Re: Two issues with 2.4.18pre3 on PPC

[<benh@kernel.crashing.org>]

>- The generic RTC driver in drivers/char/rtc.c does not work for this
>  iBook. The driver in drivers/macintosh/rtc.c does work, but it only
>  implements the two ioctls RTC_RD_TIME and RTC_SET_TIME. (Is this due to
>  hardware limitations?) Anyway, it is confusing to have both drivers
>  configurable for PPC, maybe the corresponding Config.in files should be
>  adjusted. (In addition, this is complicated by the fact that both
>  configuration options appear in different submenus and if you select
>  both as modules, then the generic driver will "shadow" the macintosh
>  one.)

That's a weirdness we haven't solved yet. Part of the problem is
that a common kernel can boot pmac, chrp and prep, and the later
ones can use the drivers/char/rtc.c driver. Actually, the
drivers/macintosh/rtc.c one may work on these too as it's just
a wrapper on some platform code selected at runtime depending on
the machine class.

Now, regarding the support of only GET/SET ioctls, it's normal.
Some of these machines don't have the legacy PC hardware RTC with
alarm support etc... That's the case of macs where the RTC hardware
is purely a real time clock. (It has other features, like scheduled
power up, but these aren't implemented yet and could be done entirely
in userland using /dev/adb anyway).

So the driver in drivers/macintosh/rtc.c is just a wrapper on the
get/set time functions provided by each type of machine.

Ben.