Re: [linuxsh-dev] Dreamcast RTC

[M. R. B. <ma...@uw...>]

On Fri, 1 Dec 2000, Philipp Rumpf wrote:

> On Thu, Nov 30, 2000 at 06:34:51PM -0600, M. R. Brown wrote:
> 
> > I'm currently working on host-tools and I have a patch to newlib for
> > gettimeofday (simply adds 20 years to the RTC val to get the Unix epoch of
> > Jan. 1, 1970).  I'll post the code when I get to my workstation, tommorow.
> 
> subtract, I hope.
> 

Er, oops, yes I meant subtract.

> so arch/sh/kernel/time.c: get_rtc_time would look like this;
> 
> static unsigned long get_rtc_time(void)
> {
> 	unsigned long val1, val2;
> 
> 	do {
> 		val1 = (ctrl_inl(high word)<<16) + (ctrl_inl(low word)&0xffff);
> 		val2 = (ctrl_inl(high word)<<16) + (ctrl_inl(low word)&0xffff);
> 	} while(val1 != val2);
> 
> 	/* should be date -d 'jan 1 0000 1950' '+%s'. */
> 	val1 -= 631152000;
> 
> 	return val1;
> }
> 
> 

I was thinking of #ifdef'ing the Dreamcast RTC code inside various
CONFIG_SH_DREAMCAST macros as it isn't standard SH4 stuff.  But other than
that your code looks good.

M. R.