resolution is 1.0
64 degree for the local temperature, 0.125 degree 64 degree for the local temperature, 0.125 degree for the remote temperature.
65 65
66 The fan speed is measured using a tachometer. 66 The fan speed is measured using a tachometer. Contrary to most chips which
67 store the value in an 8-bit register and have 67 store the value in an 8-bit register and have a selectable clock divider
68 to make sure that the result will fit in the r 68 to make sure that the result will fit in the register, the LM63 uses 16-bit
69 value for measuring the speed of the fan. It c 69 value for measuring the speed of the fan. It can measure fan speeds down to
70 83 RPM, at least in theory. 70 83 RPM, at least in theory.
71 71
72 Note that the pin used for fan monitoring is s 72 Note that the pin used for fan monitoring is shared with an alert out
73 function. Depending on how the board designer 73 function. Depending on how the board designer wanted to use the chip, fan
74 speed monitoring will or will not be possible. 74 speed monitoring will or will not be possible. The proper chip configuration
75 is left to the BIOS, and the driver will blind 75 is left to the BIOS, and the driver will blindly trust it. Only the original
76 LM63 suffers from this limitation, the LM64 an 76 LM63 suffers from this limitation, the LM64 and LM96163 have separate pins
77 for fan monitoring and alert out. On the LM64, 77 for fan monitoring and alert out. On the LM64, monitoring is always enabled;
78 on the LM96163 it can be disabled. 78 on the LM96163 it can be disabled.
79 79
80 A PWM output can be used to control the speed 80 A PWM output can be used to control the speed of the fan. The LM63 has two
81 PWM modes: manual and automatic. Automatic mod 81 PWM modes: manual and automatic. Automatic mode is not fully implemented yet
82 (you cannot define your custom PWM/temperature 82 (you cannot define your custom PWM/temperature curve), and mode change isn't
83 supported either. 83 supported either.
84 84
85 The lm63 driver will not update its values mor 85 The lm63 driver will not update its values more frequently than configured with
86 the update_interval sysfs attribute; reading t 86 the update_interval sysfs attribute; reading them more often will do no harm,
87 but will return 'old' values. Values in the au 87 but will return 'old' values. Values in the automatic fan control lookup table
88 (attributes pwm1_auto_*) have their own indepe 88 (attributes pwm1_auto_*) have their own independent lifetime of 5 seconds.
89 89
90 The LM64 is effectively an LM63 with GPIO line 90 The LM64 is effectively an LM63 with GPIO lines. The driver does not
91 support these GPIO lines at present. 91 support these GPIO lines at present.
92 92
93 The LM96163 is an enhanced version of LM63 wit 93 The LM96163 is an enhanced version of LM63 with improved temperature accuracy
94 and better PWM resolution. For LM96163, the ex 94 and better PWM resolution. For LM96163, the external temperature sensor type is
95 configurable as CPU embedded diode(1) or 3904 95 configurable as CPU embedded diode(1) or 3904 transistor(2).
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