usb: musb: add tracepoints for register access

This adds tracepoints to musb register read/write wrappers to get
trace log for register access.

The default tacepoint log prefix here would be musb_readX/writeX(),
which is not much helpful. So this patch let the tracepoints use
__buildin_return_address(0) to print the caller funciton name to
provide more context of the register access.

Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/musb/musb_core.c

@@ -102,6 +102,7 @@
 #include <linux/usb.h>
 
 #include "musb_core.h"
+#include "musb_trace.h"
 
 #define TA_WAIT_BCON(m) max_t(int, (m)->a_wait_bcon, OTG_TIME_A_WAIT_BCON)
 
@@ -258,31 +259,43 @@ static u32 musb_default_busctl_offset(u8 epnum, u16 offset)
 
 static u8 musb_default_readb(const void __iomem *addr, unsigned offset)
 {
-	return __raw_readb(addr + offset);
+	u8 data =  __raw_readb(addr + offset);
+
+	trace_musb_readb(__builtin_return_address(0), addr, offset, data);
+	return data;
 }
 
 static void musb_default_writeb(void __iomem *addr, unsigned offset, u8 data)
 {
+	trace_musb_writeb(__builtin_return_address(0), addr, offset, data);
 	__raw_writeb(data, addr + offset);
 }
 
 static u16 musb_default_readw(const void __iomem *addr, unsigned offset)
 {
-	return __raw_readw(addr + offset);
+	u16 data = __raw_readw(addr + offset);
+
+	trace_musb_readw(__builtin_return_address(0), addr, offset, data);
+	return data;
 }
 
 static void musb_default_writew(void __iomem *addr, unsigned offset, u16 data)
 {
+	trace_musb_writew(__builtin_return_address(0), addr, offset, data);
 	__raw_writew(data, addr + offset);
 }
 
 static u32 musb_default_readl(const void __iomem *addr, unsigned offset)
 {
-	return __raw_readl(addr + offset);
+	u32 data = __raw_readl(addr + offset);
+
+	trace_musb_readl(__builtin_return_address(0), addr, offset, data);
+	return data;
 }
 
 static void musb_default_writel(void __iomem *addr, unsigned offset, u32 data)
 {
+	trace_musb_writel(__builtin_return_address(0), addr, offset, data);
 	__raw_writel(data, addr + offset);
 }
 

drivers/usb/musb/musb_trace.h

@@ -41,6 +41,93 @@ TRACE_EVENT(musb_log,
 	TP_printk("%s: %s", __get_str(name), __get_str(msg))
 );
 
+DECLARE_EVENT_CLASS(musb_regb,
+	TP_PROTO(void *caller, const void *addr, unsigned int offset, u8 data),
+	TP_ARGS(caller, addr, offset, data),
+	TP_STRUCT__entry(
+		__field(void *, caller)
+		__field(const void *, addr)
+		__field(unsigned int, offset)
+		__field(u8, data)
+	),
+	TP_fast_assign(
+		__entry->caller = caller;
+		__entry->addr = addr;
+		__entry->offset = offset;
+		__entry->data = data;
+	),
+	TP_printk("%pS: %p + %04x: %02x",
+		__entry->caller, __entry->addr, __entry->offset, __entry->data)
+);
+
+DEFINE_EVENT(musb_regb, musb_readb,
+	TP_PROTO(void *caller, const void *addr, unsigned int offset, u8 data),
+	TP_ARGS(caller, addr, offset, data)
+);
+
+DEFINE_EVENT(musb_regb, musb_writeb,
+	TP_PROTO(void *caller, const void *addr, unsigned int offset, u8 data),
+	TP_ARGS(caller, addr, offset, data)
+);
+
+DECLARE_EVENT_CLASS(musb_regw,
+	TP_PROTO(void *caller, const void *addr, unsigned int offset, u16 data),
+	TP_ARGS(caller, addr, offset, data),
+	TP_STRUCT__entry(
+		__field(void *, caller)
+		__field(const void *, addr)
+		__field(unsigned int, offset)
+		__field(u16, data)
+	),
+	TP_fast_assign(
+		__entry->caller = caller;
+		__entry->addr = addr;
+		__entry->offset = offset;
+		__entry->data = data;
+	),
+	TP_printk("%pS: %p + %04x: %04x",
+		__entry->caller, __entry->addr, __entry->offset, __entry->data)
+);
+
+DEFINE_EVENT(musb_regw, musb_readw,
+	TP_PROTO(void *caller, const void *addr, unsigned int offset, u16 data),
+	TP_ARGS(caller, addr, offset, data)
+);
+
+DEFINE_EVENT(musb_regw, musb_writew,
+	TP_PROTO(void *caller, const void *addr, unsigned int offset, u16 data),
+	TP_ARGS(caller, addr, offset, data)
+);
+
+DECLARE_EVENT_CLASS(musb_regl,
+	TP_PROTO(void *caller, const void *addr, unsigned int offset, u32 data),
+	TP_ARGS(caller, addr, offset, data),
+	TP_STRUCT__entry(
+		__field(void *, caller)
+		__field(const void *, addr)
+		__field(unsigned int, offset)
+		__field(u32, data)
+	),
+	TP_fast_assign(
+		__entry->caller = caller;
+		__entry->addr = addr;
+		__entry->offset = offset;
+		__entry->data = data;
+	),
+	TP_printk("%pS: %p + %04x: %08x",
+		__entry->caller, __entry->addr, __entry->offset, __entry->data)
+);
+
+DEFINE_EVENT(musb_regl, musb_readl,
+	TP_PROTO(void *caller, const void *addr, unsigned int offset, u32 data),
+	TP_ARGS(caller, addr, offset, data)
+);
+
+DEFINE_EVENT(musb_regl, musb_writel,
+	TP_PROTO(void *caller, const void *addr, unsigned int offset, u32 data),
+	TP_ARGS(caller, addr, offset, data)
+);
+
 #endif /* __MUSB_TRACE_H */
 
 /* this part has to be here */