stmmac: support extend descriptors
This patch is to support the extend descriptors available
in the chips newer than the 3.50.
In case of the extend descriptors cannot be supported,
at runtime, the driver will continue to work using the old style.
In detail, this support extends the main descriptor structure
adding new descriptors: 4, 5, 6, 7. The desc4 gives us extra
information about the received ethernet payload when it is
carrying PTP packets or TCP/UDP/ICMP over IP packets.
The descriptors 6 and 7 are used for saving HW L/H timestamps (PTP).
V2: this new version removes the Koption added in the first implementation
because all the checks now to verify if the extended descriptors are
actually supported happen at probe time.
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
index 7ad56af..85466e5 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
@@ -155,6 +155,7 @@
/* Programmable burst length (passed thorugh platform)*/
#define DMA_BUS_MODE_PBL_MASK 0x00003f00 /* Programmable Burst Len */
#define DMA_BUS_MODE_PBL_SHIFT 8
+#define DMA_BUS_MODE_ATDS 0x00000080 /* Alternate Descriptor Size */
enum rx_tx_priority_ratio {
double_ratio = 0x00004000, /*2:1 */