17ebd8b66SMauro Carvalho ChehabKernel driver max6650 27ebd8b66SMauro Carvalho Chehab===================== 37ebd8b66SMauro Carvalho Chehab 47ebd8b66SMauro Carvalho ChehabSupported chips: 57ebd8b66SMauro Carvalho Chehab 67ebd8b66SMauro Carvalho Chehab * Maxim MAX6650 77ebd8b66SMauro Carvalho Chehab 87ebd8b66SMauro Carvalho Chehab Prefix: 'max6650' 97ebd8b66SMauro Carvalho Chehab 107ebd8b66SMauro Carvalho Chehab Addresses scanned: none 117ebd8b66SMauro Carvalho Chehab 127ebd8b66SMauro Carvalho Chehab Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf 137ebd8b66SMauro Carvalho Chehab 147ebd8b66SMauro Carvalho Chehab * Maxim MAX6651 157ebd8b66SMauro Carvalho Chehab 167ebd8b66SMauro Carvalho Chehab Prefix: 'max6651' 177ebd8b66SMauro Carvalho Chehab 187ebd8b66SMauro Carvalho Chehab Addresses scanned: none 197ebd8b66SMauro Carvalho Chehab 207ebd8b66SMauro Carvalho Chehab Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf 217ebd8b66SMauro Carvalho Chehab 227ebd8b66SMauro Carvalho ChehabAuthors: 237ebd8b66SMauro Carvalho Chehab - Hans J. Koch <hjk@hansjkoch.de> 247ebd8b66SMauro Carvalho Chehab - John Morris <john.morris@spirentcom.com> 257ebd8b66SMauro Carvalho Chehab - Claus Gindhart <claus.gindhart@kontron.com> 267ebd8b66SMauro Carvalho Chehab 277ebd8b66SMauro Carvalho ChehabDescription 287ebd8b66SMauro Carvalho Chehab----------- 297ebd8b66SMauro Carvalho Chehab 307ebd8b66SMauro Carvalho ChehabThis driver implements support for the Maxim MAX6650 and MAX6651. 317ebd8b66SMauro Carvalho Chehab 327ebd8b66SMauro Carvalho ChehabThe 2 devices are very similar, but the MAX6550 has a reduced feature 337ebd8b66SMauro Carvalho Chehabset, e.g. only one fan-input, instead of 4 for the MAX6651. 347ebd8b66SMauro Carvalho Chehab 357ebd8b66SMauro Carvalho ChehabThe driver is not able to distinguish between the 2 devices. 367ebd8b66SMauro Carvalho Chehab 377ebd8b66SMauro Carvalho ChehabThe driver provides the following sensor accesses in sysfs: 387ebd8b66SMauro Carvalho Chehab 397ebd8b66SMauro Carvalho Chehab=============== ======= ======================================================= 407ebd8b66SMauro Carvalho Chehabfan1_input ro fan tachometer speed in RPM 417ebd8b66SMauro Carvalho Chehabfan2_input ro " 427ebd8b66SMauro Carvalho Chehabfan3_input ro " 437ebd8b66SMauro Carvalho Chehabfan4_input ro " 447ebd8b66SMauro Carvalho Chehabfan1_target rw desired fan speed in RPM (closed loop mode only) 457ebd8b66SMauro Carvalho Chehabpwm1_enable rw regulator mode, 0=full on, 1=open loop, 2=closed loop 467ebd8b66SMauro Carvalho Chehab 3=off 477ebd8b66SMauro Carvalho Chehabpwm1 rw relative speed (0-255), 255=max. speed. 487ebd8b66SMauro Carvalho Chehab Used in open loop mode only. 497ebd8b66SMauro Carvalho Chehabfan1_div rw sets the speed range the inputs can handle. Legal 507ebd8b66SMauro Carvalho Chehab values are 1, 2, 4, and 8. Use lower values for 517ebd8b66SMauro Carvalho Chehab faster fans. 527ebd8b66SMauro Carvalho Chehab=============== ======= ======================================================= 537ebd8b66SMauro Carvalho Chehab 547ebd8b66SMauro Carvalho ChehabUsage notes 557ebd8b66SMauro Carvalho Chehab----------- 567ebd8b66SMauro Carvalho Chehab 577ebd8b66SMauro Carvalho ChehabThis driver does not auto-detect devices. You will have to instantiate the 58*ccf988b6SMauro Carvalho Chehabdevices explicitly. Please see Documentation/i2c/instantiating-devices.rst for 597ebd8b66SMauro Carvalho Chehabdetails. 607ebd8b66SMauro Carvalho Chehab 617ebd8b66SMauro Carvalho ChehabModule parameters 627ebd8b66SMauro Carvalho Chehab----------------- 637ebd8b66SMauro Carvalho Chehab 647ebd8b66SMauro Carvalho ChehabIf your board has a BIOS that initializes the MAX6650/6651 correctly, you can 657ebd8b66SMauro Carvalho Chehabsimply load your module without parameters. It won't touch the configuration 667ebd8b66SMauro Carvalho Chehabregisters then. If your board BIOS doesn't initialize the chip, or you want 677ebd8b66SMauro Carvalho Chehabdifferent settings, you can set the following parameters: 687ebd8b66SMauro Carvalho Chehab 697ebd8b66SMauro Carvalho Chehabvoltage_12V: 5=5V fan, 12=12V fan, 0=don't change 707ebd8b66SMauro Carvalho Chehabprescaler: Possible values are 1,2,4,8,16, or 0 for don't change 717ebd8b66SMauro Carvalho Chehabclock: The clock frequency in Hz of the chip the driver should assume [254000] 727ebd8b66SMauro Carvalho Chehab 737ebd8b66SMauro Carvalho ChehabPlease have a look at the MAX6650/6651 data sheet and make sure that you fully 747ebd8b66SMauro Carvalho Chehabunderstand the meaning of these parameters before you attempt to change them. 75