Re: [PATCH v3 28/38] rtc: add HAS_IOPORT dependencies

Arnd Bergmann
2023-05-09T08:23:41Z

On Tue, May 9, 2023, at 08:38, Geert Uytterhoeven wrote:
> On Mon, May 8, 2023 at 10:01 PM Arnd Bergmann <arnd@arndb.de> wrote:
>> On Mon, May 8, 2023, at 17:36, Niklas Schnelle wrote:
>>
>> I think the m68k/atari and mips/dec variants don't necessarily
>> qualify as PIO, those are really just pointer dereferences, and
>> they don't use the actual inb/outb functions.
>>
>> On atari, it looks like HAS_IOPORT may be set if ATARI_ROM_ISA
>> is, but on dec it's never enabled.
>
> Atari does not use RTC_DRV_CMOS, but still relies on generic RTC
> instead.

Ah right, I now remember working on that code, so we're good on
m68k then. I think it should work for everyone using

depends on HAS_IOPORT || ARCH_DECSTATION

in that case, as that is the only exception.

> Last time (in 2013?) I tried converting to RTC_DRV_CMOS by registering
> an "rtc_cmos" platform device, I couldn't get it to work.

If you ever want to revisit this, I suspect the harder part here
is to detach arch/m68k/ from the RTC_DRV_GENERIC code first, pushing
the device registration into the individual machine specific time.c
code. It's probably not even worth trying to share the rtc-cmos
driver, but it might be useful to share the library code like
RTC_DRV_ALPHA does.

Arnd