i2c: Add message transfer tracepoints for SMBUS [ver #2]

The SMBUS tracepoints can be enabled thusly:

	echo 1 >/sys/kernel/debug/tracing/events/i2c/enable

and will dump messages that can be viewed in /sys/kernel/debug/tracing/trace
that look like:

         ... smbus_read: i2c-0 a=051 f=0000 c=fa BYTE_DATA
         ... smbus_reply: i2c-0 a=051 f=0000 c=fa BYTE_DATA l=1 [39]
         ... smbus_result: i2c-0 a=051 f=0000 c=fa BYTE_DATA rd res=0

formatted as:

	i2c-<adapter-nr>
	a=<addr>
	f=<flags>
	c=<command>
	<protocol-name>
	<rd|wr>
	res=<result>
	l=<data-len>
	[<data-block>]

The adapters to be traced can be selected by something like:

	echo adapter_nr==1 >/sys/kernel/debug/tracing/events/i2c/filter

Note that this shares the same filter and enablement as i2c.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

1 files changed, 223 insertions, 1 deletions

diff --git a/include/trace/events/i2c.h b/include/trace/events/i2c.h
index 4800207..fe17187 100644
--- a/include/trace/events/i2c.h
+++ b/include/trace/events/i2c.h
@@ -1,4 +1,4 @@
-/* I2C message transfer tracepoints
+/* I2C and SMBUS message transfer tracepoints
  *
  * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
@@ -144,6 +144,228 @@ TRACE_EVENT_FN(i2c_result,
 	       i2c_transfer_trace_reg,
 	       i2c_transfer_trace_unreg);
 
+/*
+ * i2c_smbus_xfer() write data or procedure call request
+ */
+TRACE_EVENT_CONDITION(smbus_write,
+	TP_PROTO(const struct i2c_adapter *adap,
+		 u16 addr, unsigned short flags,
+		 char read_write, u8 command, int protocol,
+		 const union i2c_smbus_data *data),
+	TP_ARGS(adap, addr, flags, read_write, command, protocol, data),
+	TP_CONDITION(read_write == I2C_SMBUS_WRITE ||
+		     protocol == I2C_SMBUS_PROC_CALL ||
+		     protocol == I2C_SMBUS_BLOCK_PROC_CALL),
+	TP_STRUCT__entry(
+		__field(int,	adapter_nr		)
+		__field(__u16,	addr			)
+		__field(__u16,	flags			)
+		__field(__u8,	command			)
+		__field(__u8,	len			)
+		__field(__u32,	protocol		)
+		__array(__u8, buf, I2C_SMBUS_BLOCK_MAX + 2)	),
+	TP_fast_assign(
+		__entry->adapter_nr = adap->nr;
+		__entry->addr = addr;
+		__entry->flags = flags;
+		__entry->command = command;
+		__entry->protocol = protocol;
+
+		switch (protocol) {
+		case I2C_SMBUS_BYTE_DATA:
+			__entry->len = 1;
+			goto copy;
+		case I2C_SMBUS_WORD_DATA:
+		case I2C_SMBUS_PROC_CALL:
+			__entry->len = 2;
+			goto copy;
+		case I2C_SMBUS_BLOCK_DATA:
+		case I2C_SMBUS_BLOCK_PROC_CALL:
+		case I2C_SMBUS_I2C_BLOCK_DATA:
+			__entry->len = data->block[0] + 1;
+		copy:
+			memcpy(__entry->buf, data->block, __entry->len);
+			break;
+		case I2C_SMBUS_QUICK:
+		case I2C_SMBUS_BYTE:
+		case I2C_SMBUS_I2C_BLOCK_BROKEN:
+		default:
+			__entry->len = 0;
+		}
+		       ),
+	TP_printk("i2c-%d a=%03x f=%04x c=%x %s l=%u [%*phD]",
+		  __entry->adapter_nr,
+		  __entry->addr,
+		  __entry->flags,
+		  __entry->command,
+		  __print_symbolic(__entry->protocol,
+				   { I2C_SMBUS_QUICK,		"QUICK"	},
+				   { I2C_SMBUS_BYTE,		"BYTE"	},
+				   { I2C_SMBUS_BYTE_DATA,		"BYTE_DATA" },
+				   { I2C_SMBUS_WORD_DATA,		"WORD_DATA" },
+				   { I2C_SMBUS_PROC_CALL,		"PROC_CALL" },
+				   { I2C_SMBUS_BLOCK_DATA,		"BLOCK_DATA" },
+				   { I2C_SMBUS_I2C_BLOCK_BROKEN,	"I2C_BLOCK_BROKEN" },
+				   { I2C_SMBUS_BLOCK_PROC_CALL,	"BLOCK_PROC_CALL" },
+				   { I2C_SMBUS_I2C_BLOCK_DATA,	"I2C_BLOCK_DATA" }),
+		  __entry->len,
+		  __entry->len, __entry->buf
+		  ));
+
+/*
+ * i2c_smbus_xfer() read data request
+ */
+TRACE_EVENT_CONDITION(smbus_read,
+	TP_PROTO(const struct i2c_adapter *adap,
+		 u16 addr, unsigned short flags,
+		 char read_write, u8 command, int protocol),
+	TP_ARGS(adap, addr, flags, read_write, command, protocol),
+	TP_CONDITION(!(read_write == I2C_SMBUS_WRITE ||
+		       protocol == I2C_SMBUS_PROC_CALL ||
+		       protocol == I2C_SMBUS_BLOCK_PROC_CALL)),
+	TP_STRUCT__entry(
+		__field(int,	adapter_nr		)
+		__field(__u16,	flags			)
+		__field(__u16,	addr			)
+		__field(__u8,	command			)
+		__field(__u32,	protocol		)
+		__array(__u8, buf, I2C_SMBUS_BLOCK_MAX + 2)	),
+	TP_fast_assign(
+		__entry->adapter_nr = adap->nr;
+		__entry->addr = addr;
+		__entry->flags = flags;
+		__entry->command = command;
+		__entry->protocol = protocol;
+		       ),
+	TP_printk("i2c-%d a=%03x f=%04x c=%x %s",
+		  __entry->adapter_nr,
+		  __entry->addr,
+		  __entry->flags,
+		  __entry->command,
+		  __print_symbolic(__entry->protocol,
+				   { I2C_SMBUS_QUICK,		"QUICK"	},
+				   { I2C_SMBUS_BYTE,		"BYTE"	},
+				   { I2C_SMBUS_BYTE_DATA,		"BYTE_DATA" },
+				   { I2C_SMBUS_WORD_DATA,		"WORD_DATA" },
+				   { I2C_SMBUS_PROC_CALL,		"PROC_CALL" },
+				   { I2C_SMBUS_BLOCK_DATA,		"BLOCK_DATA" },
+				   { I2C_SMBUS_I2C_BLOCK_BROKEN,	"I2C_BLOCK_BROKEN" },
+				   { I2C_SMBUS_BLOCK_PROC_CALL,	"BLOCK_PROC_CALL" },
+				   { I2C_SMBUS_I2C_BLOCK_DATA,	"I2C_BLOCK_DATA" })
+		  ));
+
+/*
+ * i2c_smbus_xfer() read data or procedure call reply
+ */
+TRACE_EVENT_CONDITION(smbus_reply,
+	TP_PROTO(const struct i2c_adapter *adap,
+		 u16 addr, unsigned short flags,
+		 char read_write, u8 command, int protocol,
+		 const union i2c_smbus_data *data),
+	TP_ARGS(adap, addr, flags, read_write, command, protocol, data),
+	TP_CONDITION(read_write == I2C_SMBUS_READ),
+	TP_STRUCT__entry(
+		__field(int,	adapter_nr		)
+		__field(__u16,	addr			)
+		__field(__u16,	flags			)
+		__field(__u8,	command			)
+		__field(__u8,	len			)
+		__field(__u32,	protocol		)
+		__array(__u8, buf, I2C_SMBUS_BLOCK_MAX + 2)	),
+	TP_fast_assign(
+		__entry->adapter_nr = adap->nr;
+		__entry->addr = addr;
+		__entry->flags = flags;
+		__entry->command = command;
+		__entry->protocol = protocol;
+
+		switch (protocol) {
+		case I2C_SMBUS_BYTE:
+		case I2C_SMBUS_BYTE_DATA:
+			__entry->len = 1;
+			goto copy;
+		case I2C_SMBUS_WORD_DATA:
+		case I2C_SMBUS_PROC_CALL:
+			__entry->len = 2;
+			goto copy;
+		case I2C_SMBUS_BLOCK_DATA:
+		case I2C_SMBUS_BLOCK_PROC_CALL:
+		case I2C_SMBUS_I2C_BLOCK_DATA:
+			__entry->len = data->block[0] + 1;
+		copy:
+			memcpy(__entry->buf, data->block, __entry->len);
+			break;
+		case I2C_SMBUS_QUICK:
+		case I2C_SMBUS_I2C_BLOCK_BROKEN:
+		default:
+			__entry->len = 0;
+		}
+		       ),
+	TP_printk("i2c-%d a=%03x f=%04x c=%x %s l=%u [%*phD]",
+		  __entry->adapter_nr,
+		  __entry->addr,
+		  __entry->flags,
+		  __entry->command,
+		  __print_symbolic(__entry->protocol,
+				   { I2C_SMBUS_QUICK,		"QUICK"	},
+				   { I2C_SMBUS_BYTE,		"BYTE"	},
+				   { I2C_SMBUS_BYTE_DATA,		"BYTE_DATA" },
+				   { I2C_SMBUS_WORD_DATA,		"WORD_DATA" },
+				   { I2C_SMBUS_PROC_CALL,		"PROC_CALL" },
+				   { I2C_SMBUS_BLOCK_DATA,		"BLOCK_DATA" },
+				   { I2C_SMBUS_I2C_BLOCK_BROKEN,	"I2C_BLOCK_BROKEN" },
+				   { I2C_SMBUS_BLOCK_PROC_CALL,	"BLOCK_PROC_CALL" },
+				   { I2C_SMBUS_I2C_BLOCK_DATA,	"I2C_BLOCK_DATA" }),
+		  __entry->len,
+		  __entry->len, __entry->buf
+		  ));
+
+/*
+ * i2c_smbus_xfer() result
+ */
+TRACE_EVENT(smbus_result,
+	    TP_PROTO(const struct i2c_adapter *adap,
+		     u16 addr, unsigned short flags,
+		     char read_write, u8 command, int protocol,
+		     int res),
+	    TP_ARGS(adap, addr, flags, read_write, command, protocol, res),
+	    TP_STRUCT__entry(
+		    __field(int,	adapter_nr		)
+		    __field(__u16,	addr			)
+		    __field(__u16,	flags			)
+		    __field(__u8,	read_write		)
+		    __field(__u8,	command			)
+		    __field(__s16,	res			)
+		    __field(__u32,	protocol		)
+			     ),
+	    TP_fast_assign(
+		    __entry->adapter_nr = adap->nr;
+		    __entry->addr = addr;
+		    __entry->flags = flags;
+		    __entry->read_write = read_write;
+		    __entry->command = command;
+		    __entry->protocol = protocol;
+		    __entry->res = res;
+			   ),
+	    TP_printk("i2c-%d a=%03x f=%04x c=%x %s %s res=%d",
+		      __entry->adapter_nr,
+		      __entry->addr,
+		      __entry->flags,
+		      __entry->command,
+		      __print_symbolic(__entry->protocol,
+				       { I2C_SMBUS_QUICK,		"QUICK"	},
+				       { I2C_SMBUS_BYTE,		"BYTE"	},
+				       { I2C_SMBUS_BYTE_DATA,		"BYTE_DATA" },
+				       { I2C_SMBUS_WORD_DATA,		"WORD_DATA" },
+				       { I2C_SMBUS_PROC_CALL,		"PROC_CALL" },
+				       { I2C_SMBUS_BLOCK_DATA,		"BLOCK_DATA" },
+				       { I2C_SMBUS_I2C_BLOCK_BROKEN,	"I2C_BLOCK_BROKEN" },
+				       { I2C_SMBUS_BLOCK_PROC_CALL,	"BLOCK_PROC_CALL" },
+				       { I2C_SMBUS_I2C_BLOCK_DATA,	"I2C_BLOCK_DATA" }),
+		      __entry->read_write == I2C_SMBUS_WRITE ? "wr" : "rd",
+		      __entry->res
+		      ));
+
 #endif /* _TRACE_I2C_H */
 
 /* This part must be outside protection */