0001 Kernel driver max6650
0002 =====================
0003
0004 Supported chips:
0005
0006 * Maxim MAX6650
0007
0008 Prefix: 'max6650'
0009
0010 Addresses scanned: none
0011
0012 Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
0013
0014 * Maxim MAX6651
0015
0016 Prefix: 'max6651'
0017
0018 Addresses scanned: none
0019
0020 Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
0021
0022 Authors:
0023 - Hans J. Koch <hjk@hansjkoch.de>
0024 - John Morris <john.morris@spirentcom.com>
0025 - Claus Gindhart <claus.gindhart@kontron.com>
0026
0027 Description
0028 -----------
0029
0030 This driver implements support for the Maxim MAX6650 and MAX6651.
0031
0032 The 2 devices are very similar, but the MAX6550 has a reduced feature
0033 set, e.g. only one fan-input, instead of 4 for the MAX6651.
0034
0035 The driver is not able to distinguish between the 2 devices.
0036
0037 The driver provides the following sensor accesses in sysfs:
0038
0039 =============== ======= =======================================================
0040 fan1_input ro fan tachometer speed in RPM
0041 fan2_input ro "
0042 fan3_input ro "
0043 fan4_input ro "
0044 fan1_target rw desired fan speed in RPM (closed loop mode only)
0045 pwm1_enable rw regulator mode, 0=full on, 1=open loop, 2=closed loop
0046 3=off
0047 pwm1 rw relative speed (0-255), 255=max. speed.
0048 Used in open loop mode only.
0049 fan1_div rw sets the speed range the inputs can handle. Legal
0050 values are 1, 2, 4, and 8. Use lower values for
0051 faster fans.
0052 =============== ======= =======================================================
0053
0054 Usage notes
0055 -----------
0056
0057 This driver does not auto-detect devices. You will have to instantiate the
0058 devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
0059 details.
0060
0061 Module parameters
0062 -----------------
0063
0064 If your board has a BIOS that initializes the MAX6650/6651 correctly, you can
0065 simply load your module without parameters. It won't touch the configuration
0066 registers then. If your board BIOS doesn't initialize the chip, or you want
0067 different settings, you can set the following parameters:
0068
0069 voltage_12V: 5=5V fan, 12=12V fan, 0=don't change
0070 prescaler: Possible values are 1,2,4,8,16, or 0 for don't change
0071 clock: The clock frequency in Hz of the chip the driver should assume [254000]
0072
0073 Please have a look at the MAX6650/6651 data sheet and make sure that you fully
0074 understand the meaning of these parameters before you attempt to change them.
