gianfar: Add hardware TX timestamping support

If a packet has the skb_shared_tx->hardware flag set the device is
instructed to generate a TX timestamp and write it back to memory after
the frame is transmitted. During the clean_tx_ring operation the
timestamp will be extracted and copied into the skb_shared_hwtstamps
struct of the skb.

TX timestamping is enabled by setting the tx_type to something else
than HWTSTAMP_TX_OFF with the SIOCSHWTSTAMP ioctl command. It is only
supported by eTSEC devices.

Signed-off-by: Manfred Rudigier <manfred.rudigier@omicron.at>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/net/gianfar.h b/drivers/net/gianfar.h
index 1ea287cba231..ac4a92e08c09 100644
--- a/drivers/net/gianfar.h
+++ b/drivers/net/gianfar.h
@@ -540,7 +540,7 @@ struct txbd8
 
 struct txfcb {
         u8      flags;
-        u8      reserved;
+        u8      ptp;    /* Flag to enable tx timestamping */
         u8      l4os;   /* Level 4 Header Offset */
         u8      l3os;   /* Level 3 Header Offset */
         u16     phcs;   /* Pseudo-header Checksum */
@@ -1105,6 +1105,7 @@ struct gfar_private {
 
         /* HW time stamping enabled flag */
         int hwts_rx_en;
+        int hwts_tx_en;
 };
 
 extern unsigned int ftp_rqfpr[MAX_FILER_IDX + 1];