Re: [PATCH v2] watchdog: ebc-c384_wdt: Migrate to the regmap API

[Guenter Roeck]

On 3/14/23 08:50, Andy Shevchenko wrote:
> On Tue, Mar 14, 2023 at 11:29:16AM -0400, William Breathitt Gray wrote:
> > The regmap API supports IO port accessors so we can take advantage of
> > regmap abstractions rather than handling access to the device registers
> > directly in the driver.
>
> ...
>
> >   - Utilize watchdog_set_drvdata() and watchdog_get_drvdata()
>
> I'm wondering why you can't use dev_get_regmap() instead.

That function is quite expensive to use in code that is called
for each register access. Its typical use is to get the regmap
for a driver once and store it in a local data structure, not
to use it for each access.

Guenter

> >   - Map watchdog control registers based on offset 0x1 and adjust regmap
> >     configurations accordingly; offset 0x0 is unused in this driver so we
> >     should avoid unnecessary exposure of it
>
> I'm wondering what bad could happen if you expose it.