siox: add support for tracing

Implement tracing for SIOX. There are events for the data that is
written to the bus and for data being read from it.
Acked-by: Gavin Schenk <g.schenk@eckelmann.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/siox/siox-core.c

@@ -33,6 +33,9 @@
  */
 #define SIOX_STATUS_TYPE		0xf0
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/siox.h>
+
 static bool siox_is_registered;
 
 static void siox_master_lock(struct siox_master *smaster)
@@ -126,6 +129,7 @@ static void siox_poll(struct siox_master *smaster)
 {
 	struct siox_device *sdevice;
 	size_t i = smaster->setbuf_len;
+	unsigned int devno = 0;
 	int unsync_error = 0;
 
 	smaster->last_poll = jiffies;
@@ -172,6 +176,10 @@ static void siox_poll(struct siox_master *smaster)
 			sdevice->status_written &= ~SIOX_STATUS_WDG;
 
 		smaster->buf[i] = sdevice->status_written;
+
+		trace_siox_set_data(smaster, sdevice, devno, i);
+
+		devno++;
 	}
 
 	smaster->pushpull(smaster, smaster->setbuf_len, smaster->buf,
@@ -181,6 +189,7 @@ static void siox_poll(struct siox_master *smaster)
 	unsync_error = 0;
 
 	/* interpret data pulled in from devices in buf[setbuf_len..] */
+	devno = 0;
 	i = smaster->setbuf_len;
 	list_for_each_entry(sdevice, &smaster->devices, node) {
 		struct siox_driver *sdriver =
@@ -255,10 +264,13 @@ static void siox_poll(struct siox_master *smaster)
 		sdevice->status_written_lastcycle = sdevice->status_written;
 		sdevice->connected = connected;
 
+		trace_siox_get_data(smaster, sdevice, devno, status_clean, i);
+
 		/* only give data read to driver if the device is connected */
 		if (sdriver && connected)
 			sdriver->get_data(sdevice, &smaster->buf[i]);
 
+		devno++;
 		i += sdevice->outbytes;
 	}
 }

include/trace/events/siox.h

+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM siox
+
+#if !defined(_TRACE_SIOX_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SIOX_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(siox_set_data,
+	    TP_PROTO(const struct siox_master *smaster,
+		     const struct siox_device *sdevice,
+		     unsigned int devno, size_t bufoffset),
+	    TP_ARGS(smaster, sdevice, devno, bufoffset),
+	    TP_STRUCT__entry(
+			     __field(int, busno)
+			     __field(unsigned int, devno)
+			     __field(size_t, inbytes)
+			     __dynamic_array(u8, buf, sdevice->inbytes)
+			    ),
+	    TP_fast_assign(
+			   __entry->busno = smaster->busno;
+			   __entry->devno = devno;
+			   __entry->inbytes = sdevice->inbytes;
+			   memcpy(__get_dynamic_array(buf),
+				  smaster->buf + bufoffset, sdevice->inbytes);
+			  ),
+	    TP_printk("siox-%d-%u [%*phD]",
+		      __entry->busno,
+		      __entry->devno,
+		      (int)__entry->inbytes, __get_dynamic_array(buf)
+		     )
+);
+
+TRACE_EVENT(siox_get_data,
+	    TP_PROTO(const struct siox_master *smaster,
+		     const struct siox_device *sdevice,
+		     unsigned int devno, u8 status_clean,
+		     size_t bufoffset),
+	    TP_ARGS(smaster, sdevice, devno, status_clean, bufoffset),
+	    TP_STRUCT__entry(
+			     __field(int, busno)
+			     __field(unsigned int, devno)
+			     __field(u8, status_clean)
+			     __field(size_t, outbytes)
+			     __dynamic_array(u8, buf, sdevice->outbytes)
+			    ),
+	    TP_fast_assign(
+			   __entry->busno = smaster->busno;
+			   __entry->devno = devno;
+			   __entry->status_clean = status_clean;
+			   __entry->outbytes = sdevice->outbytes;
+			   memcpy(__get_dynamic_array(buf),
+				  smaster->buf + bufoffset, sdevice->outbytes);
+			  ),
+	    TP_printk("siox-%d-%u (%02hhx) [%*phD]",
+		      __entry->busno,
+		      __entry->devno,
+		      __entry->status_clean,
+		      (int)__entry->outbytes, __get_dynamic_array(buf)
+		     )
+);
+
+#endif /* if !defined(_TRACE_SIOX_H) || defined(TRACE_HEADER_MULTI_READ) */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>