summaryrefslogtreecommitdiffstats
path: root/Documentation/hwmon/max6650.rst
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/hwmon/max6650.rst')
-rw-r--r--Documentation/hwmon/max6650.rst74
1 files changed, 74 insertions, 0 deletions
diff --git a/Documentation/hwmon/max6650.rst b/Documentation/hwmon/max6650.rst
new file mode 100644
index 000000000..7952b6eca
--- /dev/null
+++ b/Documentation/hwmon/max6650.rst
@@ -0,0 +1,74 @@
+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
+ 3=off
+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.rst 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.