1Kernel driver amc6821
2=====================
3
4Supported chips:
5
6	Texas Instruments AMC6821
7
8	Prefix: 'amc6821'
9
10	Addresses scanned: 0x18, 0x19, 0x1a, 0x2c, 0x2d, 0x2e, 0x4c, 0x4d, 0x4e
11
12	Datasheet: http://focus.ti.com/docs/prod/folders/print/amc6821.html
13
14Authors:
15	Tomaz Mertelj <tomaz.mertelj@guest.arnes.si>
16
17
18Description
19-----------
20
21This driver implements support for the Texas Instruments amc6821 chip.
22The chip has one on-chip and one remote temperature sensor and one pwm fan
23regulator.
24The pwm can be controlled either from software or automatically.
25
26The driver provides the following sensor accesses in sysfs:
27
28======================= ==      ===============================================
29temp1_input		ro	on-chip temperature
30temp1_min		rw	"
31temp1_max		rw	"
32temp1_crit		rw	"
33temp1_min_alarm		ro	"
34temp1_max_alarm		ro	"
35temp1_crit_alarm	ro	"
36
37temp2_input		ro	remote temperature
38temp2_min		rw	"
39temp2_max		rw	"
40temp2_crit		rw	"
41temp2_min_alarm		ro	"
42temp2_max_alarm		ro	"
43temp2_crit_alarm	ro	"
44temp2_fault		ro	"
45
46fan1_input		ro	tachometer speed
47fan1_min		rw	"
48fan1_max		rw	"
49fan1_fault		ro	"
50fan1_pulses		rw	Pulses per revolution can be either 2 or 4.
51fan1_target		rw	Target fan speed, to be used with pwm1_enable
52				mode 4.
53
54pwm1			rw	pwm1
55pwm1_enable		rw	regulator mode, 1=open loop, 2=fan controlled
56				by remote temperature, 3=fan controlled by
57				combination of the on-chip temperature and
58				remote-sensor temperature,
59				4=fan controlled by target rpm set with
60				fan1_target attribute.
61pwm1_mode		rw	Fan duty control mode (0=DC, 1=PWM)
62pwm1_auto_channels_temp ro	1 if pwm_enable==2, 3 if pwm_enable==3
63pwm1_auto_point1_pwm	ro	Hardwired to 0, shared for both
64				temperature channels.
65pwm1_auto_point2_pwm	rw	This value is shared for both temperature
66				channels.
67pwm1_auto_point3_pwm	rw	Hardwired to 255, shared for both
68				temperature channels.
69
70temp1_auto_point1_temp	ro	Hardwired to temp2_auto_point1_temp
71				which is rw. Below this temperature fan stops.
72temp1_auto_point2_temp	rw	The low-temperature limit of the proportional
73				range. Below this temperature
74				pwm1 = pwm1_auto_point2_pwm. It can go from
75				0 degree C to 124 degree C in steps of
76				4 degree C. Read it out after writing to get
77				the actual value.
78temp1_auto_point3_temp	rw	Above this temperature fan runs at maximum
79				speed. It can go from temp1_auto_point2_temp.
80				It can only have certain discrete values
81				which depend on temp1_auto_point2_temp and
82				pwm1_auto_point2_pwm. Read it out after
83				writing to get the actual value.
84
85temp2_auto_point1_temp	rw	Must be between 0 degree C and 63 degree C and
86				it defines the passive cooling temperature.
87				Below this temperature the fan stops in
88				the closed loop mode.
89temp2_auto_point2_temp	rw	The low-temperature limit of the proportional
90				range. Below this temperature
91				pwm1 = pwm1_auto_point2_pwm. It can go from
92				0 degree C to 124 degree C in steps
93				of 4 degree C.
94
95temp2_auto_point3_temp	rw	Above this temperature fan runs at maximum
96				speed. It can only have certain discrete
97				values which depend on temp2_auto_point2_temp
98				and pwm1_auto_point2_pwm. Read it out after
99				writing to get actual value.
100======================= ==      ===============================================
101
102
103Module parameters
104-----------------
105
106If your board has a BIOS that initializes the amc6821 correctly, you should
107load the module with: init=0.
108
109If your board BIOS doesn't initialize the chip, or you want
110different settings, you can set the following parameters:
111
112- init=1,
113- pwminv: 0 default pwm output, 1 inverts pwm output.
114