> But in the end, it is still PWM in the HW level, and also, the > brightness isn't linear, or even anything like it. At least on my > backlight, the visible values range from ~230 to 255. I suspect the narrow range for you is a property of your hardware. For my WRT1900ac, 0-32 the LEDs look pretty much like off. Above that, i get light. Should the LED class layer care about this? Probably not. It seems like the generic backlight layer should have some method to reduce the 0-255 down to a couple of dozen useful working points. > That said, I feel that these frameworks, GPIO, PWM and LED are somewhat > overlapping. Not really my area of expertise, but I imagine a single > framework containing all those functionalities could be possible. Humm, i don't think the frameworks overlap that much. I think it is the hardware which overlaps. You have a device with an output which you normally connect an LED to, but you could connect anything to. You can control this pin using a very restricted PWM like scheme, or you can have it plain off/on. With hardware like this, you need to decide which it is most like, and put that framework at the bottom. Then stack generic X->Y layers on top to get the rest of the functionality. Andrew -- To unsubscribe from this list: send the line "unsubscribe linux-leds" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html