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>

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 672b192f8153aa00665daaefc541ebaf601cfe74..7e253be19ba7e8f066776e623b187012175dc3c3 100644 (file)
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -17,6 +17,9 @@
 #include <linux/log2.h>
 #include <linux/workqueue.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/rtc.h>
+
 static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer);
 static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer);
 
@@ -53,6 +56,8 @@ int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
 
        err = __rtc_read_time(rtc, tm);
        mutex_unlock(&rtc->ops_lock);
+
+       trace_rtc_read_time(rtc_tm_to_time64(tm), err);
        return err;
 }
 EXPORT_SYMBOL_GPL(rtc_read_time);
@@ -87,6 +92,8 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
        mutex_unlock(&rtc->ops_lock);
        /* A timer might have just expired */
        schedule_work(&rtc->irqwork);
+
+       trace_rtc_set_time(rtc_tm_to_time64(tm), err);
        return err;
 }
 EXPORT_SYMBOL_GPL(rtc_set_time);
@@ -119,6 +126,8 @@ static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *al
        }
 
        mutex_unlock(&rtc->ops_lock);
+
+       trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err);
        return err;
 }
 
@@ -316,6 +325,7 @@ int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
        }
        mutex_unlock(&rtc->ops_lock);
 
+       trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err);
        return err;
 }
 EXPORT_SYMBOL_GPL(rtc_read_alarm);
@@ -352,6 +362,7 @@ static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
        else
                err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
 
+       trace_rtc_set_alarm(rtc_tm_to_time64(&alarm->time), err);
        return err;
 }
 
@@ -406,6 +417,7 @@ int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 
                rtc->aie_timer.enabled = 1;
                timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);
+               trace_rtc_timer_enqueue(&rtc->aie_timer);
        }
        mutex_unlock(&rtc->ops_lock);
        return err;
@@ -435,6 +447,8 @@ int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
                err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
 
        mutex_unlock(&rtc->ops_lock);
+
+       trace_rtc_alarm_irq_enable(enabled, err);
        return err;
 }
 EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
@@ -709,6 +723,8 @@ retry:
                rtc->pie_enabled = enabled;
        }
        spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
+
+       trace_rtc_irq_set_state(enabled, err);
        return err;
 }
 EXPORT_SYMBOL_GPL(rtc_irq_set_state);
@@ -745,6 +761,8 @@ retry:
                }
        }
        spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
+
+       trace_rtc_irq_set_freq(freq, err);
        return err;
 }
 EXPORT_SYMBOL_GPL(rtc_irq_set_freq);
@@ -779,6 +797,7 @@ static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
        }
 
        timerqueue_add(&rtc->timerqueue, &timer->node);
+       trace_rtc_timer_enqueue(timer);
        if (!next || ktime_before(timer->node.expires, next->expires)) {
                struct rtc_wkalrm alarm;
                int err;
@@ -790,6 +809,7 @@ static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
                        schedule_work(&rtc->irqwork);
                } else if (err) {
                        timerqueue_del(&rtc->timerqueue, &timer->node);
+                       trace_rtc_timer_dequeue(timer);
                        timer->enabled = 0;
                        return err;
                }
@@ -803,6 +823,7 @@ static void rtc_alarm_disable(struct rtc_device *rtc)
                return;
 
        rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
+       trace_rtc_alarm_irq_enable(0, 0);
 }
 
 /**
@@ -821,6 +842,7 @@ static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
 {
        struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
        timerqueue_del(&rtc->timerqueue, &timer->node);
+       trace_rtc_timer_dequeue(timer);
        timer->enabled = 0;
        if (next == &timer->node) {
                struct rtc_wkalrm alarm;
@@ -871,16 +893,19 @@ again:
                /* expire timer */
                timer = container_of(next, struct rtc_timer, node);
                timerqueue_del(&rtc->timerqueue, &timer->node);
+               trace_rtc_timer_dequeue(timer);
                timer->enabled = 0;
                if (timer->task.func)
                        timer->task.func(timer->task.private_data);
 
+               trace_rtc_timer_fired(timer);
                /* Re-add/fwd periodic timers */
                if (ktime_to_ns(timer->period)) {
                        timer->node.expires = ktime_add(timer->node.expires,
                                                        timer->period);
                        timer->enabled = 1;
                        timerqueue_add(&rtc->timerqueue, &timer->node);
+                       trace_rtc_timer_enqueue(timer);
                }
        }
 
@@ -902,6 +927,7 @@ reprogram:
 
                        timer = container_of(next, struct rtc_timer, node);
                        timerqueue_del(&rtc->timerqueue, &timer->node);
+                       trace_rtc_timer_dequeue(timer);
                        timer->enabled = 0;
                        dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err);
                        goto again;
@@ -992,6 +1018,8 @@ int rtc_read_offset(struct rtc_device *rtc, long *offset)
        mutex_lock(&rtc->ops_lock);
        ret = rtc->ops->read_offset(rtc->dev.parent, offset);
        mutex_unlock(&rtc->ops_lock);
+
+       trace_rtc_read_offset(*offset, ret);
        return ret;
 }
 
@@ -1025,5 +1053,7 @@ int rtc_set_offset(struct rtc_device *rtc, long offset)
        mutex_lock(&rtc->ops_lock);
        ret = rtc->ops->set_offset(rtc->dev.parent, offset);
        mutex_unlock(&rtc->ops_lock);
+
+       trace_rtc_set_offset(offset, ret);
        return ret;
 }

diff --git a/include/trace/events/rtc.h b/include/trace/events/rtc.h
new file mode 100644 (file)
index 0000000..621333f
--- /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>