[PATCH 5/9] clocksource: dw_apb_timer: quirk for variants without EOI register

[heiko@sntech.de (Heiko Stübner)]

this patch should have had a

From: Ulrich Prinz <ulrich.prinz@googlemail.com>

sorry for the mistake

Am Samstag, 6. Juli 2013, 00:54:07 schrieb Heiko St?bner:
> Some variants of the dw_apb_timer don't have an eoi register but instead
> expect a one to be written to the int_status register at eoi time.
> 
> Signed-off-by: Ulrich Prinz <ulrich.prinz@googlemail.com>
> ---
>  drivers/clocksource/dw_apb_timer.c |   10 +++++++++-
>  include/linux/dw_apb_timer.h       |    5 +++++
>  2 files changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/clocksource/dw_apb_timer.c
> b/drivers/clocksource/dw_apb_timer.c index 5f80a30..23cd7c6 100644
> --- a/drivers/clocksource/dw_apb_timer.c
> +++ b/drivers/clocksource/dw_apb_timer.c
> @@ -104,6 +104,11 @@ static void apbt_eoi(struct dw_apb_timer *timer)
>  	apbt_readl(timer, timer->reg_eoi);
>  }
> 
> +static void apbt_eoi_int_status(struct dw_apb_timer *timer)
> +{
> +	apbt_writel(timer, 1, timer->reg_int_status);
> +}
> +
>  static irqreturn_t dw_apb_clockevent_irq(int irq, void *data)
>  {
>  	struct clock_event_device *evt = data;
> @@ -286,7 +291,10 @@ dw_apb_clockevent_init(int cpu, const char *name,
> unsigned rating, IRQF_NOBALANCING |
>  					  IRQF_DISABLED;
> 
> -	dw_ced->eoi = apbt_eoi;
> +	if (quirks & APBTMR_QUIRK_NO_EOI)
> +		dw_ced->eoi = apbt_eoi_int_status;
> +	else
> +		dw_ced->eoi = apbt_eoi;
>  	err = setup_irq(irq, &dw_ced->irqaction);
>  	if (err) {
>  		pr_err("failed to request timer irq\n");
> diff --git a/include/linux/dw_apb_timer.h b/include/linux/dw_apb_timer.h
> index 80f6686..fbe4c6b 100644
> --- a/include/linux/dw_apb_timer.h
> +++ b/include/linux/dw_apb_timer.h
> @@ -25,6 +25,11 @@
>   */
>  #define APBTMR_QUIRK_64BIT_COUNTER	BIT(0)
> 
> +/* The IP does not provide a end-of-interrupt register to clear pending
> + * interrupts, but requires to write a 1 to the interrupt-status register.
> + */
> +#define APBTMR_QUIRK_NO_EOI		BIT(1)
> +
>  struct dw_apb_timer {
>  	void __iomem				*base;
>  	unsigned long				freq;