can: netlink support for bus-error reporting and counters

This patch makes the bus-error reporting configurable and allows to
retrieve the CAN TX and RX bus error counters via netlink interface.
I have added support for the SJA1000. The TX and RX bus error counters
are also copied to the data fields 6..7 of error messages when state
changes are reported.

Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/can/netlink.h b/include/linux/can/netlink.h
index c818335..3250de9 100644
--- a/include/linux/can/netlink.h
+++ b/include/linux/can/netlink.h
@@ -70,6 +70,14 @@
 };
 
 /*
+ * CAN bus error counters
+ */
+struct can_berr_counter {
+	__u16 txerr;
+	__u16 rxerr;
+};
+
+/*
  * CAN controller mode
  */
 struct can_ctrlmode {
@@ -77,10 +85,11 @@
 	__u32 flags;
 };
 
-#define CAN_CTRLMODE_LOOPBACK	0x1	/* Loopback mode */
-#define CAN_CTRLMODE_LISTENONLY	0x2 	/* Listen-only mode */
-#define CAN_CTRLMODE_3_SAMPLES	0x4	/* Triple sampling mode */
-#define CAN_CTRLMODE_ONE_SHOT	0x8	/* One-Shot mode */
+#define CAN_CTRLMODE_LOOPBACK		0x01	/* Loopback mode */
+#define CAN_CTRLMODE_LISTENONLY		0x02 	/* Listen-only mode */
+#define CAN_CTRLMODE_3_SAMPLES		0x04	/* Triple sampling mode */
+#define CAN_CTRLMODE_ONE_SHOT		0x08	/* One-Shot mode */
+#define CAN_CTRLMODE_BERR_REPORTING	0x10	/* Bus-error reporting */
 
 /*
  * CAN device statistics
@@ -106,6 +115,7 @@
 	IFLA_CAN_CTRLMODE,
 	IFLA_CAN_RESTART_MS,
 	IFLA_CAN_RESTART,
+	IFLA_CAN_BERR_COUNTER,
 	__IFLA_CAN_MAX
 };