On Mon, Feb 17, 2020 at 05:44:36PM +0800, Chen-Yu Tsai wrote: > On Mon, Feb 17, 2020 at 5:14 PM Maxime Ripard <maxime@xxxxxxxxxx> wrote: > > > > Hi, > > > > On Mon, Feb 17, 2020 at 12:42:16AM -0600, Samuel Holland wrote: > > > The sun8i-codec driver, as used in the Allwinner A33 and A64, currently > > > only exposes a small subset of the available hardware features. In order > > > to use the A64 in a smartphone (the PinePhone), I've added the necessary > > > functionality to the driver: > > > * The full set of supported DAI format options > > > * Support for AIF2 and AIF3 > > > * Additional routing knobs > > > * Additional volume controls > > > > > > Unfortunately, due to preexisting issues with the driver, there are some > > > breaking changes, as explained further in the commit messages: > > > * The LRCK inversion issue means we need a new compatible for the A64. > > > * Some controls are named inaccurately, so they are renamed. > > > * Likewise, the DAPM widgets used in device trees were either named > > > wrong, or the device trees were using the wrong widgets in the first > > > place. (Specifically, the links between the analog codec and digital > > > codec happen at the ADC and DAC, not AIF1.) > > > > > > I tended to take the philosophy of "while I'm breaking things, I might > > > as well do them right", so I've probably made a few more changes than > > > absolutely necessary. I'm not sure about where all of the policy > > > boundaries are, about how far I should go to maintain compatibility. For > > > example, for the DT widget usage, I could: > > > * Rename everything and update the DTS files (which is what I did) > > > * Keep the old (misleading/wrong) name for the widgets, but repurpose > > > them to work correctly > > > (i.e. "ADC Left" would be named "AIF1 Slot 0 Left ADC", but it > > > would work just like "ADC Left" does in this patchset) > > > * Keep the old widgets around as a compatibility layer, but add new > > > widgets and update the in-tree DTS files to use them > > > (i.e. "ADC Left" would have a path from "AIF1 Slot 0 Left ADC", > > > but "AIF1 Slot 0 Left ADC" would be a no-op widget) > > > * Something else entirely > > > > I'm not sure this is really a concern here. We need to maintain the > > compatibility with old DT's, but those will have an A33 compatible > > too, and as far as I can see, you're not changing anything for that > > compatible, so we're in the clear? > > > > If not, then the third option would probably be the best, especially > > since it's only a couple of them. > > Unfortunately the description for both chips are shared, and they're wrong. > So we probably need a new compatible (or a new driver)... or like options > 2 or 3, keep the DT visible endpoints (but deprecate them), and route them > to a new set of proper widgets. And hmm, it might be a bit wild, but since it's basically just a sed on a string in DT, can't we leverage the dynamic DT stuff to rewrite the property if we find the old one at probe? That would keep the driver clean. Maxime
