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kernel/linux-imx6_3.14.28/Documentation/hwmon/max6650 2.07 KB
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  Kernel driver max6650
  =====================
  
  Supported chips:
    * Maxim MAX6650
      Prefix: 'max6650'
      Addresses scanned: none
      Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
    * Maxim MAX6651
      Prefix: 'max6651'
      Addresses scanned: none
      Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
  
  Authors:
      Hans J. Koch <hjk@hansjkoch.de>
      John Morris <john.morris@spirentcom.com>
      Claus Gindhart <claus.gindhart@kontron.com>
  
  Description
  -----------
  
  This driver implements support for the Maxim MAX6650 and MAX6651.
  
  The 2 devices are very similar, but the MAX6550 has a reduced feature
  set, e.g. only one fan-input, instead of 4 for the MAX6651.
  
  The driver is not able to distinguish between the 2 devices.
  
  The driver provides the following sensor accesses in sysfs:
  
  fan1_input	ro	fan tachometer speed in RPM
  fan2_input	ro	"
  fan3_input	ro	"
  fan4_input	ro	"
  fan1_target	rw	desired fan speed in RPM (closed loop mode only)
  pwm1_enable	rw	regulator mode, 0=full on, 1=open loop, 2=closed loop
  pwm1		rw	relative speed (0-255), 255=max. speed.
  			Used in open loop mode only.
  fan1_div	rw	sets the speed range the inputs can handle. Legal
  			values are 1, 2, 4, and 8. Use lower values for
  			faster fans.
  
  Usage notes
  -----------
  
  This driver does not auto-detect devices. You will have to instantiate the
  devices explicitly. Please see Documentation/i2c/instantiating-devices for
  details.
  
  Module parameters
  -----------------
  
  If your board has a BIOS that initializes the MAX6650/6651 correctly, you can
  simply load your module without parameters. It won't touch the configuration
  registers then. If your board BIOS doesn't initialize the chip, or you want
  different settings, you can set the following parameters:
  
  voltage_12V: 5=5V fan, 12=12V fan, 0=don't change
  prescaler: Possible values are 1,2,4,8,16, or 0 for don't change
  clock: The clock frequency in Hz of the chip the driver should assume [254000]
  
  Please have a look at the MAX6650/6651 data sheet and make sure that you fully
  understand the meaning of these parameters before you attempt to change them.