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From:   Gwendal Grignou <gwendal@chromium.org>
To:     bleung@chromium.org, enric.balletbo@collabora.com,
        groeck@chromium.org
Cc:     linux-kernel@vger.kernel.org,
        Gwendal Grignou <gwendal@chromium.org>
Subject: [PATCH] platform/chrome: sensorhub: Add trace events for sample
Date:   Thu, 13 May 2021 17:57:33 -0700
Message-Id: <20210514005733.645548-1-gwendal@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Add trace event to report samples and their timestamp coming from the
EC. It allows to check if the timestamps are correct and the filter is
working correctly without introducing too much latency.

To enable these events:

cd /sys/kernel/debug/tracing/
echo 1 > events/cros_ec/enable
echo 0 > events/cros_ec/cros_ec_request_start/enable
echo 0 > events/cros_ec/cros_ec_request_done/enable
echo 1 > tracing_on
cat trace_pipe
Observe event flowing:
irq/105-chromeo-95      [000] ....   613.659758: cros_ec_sensorhub_timestamp: ...
irq/105-chromeo-95      [000] ....   613.665219: cros_ec_sensorhub_filter: dx: ...

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
 drivers/platform/chrome/Makefile              |  2 +-
 .../platform/chrome/cros_ec_sensorhub_ring.c  | 14 +++
 drivers/platform/chrome/cros_ec_trace.h       | 94 +++++++++++++++++++
 3 files changed, 109 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index 41baccba033f7..f901d2e43166c 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -20,7 +20,7 @@ obj-$(CONFIG_CROS_EC_CHARDEV)		+= cros_ec_chardev.o
 obj-$(CONFIG_CROS_EC_LIGHTBAR)		+= cros_ec_lightbar.o
 obj-$(CONFIG_CROS_EC_VBC)		+= cros_ec_vbc.o
 obj-$(CONFIG_CROS_EC_DEBUGFS)		+= cros_ec_debugfs.o
-cros-ec-sensorhub-objs			:= cros_ec_sensorhub.o cros_ec_sensorhub_ring.o
+cros-ec-sensorhub-objs			:= cros_ec_sensorhub.o cros_ec_sensorhub_ring.o cros_ec_trace.o
 obj-$(CONFIG_CROS_EC_SENSORHUB)		+= cros-ec-sensorhub.o
 obj-$(CONFIG_CROS_EC_SYSFS)		+= cros_ec_sysfs.o
 obj-$(CONFIG_CROS_USBPD_LOGGER)		+= cros_usbpd_logger.o
diff --git a/drivers/platform/chrome/cros_ec_sensorhub_ring.c b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
index 8921f24e83bac..98e37080f7609 100644
--- a/drivers/platform/chrome/cros_ec_sensorhub_ring.c
+++ b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
@@ -17,6 +17,8 @@
 #include <linux/sort.h>
 #include <linux/slab.h>
 
+#include "cros_ec_trace.h"
+
 /* Precision of fixed point for the m values from the filter */
 #define M_PRECISION BIT(23)
 
@@ -291,6 +293,7 @@ cros_ec_sensor_ring_ts_filter_update(struct cros_ec_sensors_ts_filter_state
 		state->median_m = 0;
 		state->median_error = 0;
 	}
+	trace_cros_ec_sensorhub_filter(state, dx, dy);
 }
 
 /**
@@ -427,6 +430,11 @@ cros_ec_sensor_ring_process_event(struct cros_ec_sensorhub *sensorhub,
 			if (new_timestamp - *current_timestamp > 0)
 				*current_timestamp = new_timestamp;
 		}
+		trace_cros_ec_sensorhub_timestamp(in->timestamp,
+						  fifo_info->timestamp,
+						  fifo_timestamp,
+						  *current_timestamp,
+						  now);
 	}
 
 	if (in->flags & MOTIONSENSE_SENSOR_FLAG_ODR) {
@@ -460,6 +468,12 @@ cros_ec_sensor_ring_process_event(struct cros_ec_sensorhub *sensorhub,
 
 	/* Regular sample */
 	out->sensor_id = in->sensor_num;
+	trace_cros_ec_sensorhub_data(in->sensor_num,
+				     fifo_info->timestamp,
+				     fifo_timestamp,
+				     *current_timestamp,
+				     now);
+
 	if (*current_timestamp - now > 0) {
 		/*
 		 * This fix is needed to overcome the timestamp filter putting
diff --git a/drivers/platform/chrome/cros_ec_trace.h b/drivers/platform/chrome/cros_ec_trace.h
index f744b21bc655f..f50b9f9b86106 100644
--- a/drivers/platform/chrome/cros_ec_trace.h
+++ b/drivers/platform/chrome/cros_ec_trace.h
@@ -15,6 +15,7 @@
 #include <linux/types.h>
 #include <linux/platform_data/cros_ec_commands.h>
 #include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_data/cros_ec_sensorhub.h>
 
 #include <linux/tracepoint.h>
 
@@ -70,6 +71,99 @@ TRACE_EVENT(cros_ec_request_done,
 		  __entry->retval)
 );
 
+TRACE_EVENT(cros_ec_sensorhub_timestamp,
+	    TP_PROTO(u32 ec_sample_timestamp, u32 ec_fifo_timestamp, s64 fifo_timestamp,
+		     s64 current_timestamp, s64 current_time),
+	TP_ARGS(ec_sample_timestamp, ec_fifo_timestamp, fifo_timestamp, current_timestamp,
+		current_time),
+	TP_STRUCT__entry(
+		__field(u32, ec_sample_timestamp)
+		__field(u32, ec_fifo_timestamp)
+		__field(s64, fifo_timestamp)
+		__field(s64, current_timestamp)
+		__field(s64, current_time)
+		__field(s64, delta)
+	),
+	TP_fast_assign(
+		__entry->ec_sample_timestamp = ec_sample_timestamp;
+		__entry->ec_fifo_timestamp = ec_fifo_timestamp;
+		__entry->fifo_timestamp = fifo_timestamp;
+		__entry->current_timestamp = current_timestamp;
+		__entry->current_time = current_time;
+		__entry->delta = current_timestamp - current_time;
+	),
+	TP_printk("ec_ts: %12lld, ec_fifo_ts: %12lld, fifo_ts: %12lld, curr_ts: %12lld, curr_time: %12lld, delta %12lld",
+		  __entry->ec_sample_timestamp,
+		__entry->ec_fifo_timestamp,
+		__entry->fifo_timestamp,
+		__entry->current_timestamp,
+		__entry->current_time,
+		__entry->delta
+	)
+);
+
+TRACE_EVENT(cros_ec_sensorhub_data,
+	    TP_PROTO(u32 ec_sensor_num, u32 ec_fifo_timestamp, s64 fifo_timestamp,
+		     s64 current_timestamp, s64 current_time),
+	TP_ARGS(ec_sensor_num, ec_fifo_timestamp, fifo_timestamp, current_timestamp, current_time),
+	TP_STRUCT__entry(
+		__field(u32, ec_sensor_num)
+		__field(u32, ec_fifo_timestamp)
+		__field(s64, fifo_timestamp)
+		__field(s64, current_timestamp)
+		__field(s64, current_time)
+		__field(s64, delta)
+	),
+	TP_fast_assign(
+		__entry->ec_sensor_num = ec_sensor_num;
+		__entry->ec_fifo_timestamp = ec_fifo_timestamp;
+		__entry->fifo_timestamp = fifo_timestamp;
+		__entry->current_timestamp = current_timestamp;
+		__entry->current_time = current_time;
+		__entry->delta = current_timestamp - current_time;
+	),
+	TP_printk("ec_num: %4d, ec_fifo_ts: %12lld, fifo_ts: %12lld, curr_ts: %12lld, curr_time: %12lld, delta %12lld",
+		  __entry->ec_sensor_num,
+		__entry->ec_fifo_timestamp,
+		__entry->fifo_timestamp,
+		__entry->current_timestamp,
+		__entry->current_time,
+		__entry->delta
+	)
+);
+
+TRACE_EVENT(cros_ec_sensorhub_filter,
+	    TP_PROTO(struct cros_ec_sensors_ts_filter_state *state, s64 dx, s64 dy),
+	TP_ARGS(state, dx, dy),
+	TP_STRUCT__entry(
+		__field(s64, dx)
+		__field(s64, dy)
+		__field(s64, median_m)
+		__field(s64, median_error)
+		__field(s64, history_len)
+		__field(s64, x)
+		__field(s64, y)
+	),
+	TP_fast_assign(
+		__entry->dx = dx;
+		__entry->dy = dy;
+		__entry->median_m = state->median_m;
+		__entry->median_error = state->median_error;
+		__entry->history_len = state->history_len;
+		__entry->x = state->x_offset;
+		__entry->y = state->y_offset;
+	),
+	TP_printk("dx: %12lld. dy: %12lld median_m: %12lld median_error: %12lld len: %d x: %12lld y: %12lld",
+		  __entry->dx,
+		__entry->dy,
+		__entry->median_m,
+		__entry->median_error,
+		__entry->history_len,
+		__entry->x,
+		__entry->y
+	)
+);
+
 
 #endif /* _CROS_EC_TRACE_H_ */
 
-- 
2.31.1.751.gd2f1c929bd-goog