leds: core: add documentation for color extension

PATCH Superseded Heiner Kallweit 2 participants 2 messages Feb 16, 2016 – Feb 17, 2016

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Heiner Kallweit

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2016-02-16 19:30 UTC #0 lore raw

PATCH v2 3/4 leds: core: add documentation for color extension

Document the color extension in Documentation/leds/led-class.txt

Signed-off-by Heiner Kallweit <[email protected]>

---
v2:
- introduced to patch series

---
 Documentation/leds/leds-class.txt | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

Documentation/leds/leds-class.txt +14 -5

index d406d98..fbd9062 100644
@@ -8,6 +8,14 @@ LED is defined in max_brightness file. The brightness file will set the brightne
 of the LED (taking a value 0-max_brightness). Most LEDs don't have hardware
 brightness support so will just be turned on for non-zero brightness settings.
 
+If a driver uses the colour extension of the LED core then the brightness
+file can be used to set hue / saturation / value. The brightness value is
+interpreted as: <0000000F><HHHHHHHH><SSSSSSSS><VVVVVVVV>
+Usage of the least byte is identical to monochrome mode. Saturation can be
+0-255 and hue 0-251 (Colour circle is mapped to 0-252).
+If hue and saturation both are 0 the current colour is not changed and only
+the brightness is set. This can be overridden with flag F (LED_SET_HSV).
+
 The class also introduces the optional concept of an LED trigger. A trigger
 is a kernel based source of led events. Triggers can either be simple or
 complex. A simple trigger isn't configurable and is designed to slot into

@@ -45,11 +53,12 @@ Is currently of the form:
 
 "devicename:colour:function"
 
-There have been calls for LED properties such as colour to be exported as
-individual led class attributes. As a solution which doesn't incur as much
-overhead, I suggest these become part of the device name. The naming scheme
-above leaves scope for further attributes should they be needed. If sections
-of the name don't apply, just leave that section blank.
+If the colour extension is used hsv / rgb can be used instead of a specific
+colour.  There have been calls for LED properties such as colour to be
+exported as individual led class attributes. As a solution which doesn't
+incur as much overhead, I suggest these become part of the device name.
+The naming scheme above leaves scope for further attributes should they be
+needed. If sections of the name don't apply, just leave that section blank.
 
 
 Brightness setting API

Signature · 1 line

2.7.1

Jacek Anaszewski

2016-02-17 12:34 UTC #1 lore raw

Quoted 15 lines · Heiner Kallweit

Document the color extension in Documentation/leds/led-class.txt
Signed-off-by Heiner Kallweit <[email protected]>
---
v2:
- introduced to patch series
---
  Documentation/leds/leds-class.txt | 19 ++++++++++++++-----
  1 file changed, 14 insertions(+), 5 deletions(-)
Documentation/leds/leds-class.txt +0 -0
index d406d98..fbd9062 100644

Documentation/leds/leds-class.txt LED is defined in max_brightness file. The brightness file will set the brightne · line 17

Quoted 10 lines

Documentation/leds/leds-class.txt +7 -0

@@ -8,6 +8,14 @@ LED is defined in max_brightness file. The brightness file will set the brightne
  of the LED (taking a value 0-max_brightness). Most LEDs don't have hardware
  brightness support so will just be turned on for non-zero brightness settings.
 
+If a driver uses the colour extension of the LED core then the brightness
+file can be used to set hue / saturation / value. The brightness value is
+interpreted as: <0000000F><HHHHHHHH><SSSSSSSS><VVVVVVVV>
+Usage of the least byte is identical to monochrome mode. Saturation can be
+0-255 and hue 0-251 (Colour circle is mapped to 0-252).
+If hue and saturation both are 0 the current colour is not changed and only
+the brightness is set. This can be overridden with flag F (LED_SET_HSV).

Here similarly as in the commit message of 1/4 - more information on why LED_SET_HSV is needed. btw - I liked LED_SET_COLOR more.

Quoted 23 lines

Documentation/leds/leds-class.txt +7 -5

+
  The class also introduces the optional concept of an LED trigger. A trigger
  is a kernel based source of led events. Triggers can either be simple or
  complex. A simple trigger isn't configurable and is designed to slot into

@@ -45,11 +53,12 @@ Is currently of the form:
 
  "devicename:colour:function"
 
-There have been calls for LED properties such as colour to be exported as
-individual led class attributes. As a solution which doesn't incur as much
-overhead, I suggest these become part of the device name. The naming scheme
-above leaves scope for further attributes should they be needed. If sections
-of the name don't apply, just leave that section blank.
+If the colour extension is used hsv / rgb can be used instead of a specific
+colour.  There have been calls for LED properties such as colour to be
+exported as individual led class attributes. As a solution which doesn't
+incur as much overhead, I suggest these become part of the device name.
+The naming scheme above leaves scope for further attributes should they be
+needed. If sections of the name don't apply, just leave that section blank.
 
 
  Brightness setting API

Signature · 2 lines

Best regards,
Jacek Anaszewski