Re: [PATCH 01/28] mfd: Add Microchip ZL3073x support

Andy Shevchenko
2025-04-14T13:56:19Z

On Mon, Apr 14, 2025 at 2:52 PM Ivan Vecera <ivecera@redhat.com> wrote:
> On 14. 04. 25 1:39 odp., Ivan Vecera wrote:
> > On 14. 04. 25 8:36 dop., Andy Shevchenko wrote:
> >>> What is wrong here?
> >>>
> >>> I have a device that uses 7-bit addresses and have 16 register pages.
> >>> Each pages is from 0x00-0x7f and register 0x7f is used as page selector
> >>> where bits 0-3 select the page.
> >> The problem is that you overlap virtual page over the real one (the
> >> main one).
> >>
> >> The drivers you mentioned in v2 discussions most likely are also buggy.
> >> As I implied in the above question the developers hardly get the
> >> regmap ranges
> >> right. It took me quite a while to see the issue, so it's not
> >> particularly your
> >> fault.
> > Hi Andy,
> >
> > thank you I see the point.
> >
> > Do you mean that the selector register should not be part of the range?
> >
> > If so, does it mean that I have to specify a range for each page? Like
> > this:
> >
> > {
> > /* Page 0 */
> > .range_min = 0x000,
> > .range_max = 0x07e,
> > .selector_reg = ZL3073x_PAGE_SEL,
> > .selector_mask = GENMASK(3, 0),
> > .selector_shift = 0,
> > .window_start = 0,
> > .window_len = 0x7e,
> > },
> > {
> > /* Page 1 */
> > .range_min = 0x080,
> > .range_max = 0x0fe,
> > .selector_reg = ZL3073x_PAGE_SEL,
> > .selector_mask = GENMASK(3, 0),
> > .selector_shift = 0,
> > .window_start = 0,
> > .window_len = 0x7e,
> > },

...

> Sorry,
> .window_len = 0x7f /* Exclude selector reg */

It actually will make things worse. If selector register is accessible
to all of the pages, it's better to include it in all pages.

--
With Best Regards,
Andy Shevchenko