Thierry Reding wrote at Wednesday, December 21, 2011 7:10 AM: > * Thierry Reding wrote: > > * Stephen Warren wrote: > > > In other words, can you do away with NR_PWM, and make it completely > > > dynamic? > > > > IRQ can be configured to use a radix tree if CONFIG_SPARSE_IRQ=y. I guess it > > doesn't hurt to always use a radix tree for PWM, so I'll read up on it and > > will try to address that in the next version. > > I guess something like idr/ida can be used to dynamically assign a PWM ID, > which would allow us to get rid of the bitmap. Then again, ida itself is not > much more than a bitmap either. It would complicate things a little in that > the ID assignment could no longer be assumed to be sequential for one given > PWM chip, so the lookup (or rather mapping the ID to a chip-relative number) > will be trickier to do. You can support both dynamic assignment of IDs, and assigning each PWM chip's IDs in a contiguous block. Just search for n contiguous free IDs instead of looping n times looking for 1 free ID. ... > pinctrl doesn't solve this because it uses statically allocated pin numbers. Well, they're per-device IDs, so the issue doesn't really come up. > Interestingly though it uses per-device numbering as well, which would be > fine for PWM as well if we had only device tree based probing. In order to > support other devices, we'll still need a global namespace. Yes, that's probably true. I guess a global namespace is reasonable for now. If you do plan to rework the API though, the sooner the better since the tree will grow fewer users before it's done:-) -- nvpublic -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
