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.brinkm...@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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