Hi! > >>> Milo if sysfs is used can't the old userspace be mapped to use the new > >>> sysfs interface through a wrapper of some sort ? What exactly would be > >>> needed to ensure old userspace will not break? > >> > >> LP5521 and LP5523 have two ways to load hex code from the userspace - the > >> sysfs and firmware I/F. So user program supports both interfaces. Even if > >> the firmware I/F is not available, user can still run LED effect through the > >> sysfs. > >> > >> However, LP5562 and LP8501 support only single way which is the firmware > >> I/F. So user-space program for LP5562/8501 should be modified if lp55xx > >> removes the interface. My idea is > > > > Actually... it would be good to have some reasonable interface for RGB > > LEDs. This way, we need separate "firmware" for each LED > > controller. It would be good to have common format for LED effects. > > We still haven't tried trigger approach discussed over half a year ago. > If we used firmware approach we would still have to overcome the problem > of defining the LED class drivers affected by the firmware program. The firmware approach is in the tree today :-(. > >> Device manufactures in Asia & North America requested lp55xx drivers, but I > >> don't know how many vendors uses the firmware I/F. Some vendors embeds the > >> binary code inside the driver instead of using user-program. > > > > Nokia N900 uses lp55xx, and I have custom scripts interfacing sysfs. > > > > Maemo uses the LEDs, too, but maemo is not open source. > > > > So no, I don't think there's anything important that could be broken. > > We can't guarantee that. Is there any problem in just using the > currently introduced DECLARE_FW_CUSTOM_FALLBACK() in > drivers/leds/leds-lp55xx-common.c? Well, it would be good to get rid of the custom fallback functionality. And no, we don't need to "guarantee" that. Removing obscure functionality noone uses is far game... providing noone complains ;-). Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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