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_div		rw	Fan divisor can be either 2 or 4.
51
52pwm1			rw	pwm1
53pwm1_enable		rw	regulator mode, 1=open loop, 2=fan controlled
54				by remote temperature, 3=fan controlled by
55				combination of the on-chip temperature and
56				remote-sensor temperature,
57pwm1_auto_channels_temp ro	1 if pwm_enable==2, 3 if pwm_enable==3
58pwm1_auto_point1_pwm	ro	Hardwired to 0, shared for both
59				temperature channels.
60pwm1_auto_point2_pwm	rw	This value is shared for both temperature
61				channels.
62pwm1_auto_point3_pwm	rw	Hardwired to 255, shared for both
63				temperature channels.
64
65temp1_auto_point1_temp	ro	Hardwired to temp2_auto_point1_temp
66				which is rw. Below this temperature fan stops.
67temp1_auto_point2_temp	rw	The low-temperature limit of the proportional
68				range. Below this temperature
69				pwm1 = pwm1_auto_point2_pwm. It can go from
70				0 degree C to 124 degree C in steps of
71				4 degree C. Read it out after writing to get
72				the actual value.
73temp1_auto_point3_temp	rw	Above this temperature fan runs at maximum
74				speed. It can go from temp1_auto_point2_temp.
75				It can only have certain discrete values
76				which depend on temp1_auto_point2_temp and
77				pwm1_auto_point2_pwm. Read it out after
78				writing to get the actual value.
79
80temp2_auto_point1_temp	rw	Must be between 0 degree C and 63 degree C and
81				it defines the passive cooling temperature.
82				Below this temperature the fan stops in
83				the closed loop mode.
84temp2_auto_point2_temp	rw	The low-temperature limit of the proportional
85				range. Below this temperature
86				pwm1 = pwm1_auto_point2_pwm. It can go from
87				0 degree C to 124 degree C in steps
88				of 4 degree C.
89
90temp2_auto_point3_temp	rw	Above this temperature fan runs at maximum
91				speed. It can only have certain discrete
92				values which depend on temp2_auto_point2_temp
93				and pwm1_auto_point2_pwm. Read it out after
94				writing to get actual value.
95======================= ==      ===============================================
96
97
98Module parameters
99-----------------
100
101If your board has a BIOS that initializes the amc6821 correctly, you should
102load the module with: init=0.
103
104If your board BIOS doesn't initialize the chip, or you want
105different settings, you can set the following parameters:
106
107- init=1,
108- pwminv: 0 default pwm output, 1 inverts pwm output.
109