rtc: Add tracepoints for RTC system

It will be more helpful to add some tracepoints to track RTC actions when
debugging RTC driver. Below sample is that we set/read the RTC time, then
set 2 alarms, so we can see the trace logs:

set/read RTC time:
kworker/0:1-67 [000] 21.814245: rtc_set_time: UTC (1510301580) (0)
kworker/0:1-67 [000] 21.814312: rtc_read_time: UTC (1510301580) (0)

set the first alarm timer:
kworker/0:1-67 [000] 21.829238: rtc_timer_enqueue: RTC timer:(ffffffc15eb49bc8) expires:1510301700000000000 period:0
kworker/0:1-67 [000] 22.018279: rtc_set_alarm: UTC (1510301700) (0)

set the second alarm timer:
kworker/0:1-67 [000] 22.230284: rtc_timer_enqueue: RTC timer:(ffffff80088e6430) expires:1510301820000000000 period:0

the first alarm timer was expired:
kworker/0:1-67 [000] 145.155584: rtc_timer_dequeue: RTC timer:(ffffffc15eb49bc8) expires:1510301700000000000 period:0
kworker/0:1-67 [000] 145.155593: rtc_timer_fired: RTC timer:(ffffffc15eb49bc8) expires:1510301700000000000 period:0
kworker/0:1-67 [000] 145.172504: rtc_set_alarm: UTC (1510301820) (0)

the second alarm timer was expired:
kworker/0:1-67 [000] 269.102353: rtc_timer_dequeue: RTC timer:(ffffff80088e6430) expires:1510301820000000000 period:0
kworker/0:1-67 [000] 269.102360: rtc_timer_fired: RTC timer:(ffffff80088e6430) expires:1510301820000000000 period:0

disable alarm irq:
kworker/0:1-67 [000] 269.102469: rtc_alarm_irq_enable: disable RTC alarm IRQ (0)

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

1 files changed, 206 insertions, 0 deletions

diff --git a/include/trace/events/rtc.h b/include/trace/events/rtc.h
new file mode 100644
index 000000000000..621333f1c890
--- /dev/null
+++ b/include/trace/events/rtc.h
@@ -0,0 +1,206 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM rtc
+
+#if !defined(_TRACE_RTC_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_RTC_H
+
+#include <linux/rtc.h>
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(rtc_time_alarm_class,
+
+	TP_PROTO(time64_t secs, int err),
+
+	TP_ARGS(secs, err),
+
+	TP_STRUCT__entry(
+		__field(time64_t, secs)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__entry->secs = secs;
+		__entry->err = err;
+	),
+
+	TP_printk("UTC (%lld) (%d)",
+		  __entry->secs, __entry->err
+	)
+);
+
+DEFINE_EVENT(rtc_time_alarm_class, rtc_set_time,
+
+	TP_PROTO(time64_t secs, int err),
+
+	TP_ARGS(secs, err)
+);
+
+DEFINE_EVENT(rtc_time_alarm_class, rtc_read_time,
+
+	TP_PROTO(time64_t secs, int err),
+
+	TP_ARGS(secs, err)
+);
+
+DEFINE_EVENT(rtc_time_alarm_class, rtc_set_alarm,
+
+	TP_PROTO(time64_t secs, int err),
+
+	TP_ARGS(secs, err)
+);
+
+DEFINE_EVENT(rtc_time_alarm_class, rtc_read_alarm,
+
+	TP_PROTO(time64_t secs, int err),
+
+	TP_ARGS(secs, err)
+);
+
+TRACE_EVENT(rtc_irq_set_freq,
+
+	TP_PROTO(int freq, int err),
+
+	TP_ARGS(freq, err),
+
+	TP_STRUCT__entry(
+		__field(int, freq)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__entry->freq = freq;
+		__entry->err = err;
+	),
+
+	TP_printk("set RTC periodic IRQ frequency:%u (%d)",
+		  __entry->freq, __entry->err
+	)
+);
+
+TRACE_EVENT(rtc_irq_set_state,
+
+	TP_PROTO(int enabled, int err),
+
+	TP_ARGS(enabled, err),
+
+	TP_STRUCT__entry(
+		__field(int, enabled)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__entry->enabled = enabled;
+		__entry->err = err;
+	),
+
+	TP_printk("%s RTC 2^N Hz periodic IRQs (%d)",
+		  __entry->enabled ? "enable" : "disable",
+		  __entry->err
+	)
+);
+
+TRACE_EVENT(rtc_alarm_irq_enable,
+
+	TP_PROTO(unsigned int enabled, int err),
+
+	TP_ARGS(enabled, err),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, enabled)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__entry->enabled = enabled;
+		__entry->err = err;
+	),
+
+	TP_printk("%s RTC alarm IRQ (%d)",
+		  __entry->enabled ? "enable" : "disable",
+		  __entry->err
+	)
+);
+
+DECLARE_EVENT_CLASS(rtc_offset_class,
+
+	TP_PROTO(long offset, int err),
+
+	TP_ARGS(offset, err),
+
+	TP_STRUCT__entry(
+		__field(long, offset)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__entry->offset = offset;
+		__entry->err = err;
+	),
+
+	TP_printk("RTC offset: %ld (%d)",
+		  __entry->offset, __entry->err
+	)
+);
+
+DEFINE_EVENT(rtc_offset_class, rtc_set_offset,
+
+	TP_PROTO(long offset, int err),
+
+	TP_ARGS(offset, err)
+);
+
+DEFINE_EVENT(rtc_offset_class, rtc_read_offset,
+
+	TP_PROTO(long offset, int err),
+
+	TP_ARGS(offset, err)
+);
+
+DECLARE_EVENT_CLASS(rtc_timer_class,
+
+	TP_PROTO(struct rtc_timer *timer),
+
+	TP_ARGS(timer),
+
+	TP_STRUCT__entry(
+		__field(struct rtc_timer *, timer)
+		__field(ktime_t, expires)
+		__field(ktime_t, period)
+	),
+
+	TP_fast_assign(
+		__entry->timer = timer;
+		__entry->expires = timer->node.expires;
+		__entry->period = timer->period;
+	),
+
+	TP_printk("RTC timer:(%p) expires:%lld period:%lld",
+		  __entry->timer, __entry->expires, __entry->period
+	)
+);
+
+DEFINE_EVENT(rtc_timer_class, rtc_timer_enqueue,
+
+	TP_PROTO(struct rtc_timer *timer),
+
+	TP_ARGS(timer)
+);
+
+DEFINE_EVENT(rtc_timer_class, rtc_timer_dequeue,
+
+	TP_PROTO(struct rtc_timer *timer),
+
+	TP_ARGS(timer)
+);
+
+DEFINE_EVENT(rtc_timer_class, rtc_timer_fired,
+
+	TP_PROTO(struct rtc_timer *timer),
+
+	TP_ARGS(timer)
+);
+
+#endif /* _TRACE_RTC_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>