pwm: Add tracing for waveform callbacks

This adds trace events for the recently introduced waveform callbacks.
With the introduction of some helper macros consistency among the
different events is ensured.

Signed-off-by: Uwe Kleine-König <[email protected]>
Link: https://lore.kernel.org/r/1d71879b0de3bf01459c7a9d0f040d43eb5ace56.1726819463.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <[email protected]>

Author: ukleinek

drivers/pwm/core.c

@@ -164,30 +164,46 @@ static int __pwm_round_waveform_tohw(struct pwm_chip *chip, struct pwm_device *p
 				     const struct pwm_waveform *wf, void *wfhw)
 {
 	const struct pwm_ops *ops = chip->ops;
+	int ret;
+
+	ret = ops->round_waveform_tohw(chip, pwm, wf, wfhw);
+	trace_pwm_round_waveform_tohw(pwm, wf, wfhw, ret);
 
-	return ops->round_waveform_tohw(chip, pwm, wf, wfhw);
+	return ret;
 }
 
 static int __pwm_round_waveform_fromhw(struct pwm_chip *chip, struct pwm_device *pwm,
 				       const void *wfhw, struct pwm_waveform *wf)
 {
 	const struct pwm_ops *ops = chip->ops;
+	int ret;
+
+	ret = ops->round_waveform_fromhw(chip, pwm, wfhw, wf);
+	trace_pwm_round_waveform_fromhw(pwm, wfhw, wf, ret);
 
-	return ops->round_waveform_fromhw(chip, pwm, wfhw, wf);
+	return ret;
 }
 
 static int __pwm_read_waveform(struct pwm_chip *chip, struct pwm_device *pwm, void *wfhw)
 {
 	const struct pwm_ops *ops = chip->ops;
+	int ret;
+
+	ret = ops->read_waveform(chip, pwm, wfhw);
+	trace_pwm_read_waveform(pwm, wfhw, ret);
 
-	return ops->read_waveform(chip, pwm, wfhw);
+	return ret;
 }
 
 static int __pwm_write_waveform(struct pwm_chip *chip, struct pwm_device *pwm, const void *wfhw)
 {
 	const struct pwm_ops *ops = chip->ops;
+	int ret;
+
+	ret = ops->write_waveform(chip, pwm, wfhw);
+	trace_pwm_write_waveform(pwm, wfhw, ret);
 
-	return ops->write_waveform(chip, pwm, wfhw);
+	return ret;
 }
 
 #define WFHWSIZE 20

include/trace/events/pwm.h

@@ -8,34 +8,152 @@
 #include <linux/pwm.h>
 #include <linux/tracepoint.h>
 
+#define TP_PROTO_pwm(args...)							\
+	TP_PROTO(struct pwm_device *pwm, args)
+
+#define TP_ARGS_pwm(args...)							\
+	TP_ARGS(pwm, args)
+
+#define TP_STRUCT__entry_pwm(args...)						\
+	TP_STRUCT__entry(							\
+		__field(unsigned int, chipid)					\
+		__field(unsigned int, hwpwm)					\
+		args)
+
+#define TP_fast_assign_pwm(args...)						\
+	TP_fast_assign(								\
+		__entry->chipid = pwm->chip->id;				\
+		__entry->hwpwm = pwm->hwpwm;					\
+		args)
+
+#define TP_printk_pwm(fmt, args...)						\
+	TP_printk("pwmchip%u.%u: " fmt, __entry->chipid, __entry->hwpwm, args)
+
+#define __field_pwmwf(wf)							\
+	__field(u64, wf ## _period_length_ns)					\
+	__field(u64, wf ## _duty_length_ns)					\
+	__field(u64, wf ## _duty_offset_ns)					\
+
+#define fast_assign_pwmwf(wf)							\
+	__entry->wf ## _period_length_ns = wf->period_length_ns;		\
+	__entry->wf ## _duty_length_ns = wf->duty_length_ns;			\
+	__entry->wf ## _duty_offset_ns = wf->duty_offset_ns
+
+#define printk_pwmwf_format(wf)							\
+	"%lld/%lld [+%lld]"
+
+#define printk_pwmwf_formatargs(wf)						\
+	__entry->wf ## _duty_length_ns, __entry->wf ## _period_length_ns, __entry->wf ## _duty_offset_ns
+
+TRACE_EVENT(pwm_round_waveform_tohw,
+
+	TP_PROTO_pwm(const struct pwm_waveform *wf, void *wfhw, int err),
+
+	TP_ARGS_pwm(wf, wfhw, err),
+
+	TP_STRUCT__entry_pwm(
+		__field_pwmwf(wf)
+		__field(void *, wfhw)
+		__field(int, err)
+	),
+
+	TP_fast_assign_pwm(
+		fast_assign_pwmwf(wf);
+		__entry->wfhw = wfhw;
+		__entry->err = err;
+	),
+
+	TP_printk_pwm(printk_pwmwf_format(wf) " > %p err=%d",
+		printk_pwmwf_formatargs(wf), __entry->wfhw, __entry->err)
+);
+
+TRACE_EVENT(pwm_round_waveform_fromhw,
+
+	TP_PROTO_pwm(const void *wfhw, struct pwm_waveform *wf, int err),
+
+	TP_ARGS_pwm(wfhw, wf, err),
+
+	TP_STRUCT__entry_pwm(
+		__field(const void *, wfhw)
+		__field_pwmwf(wf)
+		__field(int, err)
+	),
+
+	TP_fast_assign_pwm(
+		__entry->wfhw = wfhw;
+		fast_assign_pwmwf(wf);
+		__entry->err = err;
+	),
+
+	TP_printk_pwm("%p > " printk_pwmwf_format(wf) " err=%d",
+		__entry->wfhw, printk_pwmwf_formatargs(wf), __entry->err)
+);
+
+TRACE_EVENT(pwm_read_waveform,
+
+	TP_PROTO_pwm(void *wfhw, int err),
+
+	TP_ARGS_pwm(wfhw, err),
+
+	TP_STRUCT__entry_pwm(
+		__field(void *, wfhw)
+		__field(int, err)
+	),
+
+	TP_fast_assign_pwm(
+		__entry->wfhw = wfhw;
+		__entry->err = err;
+	),
+
+	TP_printk_pwm("%p err=%d",
+		__entry->wfhw, __entry->err)
+);
+
+TRACE_EVENT(pwm_write_waveform,
+
+	TP_PROTO_pwm(const void *wfhw, int err),
+
+	TP_ARGS_pwm(wfhw, err),
+
+	TP_STRUCT__entry_pwm(
+		__field(const void *, wfhw)
+		__field(int, err)
+	),
+
+	TP_fast_assign_pwm(
+		__entry->wfhw = wfhw;
+		__entry->err = err;
+	),
+
+	TP_printk_pwm("%p err=%d",
+		__entry->wfhw, __entry->err)
+);
+
+
 DECLARE_EVENT_CLASS(pwm,
 
 	TP_PROTO(struct pwm_device *pwm, const struct pwm_state *state, int err),
 
 	TP_ARGS(pwm, state, err),
 
-	TP_STRUCT__entry(
-		__field(unsigned int, chipid)
-		__field(unsigned int, hwpwm)
+	TP_STRUCT__entry_pwm(
 		__field(u64, period)
 		__field(u64, duty_cycle)
 		__field(enum pwm_polarity, polarity)
 		__field(bool, enabled)
 		__field(int, err)
 	),
 
-	TP_fast_assign(
-		__entry->chipid = pwm->chip->id;
-		__entry->hwpwm = pwm->hwpwm;
+	TP_fast_assign_pwm(
 		__entry->period = state->period;
 		__entry->duty_cycle = state->duty_cycle;
 		__entry->polarity = state->polarity;
 		__entry->enabled = state->enabled;
 		__entry->err = err;
 	),
 
-	TP_printk("pwmchip%u.%u: period=%llu duty_cycle=%llu polarity=%d enabled=%d err=%d",
-		  __entry->chipid, __entry->hwpwm, __entry->period, __entry->duty_cycle,
+	TP_printk_pwm("period=%llu duty_cycle=%llu polarity=%d enabled=%d err=%d",
+		  __entry->period, __entry->duty_cycle,
 		  __entry->polarity, __entry->enabled, __entry->err)
 
 );