[PATCH v4 1/2] leds: multicolor: Add sysfs interface definition

[Dan Murphy <dmurphy@ti.com>]

Add a documentation of LED Multicolor LED class specific
sysfs attributes.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
---

v4 - Add LED class parent brightness definition to the text - https://lore.kernel.org/patchwork/patch/1078398/

 .../ABI/testing/sysfs-class-led-multicolor    | 74 +++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-class-led-multicolor

diff --git a/Documentation/ABI/testing/sysfs-class-led-multicolor b/Documentation/ABI/testing/sysfs-class-led-multicolor
new file mode 100644
index 000000000000..ec2b6ac63ecc
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-led-multicolor
@@ -0,0 +1,74 @@
+What:		/sys/class/leds/<led>/brightness
+Date:		April 2019
+KernelVersion:	5.2
+Contact:	Dan Murphy <dmurphy@ti.com>
+Description:	read/write
+		The multicolor class will redirect the device drivers call back
+		function for brightness control to the multicolor class
+		brightness control function.
+
+		Writing to this file will update all LEDs within the group to a
+		calculated percentage of what each color LED in the group is set
+		to.  Please refer to the leds-class-multicolor.txt in the
+		Documentation directory for a complete description.
+
+		The value of the color is from 0 to
+		/sys/class/leds/<led>/max_brightness.
+
+What:		/sys/class/leds/<led>/colors/sync_enable
+Date:		April 2019
+KernelVersion:	5.2
+Contact:	Dan Murphy <dmurphy@ti.com>
+Description:	read/write
+		Writing a 1 to this file will enable the synchronization of all
+		the defined color LEDs within the LED node.  Brightness values
+		for each LED will be stored and written when sync is set to 1.
+		Writing a 0 to this file will disable syncing and allow
+		individual control of the LEDs brightness settings.
+
+What:		/sys/class/leds/<led>/colors/sync
+Date:		April 2019
+KernelVersion:	5.2
+Contact:	Dan Murphy <dmurphy@ti.com>
+Description:	write only
+		Writing a 1 to this file while sync_enable is set to 1 will
+		write the current brightness values to all defined LEDs within
+		the LED node.  All LEDs defined will be configured based
+		on the brightness that has been requested.
+
+		If sync_enable is set to 0 then writing a 1 to sync has no
+		affect on the LEDs.
+
+What:		/sys/class/leds/<led>/colors/<led_color>/brightness
+Date:		April 2019
+KernelVersion:	5.2
+Contact:	Dan Murphy <dmurphy@ti.com>
+Description:	read/write
+		The led_color directory is dynamically created based on the
+		colors defined by the registrar of the class.
+		The led_color can be but not limited to red, green, blue,
+		white, amber, yellow and violet.  Drivers can also declare a
+		LED color for presentation.  There is one directory per color
+		presented.  The brightness file is created under each
+		led_color directory and controls the individual LED color
+		setting.
+
+		If sync is enabled then	writing the brightness value of the LED
+		is deferred until a 1 is written to
+		/sys/class/leds/<led>/color/sync.  If syncing is
+		disabled then the LED brightness value will be written
+		immediately to the LED driver.
+
+		The value of the color is from 0 to
+		/sys/class/leds/<led>/colors/<led_color>/max_brightness.
+
+What:		/sys/class/leds/<led>/colors/<led_color>/max_brightness
+Date:		April 2019
+KernelVersion:	5.2
+Contact:	Dan Murphy <dmurphy@ti.com>
+Description:	read only
+		Maximum brightness level for the LED color, default is
+		255 (LED_FULL).
+
+		If the LED does not support different brightness levels, this
+		should be 1.
-- 
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