path: root/Documentation
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authorHans-Juergen Koch <hjk@linutronix.de>2007-05-08 17:22:00 +0200
committerJean Delvare <khali@hyperion.delvare>2007-05-08 17:22:00 +0200
commitd20620de0c3de622a9d6a841725bafaed6d1aec2 (patch)
tree5dbd1f0f04b44c0af6711b28a4fccc41b8bdaace /Documentation
parente84cfbcbe830c20af030fd7ba37edf8ed88fda5f (diff)
hwmon: New max6650 driver
This driver supports the Maxim MAX6650 and MAX6651 fan speed monitoring and control chips. Signed-off-by: Hans J. Koch <hjk@linutronix.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
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+Kernel driver max6650
+Supported chips:
+ * Maxim 6650 / 6651
+ Prefix: 'max6650'
+ Addresses scanned: I2C 0x1b, 0x1f, 0x48, 0x4b
+ Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
+ Hans J. Koch <hjk@linutronix.de>
+ John Morris <john.morris@spirentcom.com>
+ Claus Gindhart <claus.gindhart@kontron.com>
+This driver implements support for the Maxim 6650/6651
+The 2 devices are very similar, but the Maxim 6550 has a reduced feature
+set, e.g. only one fan-input, instead of 4 for the 6651.
+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.
+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.