1*7ebd8b66SMauro Carvalho ChehabKernel driver max6650 2*7ebd8b66SMauro Carvalho Chehab===================== 3*7ebd8b66SMauro Carvalho Chehab 4*7ebd8b66SMauro Carvalho ChehabSupported chips: 5*7ebd8b66SMauro Carvalho Chehab 6*7ebd8b66SMauro Carvalho Chehab * Maxim MAX6650 7*7ebd8b66SMauro Carvalho Chehab 8*7ebd8b66SMauro Carvalho Chehab Prefix: 'max6650' 9*7ebd8b66SMauro Carvalho Chehab 10*7ebd8b66SMauro Carvalho Chehab Addresses scanned: none 11*7ebd8b66SMauro Carvalho Chehab 12*7ebd8b66SMauro Carvalho Chehab Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf 13*7ebd8b66SMauro Carvalho Chehab 14*7ebd8b66SMauro Carvalho Chehab * Maxim MAX6651 15*7ebd8b66SMauro Carvalho Chehab 16*7ebd8b66SMauro Carvalho Chehab Prefix: 'max6651' 17*7ebd8b66SMauro Carvalho Chehab 18*7ebd8b66SMauro Carvalho Chehab Addresses scanned: none 19*7ebd8b66SMauro Carvalho Chehab 20*7ebd8b66SMauro Carvalho Chehab Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf 21*7ebd8b66SMauro Carvalho Chehab 22*7ebd8b66SMauro Carvalho ChehabAuthors: 23*7ebd8b66SMauro Carvalho Chehab - Hans J. Koch <hjk@hansjkoch.de> 24*7ebd8b66SMauro Carvalho Chehab - John Morris <john.morris@spirentcom.com> 25*7ebd8b66SMauro Carvalho Chehab - Claus Gindhart <claus.gindhart@kontron.com> 26*7ebd8b66SMauro Carvalho Chehab 27*7ebd8b66SMauro Carvalho ChehabDescription 28*7ebd8b66SMauro Carvalho Chehab----------- 29*7ebd8b66SMauro Carvalho Chehab 30*7ebd8b66SMauro Carvalho ChehabThis driver implements support for the Maxim MAX6650 and MAX6651. 31*7ebd8b66SMauro Carvalho Chehab 32*7ebd8b66SMauro Carvalho ChehabThe 2 devices are very similar, but the MAX6550 has a reduced feature 33*7ebd8b66SMauro Carvalho Chehabset, e.g. only one fan-input, instead of 4 for the MAX6651. 34*7ebd8b66SMauro Carvalho Chehab 35*7ebd8b66SMauro Carvalho ChehabThe driver is not able to distinguish between the 2 devices. 36*7ebd8b66SMauro Carvalho Chehab 37*7ebd8b66SMauro Carvalho ChehabThe driver provides the following sensor accesses in sysfs: 38*7ebd8b66SMauro Carvalho Chehab 39*7ebd8b66SMauro Carvalho Chehab=============== ======= ======================================================= 40*7ebd8b66SMauro Carvalho Chehabfan1_input ro fan tachometer speed in RPM 41*7ebd8b66SMauro Carvalho Chehabfan2_input ro " 42*7ebd8b66SMauro Carvalho Chehabfan3_input ro " 43*7ebd8b66SMauro Carvalho Chehabfan4_input ro " 44*7ebd8b66SMauro Carvalho Chehabfan1_target rw desired fan speed in RPM (closed loop mode only) 45*7ebd8b66SMauro Carvalho Chehabpwm1_enable rw regulator mode, 0=full on, 1=open loop, 2=closed loop 46*7ebd8b66SMauro Carvalho Chehab 3=off 47*7ebd8b66SMauro Carvalho Chehabpwm1 rw relative speed (0-255), 255=max. speed. 48*7ebd8b66SMauro Carvalho Chehab Used in open loop mode only. 49*7ebd8b66SMauro Carvalho Chehabfan1_div rw sets the speed range the inputs can handle. Legal 50*7ebd8b66SMauro Carvalho Chehab values are 1, 2, 4, and 8. Use lower values for 51*7ebd8b66SMauro Carvalho Chehab faster fans. 52*7ebd8b66SMauro Carvalho Chehab=============== ======= ======================================================= 53*7ebd8b66SMauro Carvalho Chehab 54*7ebd8b66SMauro Carvalho ChehabUsage notes 55*7ebd8b66SMauro Carvalho Chehab----------- 56*7ebd8b66SMauro Carvalho Chehab 57*7ebd8b66SMauro Carvalho ChehabThis driver does not auto-detect devices. You will have to instantiate the 58*7ebd8b66SMauro Carvalho Chehabdevices explicitly. Please see Documentation/i2c/instantiating-devices for 59*7ebd8b66SMauro Carvalho Chehabdetails. 60*7ebd8b66SMauro Carvalho Chehab 61*7ebd8b66SMauro Carvalho ChehabModule parameters 62*7ebd8b66SMauro Carvalho Chehab----------------- 63*7ebd8b66SMauro Carvalho Chehab 64*7ebd8b66SMauro Carvalho ChehabIf your board has a BIOS that initializes the MAX6650/6651 correctly, you can 65*7ebd8b66SMauro Carvalho Chehabsimply load your module without parameters. It won't touch the configuration 66*7ebd8b66SMauro Carvalho Chehabregisters then. If your board BIOS doesn't initialize the chip, or you want 67*7ebd8b66SMauro Carvalho Chehabdifferent settings, you can set the following parameters: 68*7ebd8b66SMauro Carvalho Chehab 69*7ebd8b66SMauro Carvalho Chehabvoltage_12V: 5=5V fan, 12=12V fan, 0=don't change 70*7ebd8b66SMauro Carvalho Chehabprescaler: Possible values are 1,2,4,8,16, or 0 for don't change 71*7ebd8b66SMauro Carvalho Chehabclock: The clock frequency in Hz of the chip the driver should assume [254000] 72*7ebd8b66SMauro Carvalho Chehab 73*7ebd8b66SMauro Carvalho ChehabPlease have a look at the MAX6650/6651 data sheet and make sure that you fully 74*7ebd8b66SMauro Carvalho Chehabunderstand the meaning of these parameters before you attempt to change them. 75