enetc: add support time specific departure base on the qos etf

ENETC implement time specific departure capability, which enables
the user to specify when a frame can be transmitted. When this
capability is enabled, the device will delay the transmission of
the frame so that it can be transmitted at the precisely specified time.
The delay departure time up to 0.5 seconds in the future. If the
departure time in the transmit BD has not yet been reached, based
on the current time, the packet will not be transmitted.

This driver was loaded by Qos driver ETF. User could load it by tc
commands. Here are the example commands:

tc qdisc add dev eth0 root handle 1: mqprio \
	   num_tc 8 map 0 1 2 3 4 5 6 7 hw 1
tc qdisc replace dev eth0 parent 1:8 etf \
	   clockid CLOCK_TAI delta 30000  offload

These example try to set queue mapping first and then set queue 7
with 30us ahead dequeue time.

Then user send test frame should set SO_TXTIME feature for socket.

There are also some limitations for this feature in hardware:
- Transmit checksum offloads and time specific departure operation
are mutually exclusive.
- Time Aware Shaper feature (Qbv) offload and time specific departure
operation are mutually exclusive.

Signed-off-by: Po Liu <Po.Liu@nxp.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
index 51f543ef37a8..8375cd886dba 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
@@ -358,6 +358,7 @@ union enetc_tx_bd {
 				u8 l4_csoff;
 				u8 flags;
 			}; /* default layout */
+			__le32 txstart;
 			__le32 lstatus;
 		};
 	};
@@ -378,11 +379,14 @@ union enetc_tx_bd {
 };
 
 #define ENETC_TXBD_FLAGS_L4CS	BIT(0)
+#define ENETC_TXBD_FLAGS_TSE	BIT(1)
 #define ENETC_TXBD_FLAGS_W	BIT(2)
 #define ENETC_TXBD_FLAGS_CSUM	BIT(3)
+#define ENETC_TXBD_FLAGS_TXSTART BIT(4)
 #define ENETC_TXBD_FLAGS_EX	BIT(6)
 #define ENETC_TXBD_FLAGS_F	BIT(7)
-
+#define ENETC_TXBD_TXSTART_MASK GENMASK(24, 0)
+#define ENETC_TXBD_FLAGS_OFFSET 24
 static inline void enetc_clear_tx_bd(union enetc_tx_bd *txbd)
 {
 	memset(txbd, 0, sizeof(*txbd));
@@ -615,3 +619,7 @@ struct enetc_cbd {
 /* Port time gating capability register */
 #define ENETC_QBV_PTGCAPR_OFFSET	0x11a08
 #define ENETC_QBV_MAX_GCL_LEN_MASK	GENMASK(15, 0)
+
+/* Port time specific departure */
+#define ENETC_PTCTSDR(n)	(0x1210 + 4 * (n))
+#define ENETC_TSDE		BIT(31)