Add basic trace events for i2c_master_send() and i2c_master_recv() so we
can observe the I2C activity without filling up the dmesg ring buffer. It
also makes it easy to enable and disable tracing of the i2c-core.
Signed-off-by: Dimitris Papastamos <dp@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
---
drivers/i2c/i2c-core.c | 4 +++
include/trace/events/i2c.h | 55 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 59 insertions(+), 0 deletions(-)
create mode 100644 include/trace/events/i2c.h
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index f0bd5bc..2c2bb45 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -42,6 +42,8 @@
#include "i2c-core.h"
+#define CREATE_TRACE_POINTS
+#include <trace/events/i2c.h>
/* core_lock protects i2c_adapter_idr, and guarantees
that device detection, deletion of detected devices, and attach_adapter
@@ -1366,6 +1368,7 @@ int i2c_master_send(const struct i2c_client *client, const char *buf, int count)
msg.buf = (char *)buf;
ret = i2c_transfer(adap, &msg, 1);
+ trace_i2c_master_send(&msg, ret);
/* If everything went ok (i.e. 1 msg transmitted), return #bytes
transmitted, else error code. */
@@ -1394,6 +1397,7 @@ int i2c_master_recv(const struct i2c_client *client, char *buf, int count)
msg.buf = buf;
ret = i2c_transfer(adap, &msg, 1);
+ trace_i2c_master_recv(&msg, ret);
/* If everything went ok (i.e. 1 msg transmitted), return #bytes
transmitted, else error code. */
diff --git a/include/trace/events/i2c.h b/include/trace/events/i2c.h
new file mode 100644
index 0000000..cdf64e8
--- /dev/null
+++ b/include/trace/events/i2c.h
@@ -0,0 +1,55 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM i2c
+
+#if !defined(_TRACE_I2C_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_I2C_H
+
+#include <linux/ktime.h>
+#include <linux/tracepoint.h>
+
+struct i2c_msg;
+
+DECLARE_EVENT_CLASS(i2c_master,
+
+ TP_PROTO(struct i2c_msg *msg, int ret),
+
+ TP_ARGS(msg, ret),
+
+ TP_STRUCT__entry(
+ __field( u16, addr )
+ __field( u16, len )
+ __field( u16, flags )
+ __field( int, ret )
+ ),
+
+ TP_fast_assign(
+ __entry->addr = msg->addr;
+ __entry->len = msg->len;
+ __entry->flags = msg->flags;
+ __entry->ret = ret;
+ ),
+
+ TP_printk("addr=%x len=%x flags=%x ret=%d", (u16)__entry->addr,
+ (u16)__entry->len, (u16)__entry->flags, (int)__entry->ret)
+);
+
+DEFINE_EVENT(i2c_master, i2c_master_send,
+
+ TP_PROTO(struct i2c_msg *msg, int ret),
+
+ TP_ARGS(msg, ret)
+
+);
+
+DEFINE_EVENT(i2c_master, i2c_master_recv,
+
+ TP_PROTO(struct i2c_msg *msg, int ret),
+
+ TP_ARGS(msg, ret)
+
+);
+
+#endif /* _TRACE_I2C_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
--
1.7.3.5
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
