hwmon: driver for Texas Instruments amc6821 chip
Signed-off-by: <tomaz.mertelj@guest.arnes.si>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/hwmon/amc6821 b/Documentation/hwmon/amc6821
new file mode 100644
index 0000000..ced8359
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+Kernel driver amc6821
+=====================
+
+Supported chips:
+ Texas Instruments AMC6821
+ Prefix: 'amc6821'
+ Addresses scanned: 0x18, 0x19, 0x1a, 0x2c, 0x2d, 0x2e, 0x4c, 0x4d, 0x4e
+ Datasheet: http://focus.ti.com/docs/prod/folders/print/amc6821.html
+
+Authors:
+ Tomaz Mertelj <tomaz.mertelj@guest.arnes.si>
+
+
+Description
+-----------
+
+This driver implements support for the Texas Instruments amc6821 chip.
+The chip has one on-chip and one remote temperature sensor and one pwm fan
+regulator.
+The pwm can be controlled either from software or automatically.
+
+The driver provides the following sensor accesses in sysfs:
+
+temp1_input ro on-chip temperature
+temp1_min rw "
+temp1_max rw "
+temp1_crit rw "
+temp1_min_alarm ro "
+temp1_max_alarm ro "
+temp1_crit_alarm ro "
+
+temp2_input ro remote temperature
+temp2_min rw "
+temp2_max rw "
+temp2_crit rw "
+temp2_min_alarm ro "
+temp2_max_alarm ro "
+temp2_crit_alarm ro "
+temp2_fault ro "
+
+fan1_input ro tachometer speed
+fan1_min rw "
+fan1_max rw "
+fan1_fault ro "
+fan1_div rw Fan divisor can be either 2 or 4.
+
+pwm1 rw pwm1
+pwm1_enable rw regulator mode, 1=open loop, 2=fan controlled
+ by remote temperature, 3=fan controlled by
+ combination of the on-chip temperature and
+ remote-sensor temperature,
+pwm1_auto_channels_temp ro 1 if pwm_enable==2, 3 if pwm_enable==3
+pwm1_auto_point1_pwm ro Hardwired to 0, shared for both
+ temperature channels.
+pwm1_auto_point2_pwm rw This value is shared for both temperature
+ channels.
+pwm1_auto_point3_pwm rw Hardwired to 255, shared for both
+ temperature channels.
+
+temp1_auto_point1_temp ro Hardwired to temp2_auto_point1_temp
+ which is rw. Below this temperature fan stops.
+temp1_auto_point2_temp rw The low-temperature limit of the proportional
+ range. Below this temperature
+ pwm1 = pwm1_auto_point2_pwm. It can go from
+ 0 degree C to 124 degree C in steps of
+ 4 degree C. Read it out after writing to get
+ the actual value.
+temp1_auto_point3_temp rw Above this temperature fan runs at maximum
+ speed. It can go from temp1_auto_point2_temp.
+ It can only have certain discrete values
+ which depend on temp1_auto_point2_temp and
+ pwm1_auto_point2_pwm. Read it out after
+ writing to get the actual value.
+
+temp2_auto_point1_temp rw Must be between 0 degree C and 63 degree C and
+ it defines the passive cooling temperature.
+ Below this temperature the fan stops in
+ the closed loop mode.
+temp2_auto_point2_temp rw The low-temperature limit of the proportional
+ range. Below this temperature
+ pwm1 = pwm1_auto_point2_pwm. It can go from
+ 0 degree C to 124 degree C in steps
+ of 4 degree C.
+
+temp2_auto_point3_temp rw Above this temperature fan runs at maximum
+ speed. It can only have certain discrete
+ values which depend on temp2_auto_point2_temp
+ and pwm1_auto_point2_pwm. Read it out after
+ writing to get actual value.
+
+
+Module parameters
+-----------------
+
+If your board has a BIOS that initializes the amc6821 correctly, you should
+load the module with: init=0.
+
+If your board BIOS doesn't initialize the chip, or you want
+different settings, you can set the following parameters:
+init=1,
+pwminv: 0 default pwm output, 1 inverts pwm output.
+