Re: [PATCH] pinctrl: cy8c95x0: Cache muxed registers

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Tue, May 14, 2024 at 10:39 AM Patrick Rudolph
<patrick.rudolph@xxxxxxxxxxxxx> wrote:

> Do you have an example where muxed registers are used in a regmap?
> Is there some documentation available explaining the existing
> mechanism? I'm not aware of anything.

The regmap is sadly undocumented I have had it on my list for a long
time to document this gem, but I never find the time.

You have to mark registers that cannot be cached as volatile, then
enable caching in the regmap with e.g. .cache_type = REGCACHE_FLAT
in the regmap config, then it pretty much caches itself.
<linux/regmap.h> has some cache maintenance functions if you
run into corner cases.

(Mark will correct me if I say something wrong...)

Yours,
Linus Walleij