Re: [Qemu-devel] [PATCH v3 5/7] allwinner-a10-pit: implement prescaler and source selection

[Li Guang <lig.fnst@cn.fujitsu.com>]

在 2014-03-15六的 14:01 +0100，Beniamino Galvani写道：
> This implements the prescaler and source fields of the timer control
> register as described in the A10 user manual.
> 
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>

Reviewed-by: Li Guang <lig.fnst@cn.fujitsu.com>

> ---
>  hw/timer/allwinner-a10-pit.c         |   30 +++++++++++++++++++++++++++++-
>  include/hw/timer/allwinner-a10-pit.h |    8 ++++++++
>  2 files changed, 37 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/timer/allwinner-a10-pit.c b/hw/timer/allwinner-a10-pit.c
> index f8c9236..a448689 100644
> --- a/hw/timer/allwinner-a10-pit.c
> +++ b/hw/timer/allwinner-a10-pit.c
> @@ -74,6 +74,34 @@ 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 = AW_A10_PIT_OSC24M_FREQ;
> +
> +    prescaler = 1 << extract32(s->control[index], 4, 3);
> +    source = extract32(s->control[index], 2, 2);
> +
> +    switch (source) {
> +    case AW_A10_PIT_SOURCE_LS_OSC:
> +        source_freq = AW_A10_PIT_LS_OSC_FREQ;
> +        break;
> +    case AW_A10_PIT_SOURCE_OSC24M:
> +        source_freq = AW_A10_PIT_OSC24M_FREQ;
> +        break;
> +    case AW_A10_PIT_SOURCE_PLL6:
> +        qemu_log_mask(LOG_UNIMP, "%s: unimplemented clock source %u", __func__,
> +                      source);
> +        break;
> +    case AW_A10_PIT_SOURCE_UNDEF:
> +        qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid clock source %u", __func__,
> +                      source);
> +        break;
> +    }
> +
> +    ptimer_set_freq(s->timer[index], source_freq / prescaler);
> +}
> +
>  static void a10_pit_write(void *opaque, hwaddr offset, uint64_t value,
>                              unsigned size)
>  {
> @@ -96,6 +124,7 @@ 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]);
>              }
> @@ -239,7 +268,6 @@ 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);
>      }
>  }
>  
> diff --git a/include/hw/timer/allwinner-a10-pit.h b/include/hw/timer/allwinner-a10-pit.h
> index a48d3c7..37a2662 100644
> --- a/include/hw/timer/allwinner-a10-pit.h
> +++ b/include/hw/timer/allwinner-a10-pit.h
> @@ -33,6 +33,14 @@
>  #define AW_A10_PIT_TIMER_BASE_END  \
>      (AW_A10_PIT_TIMER_BASE * 6 + AW_A10_PIT_TIMER_COUNT)
>  
> +#define AW_A10_PIT_SOURCE_LS_OSC   0
> +#define AW_A10_PIT_SOURCE_OSC24M   1
> +#define AW_A10_PIT_SOURCE_PLL6     2
> +#define AW_A10_PIT_SOURCE_UNDEF    3
> +
> +#define AW_A10_PIT_LS_OSC_FREQ     32768
> +#define AW_A10_PIT_OSC24M_FREQ     24000000
> +
>  #define AW_A10_PIT_DEFAULT_CLOCK   0x4
>  
>  typedef struct AwA10PITState AwA10PITState;