Messages in this thread Patch in this message | | | From | Soren Brinkmann <> | Subject | [PATCH] clocksource/cadence_ttc: Reuse clocksource as sched_clock | Date | Wed, 3 Jul 2013 14:50:16 -0700 |
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Reuse the TTC clocksource timer as sched clock, too. Since only a single sched clock is supported in Linux, this feature optional and can be selected through Kconfig.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> --- drivers/clocksource/Kconfig | 7 +++++++ drivers/clocksource/cadence_ttc_timer.c | 18 ++++++++++++++++++ 2 files changed, 25 insertions(+)
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 5871933..8dda767 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -36,6 +36,13 @@ config VT8500_TIMER config CADENCE_TTC_TIMER bool +config CADENCE_TTC_TIMER_SCHED_CLOCK + bool "Cadence TTC Sched Clock" + depends on CADENCE_TTC_TIMER + help + Use the clocksource timer provided by the TTC as + sched clock, also. + config CLKSRC_NOMADIK_MTU bool depends on (ARCH_NOMADIK || ARCH_U8500) diff --git a/drivers/clocksource/cadence_ttc_timer.c b/drivers/clocksource/cadence_ttc_timer.c index 4cbe28c..ef0f52b 100644 --- a/drivers/clocksource/cadence_ttc_timer.c +++ b/drivers/clocksource/cadence_ttc_timer.c @@ -22,6 +22,7 @@ #include <linux/of_irq.h> #include <linux/slab.h> #include <linux/clk-provider.h> +#include <asm/sched_clock.h> /* * This driver configures the 2 16-bit count-up timers as follows: @@ -95,6 +96,10 @@ struct ttc_timer_clockevent { #define to_ttc_timer_clkevent(x) \ container_of(x, struct ttc_timer_clockevent, ce) +#ifdef CONFIG_CADENCE_TTC_TIMER_SCHED_CLOCK +static void __iomem *ttc_sched_clock_val_reg; +#endif + /** * ttc_set_interval - Set the timer interval value * @@ -156,6 +161,13 @@ static cycle_t __ttc_clocksource_read(struct clocksource *cs) TTC_COUNT_VAL_OFFSET); } +#ifdef CONFIG_CADENCE_TTC_TIMER_SCHED_CLOCK +static u32 notrace ttc_sched_clock_read(void) +{ + return __raw_readl(ttc_sched_clock_val_reg); +} +#endif + /** * ttc_set_next_event - Sets the time interval for next event * @@ -297,6 +309,12 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base) kfree(ttccs); return; } + +#ifdef CONFIG_CADENCE_TTC_TIMER_SCHED_CLOCK + 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); +#endif } static int ttc_rate_change_clockevent_cb(struct notifier_block *nb, -- 1.8.3.2
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