[PATCH 2/3] powerpc/mpic: add global timer support

[Wang Dongsheng-B40534]

> -----Original Message-----
> From: Wood Scott-B07421
> Sent: Saturday, March 23, 2013 6:30 AM
> To: Wang Dongsheng-B40534
> Cc: Wood Scott-B07421; Gala Kumar-B11780; linuxppc-dev at lists.ozlabs.org;
> Li Yang-R58472
> Subject: Re: [PATCH 2/3] powerpc/mpic: add global timer support
> 
> On 03/22/2013 01:14:51 AM, Wang Dongsheng-B40534 wrote:
> >
> >
> > > -----Original Message-----
> > > From: Wood Scott-B07421
> > > Sent: Thursday, March 21, 2013 7:00 AM
> > > To: Wang Dongsheng-B40534
> > > Cc: Wood Scott-B07421; Gala Kumar-B11780;
> > linuxppc-dev at lists.ozlabs.org;
> > > Li Yang-R58472
> > > Subject: Re: [PATCH 2/3] powerpc/mpic: add global timer support
> > >
> > > BTW, the input clock frequency has been similarly scaled, yet you
> > don't
> > > try to scrounge up that information to get further precision...
> > >
> > Let's go back patch, do you think the code is repeated?
> > I will remove "if (!(priv->flags & FSL_GLOBAL_TIMER))" branch, there
> > will be no redundant code.
> 
> I'd rather that branch be kept and the more complicated branch deleted,
> and priv->timerfreq frequency be adjusted on initialization to account
> for the scaler.

static void convert_ticks_to_time(struct timer_group_priv *priv,
                const u64 ticks, struct timeval *time)
{
        u64 tmp_sec;

        time->tv_sec = (__kernel_time_t)div_u64(ticks, priv->timerfreq);
        tmp_sec = (u64)time->tv_sec * (u64)priv->timerfreq;

        time->tv_usec = (__kernel_suseconds_t)
                div_u64((ticks - tmp_sec) * 1000000, priv->timerfreq);

        return;
}

timer_group_get_freq() {
	...
	if (priv->flags & FSL_GLOBAL_TIMER) {
		div = (1 << (MPIC_TIMER_TCR_CLKDIV_64 >> 8)) * 8;
		priv->timerfreq /= div;
	}
	...
}
Do you want to do that?