Re: [PATCH 18/25] hw/timer/cmsdk-apb-timer: Convert to use Clock input

[Philippe Mathieu-Daudé]

On 1/21/21 8:06 PM, Peter Maydell wrote:
> Switch the CMSDK APB timer 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-timer.c | 18 ++++++++++++++----
>  1 file changed, 14 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/timer/cmsdk-apb-timer.c b/hw/timer/cmsdk-apb-timer.c
> index c63145ff553..f053146d88f 100644
> --- a/hw/timer/cmsdk-apb-timer.c
> +++ b/hw/timer/cmsdk-apb-timer.c
> @@ -204,6 +204,15 @@ static void cmsdk_apb_timer_reset(DeviceState *dev)
>      ptimer_transaction_commit(s->timer);
>  }
>  
> +static void cmsdk_apb_timer_clk_update(void *opaque)
> +{
> +    CMSDKAPBTimer *s = CMSDK_APB_TIMER(opaque);
> +
> +    ptimer_transaction_begin(s->timer);
> +    ptimer_set_period_from_clock(s->timer, s->pclk, 1);
> +    ptimer_transaction_commit(s->timer);
> +}
> +
>  static void cmsdk_apb_timer_init(Object *obj)
>  {
>      SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
> @@ -213,15 +222,16 @@ static void cmsdk_apb_timer_init(Object *obj)
>                            s, "cmsdk-apb-timer", 0x1000);
>      sysbus_init_mmio(sbd, &s->iomem);
>      sysbus_init_irq(sbd, &s->timerint);
> -    s->pclk = qdev_init_clock_in(DEVICE(s), "pclk", NULL, NULL);
> +    s->pclk = qdev_init_clock_in(DEVICE(s), "pclk",
> +                                 cmsdk_apb_timer_clk_update, s);
>  }
>  
>  static void cmsdk_apb_timer_realize(DeviceState *dev, Error **errp)
>  {
>      CMSDKAPBTimer *s = CMSDK_APB_TIMER(dev);
>  
> -    if (s->pclk_frq == 0) {
> -        error_setg(errp, "CMSDK APB timer: pclk-frq property must be set");
> +    if (!clock_has_source(s->pclk)) {
> +        error_setg(errp, "CMSDK APB timer: pclk clock must be connected");
>          return;
>      }
>  
> @@ -232,7 +242,7 @@ static void cmsdk_apb_timer_realize(DeviceState *dev, 
> Error **errp)
>                             PTIMER_POLICY_NO_COUNTER_ROUND_DOWN);
>  
>      ptimer_transaction_begin(s->timer);
> -    ptimer_set_freq(s->timer, s->pclk_frq);
> +    ptimer_set_period_from_clock(s->timer, s->pclk, 1);
>      ptimer_transaction_commit(s->timer);
>  }

Nice to see how ptimer_set_period_from_clock() fits :)

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>