Documentation/hwmon/max6650

   1 Kernel driver max6650
   2 =====================
   3
   4 Supported chips:
   5   * Maxim MAX6650
   6     Prefix: 'max6650'
   7     Addresses scanned: none
   8     Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
   9   * Maxim MAX6651
  10     Prefix: 'max6651'
  11     Addresses scanned: none
  12     Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
  13
  14 Authors:
  15     Hans J. Koch <hjk@hansjkoch.de>
  16     John Morris <john.morris@spirentcom.com>
  17     Claus Gindhart <claus.gindhart@kontron.com>
  18
  19 Description
  20 -----------
  21
  22 This driver implements support for the Maxim MAX6650 and MAX6651.
  23
  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.
  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
  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
  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