Hi,

I recently submitted a patch to add a platform driver for Alienware that one of the functions will be to control some lighting zones on the machine.  I originally started implementing it using the LED class but started to find it didn't really fit the LED class well so decided to do a custom sysfs interface.

After submitting it, the platform driver maintainer (mjg59) recommended that I instead reach out to you to extend the LED class to better fit how the system is architected.

The system has 3 lighting zones (HEAD, Left, Right).  Each of those lighting zones can independently customize the shades of red, green, blue, as well as the brightness intensity for the zone.

So each zone has:
0x00 - 0xFF red shade
0x00 - 0xFF blue shade
0x00 - 0xFF green shade
0x00 - 0xFF brightness intensity

Additionally the zone can be configured for different lighting combinations for three different states: Running, Booting, Suspended.  Running immediately modifies the colors in the zone. Booting modifies the colors when turned on but before the next modification of "running".  Suspended modifies the colors while the system is in S3.

When I first started to implement this using the LED class I create it with 36 different LED nodes:

alienware-wmi::running::head_red
alienware-wmi::running::head_blue
alienware-wmi::running::head_green
alienware-wmi::running::head_brightness
alienware-wmi::running::left_red
alienware-wmi::running::left_blue
alienware-wmi::running::left_green
alienware-wmi::running::left_brightness
alienware-wmi::running::right_red
alienware-wmi::running::right_blue
alienware-wmi::running::right_green
alienware-wmi::running::right_brightness

alienware-wmi::booting::head_red
alienware-wmi::booting::head_blue
alienware-wmi::booting::head_green
alienware-wmi::booting::head_brightness
alienware-wmi::booting::left_red
alienware-wmi::booting::left_blue
alienware-wmi::booting::left_green
alienware-wmi::booting::left_brightness
alienware-wmi::booting::right_red
alienware-wmi::booting::right_blue
alienware-wmi::booting::right_green
alienware-wmi::booting::right_brightness

alienware-wmi::suspend::head_red
alienware-wmi::suspend::head_blue
alienware-wmi::suspend::head_green
alienware-wmi::suspend::head_brightness
alienware-wmi::suspend::left_red
alienware-wmi::suspend::left_blue
alienware-wmi::suspend::left_green
alienware-wmi::suspend::left_brightness
alienware-wmi::suspend::right_red
alienware-wmi::suspend::right_blue
alienware-wmi::suspend::right_green
alienware-wmi::suspend::right_brightness

I thought this was rather confusing though because each individual node only has a single "brightness" member which doesn't really identify what is being changed.  The brightness node changes the overall brightness of the whole zone.  The color shades selected for each node are mixed to come up with the overall color for the zone.

The three different modes (running/booting/suspend) all modify the same LEDs too, so it didn't seem to make sense to me that they had their own nodes.

So given all of that, can you advise how you think this should be implemented?  Would it make sense to extend the LED class to better adapt to this?  Or do you think this is better suited for a custom sysfs interface as I've already done?  I'll attach the patch for the driver so you can see how I put it together with the custom sysfs interface.

Thanks,