On Mon, 4 Dec 2023 19:48:05 +0000 Mark Brown <broonie@xxxxxxxxxx> wrote: > On Mon, Dec 04, 2023 at 02:41:36PM -0500, Hugo Villeneuve wrote: > > > But that is not was my question was about. Here a pseudo code > > example to select "page" 1: > > > 1. save original value of LCR register. > > 2. write 0xBF to LCR register > > 3. access desired register in page 1 > > 4. restore original LCR value saved in step 1 > > > How do you do that with regmap range? > > Are you saying that the selector has other, non-selector functions? Yes! There is no bit or bit range in that register that is used to select a praticular set of registers or "page". It is only when writing the special magic value of $BF that the IC switches to "page" 1. And if the value is NOT $BF, then it switches back to "page" 0. When I told you if you could point to other IC/drivers that had the same configuration, I tough you were aware of this. That explains some of the confusion. > This is truly innovative hardware,... Well, I would not say innovative, but more "crappy" hardware design :) > ...generally the selector is just a > bitfield that you write paging values to. This is also what I am accustomed to normally. > You'd need to extend the core > so that it knows about this quirk, right now that's not possible and > we'll just leave the window pointing at whatever was last accessed. Ok. I am not sure that adding support for it would make sense, since I do not know of other ICs that could reuse this very specific and particular method for switching "paged" registers. Thank you, Hugo Villeneuve
