Dan, On 4/3/20 4:39 PM, Dan Murphy wrote: > Randy > > Thanks for the review > > On 4/2/20 10:47 PM, Randy Dunlap wrote: >> Hi, >> Here are a few changes for you to consider: >> >> On 4/2/20 1:42 PM, Dan Murphy wrote: >>> Introduce a multicolor class that groups colored LEDs >>> within a LED node. >>> >>> The multi color class groups monochrome LEDs and allows controlling two >> multicolor > Ack >> >>> aspects of the final combined color: hue and lightness. The former is >>> controlled via <color>_intensity files and the latter is controlled >>> via brightness file. >>> >>> Signed-off-by: Dan Murphy <dmurphy@xxxxxx> >>> --- >> >>> diff --git a/Documentation/leds/leds-class-multicolor.rst >>> b/Documentation/leds/leds-class-multicolor.rst >>> new file mode 100644 >>> index 000000000000..5bb004999248 >>> --- /dev/null >>> +++ b/Documentation/leds/leds-class-multicolor.rst >>> @@ -0,0 +1,95 @@ >>> +==================================== >>> +Multi Color LED handling under Linux >> Multicolor > Ack >> >>> +==================================== >>> + >>> +Description >>> +=========== >>> +The multi color class groups monochrome LEDs and allows controlling two >> multicolor > Ack >> >>> +aspects of the final combined color: hue and lightness. The former is >>> +controlled via the color_intensity array file and the latter is >>> controlled >>> +via brightness file. >>> + >>> +For more details on hue and lightness notions please refer to >>> +https://en.wikipedia.org/wiki/CIECAM02. >>> + >>> +Multicolor Class Control >>> +======================== >>> +The multicolor class presents files that groups the colors as >>> indexes in an >>> +array. These files are children under the LED parent node created >>> by the >>> +led_class framework. The led_class framework is documented in >>> led-class.rst >>> +within this documentation directory. >>> + >>> +Each colored LED will be indexed under the color_* files. The order >>> of the >>> +colors are arbitrary the color_index file can be read to determine >>> the color >>> +to index value. >>> + >>> +The color_index file is an array that contains the string list of >>> the colors as >>> +they are defined in each color_* array file. >>> + >>> +The color_intensity is an array that can be read or written to for the >>> +individual color intensities. All elements within this array must >>> be written in >>> +order for the color LED intensities to be updated. >>> + >>> +The color_max_intensity is an array that can be read to indicate >>> each color LED >>> +maximum intensity value. >>> + >>> +The num_color_leds file returns the total number of color LEDs that are >>> +presented in each color_* array. >>> + >>> +Directory Layout Example >>> +======================== >>> +root:/sys/class/leds/multicolor:status# ls -lR >>> +-rw-r--r-- 1 root root 4096 Oct 19 16:16 brightness >>> +-r--r--r-- 1 root root 4096 Oct 19 16:16 color_index >>> +-rw-r--r-- 1 root root 4096 Oct 19 16:16 >>> color_intensity >>> +-r--r--r-- 1 root root 4096 Oct 19 16:16 num_color_leds >>> + >>> +Multicolor Class Brightness Control >>> +=================================== >>> +The multiclor class framework will calculate each monochrome LEDs >>> intensity. >> multicolor > Ack >> >>> + >>> +The brightness level for each LED is calculated based on the color LED >>> +intensity setting divided by the parent max_brightness setting >>> multiplied by >>> +the requested brightness. >>> + >>> +led_brightness = brightness * color_intensity/max_brightness >>> + >>> +Example: >>> +A user first writes the color_intensity file with the brightness levels >>> +that for each LED that is necessary to achieve a blueish violet >>> output from a >> drop first "that". > Ack >> that are >> necessary from an > Ack and NACK the "from an". It is from a since R is a consonant But it sounds like a vowel and this rule for creating articles "applies to the sound of the letter beginning the word, not just the letter itself" [0]. [0] https://www.grammar.com/a-vs-an-when-to-use/ -- Best regards, Jacek Anaszewski
