Commit | Line | Data |
---|---|---|
d20620de HJK |
1 | Kernel driver max6650 |
2 | ===================== | |
3 | ||
4 | Supported chips: | |
9c084dae | 5 | * Maxim MAX6650 |
d20620de | 6 | Prefix: 'max6650' |
67b670ff | 7 | Addresses scanned: none |
d20620de | 8 | Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf |
9c084dae JD |
9 | * Maxim MAX6651 |
10 | Prefix: 'max6651' | |
11 | Addresses scanned: none | |
12 | Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf | |
d20620de HJK |
13 | |
14 | Authors: | |
f99e0e98 | 15 | Hans J. Koch <hjk@hansjkoch.de> |
d20620de HJK |
16 | John Morris <john.morris@spirentcom.com> |
17 | Claus Gindhart <claus.gindhart@kontron.com> | |
18 | ||
19 | Description | |
20 | ----------- | |
21 | ||
9c084dae | 22 | This driver implements support for the Maxim MAX6650 and MAX6651. |
d20620de | 23 | |
9c084dae JD |
24 | The 2 devices are very similar, but the MAX6550 has a reduced feature |
25 | set, e.g. only one fan-input, instead of 4 for the MAX6651. | |
d20620de HJK |
26 | |
27 | The driver is not able to distinguish between the 2 devices. | |
28 | ||
29 | The driver provides the following sensor accesses in sysfs: | |
30 | ||
31 | fan1_input ro fan tachometer speed in RPM | |
32 | fan2_input ro " | |
33 | fan3_input ro " | |
34 | fan4_input ro " | |
35 | fan1_target rw desired fan speed in RPM (closed loop mode only) | |
36 | pwm1_enable rw regulator mode, 0=full on, 1=open loop, 2=closed loop | |
37 | pwm1 rw relative speed (0-255), 255=max. speed. | |
38 | Used in open loop mode only. | |
39 | fan1_div rw sets the speed range the inputs can handle. Legal | |
40 | values are 1, 2, 4, and 8. Use lower values for | |
41 | faster fans. | |
42 | ||
67b670ff JD |
43 | Usage notes |
44 | ----------- | |
45 | ||
46 | This driver does not auto-detect devices. You will have to instantiate the | |
47 | devices explicitly. Please see Documentation/i2c/instantiating-devices for | |
48 | details. | |
49 | ||
d20620de HJK |
50 | Module parameters |
51 | ----------------- | |
52 | ||
53 | If your board has a BIOS that initializes the MAX6650/6651 correctly, you can | |
54 | simply load your module without parameters. It won't touch the configuration | |
55 | registers then. If your board BIOS doesn't initialize the chip, or you want | |
56 | different settings, you can set the following parameters: | |
57 | ||
58 | voltage_12V: 5=5V fan, 12=12V fan, 0=don't change | |
59 | prescaler: Possible values are 1,2,4,8,16, or 0 for don't change | |
60 | clock: The clock frequency in Hz of the chip the driver should assume [254000] | |
61 | ||
62 | Please have a look at the MAX6650/6651 data sheet and make sure that you fully | |
63 | understand the meaning of these parameters before you attempt to change them. | |
64 |