pwm: Implement tracing for .get_state() and .apply_state()

This allows to log all calls to the driver's lowlevel functions which
simplifies debugging in some cases.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index e067873..5a7f659 100644 (file)
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -20,6 +20,9 @@
 
 #include <dt-bindings/pwm/pwm.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/pwm.h>
+
 #define MAX_PWMS 1024
 
 static DEFINE_MUTEX(pwm_lookup_lock);
@@ -114,8 +117,10 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label)
                }
        }
 
-       if (pwm->chip->ops->get_state)
+       if (pwm->chip->ops->get_state) {
                pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state);
+               trace_pwm_get(pwm, &pwm->state);
+       }
 
        set_bit(PWMF_REQUESTED, &pwm->flags);
        pwm->label = label;
@@ -472,6 +477,8 @@ int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state)
                if (err)
                        return err;
 
+               trace_pwm_apply(pwm, state);
+
                pwm->state = *state;
        } else {
                /*

diff --git a/include/trace/events/pwm.h b/include/trace/events/pwm.h
new file mode 100644 (file)
index 0000000..cf243de
--- /dev/null
+++ b/include/trace/events/pwm.h
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM pwm
+
+#if !defined(_TRACE_PWM_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_PWM_H
+
+#include <linux/pwm.h>
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(pwm,
+
+       TP_PROTO(struct pwm_device *pwm, const struct pwm_state *state),
+
+       TP_ARGS(pwm, state),
+
+       TP_STRUCT__entry(
+               __field(struct pwm_device *, pwm)
+               __field(u64, period)
+               __field(u64, duty_cycle)
+               __field(enum pwm_polarity, polarity)
+               __field(bool, enabled)
+       ),
+
+       TP_fast_assign(
+               __entry->pwm = pwm;
+               __entry->period = state->period;
+               __entry->duty_cycle = state->duty_cycle;
+               __entry->polarity = state->polarity;
+               __entry->enabled = state->enabled;
+       ),
+
+       TP_printk("%p: period=%llu duty_cycle=%llu polarity=%d enabled=%d",
+                 __entry->pwm, __entry->period, __entry->duty_cycle,
+                 __entry->polarity, __entry->enabled)
+
+);
+
+DEFINE_EVENT(pwm, pwm_apply,
+
+       TP_PROTO(struct pwm_device *pwm, const struct pwm_state *state),
+
+       TP_ARGS(pwm, state)
+
+);
+
+DEFINE_EVENT(pwm, pwm_get,
+
+       TP_PROTO(struct pwm_device *pwm, const struct pwm_state *state),
+
+       TP_ARGS(pwm, state)
+
+);
+
+#endif /* _TRACE_PWM_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>