1 Kernel driver amc6821 1 Kernel driver amc6821
2 ===================== 2 =====================
3 3
4 Supported chips: 4 Supported chips:
5 5
6 Texas Instruments AMC6821 6 Texas Instruments AMC6821
7 7
8 Prefix: 'amc6821' 8 Prefix: 'amc6821'
9 9
10 Addresses scanned: 0x18, 0x19, 0x1a, 0 10 Addresses scanned: 0x18, 0x19, 0x1a, 0x2c, 0x2d, 0x2e, 0x4c, 0x4d, 0x4e
11 11
12 Datasheet: http://focus.ti.com/docs/pr 12 Datasheet: http://focus.ti.com/docs/prod/folders/print/amc6821.html
13 13
14 Authors: 14 Authors:
15 Tomaz Mertelj <tomaz.mertelj@guest.arne 15 Tomaz Mertelj <tomaz.mertelj@guest.arnes.si>
16 16
17 17
18 Description 18 Description
19 ----------- 19 -----------
20 20
21 This driver implements support for the Texas I 21 This driver implements support for the Texas Instruments amc6821 chip.
22 The chip has one on-chip and one remote temper 22 The chip has one on-chip and one remote temperature sensor and one pwm fan
23 regulator. 23 regulator.
24 The pwm can be controlled either from software 24 The pwm can be controlled either from software or automatically.
25 25
26 The driver provides the following sensor acces 26 The driver provides the following sensor accesses in sysfs:
27 27
28 ======================= == ============== 28 ======================= == ===============================================
29 temp1_input ro on-chip temper 29 temp1_input ro on-chip temperature
30 temp1_min rw " 30 temp1_min rw "
31 temp1_max rw " 31 temp1_max rw "
32 temp1_crit rw " 32 temp1_crit rw "
33 temp1_min_alarm ro " 33 temp1_min_alarm ro "
34 temp1_max_alarm ro " 34 temp1_max_alarm ro "
35 temp1_crit_alarm ro " 35 temp1_crit_alarm ro "
36 36
37 temp2_input ro remote tempera 37 temp2_input ro remote temperature
38 temp2_min rw " 38 temp2_min rw "
39 temp2_max rw " 39 temp2_max rw "
40 temp2_crit rw " 40 temp2_crit rw "
41 temp2_min_alarm ro " 41 temp2_min_alarm ro "
42 temp2_max_alarm ro " 42 temp2_max_alarm ro "
43 temp2_crit_alarm ro " 43 temp2_crit_alarm ro "
44 temp2_fault ro " 44 temp2_fault ro "
45 45
46 fan1_input ro tachometer spe 46 fan1_input ro tachometer speed
47 fan1_min rw " 47 fan1_min rw "
48 fan1_max rw " 48 fan1_max rw "
49 fan1_fault ro " 49 fan1_fault ro "
50 fan1_pulses rw Pulses per rev 50 fan1_pulses rw Pulses per revolution can be either 2 or 4.
51 fan1_target rw Target fan spe 51 fan1_target rw Target fan speed, to be used with pwm1_enable
52 mode 4. 52 mode 4.
53 53
54 pwm1 rw pwm1 54 pwm1 rw pwm1
55 pwm1_enable rw regulator mode 55 pwm1_enable rw regulator mode, 1=open loop, 2=fan controlled
56 by remote temp 56 by remote temperature, 3=fan controlled by
57 combination of 57 combination of the on-chip temperature and
58 remote-sensor 58 remote-sensor temperature,
59 4=fan controll 59 4=fan controlled by target rpm set with
60 fan1_target at 60 fan1_target attribute.
61 pwm1_mode rw Fan duty contr 61 pwm1_mode rw Fan duty control mode (0=DC, 1=PWM)
62 pwm1_auto_channels_temp ro 1 if pwm_enabl 62 pwm1_auto_channels_temp ro 1 if pwm_enable==2, 3 if pwm_enable==3
63 pwm1_auto_point1_pwm ro Hardwired to 0 63 pwm1_auto_point1_pwm ro Hardwired to 0, shared for both
64 temperature ch 64 temperature channels.
65 pwm1_auto_point2_pwm rw This value is 65 pwm1_auto_point2_pwm rw This value is shared for both temperature
66 channels. 66 channels.
67 pwm1_auto_point3_pwm rw Hardwired to 2 67 pwm1_auto_point3_pwm rw Hardwired to 255, shared for both
68 temperature ch 68 temperature channels.
69 69
70 temp1_auto_point1_temp ro Hardwired to t 70 temp1_auto_point1_temp ro Hardwired to temp2_auto_point1_temp
71 which is rw. B 71 which is rw. Below this temperature fan stops.
72 temp1_auto_point2_temp rw The low-temper 72 temp1_auto_point2_temp rw The low-temperature limit of the proportional
73 range. Below t 73 range. Below this temperature
74 pwm1 = pwm1_au 74 pwm1 = pwm1_auto_point2_pwm. It can go from
75 0 degree C to 75 0 degree C to 124 degree C in steps of
76 4 degree C. Re 76 4 degree C. Read it out after writing to get
77 the actual val 77 the actual value.
78 temp1_auto_point3_temp rw Above this tem 78 temp1_auto_point3_temp rw Above this temperature fan runs at maximum
79 speed. It can 79 speed. It can go from temp1_auto_point2_temp.
80 It can only ha 80 It can only have certain discrete values
81 which depend o 81 which depend on temp1_auto_point2_temp and
82 pwm1_auto_poin 82 pwm1_auto_point2_pwm. Read it out after
83 writing to get 83 writing to get the actual value.
84 84
85 temp2_auto_point1_temp rw Must be betwee 85 temp2_auto_point1_temp rw Must be between 0 degree C and 63 degree C and
86 it defines the 86 it defines the passive cooling temperature.
87 Below this tem 87 Below this temperature the fan stops in
88 the closed loo 88 the closed loop mode.
89 temp2_auto_point2_temp rw The low-temper 89 temp2_auto_point2_temp rw The low-temperature limit of the proportional
90 range. Below t 90 range. Below this temperature
91 pwm1 = pwm1_au 91 pwm1 = pwm1_auto_point2_pwm. It can go from
92 0 degree C to 92 0 degree C to 124 degree C in steps
93 of 4 degree C. 93 of 4 degree C.
94 94
95 temp2_auto_point3_temp rw Above this tem 95 temp2_auto_point3_temp rw Above this temperature fan runs at maximum
96 speed. It can 96 speed. It can only have certain discrete
97 values which d 97 values which depend on temp2_auto_point2_temp
98 and pwm1_auto_ 98 and pwm1_auto_point2_pwm. Read it out after
99 writing to get 99 writing to get actual value.
100 ======================= == ============== 100 ======================= == ===============================================
101 101
102 102
103 Module parameters 103 Module parameters
104 ----------------- 104 -----------------
105 105
106 If your board has a BIOS that initializes the 106 If your board has a BIOS that initializes the amc6821 correctly, you should
107 load the module with: init=0. 107 load the module with: init=0.
108 108
109 If your board BIOS doesn't initialize the chip 109 If your board BIOS doesn't initialize the chip, or you want
110 different settings, you can set the following 110 different settings, you can set the following parameters:
111 111
112 - init=1, 112 - init=1,
113 - pwminv: 0 default pwm output, 1 inverts pwm 113 - pwminv: 0 default pwm output, 1 inverts pwm output.
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