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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2011-05-20 15:36:52 +1000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2011-05-20 15:36:52 +1000
commit880102e78547c1db158a17e36cf0cdd98e7ad710 (patch)
tree3fff9cc54c44dafe275cfabefb96c589e08d971d /kernel/time/clockevents.c
parent3d07f0e83d4323d2cd45cc583f7cf1957aca3cac (diff)
parent39ab05c8e0b519ff0a04a869f065746e6e8c3d95 (diff)
downloadlinux-rt-880102e78547c1db158a17e36cf0cdd98e7ad710.tar.gz
Merge remote branch 'origin/master' into merge
Manual merge of arch/powerpc/kernel/smp.c and add missing scheduler_ipi() call to arch/powerpc/platforms/cell/interrupt.c Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'kernel/time/clockevents.c')
-rw-r--r--kernel/time/clockevents.c64
1 files changed, 64 insertions, 0 deletions
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 0d74b9ba90c8..22a9da9a9c96 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -194,6 +194,70 @@ void clockevents_register_device(struct clock_event_device *dev)
}
EXPORT_SYMBOL_GPL(clockevents_register_device);
+static void clockevents_config(struct clock_event_device *dev,
+ u32 freq)
+{
+ unsigned long sec;
+
+ if (!(dev->features & CLOCK_EVT_FEAT_ONESHOT))
+ return;
+
+ /*
+ * Calculate the maximum number of seconds we can sleep. Limit
+ * to 10 minutes for hardware which can program more than
+ * 32bit ticks so we still get reasonable conversion values.
+ */
+ sec = dev->max_delta_ticks;
+ do_div(sec, freq);
+ if (!sec)
+ sec = 1;
+ else if (sec > 600 && dev->max_delta_ticks > UINT_MAX)
+ sec = 600;
+
+ clockevents_calc_mult_shift(dev, freq, sec);
+ dev->min_delta_ns = clockevent_delta2ns(dev->min_delta_ticks, dev);
+ dev->max_delta_ns = clockevent_delta2ns(dev->max_delta_ticks, dev);
+}
+
+/**
+ * clockevents_config_and_register - Configure and register a clock event device
+ * @dev: device to register
+ * @freq: The clock frequency
+ * @min_delta: The minimum clock ticks to program in oneshot mode
+ * @max_delta: The maximum clock ticks to program in oneshot mode
+ *
+ * min/max_delta can be 0 for devices which do not support oneshot mode.
+ */
+void clockevents_config_and_register(struct clock_event_device *dev,
+ u32 freq, unsigned long min_delta,
+ unsigned long max_delta)
+{
+ dev->min_delta_ticks = min_delta;
+ dev->max_delta_ticks = max_delta;
+ clockevents_config(dev, freq);
+ clockevents_register_device(dev);
+}
+
+/**
+ * clockevents_update_freq - Update frequency and reprogram a clock event device.
+ * @dev: device to modify
+ * @freq: new device frequency
+ *
+ * Reconfigure and reprogram a clock event device in oneshot
+ * mode. Must be called on the cpu for which the device delivers per
+ * cpu timer events with interrupts disabled! Returns 0 on success,
+ * -ETIME when the event is in the past.
+ */
+int clockevents_update_freq(struct clock_event_device *dev, u32 freq)
+{
+ clockevents_config(dev, freq);
+
+ if (dev->mode != CLOCK_EVT_MODE_ONESHOT)
+ return 0;
+
+ return clockevents_program_event(dev, dev->next_event, ktime_get());
+}
+
/*
* Noop handler when we shut down an event device
*/