I sent out a new patch that enables/disables the backlight enable gpio. > On 03/05/2013 01:00 PM, Andrew Chew wrote: > > I did come to the same conclusion regarding the platform data breakage. > > I'm expecting that the use of platform data will go away, at least on > > ARM, since we are all aggressively moving what used to be in platform > > data into the device tree. Do other platforms use this driver? > > I can see at least 29 users of platform_pwm_backlight_data, all ARM with the > exception of one unicore32. I guess at least for the foreseeable future > platform data will remain.
I'm not sure how to solve this, then. Any suggestions? > > I remember hearing that there is some work in progress to encapsulate > > gpios into a struct, rather than passing it around as a bare integer, > > so when that happens, we can use NULL for no-gpio, which should take > > care of the platform data issue as well. It's kind of difficult to > > work around this problem otherwise. > > Yes, actually I am doing the GPIO rework. If you are not too much in a hurry > you might want for it to happen (should not be too long now that the core > has been reworked). At the same time, GPIO descriptors will also enable the > power sequences, so if you wait even longer (or help me with it), this patch > might not even be needed at all. Of course if you want to support this > *now*, this is still the shortest path. Sadly, I do need this now, and I'd rather do it as cleanly as possible rather than maintaining a hack. The project I am working on is very pedantic. > > I agree that we should be turning on and off the backlight enable gpio > > as needed to save power. I just haven't gotten there yet. I can try > > to modify this patch if that's your preference, or I can follow up > > with a patch to add this in the very near future. > > That's ultimately for Thierry to say, but submitting a new revision makes > more sense IMHO - it is not a big change and there are other issues to > address (uninitialized GPIO in platform data) anyway. Done. > > To answer your last question, yes, this single patch does allow me to > > enable the backlight on some boards (in particular, the one I'm working > on). > > Cool - may I ask which one? All the NV boards I tried to far required more > complex sequences for their panels. This is for t114-dalmore. There may be other gpios that are needed that I'm not aware of off the top of my head. For the backlight itself, this seems to be the only one. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/