diff mbox series

[19/25] hw/timer/cmsdk-apb-dualtimer: Convert to use Clock input

Message ID 20210121190622.22000-20-peter.maydell@linaro.org (mailing list archive)
State New, archived
Headers show
Series Convert CMSDK timer, watchdog, dualtimer to Clock framework | expand

Commit Message

Peter Maydell Jan. 21, 2021, 7:06 p.m. UTC 
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.maydell@linaro.org>
---
 hw/timer/cmsdk-apb-dualtimer.c | 42 ++++++++++++++++++++++++++++++----
 1 file changed, 37 insertions(+), 5 deletions(-)

Comments

Luc Michel Jan. 22, 2021, 8:49 p.m. UTC | #1 
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.maydell@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));
}

With or without this modification:
Reviewed-by: Luc Michel <luc@lmichel.fr>


Luc

>      }
>  
>      if (changed & R_CONTROL_MODE_MASK) {
> @@ -414,7 +430,8 @@ static void cmsdk_dualtimermod_reset(CMSDKAPBDualTimerModule *m)
>       * limit must both be set to 0xffff, so we wrap at 16 bits.
>       */
>      ptimer_set_limit(m->timer, 0xffff, 1);
> -    ptimer_set_freq(m->timer, m->parent->pclk_frq);
> +    ptimer_set_period_from_clock(m->timer, m->parent->timclk,
> +                                 cmsdk_dualtimermod_divisor(m));
>      ptimer_transaction_commit(m->timer);
>  }
>  
> @@ -432,6 +449,20 @@ static void cmsdk_apb_dualtimer_reset(DeviceState *dev)
>      s->timeritop = 0;
>  }
>  
> +static void cmsdk_apb_dualtimer_clk_update(void *opaque)
> +{
> +    CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(opaque);
> +    int i;
> +
> +    for (i = 0; i < ARRAY_SIZE(s->timermod); i++) {
> +        CMSDKAPBDualTimerModule *m = &s->timermod[i];
> +        ptimer_transaction_begin(m->timer);
> +        ptimer_set_period_from_clock(m->timer, m->parent->timclk,
> +                                     cmsdk_dualtimermod_divisor(m));
> +        ptimer_transaction_commit(m->timer);
> +    }
> +}
> +
>  static void cmsdk_apb_dualtimer_init(Object *obj)
>  {
>      SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
> @@ -446,7 +477,8 @@ static void cmsdk_apb_dualtimer_init(Object *obj)
>      for (i = 0; i < ARRAY_SIZE(s->timermod); i++) {
>          sysbus_init_irq(sbd, &s->timermod[i].timerint);
>      }
> -    s->timclk = qdev_init_clock_in(DEVICE(s), "TIMCLK", NULL, NULL);
> +    s->timclk = qdev_init_clock_in(DEVICE(s), "TIMCLK",
> +                                   cmsdk_apb_dualtimer_clk_update, s);
>  }
>  
>  static void cmsdk_apb_dualtimer_realize(DeviceState *dev, Error **errp)
> @@ -454,8 +486,8 @@ static void cmsdk_apb_dualtimer_realize(DeviceState *dev, Error **errp)
>      CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(dev);
>      int i;
>  
> -    if (s->pclk_frq == 0) {
> -        error_setg(errp, "CMSDK APB timer: pclk-frq property must be set");
> +    if (!clock_has_source(s->timclk)) {
> +        error_setg(errp, "CMSDK APB dualtimer: TIMCLK clock must be connected");
>          return;
>      }
>  
> -- 
> 2.20.1
> 

--
Peter Maydell Jan. 22, 2021, 9:41 p.m. UTC | #2 
On Fri, 22 Jan 2021 at 20:48, Luc Michel <luc@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.maydell@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.

thanks
-- PMM
Luc Michel Jan. 23, 2021, 7:58 p.m. UTC | #3 
On 21:41 Fri 22 Jan     , Peter Maydell wrote:
> On Fri, 22 Jan 2021 at 20:48, Luc Michel <luc@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.maydell@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

--
Philippe Mathieu-Daudé Jan. 27, 2021, 10 p.m. UTC | #4 
On 1/21/21 8:06 PM, 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.maydell@linaro.org>
> ---
>  hw/timer/cmsdk-apb-dualtimer.c | 42 ++++++++++++++++++++++++++++++----
>  1 file changed, 37 insertions(+), 5 deletions(-)
...

> @@ -454,8 +486,8 @@ static void cmsdk_apb_dualtimer_realize(DeviceState *dev, Error **errp)
>      CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(dev);
>      int i;
>  
> -    if (s->pclk_frq == 0) {
> -        error_setg(errp, "CMSDK APB timer: pclk-frq property must be set");
> +    if (!clock_has_source(s->timclk)) {
> +        error_setg(errp, "CMSDK APB dualtimer: TIMCLK clock must be connected");
>          return;
>      }
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
diff mbox series

Patch

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);
     }
 
     if (changed & R_CONTROL_MODE_MASK) {
@@ -414,7 +430,8 @@  static void cmsdk_dualtimermod_reset(CMSDKAPBDualTimerModule *m)
      * limit must both be set to 0xffff, so we wrap at 16 bits.
      */
     ptimer_set_limit(m->timer, 0xffff, 1);
-    ptimer_set_freq(m->timer, m->parent->pclk_frq);
+    ptimer_set_period_from_clock(m->timer, m->parent->timclk,
+                                 cmsdk_dualtimermod_divisor(m));
     ptimer_transaction_commit(m->timer);
 }
 
@@ -432,6 +449,20 @@  static void cmsdk_apb_dualtimer_reset(DeviceState *dev)
     s->timeritop = 0;
 }
 
+static void cmsdk_apb_dualtimer_clk_update(void *opaque)
+{
+    CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(opaque);
+    int i;
+
+    for (i = 0; i < ARRAY_SIZE(s->timermod); i++) {
+        CMSDKAPBDualTimerModule *m = &s->timermod[i];
+        ptimer_transaction_begin(m->timer);
+        ptimer_set_period_from_clock(m->timer, m->parent->timclk,
+                                     cmsdk_dualtimermod_divisor(m));
+        ptimer_transaction_commit(m->timer);
+    }
+}
+
 static void cmsdk_apb_dualtimer_init(Object *obj)
 {
     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
@@ -446,7 +477,8 @@  static void cmsdk_apb_dualtimer_init(Object *obj)
     for (i = 0; i < ARRAY_SIZE(s->timermod); i++) {
         sysbus_init_irq(sbd, &s->timermod[i].timerint);
     }
-    s->timclk = qdev_init_clock_in(DEVICE(s), "TIMCLK", NULL, NULL);
+    s->timclk = qdev_init_clock_in(DEVICE(s), "TIMCLK",
+                                   cmsdk_apb_dualtimer_clk_update, s);
 }
 
 static void cmsdk_apb_dualtimer_realize(DeviceState *dev, Error **errp)
@@ -454,8 +486,8 @@  static void cmsdk_apb_dualtimer_realize(DeviceState *dev, Error **errp)
     CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(dev);
     int i;
 
-    if (s->pclk_frq == 0) {
-        error_setg(errp, "CMSDK APB timer: pclk-frq property must be set");
+    if (!clock_has_source(s->timclk)) {
+        error_setg(errp, "CMSDK APB dualtimer: TIMCLK clock must be connected");
         return;
     }