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
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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.
+