On 21:41 Fri 22 Jan , Peter Maydell wrote:
> On Fri, 22 Jan 2021 at 20:48, Luc Michel <l...@lmichel.fr> wrote:
> >
> > On 19:06 Thu 21 Jan , Peter Maydell wrote:
> > > Switch the CMSDK APB dualtimer device over to using its Clock input;
> > > the pclk-frq property is now ignored.
> > >
> > > Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
> > > ---
> > > hw/timer/cmsdk-apb-dualtimer.c | 42 ++++++++++++++++++++++++++++++----
> > > 1 file changed, 37 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/hw/timer/cmsdk-apb-dualtimer.c
> > > b/hw/timer/cmsdk-apb-dualtimer.c
> > > index 781b496037b..828127b366f 100644
> > > --- a/hw/timer/cmsdk-apb-dualtimer.c
> > > +++ b/hw/timer/cmsdk-apb-dualtimer.c
> > > @@ -106,6 +106,22 @@ static void
> > > cmsdk_apb_dualtimer_update(CMSDKAPBDualTimer *s)
> > > qemu_set_irq(s->timerintc, timintc);
> > > }
> > >
> > > +static int cmsdk_dualtimermod_divisor(CMSDKAPBDualTimerModule *m)
> > > +{
> > > + /* Return the divisor set by the current CONTROL.PRESCALE value */
> > > + switch (FIELD_EX32(m->control, CONTROL, PRESCALE)) {
> > > + case 0:
> > > + return 1;
> > > + case 1:
> > > + return 16;
> > > + case 2:
> > > + case 3: /* UNDEFINED, we treat like 2 (and complained when it was
> > > set) */
> > > + return 256;
> > > + default:
> > > + g_assert_not_reached();
> > > + }
> > > +}
> > > +
> > > static void cmsdk_dualtimermod_write_control(CMSDKAPBDualTimerModule *m,
> > > uint32_t newctrl)
> > > {
> > > @@ -146,7 +162,7 @@ static void
> > > cmsdk_dualtimermod_write_control(CMSDKAPBDualTimerModule *m,
> > > default:
> > > g_assert_not_reached();
> > > }
> > > - ptimer_set_freq(m->timer, m->parent->pclk_frq / divisor);
> > > + ptimer_set_period_from_clock(m->timer, m->parent->timclk,
> > > divisor);
> >
> > Just a small cosmetic note, maybe you can use your new
> > cmsdk_dualtimermod_divisor function to factor out the switch above?
> > Something like:
> >
> > if (changed & R_CONTROL_PRESCALE_MASK) {
> > if (FIELD_EX32(newctrl, CONTROL, PRESCALE) == 3) {
> > qemu_log_mask(LOG_GUEST_ERROR,
> > "CMSDK APB dual-timer: CONTROL.PRESCALE==0b11"
> > " is undefined behaviour\n");
> > }
> >
> > ptimer_set_period_from_clock(m->timer, m->parent->timclk,
> > cmsdk_dualtimermod_divisor(m));
> > }
>
> Nope, because cmsdk_dualtimermod_divisor() uses the current
> m->control value, and at this point in the code we need the
> divisor from the new control value which isn't in m->control yet.
> I liked the slight duplication better than either having to
> pass m->control in in all the other callsites or trying to
> refactor the control write handling so that m->control is
> updated before this point in the code.
Oops yes I missed that. Sure make sense, forget what I said.
>
> thanks
> -- PMM
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