projects / mirror_ubuntu-artful-kernel.git / blame
| 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 | |
| 20005cc5 | 37 | 3=off |
| d20620de HJK |
38 | pwm1 rw relative speed (0-255), 255=max. speed. |
| 39 | Used in open loop mode only. | |
| 40 | fan1_div rw sets the speed range the inputs can handle. Legal | |
| 41 | values are 1, 2, 4, and 8. Use lower values for | |
| 42 | faster fans. | |
| 43 | ||
| 67b670ff JD |
44 | Usage notes |
| 45 | ----------- | |
| 46 | ||
| 47 | This driver does not auto-detect devices. You will have to instantiate the | |
| 48 | devices explicitly. Please see Documentation/i2c/instantiating-devices for | |
| 49 | details. | |
| 50 | ||
| d20620de HJK |
51 | Module parameters |
| 52 | ----------------- | |
| 53 | ||
| 54 | If your board has a BIOS that initializes the MAX6650/6651 correctly, you can | |
| 55 | simply load your module without parameters. It won't touch the configuration | |
| 56 | registers then. If your board BIOS doesn't initialize the chip, or you want | |
| 57 | different settings, you can set the following parameters: | |
| 58 | ||
| 59 | voltage_12V: 5=5V fan, 12=12V fan, 0=don't change | |
| 60 | prescaler: Possible values are 1,2,4,8,16, or 0 for don't change | |
| 61 | clock: The clock frequency in Hz of the chip the driver should assume [254000] | |
| 62 | ||
| 63 | Please have a look at the MAX6650/6651 data sheet and make sure that you fully | |
| 64 | understand the meaning of these parameters before you attempt to change them. | |
| 65 |