Re: [PATCH v2 2/2] clocksource/cadence_ttc: Reuse clocksource assched_clock

From: Michal Simek
Date: Fri Jul 12 2013 - 08:08:36 EST


On 07/08/2013 06:51 PM, Soren Brinkmann wrote:
> Reuse the TTC clocksource timer as sched clock provider.
>
> Signed-off-by: Soren Brinkmann <soren.brinkmann@xxxxxxxxxx>
> ---
> v2:
> - #include linux/sched_clock.h instead of asm/sched_clock.h
> - remove Kconfig options and #ifdefs around sched_clock related code
> The reasons for having those are obsolete, since ARM deprecated its
> custom sched_clock framework and migrated to the common one.
>
> drivers/clocksource/cadence_ttc_timer.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/clocksource/cadence_ttc_timer.c b/drivers/clocksource/cadence_ttc_timer.c
> index 0eefc8d..b2bb3a4b 100644
> --- a/drivers/clocksource/cadence_ttc_timer.c
> +++ b/drivers/clocksource/cadence_ttc_timer.c
> @@ -21,6 +21,7 @@
> #include <linux/of_address.h>
> #include <linux/of_irq.h>
> #include <linux/slab.h>
> +#include <linux/sched_clock.h>
>
> /*
> * This driver configures the 2 16-bit count-up timers as follows:
> @@ -94,6 +95,8 @@ struct ttc_timer_clockevent {
> #define to_ttc_timer_clkevent(x) \
> container_of(x, struct ttc_timer_clockevent, ce)
>
> +static void __iomem *ttc_sched_clock_val_reg;
> +
> /**
> * ttc_set_interval - Set the timer interval value
> *
> @@ -155,6 +158,11 @@ static cycle_t __ttc_clocksource_read(struct clocksource *cs)
> TTC_COUNT_VAL_OFFSET);
> }
>
> +static u32 notrace ttc_sched_clock_read(void)
> +{
> + return __raw_readl(ttc_sched_clock_val_reg);
> +}
> +
> /**
> * ttc_set_next_event - Sets the time interval for next event
> *
> @@ -296,6 +304,10 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base)
> kfree(ttccs);
> return;
> }
> +
> + ttc_sched_clock_val_reg = base + TTC_COUNT_VAL_OFFSET;
> + setup_sched_clock(ttc_sched_clock_read, 16,
> + clk_get_rate(ttccs->ttc.clk) / PRESCALE);
> }
>
> static int ttc_rate_change_clockevent_cb(struct notifier_block *nb,
>

Acked-by: Michal Simek <monstr@xxxxxxxxx>

Thomas, John: Can you please add this patch to your queue?
IRC all these timer patches should go through your trees.

Thanks,
Michal

--
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/
Maintainer of Linux kernel - Xilinx Zynq ARM architecture
Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform


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