gianfar: Add hardware RX timestamping support

The device is configured to insert hardware timestamps into all
received packets. The RX timestamps are extracted from the padding
alingment bytes during the clean_rx_ring operation and copied into the
skb_shared_hwtstamps struct of the skb. This extraction only happens if
the rx_filter was set to something else than HWTSTAMP_FILTER_NONE with
the SIOCSHWTSTAMP ioctl command.

Hardware timestamping is only supported for eTSEC devices. To indicate
device support the new FSL_GIANFAR_DEV_HAS_TIMER flag was introduced.

Signed-off-by: Manfred Rudigier <manfred.rudigier@omicron.at>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/gianfar.h b/drivers/net/gianfar.h
index 17d25e7..1ea287c 100644
--- a/drivers/net/gianfar.h
+++ b/drivers/net/gianfar.h
@@ -262,6 +262,7 @@
 
 #define next_bd(bdp, base, ring_size) skip_bd(bdp, 1, base, ring_size)
 
+#define RCTRL_TS_ENABLE 	0x01000000
 #define RCTRL_PAL_MASK		0x001f0000
 #define RCTRL_VLEX		0x00002000
 #define RCTRL_FILREN		0x00001000
@@ -885,6 +886,7 @@
 #define FSL_GIANFAR_DEV_HAS_MAGIC_PACKET	0x00000100
 #define FSL_GIANFAR_DEV_HAS_BD_STASHING		0x00000200
 #define FSL_GIANFAR_DEV_HAS_BUF_STASHING	0x00000400
+#define FSL_GIANFAR_DEV_HAS_TIMER		0x00000800
 
 #if (MAXGROUPS == 2)
 #define DEFAULT_MAPPING 	0xAA
@@ -1100,6 +1102,9 @@
 
 	/* Network Statistics */
 	struct gfar_extra_stats extra_stats;
+
+	/* HW time stamping enabled flag */
+	int hwts_rx_en;
 };
 
 extern unsigned int ftp_rqfpr[MAX_FILER_IDX + 1];