projects / thirdparty / kernel / stable.git / blame
| Commit | Line | Data |
|---|---|---|
| d20620de HJK |
1 | Kernel driver max6650 |
| 2 | ===================== | |
| 3 | ||
| 4 | Supported chips: | |
| b04f2f7d | 5 | |
| 9c084dae | 6 | * Maxim MAX6650 |
| b04f2f7d | 7 | |
| d20620de | 8 | Prefix: 'max6650' |
| b04f2f7d | 9 | |
| 67b670ff | 10 | Addresses scanned: none |
| b04f2f7d | 11 | |
| d20620de | 12 | Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf |
| b04f2f7d | 13 | |
| 9c084dae | 14 | * Maxim MAX6651 |
| b04f2f7d | 15 | |
| 9c084dae | 16 | Prefix: 'max6651' |
| b04f2f7d | 17 | |
| 9c084dae | 18 | Addresses scanned: none |
| b04f2f7d | 19 | |
| 9c084dae | 20 | Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf |
| d20620de HJK |
21 | |
| 22 | Authors: | |
| b04f2f7d MCC |
23 | - Hans J. Koch <hjk@hansjkoch.de> |
| 24 | - John Morris <john.morris@spirentcom.com> | |
| 25 | - Claus Gindhart <claus.gindhart@kontron.com> | |
| d20620de HJK |
26 | |
| 27 | Description | |
| 28 | ----------- | |
| 29 | ||
| 9c084dae | 30 | This driver implements support for the Maxim MAX6650 and MAX6651. |
| d20620de | 31 | |
| 9c084dae JD |
32 | The 2 devices are very similar, but the MAX6550 has a reduced feature |
| 33 | set, e.g. only one fan-input, instead of 4 for the MAX6651. | |
| d20620de HJK |
34 | |
| 35 | The driver is not able to distinguish between the 2 devices. | |
| 36 | ||
| 37 | The driver provides the following sensor accesses in sysfs: | |
| 38 | ||
| b04f2f7d | 39 | =============== ======= ======================================================= |
| d20620de HJK |
40 | fan1_input ro fan tachometer speed in RPM |
| 41 | fan2_input ro " | |
| 42 | fan3_input ro " | |
| 43 | fan4_input ro " | |
| 44 | fan1_target rw desired fan speed in RPM (closed loop mode only) | |
| 45 | pwm1_enable rw regulator mode, 0=full on, 1=open loop, 2=closed loop | |
| 20005cc5 | 46 | 3=off |
| d20620de HJK |
47 | pwm1 rw relative speed (0-255), 255=max. speed. |
| 48 | Used in open loop mode only. | |
| 49 | fan1_div rw sets the speed range the inputs can handle. Legal | |
| 50 | values are 1, 2, 4, and 8. Use lower values for | |
| 51 | faster fans. | |
| b04f2f7d | 52 | =============== ======= ======================================================= |
| d20620de | 53 | |
| 67b670ff JD |
54 | Usage notes |
| 55 | ----------- | |
| 56 | ||
| 57 | This driver does not auto-detect devices. You will have to instantiate the | |
| 58 | devices explicitly. Please see Documentation/i2c/instantiating-devices for | |
| 59 | details. | |
| 60 | ||
| d20620de HJK |
61 | Module parameters |
| 62 | ----------------- | |
| 63 | ||
| 64 | If your board has a BIOS that initializes the MAX6650/6651 correctly, you can | |
| 65 | simply load your module without parameters. It won't touch the configuration | |
| 66 | registers then. If your board BIOS doesn't initialize the chip, or you want | |
| 67 | different settings, you can set the following parameters: | |
| 68 | ||
| 69 | voltage_12V: 5=5V fan, 12=12V fan, 0=don't change | |
| 70 | prescaler: Possible values are 1,2,4,8,16, or 0 for don't change | |
| 71 | clock: The clock frequency in Hz of the chip the driver should assume [254000] | |
| 72 | ||
| 73 | Please have a look at the MAX6650/6651 data sheet and make sure that you fully | |
| 74 | understand the meaning of these parameters before you attempt to change them. |