On Tue, Nov 8, 2022 at 3:31 AM Zhang Rui <rui.zhang@xxxxxxxxx> wrote:
>
> On Mon, 2022-11-07 at 20:59 +0100, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> >
> > Notice that cmos_wake_setup() is the only user of acpi_rtc_info and
> > it
> > can operate on the cmos_rtc variable directly, so it need not set the
> > platform_data pointer before cmos_do_probe() is called. Instead, it
> > can be called by cmos_do_probe() in the case when the platform_data
> > pointer is not set to implement the default behavior (which is to use
> > the FADT information as long as ACPI support is enabled).
> >
>
> ...
>
> >
> > @@ -827,19 +829,27 @@ cmos_do_probe(struct device *dev, struct
> > if (info->address_space)
> > address_space = info->address_space;
> >
> > - if (info->rtc_day_alarm && info->rtc_day_alarm < 128)
> > - cmos_rtc.day_alrm = info->rtc_day_alarm;
> > - if (info->rtc_mon_alarm && info->rtc_mon_alarm < 128)
> > - cmos_rtc.mon_alrm = info->rtc_mon_alarm;
> > - if (info->rtc_century && info->rtc_century < 128)
> > - cmos_rtc.century = info->rtc_century;
> > + cmos_rtc.day_alrm = info->rtc_day_alarm;
> > + cmos_rtc.mon_alrm = info->rtc_mon_alarm;
> > + cmos_rtc.century = info->rtc_century;
> >
> > if (info->wake_on && info->wake_off) {
> > cmos_rtc.wake_on = info->wake_on;
> > cmos_rtc.wake_off = info->wake_off;
> > }
> > + } else {
> > + cmos_wake_setup(dev);
> > }
> >
> >
>
> Previously, before commit a474aaedac99 ("rtc-cmos: move wake setup from
> ACPI glue into RTC driver"), dev->platform_data is set in
> drivers/acpi/glue.c, and the above commit moves it to cmos_wake_setup()
> in this file.
>
> Now, with this patch, my understanding is that dev->platform_data is
> never set, thus we can remove the 'info' variable and the
> if (info)
> check above.
There are other users of this driver which can be found by grepping
for cmos_rtc_board_info.
They create platform device objects with platform_data set which are
then bound to by this driver.
