ARM: local timers: introduce a new registration interface
In order to switch to a runtime selectable local timer,
add a registration interface that timer drivers can use to
register to the core.
local_timer_setup() and local_timer_stop() are made weak symbols
in order not to break existing setups.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm/include/asm/localtimer.h b/arch/arm/include/asm/localtimer.h
index 7e1b2c5..f088d63 100644
--- a/arch/arm/include/asm/localtimer.h
+++ b/arch/arm/include/asm/localtimer.h
@@ -15,6 +15,11 @@
struct clock_event_device;
+struct local_timer_ops {
+ int (*setup)(struct clock_event_device *);
+ void (*stop)(struct clock_event_device *);
+};
+
/*
* Setup a per-cpu timer, whether it be a local timer or dummy broadcast
*/
@@ -38,6 +43,11 @@
*/
int local_timer_setup(struct clock_event_device *);
+/*
+ * Register a local timer driver
+ */
+int local_timer_register(struct local_timer_ops *);
+
#else
static inline int local_timer_setup(struct clock_event_device *evt)
@@ -48,6 +58,11 @@
static inline void local_timer_stop(struct clock_event_device *evt)
{
}
+
+static inline int local_timer_register(struct local_timer_ops *ops)
+{
+ return -ENXIO;
+}
#endif
#endif
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index cdeb727..89bb02c 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -459,6 +459,33 @@
clockevents_register_device(evt);
}
+static struct local_timer_ops *lt_ops;
+
+#ifdef CONFIG_LOCAL_TIMERS
+int local_timer_register(struct local_timer_ops *ops)
+{
+ if (lt_ops)
+ return -EBUSY;
+
+ lt_ops = ops;
+ return 0;
+}
+#endif
+
+int __cpuinit __attribute__ ((weak)) local_timer_setup(struct clock_event_device *clk)
+{
+ if (lt_ops)
+ return lt_ops->setup(clk);
+
+ return -ENXIO;
+}
+
+void __attribute__ ((weak)) local_timer_stop(struct clock_event_device *clk)
+{
+ if (lt_ops)
+ lt_ops->stop(clk);
+}
+
void __cpuinit percpu_timer_setup(void)
{
unsigned int cpu = smp_processor_id();