backlight: document sysfs interfaces

Add documentation for sysfs interface of adp5520/adp5501 analog devices backlight driver by reading code and looking through git commit logs.

Signed-off-by Aishwarya Pant <[email protected]>

Acked-by Michael Hennerich <[email protected]>

---
 .../ABI/testing/sysfs-class-backlight-adp5520      | 31 ++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-class-backlight-adp5520

Documentation/ABI/testing/sysfs-class-backlight-adp5520 new file +31 -0

new file mode 100644
index 000000000000..34b6ebafa210
@@ -0,0 +1,31 @@
+sysfs interface for analog devices adp5520(01) backlight driver
+---------------------------------------------------------------
+
+The backlight brightness control operates at three different levels for the
+adp5520 and adp5501 devices: daylight (level 1), office (level 2) and dark
+(level 3). By default the brightness operates at the daylight brightness level.
+
+What:		/sys/class/backlight/<backlight>/daylight_max
+What:		/sys/class/backlight/<backlight>/office_max
+What:		/sys/class/backlight/<backlight>/dark_max
+Date:		Sep, 2009
+KernelVersion:	v2.6.32
+Contact:	Michael Hennerich <[email protected]>
+Description:
+		(RW) Maximum current setting for the backlight when brightness
+		is at one of the three levels (daylight, office or dark). This
+		is an input code between 0 and 127, which is transformed to a
+		value between 0 mA and 30 mA using linear or non-linear
+		algorithms.
+
+What:		/sys/class/backlight/<backlight>/daylight_dim
+What:		/sys/class/backlight/<backlight>/office_dim
+What:		/sys/class/backlight/<backlight>/dark_dim
+Date:		Sep, 2009
+KernelVersion:	v2.6.32
+Contact:	Michael Hennerich <[email protected]>
+Description:
+		(RW) Dim current setting for the backlight when brightness is at
+		one of the three levels (daylight, office or dark). This is an
+		input code between 0 and 127, which is transformed to a value
+		between 0 mA and 30 mA using linear or non-linear algorithms.

Signature · 1 line

2.16.1

Add documentation for sysfs interface of adp8860 series backlight devices by reading through code and git commits.

Signed-off-by Aishwarya Pant <[email protected]>

Acked-by Michael Hennerich <[email protected]>

---
 .../ABI/testing/sysfs-class-backlight-adp8860      | 54 ++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-class-backlight-adp8860

Documentation/ABI/testing/sysfs-class-backlight-adp8860 new file +54 -0

new file mode 100644
index 000000000000..54d61c788b1b
@@ -0,0 +1,54 @@
+sysfs interface for analog devices adp8860 backlight driver
+-----------------------------------------------------------
+
+The backlight brightness control operates at three different levels for the
+adp8860, adp8861 and adp8863 devices: daylight (level 1), office (level 2) and
+dark (level 3). By default the brightness operates at the daylight brightness
+level.
+
+What:		/sys/class/backlight/<backlight>/ambient_light_level
+Date:		Apr, 2010
+KernelVersion:	v2.6.35
+Contact:	Michael Hennerich <[email protected]>
+Description:
+		(RO) 13-bit conversion value for the first light sensor—high
+		byte (Bit 12 to Bit 8). The value is updated every 80 ms (when
+		the light sensor is enabled).
+
+
+What:		/sys/class/backlight/<backlight>/ambient_light_zone
+Date:		Apr, 2010
+KernelVersion:	v2.6.35
+Contact:	Michael Hennerich <[email protected]>
+Description:
+		(RW) Read or write the specific level at which the backlight
+		operates. Value "0" enables automatic ambient light sensing, and
+		values "1", "2" or "3" set the control to daylight, office or
+		dark respectively.
+
+
+What:		/sys/class/backlight/<backlight>/l1_daylight_max
+What:		/sys/class/backlight/<backlight>/l2_office_max
+What:		/sys/class/backlight/<backlight>/l3_dark_max
+Date:		Apr, 2010
+KernelVersion:	v2.6.35
+Contact:	Michael Hennerich <[email protected]>
+Description:
+		(RW) Maximum current setting for the backlight when brightness
+		is at one of the three levels (daylight, office or dark). This
+		is an input code between 0 and 127, which is transformed to a
+		value between 0 mA and 30 mA using linear or non-linear
+		algorithms.
+
+
+What:		/sys/class/backlight/<backlight>/l1_daylight_dim
+What:		/sys/class/backlight/<backlight>/l2_office_dim
+What:		/sys/class/backlight/<backlight>/l3_dark_dim
+Date:		Apr, 2010
+KernelVersion:	v2.6.35
+Contact:	Michael Hennerich <[email protected]>
+Description:
+		(RW) Dim current setting for the backlight when brightness is at
+		one of the three levels (daylight, office or dark). This is an
+		input code between 0 and 127, which is transformed to a value
+		between 0 mA and 30 mA using linear or non-linear algorithms.

Signature · 1 line

2.16.1

Patchset contains documentation of the sysfs interfaces for the following five backlight drivers-
1) lm3639
2) adp5520
3) adp8860

It was compiled from data sheets, reading code and git history logs. In v2 of the patches, documentation for lp8788 and lp855x devices was dropped as the attributes contained debug information.