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

Andy Shevchenko
2025-04-14T13:59:06Z

On Mon, Apr 14, 2025 at 2:40 PM Ivan Vecera <ivecera@redhat.com> 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.

> thank you I see the point.
>
> Do you mean that the selector register should not be part of the range?

No.

> If so, does it mean that I have to specify a range for each page? Like this:

No.

Yes, tough thingy :-)

> {
> /* 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 0 shouldn't exist in your case in the *virtual* ranges. And this
struct defines the *virtual* ranges.

> {
> /* 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,
> },

--
With Best Regards,
Andy Shevchenko