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 <[email protected]> --- 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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
