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>

1 files changed, 102 insertions, 0 deletions

diff --git a/Documentation/hwmon/amc6821 b/Documentation/hwmon/amc6821
new file mode 100644
index 000000000000..ced8359c50f8
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+++ b/Documentation/hwmon/amc6821
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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.
+