Re: [Qemu-devel] [PATCH v4 5/7] allwinner-a10-pit: implement prescaler and source selection

[Peter Crosthwaite]

On Fri, Mar 21, 2014 at 7:25 AM, Beniamino Galvani <address@hidden> wrote:
> This implements the prescaler and source fields of the timer control
> register. The source for each timer can be selected among 4 clock
> inputs whose frequencies are set through model properties.
>
> Signed-off-by: Beniamino Galvani <address@hidden>
> ---
>  hw/arm/cubieboard.c                  |   13 ++++++++++
>  hw/timer/allwinner-a10-pit.c         |   43 
> +++++++++++++++++++++++++++++++++-
>  include/hw/timer/allwinner-a10-pit.h |    4 ++++
>  3 files changed, 59 insertions(+), 1 deletion(-)
>
> diff --git a/hw/arm/cubieboard.c b/hw/arm/cubieboard.c
> index d95a7f3..9d158c7 100644
> --- a/hw/arm/cubieboard.c
> +++ b/hw/arm/cubieboard.c
> @@ -43,6 +43,19 @@ static void cubieboard_init(QEMUMachineInitArgs *args)
>          exit(1);
>      }
>
> +    object_property_set_int(OBJECT(&s->a10->timer), 32768, "clk0-freq", 
> &err);
> +    if (err != NULL) {
> +        error_report("Couldn't set clk0 frequency: %s", 
> error_get_pretty(err));
> +        exit(1);
> +    }
> +
> +    object_property_set_int(OBJECT(&s->a10->timer), 24000000, "clk1-freq",
> +                            &err);
> +    if (err != NULL) {
> +        error_report("Couldn't set clk1 frequency: %s", 
> error_get_pretty(err));
> +        exit(1);
> +    }
> +
>      object_property_set_bool(OBJECT(s->a10), true, "realized", &err);
>      if (err != NULL) {
>          error_report("Couldn't realize Allwinner A10: %s",
> diff --git a/hw/timer/allwinner-a10-pit.c b/hw/timer/allwinner-a10-pit.c
> index 5aa78a9..5c1ffba 100644
> --- a/hw/timer/allwinner-a10-pit.c
> +++ b/hw/timer/allwinner-a10-pit.c
> @@ -74,6 +74,37 @@ static uint64_t a10_pit_read(void *opaque, hwaddr offset, 
> unsigned size)
>      return 0;
>  }
>
> +static void a10_pit_set_freq(AwA10PITState *s, int index)
> +{
> +    uint32_t prescaler, source;
> +    uint32_t source_freq;
> +
> +    prescaler = 1 << extract32(s->control[index], 4, 3);
> +    source = extract32(s->control[index], 2, 2);
> +
> +    switch (source) {
> +    case 0:
> +        source_freq = s->clk0_freq;
> +        break;
> +    case 1:
> +        source_freq = s->clk1_freq;
> +        break;
> +    case 2:
> +        source_freq = s->clk2_freq;
> +        break;
> +    case 3:
> +        source_freq = s->clk3_freq;
> +        break;
> +    }

You can get rid of this [1] ...

> +
> +    if (source_freq) {
> +        ptimer_set_freq(s->timer[index], source_freq / prescaler);
> +    } else {
> +        qemu_log_mask(LOG_GUEST_ERROR, "%s: Invalid clock source %u\n",
> +                      __func__, source);
> +    }
> +}
> +
>  static void a10_pit_write(void *opaque, hwaddr offset, uint64_t value,
>                              unsigned size)
>  {
> @@ -96,6 +127,7 @@ static void a10_pit_write(void *opaque, hwaddr offset, 
> uint64_t value,
>          switch (offset & 0x0f) {
>          case AW_A10_PIT_TIMER_CONTROL:
>              s->control[index] = value;
> +            a10_pit_set_freq(s, index);
>              if (s->control[index] & AW_A10_PIT_TIMER_RELOAD) {
>                  ptimer_set_count(s->timer[index], s->interval[index]);
>              }
> @@ -161,6 +193,14 @@ static const MemoryRegionOps a10_pit_ops = {
>      .endianness = DEVICE_NATIVE_ENDIAN,
>  };
>
> +static Property a10_pit_properties[] = {
> +    DEFINE_PROP_UINT32("clk0-freq", AwA10PITState, clk0_freq, 0),

... [1] by changing this to:

DEFINE_PROP_UINT32("clk0-freq", AwA10PITState, clk_freq[0], 0),

> +    DEFINE_PROP_UINT32("clk1-freq", AwA10PITState, clk1_freq, 0),
> +    DEFINE_PROP_UINT32("clk2-freq", AwA10PITState, clk2_freq, 0),
> +    DEFINE_PROP_UINT32("clk3-freq", AwA10PITState, clk3_freq, 0),


Note that there is an array property system (DEFINE_PROP_ARRAY) that
should kinda work here. Although it requires you to set the length of
the array on the setter level, which should be fixed to 4 in this
case. Check the "db-voltage" property of arm_sysctrl and its usage in
vexpress. But I can't see a clean way of fixing this imminently
without patching that property system. Curious it works nicely for
dynamic arrays but not static (unless I am missing something).

> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
>  static const VMStateDescription vmstate_a10_pit = {
>      .name = "a10.pit",
>      .version_id = 1,
> @@ -196,6 +236,7 @@ static void a10_pit_reset(DeviceState *dev)
>          s->interval[i] = 0;
>          s->count[i] = 0;
>          ptimer_stop(s->timer[i]);
> +        a10_pit_set_freq(s, i);
>      }
>      s->watch_dog_mode = 0;
>      s->watch_dog_control = 0;
> @@ -241,7 +282,6 @@ static void a10_pit_init(Object *obj)
>          tc->index = i;
>          bh[i] = qemu_bh_new(a10_pit_timer_cb, tc);
>          s->timer[i] = ptimer_init(bh[i]);
> -        ptimer_set_freq(s->timer[i], 240000);
>      }
>  }
>
> @@ -250,6 +290,7 @@ static void a10_pit_class_init(ObjectClass *klass, void 
> *data)
>      DeviceClass *dc = DEVICE_CLASS(klass);
>
>      dc->reset = a10_pit_reset;
> +    dc->props = a10_pit_properties;
>      dc->desc = "allwinner a10 timer";
>      dc->vmsd = &vmstate_a10_pit;
>  }
> diff --git a/include/hw/timer/allwinner-a10-pit.h 
> b/include/hw/timer/allwinner-a10-pit.h
> index a48d3c7..5388b2b 100644
> --- a/include/hw/timer/allwinner-a10-pit.h
> +++ b/include/hw/timer/allwinner-a10-pit.h
> @@ -50,6 +50,10 @@ typedef struct AwA10PITState {
>      ptimer_state * timer[AW_A10_PIT_TIMER_NR];
>      AwA10TimerContext timer_context[AW_A10_PIT_TIMER_NR];
>      MemoryRegion iomem;
> +    uint32_t clk0_freq;
> +    uint32_t clk1_freq;
> +    uint32_t clk2_freq;
> +    uint32_t clk3_freq;
>

And this becomes an array.

With just the arrayification change:

Reviewed-by: Peter Crosthwaite <address@hidden>

Regards,
Peter

>      uint32_t irq_enable;
>      uint32_t irq_status;
> --
> 1.7.10.4
>
>