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authorMichal Simek <monstr@monstr.eu>2007-08-05 15:53:50 +0200
committerMichal Simek <monstr@monstr.eu>2007-08-05 15:53:50 +0200
commit537091b4eed9302865d03fef3f7212b4fe5cf28f (patch)
treecb6efe987dd9614b8d417718eda87b6e9d42e619 /drivers/net
parent0c0a9cda1bde37106520476ed486bd67eb8d30ae (diff)
[PATCH] Added support for Xilinx Emac community driver
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/Makefile2
-rw-r--r--drivers/net/xilinx_emac.c372
-rw-r--r--drivers/net/xilinx_emac.h128
3 files changed, 501 insertions, 1 deletions
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index a10d0819f98..7342dc8ce6c 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -25,7 +25,7 @@ include $(TOPDIR)/config.mk
LIB := $(obj)libnetdrv.a
-COBJS := xilinx_emaclite.o
+COBJS := xilinx_emaclite.o xilinx_emac.o
SRCS := $(COBJS:.o=.c)
OBJS := $(addprefix $(obj),$(COBJS))
diff --git a/drivers/net/xilinx_emac.c b/drivers/net/xilinx_emac.c
new file mode 100644
index 00000000000..d44f31e8aff
--- /dev/null
+++ b/drivers/net/xilinx_emac.c
@@ -0,0 +1,372 @@
+/*
+ * (C) Copyright 2007 Michal Simek
+ *
+ * Michal SIMEK <monstr@monstr.eu>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ * Based on Xilinx drivers
+ *
+ */
+
+#include <config.h>
+#include <common.h>
+#include <net.h>
+#include <asm/io.h>
+#include <asm/asm.h>
+#include "xilinx_emac.h"
+
+#ifdef XILINX_EMAC
+
+#undef DEBUG
+
+#define ENET_MAX_MTU PKTSIZE
+#define ENET_ADDR_LENGTH 6
+
+static unsigned int etherrxbuff[PKTSIZE_ALIGN/4]; /* Receive buffer */
+
+static u8 EMACAddr[ENET_ADDR_LENGTH] = { 0x00, 0x0a, 0x35, 0x00, 0x22, 0x01 };
+
+static XEmac Emac;
+
+void eth_halt(void)
+{
+ return;
+}
+
+int eth_init(bd_t * bis)
+{
+ u32 HelpReg;
+#ifdef DEBUG
+ printf("EMAC Initialization Started\n\r");
+#endif
+ if (Emac.IsStarted) {
+ puts("Emac is started\n");
+ return 0;
+ }
+
+ memset (&Emac, 0, sizeof (XEmac));
+
+ Emac.BaseAddress = XILINX_EMAC_BASEADDR;
+
+ /* Setting up FIFOs */
+ Emac.RecvFifo.RegBaseAddress = Emac.BaseAddress +
+ XEM_PFIFO_RXREG_OFFSET;
+ Emac.RecvFifo.DataBaseAddress = Emac.BaseAddress +
+ XEM_PFIFO_RXDATA_OFFSET;
+ out_be32 (Emac.RecvFifo.RegBaseAddress, XPF_RESET_FIFO_MASK);
+
+ Emac.SendFifo.RegBaseAddress = Emac.BaseAddress +
+ XEM_PFIFO_TXREG_OFFSET;
+ Emac.SendFifo.DataBaseAddress = Emac.BaseAddress +
+ XEM_PFIFO_TXDATA_OFFSET;
+ out_be32 (Emac.SendFifo.RegBaseAddress, XPF_RESET_FIFO_MASK);
+
+ /* Reset the entire IPIF */
+ out_be32 (Emac.BaseAddress + XIIF_V123B_RESETR_OFFSET,
+ XIIF_V123B_RESET_MASK);
+
+ /* Stopping EMAC for setting up MAC */
+ HelpReg = in_be32 (Emac.BaseAddress + XEM_ECR_OFFSET);
+ HelpReg &= ~(XEM_ECR_XMIT_ENABLE_MASK | XEM_ECR_RECV_ENABLE_MASK);
+ out_be32 (Emac.BaseAddress + XEM_ECR_OFFSET, HelpReg);
+
+ if (!getenv("ethaddr")) {
+ memcpy(bis->bi_enetaddr, EMACAddr, ENET_ADDR_LENGTH);
+ }
+
+ /* Set the device station address high and low registers */
+ HelpReg = (bis->bi_enetaddr[0] << 8) | bis->bi_enetaddr[1];
+ out_be32 (Emac.BaseAddress + XEM_SAH_OFFSET, HelpReg);
+ HelpReg = (bis->bi_enetaddr[2] << 24) | (bis->bi_enetaddr[3] << 16) |
+ (bis->bi_enetaddr[4] << 8) | bis->bi_enetaddr[5];
+ out_be32 (Emac.BaseAddress + XEM_SAL_OFFSET, HelpReg);
+
+
+ HelpReg = XEM_ECR_UNICAST_ENABLE_MASK | XEM_ECR_BROAD_ENABLE_MASK |
+ XEM_ECR_FULL_DUPLEX_MASK | XEM_ECR_XMIT_FCS_ENABLE_MASK |
+ XEM_ECR_XMIT_PAD_ENABLE_MASK | XEM_ECR_PHY_ENABLE_MASK;
+ out_be32 (Emac.BaseAddress + XEM_ECR_OFFSET, HelpReg);
+
+ Emac.IsStarted = 1;
+
+ /* Enable the transmitter, and receiver */
+ HelpReg = in_be32 (Emac.BaseAddress + XEM_ECR_OFFSET);
+ HelpReg &= ~(XEM_ECR_XMIT_RESET_MASK | XEM_ECR_RECV_RESET_MASK);
+ HelpReg |= (XEM_ECR_XMIT_ENABLE_MASK | XEM_ECR_RECV_ENABLE_MASK);
+ out_be32 (Emac.BaseAddress + XEM_ECR_OFFSET, HelpReg);
+
+ printf("EMAC Initialization complete\n\r");
+ return 0;
+}
+
+int eth_send(volatile void *ptr, int len)
+{
+ u32 IntrStatus;
+ u32 XmitStatus;
+ u32 FifoCount;
+ u32 WordCount;
+ u32 ExtraByteCount;
+ u32 *WordBuffer = (u32 *) ptr;
+
+ if (len > ENET_MAX_MTU)
+ len = ENET_MAX_MTU;
+
+ /*
+ * Check for overruns and underruns for the transmit status and length
+ * FIFOs and make sure the send packet FIFO is not deadlocked.
+ * Any of these conditions is bad enough that we do not want to
+ * continue. The upper layer software should reset the device to resolve
+ * the error.
+ */
+ IntrStatus = in_be32 ((Emac.BaseAddress) + XIIF_V123B_IISR_OFFSET);
+ if (IntrStatus & (XEM_EIR_XMIT_SFIFO_OVER_MASK |
+ XEM_EIR_XMIT_LFIFO_OVER_MASK)) {
+#ifdef DEBUG
+ puts ("Transmitting overrun error\n");
+#endif
+ return 0;
+ } else if (IntrStatus & (XEM_EIR_XMIT_SFIFO_UNDER_MASK |
+ XEM_EIR_XMIT_LFIFO_UNDER_MASK)) {
+#ifdef DEBUG
+ puts ("Transmitting underrun error\n");
+#endif
+ return 0;
+ } else if (in_be32 (Emac.SendFifo.RegBaseAddress +
+ XPF_COUNT_STATUS_REG_OFFSET) & XPF_DEADLOCK_MASK) {
+#ifdef DEBUG
+ puts("Transmitting fifo error\n");
+#endif
+ return 0;
+ }
+
+ /*
+ * Before writing to the data FIFO, make sure the length FIFO is not
+ * full. The data FIFO might not be full yet even though the length FIFO
+ * is. This avoids an overrun condition on the length FIFO and keeps the
+ * FIFOs in sync.
+ *
+ * Clear the latched LFIFO_FULL bit so next time around the most
+ * current status is represented
+ */
+ if (IntrStatus & XEM_EIR_XMIT_LFIFO_FULL_MASK) {
+ out_be32 ((Emac.BaseAddress) + XIIF_V123B_IISR_OFFSET, IntrStatus
+ & XEM_EIR_XMIT_LFIFO_FULL_MASK);
+#ifdef DEBUG
+ puts ("Fifo is full\n");
+#endif
+ return 0;
+ }
+
+ /* get the count of how many words may be inserted into the FIFO */
+ FifoCount = in_be32 (Emac.SendFifo.RegBaseAddress +
+ XPF_COUNT_STATUS_REG_OFFSET) & XPF_COUNT_MASK;
+ WordCount = len >> 2;
+ ExtraByteCount = len & 0x3;
+
+ if (FifoCount < WordCount) {
+#ifdef DEBUG
+ puts ("Sending packet is larger then size of FIFO\n");
+#endif
+ return 0;
+ }
+
+ for (FifoCount = 0; FifoCount < WordCount; FifoCount++) {
+ out_be32 (Emac.SendFifo.DataBaseAddress, WordBuffer[FifoCount]);
+ }
+ if (ExtraByteCount > 0) {
+ u32 LastWord = 0;
+ u8 *ExtraBytesBuffer = (u8 *) (WordBuffer + WordCount);
+
+ if (ExtraByteCount == 1) {
+ LastWord = ExtraBytesBuffer[0] << 24;
+ } else if (ExtraByteCount == 2) {
+ LastWord = ExtraBytesBuffer[0] << 24 |
+ ExtraBytesBuffer[1] << 16;
+ } else if (ExtraByteCount == 3) {
+ LastWord = ExtraBytesBuffer[0] << 24 |
+ ExtraBytesBuffer[1] << 16 |
+ ExtraBytesBuffer[2] << 8;
+ }
+ out_be32 (Emac.SendFifo.DataBaseAddress, LastWord);
+ }
+
+ /* Loop on the MAC's status to wait for any pause to complete */
+ IntrStatus = in_be32 ((Emac.BaseAddress) + XIIF_V123B_IISR_OFFSET);
+ while ((IntrStatus & XEM_EIR_XMIT_PAUSE_MASK) != 0) {
+ IntrStatus = in_be32 ((Emac.BaseAddress) +
+ XIIF_V123B_IISR_OFFSET);
+ /* Clear the pause status from the transmit status register */
+ out_be32 ((Emac.BaseAddress) + XIIF_V123B_IISR_OFFSET,
+ IntrStatus & XEM_EIR_XMIT_PAUSE_MASK);
+ }
+
+ /*
+ * Set the MAC's transmit packet length register to tell it to transmit
+ */
+ out_be32 (Emac.BaseAddress + XEM_TPLR_OFFSET, len);
+
+ /*
+ * Loop on the MAC's status to wait for the transmit to complete.
+ * The transmit status is in the FIFO when the XMIT_DONE bit is set.
+ */
+ do {
+ IntrStatus = in_be32 ((Emac.BaseAddress) +
+ XIIF_V123B_IISR_OFFSET);
+ }
+ while ((IntrStatus & XEM_EIR_XMIT_DONE_MASK) == 0);
+
+ XmitStatus = in_be32 (Emac.BaseAddress + XEM_TSR_OFFSET);
+
+ if (IntrStatus & (XEM_EIR_XMIT_SFIFO_OVER_MASK |
+ XEM_EIR_XMIT_LFIFO_OVER_MASK)) {
+#ifdef DEBUG
+ puts ("Transmitting overrun error\n");
+#endif
+ return 0;
+ } else if (IntrStatus & (XEM_EIR_XMIT_SFIFO_UNDER_MASK |
+ XEM_EIR_XMIT_LFIFO_UNDER_MASK)) {
+#ifdef DEBUG
+ puts ("Transmitting underrun error\n");
+#endif
+ return 0;
+ }
+
+ /* Clear the interrupt status register of transmit statuses */
+ out_be32 ((Emac.BaseAddress) + XIIF_V123B_IISR_OFFSET,
+ IntrStatus & XEM_EIR_XMIT_ALL_MASK);
+
+ /*
+ * Collision errors are stored in the transmit status register
+ * instead of the interrupt status register
+ */
+ if ((XmitStatus & XEM_TSR_EXCESS_DEFERRAL_MASK) ||
+ (XmitStatus & XEM_TSR_LATE_COLLISION_MASK)) {
+#ifdef DEBUG
+ puts ("Transmitting collision error\n");
+#endif
+ return 0;
+ }
+ return 1;
+}
+
+int eth_rx(void)
+{
+ u32 PktLength;
+ u32 IntrStatus;
+ u32 FifoCount;
+ u32 WordCount;
+ u32 ExtraByteCount;
+ u32 LastWord;
+ u8 *ExtraBytesBuffer;
+
+ if (in_be32 (Emac.RecvFifo.RegBaseAddress + XPF_COUNT_STATUS_REG_OFFSET)
+ & XPF_DEADLOCK_MASK) {
+ out_be32 (Emac.RecvFifo.RegBaseAddress, XPF_RESET_FIFO_MASK);
+#ifdef DEBUG
+ puts ("Receiving FIFO deadlock\n");
+#endif
+ return 0;
+ }
+
+ /*
+ * Get the interrupt status to know what happened (whether an error occurred
+ * and/or whether frames have been received successfully). When clearing the
+ * intr status register, clear only statuses that pertain to receive.
+ */
+ IntrStatus = in_be32 ((Emac.BaseAddress) + XIIF_V123B_IISR_OFFSET);
+ /*
+ * Before reading from the length FIFO, make sure the length FIFO is not
+ * empty. We could cause an underrun error if we try to read from an
+ * empty FIFO.
+ */
+ if (!(IntrStatus & XEM_EIR_RECV_DONE_MASK)) {
+#ifdef DEBUG
+ /* puts("Receiving FIFO is empty\n"); */
+#endif
+ return 0;
+ }
+
+ /*
+ * Determine, from the MAC, the length of the next packet available
+ * in the data FIFO (there should be a non-zero length here)
+ */
+ PktLength = in_be32 (Emac.BaseAddress + XEM_RPLR_OFFSET);
+ if (!PktLength) {
+ return 0;
+ }
+
+ /*
+ * Write the RECV_DONE bit in the status register to clear it. This bit
+ * indicates the RPLR is non-empty, and we know it's set at this point.
+ * We clear it so that subsequent entry into this routine will reflect
+ * the current status. This is done because the non-empty bit is latched
+ * in the IPIF, which means it may indicate a non-empty condition even
+ * though there is something in the FIFO.
+ */
+ out_be32 ((Emac.BaseAddress) + XIIF_V123B_IISR_OFFSET,
+ XEM_EIR_RECV_DONE_MASK);
+
+ FifoCount = in_be32 (Emac.RecvFifo.RegBaseAddress +
+ XPF_COUNT_STATUS_REG_OFFSET) & XPF_COUNT_MASK;
+
+ if ((FifoCount * 4) < PktLength) {
+#ifdef DEBUG
+ puts ("Receiving FIFO is smaller than packet size.\n");
+#endif
+ return 0;
+ }
+
+ WordCount = PktLength >> 2;
+ ExtraByteCount = PktLength & 0x3;
+
+ for (FifoCount = 0; FifoCount < WordCount; FifoCount++) {
+ etherrxbuff[FifoCount] =
+ in_be32 (Emac.RecvFifo.DataBaseAddress);
+ }
+
+ /*
+ * if there are extra bytes to handle, read the last word from the FIFO
+ * and insert the extra bytes into the buffer
+ */
+ if (ExtraByteCount > 0) {
+ ExtraBytesBuffer = (u8 *) (etherrxbuff + WordCount);
+
+ LastWord = in_be32 (Emac.RecvFifo.DataBaseAddress);
+
+ /*
+ * one extra byte in the last word, put the byte into the next
+ * location of the buffer, bytes in a word of the FIFO are
+ * ordered from most significant byte to least
+ */
+ if (ExtraByteCount == 1) {
+ ExtraBytesBuffer[0] = (u8) (LastWord >> 24);
+ } else if (ExtraByteCount == 2) {
+ ExtraBytesBuffer[0] = (u8) (LastWord >> 24);
+ ExtraBytesBuffer[1] = (u8) (LastWord >> 16);
+ } else if (ExtraByteCount == 3) {
+ ExtraBytesBuffer[0] = (u8) (LastWord >> 24);
+ ExtraBytesBuffer[1] = (u8) (LastWord >> 16);
+ ExtraBytesBuffer[2] = (u8) (LastWord >> 8);
+ }
+ }
+ NetReceive((uchar *)etherrxbuff, PktLength);
+ return 1;
+}
+#endif
diff --git a/drivers/net/xilinx_emac.h b/drivers/net/xilinx_emac.h
new file mode 100644
index 00000000000..ab4d2121f13
--- /dev/null
+++ b/drivers/net/xilinx_emac.h
@@ -0,0 +1,128 @@
+/*
+ * (C) Copyright 2007 Michal Simek
+ *
+ * Michal SIMEK <monstr@monstr.eu>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ * Based on Xilinx drivers
+ *
+ */
+
+typedef struct {
+ u32 RegBaseAddress; /* Base address of registers */
+ u32 DataBaseAddress; /* Base address of data for FIFOs */
+} XPacketFifoV100b;
+
+typedef struct {
+ u32 BaseAddress; /* Base address (of IPIF) */
+ u32 IsStarted; /* Device is currently started 0-no, 1-yes */
+ XPacketFifoV100b RecvFifo; /* FIFO used to receive frames */
+ XPacketFifoV100b SendFifo; /* FIFO used to send frames */
+
+} XEmac;
+
+#define XIIF_V123B_IISR_OFFSET 32UL /* IP interrupt status register */
+#define XIIF_V123B_RESET_MASK 0xAUL
+#define XIIF_V123B_RESETR_OFFSET 64UL /* reset register */
+
+/* This constant is used with the Reset Register */
+#define XPF_RESET_FIFO_MASK 0x0000000A
+#define XPF_COUNT_STATUS_REG_OFFSET 4UL
+
+/* * These constants are used with the Occupancy/Vacancy Count Register. This
+ * register also contains FIFO status */
+#define XPF_COUNT_MASK 0x0000FFFF
+#define XPF_DEADLOCK_MASK 0x20000000
+
+/* Offset of the MAC registers from the IPIF base address */
+#define XEM_REG_OFFSET 0x1100UL
+
+/*
+ * Register offsets for the Ethernet MAC. Each register is 32 bits.
+ */
+#define XEM_ECR_OFFSET (XEM_REG_OFFSET + 0x4) /* MAC Control */
+#define XEM_SAH_OFFSET (XEM_REG_OFFSET + 0xC) /* Station addr, high */
+#define XEM_SAL_OFFSET (XEM_REG_OFFSET + 0x10) /* Station addr, low */
+#define XEM_RPLR_OFFSET (XEM_REG_OFFSET + 0x1C) /* Rx packet length */
+#define XEM_TPLR_OFFSET (XEM_REG_OFFSET + 0x20) /* Tx packet length */
+#define XEM_TSR_OFFSET (XEM_REG_OFFSET + 0x24) /* Tx status */
+
+
+
+#define XEM_PFIFO_OFFSET 0x2000UL
+#define XEM_PFIFO_TXREG_OFFSET (XEM_PFIFO_OFFSET + 0x0) /* Tx registers */
+#define XEM_PFIFO_RXREG_OFFSET (XEM_PFIFO_OFFSET + 0x10) /* Rx registers */
+#define XEM_PFIFO_TXDATA_OFFSET (XEM_PFIFO_OFFSET + 0x100) /* Tx keyhole */
+#define XEM_PFIFO_RXDATA_OFFSET (XEM_PFIFO_OFFSET + 0x200) /* Rx keyhole */
+
+
+/*
+ * EMAC Interrupt Registers (Status and Enable) masks. These registers are
+ * part of the IPIF IP Interrupt registers
+ */
+/* A mask for all transmit interrupts, used in polled mode */
+#define XEM_EIR_XMIT_ALL_MASK (XEM_EIR_XMIT_DONE_MASK | \
+ XEM_EIR_XMIT_ERROR_MASK | \
+ XEM_EIR_XMIT_SFIFO_EMPTY_MASK | \
+ XEM_EIR_XMIT_LFIFO_FULL_MASK)
+
+#define XEM_EIR_XMIT_DONE_MASK 0x00000001UL /* Xmit complete */
+#define XEM_EIR_RECV_DONE_MASK 0x00000002UL /* Recv complete */
+#define XEM_EIR_XMIT_ERROR_MASK 0x00000004UL /* Xmit error */
+#define XEM_EIR_RECV_ERROR_MASK 0x00000008UL /* Recv error */
+#define XEM_EIR_XMIT_SFIFO_EMPTY_MASK 0x00000010UL /* Xmit status fifo empty */
+#define XEM_EIR_RECV_LFIFO_EMPTY_MASK 0x00000020UL /* Recv length fifo empty */
+#define XEM_EIR_XMIT_LFIFO_FULL_MASK 0x00000040UL /* Xmit length fifo full */
+#define XEM_EIR_RECV_LFIFO_OVER_MASK 0x00000080UL /* Recv length fifo
+ * overrun */
+#define XEM_EIR_RECV_LFIFO_UNDER_MASK 0x00000100UL /* Recv length fifo
+ * underrun */
+#define XEM_EIR_XMIT_SFIFO_OVER_MASK 0x00000200UL /* Xmit status fifo
+ * overrun */
+#define XEM_EIR_XMIT_SFIFO_UNDER_MASK 0x00000400UL /* Transmit status fifo
+ * underrun */
+#define XEM_EIR_XMIT_LFIFO_OVER_MASK 0x00000800UL /* Transmit length fifo
+ * overrun */
+#define XEM_EIR_XMIT_LFIFO_UNDER_MASK 0x00001000UL /* Transmit length fifo
+ * underrun */
+#define XEM_EIR_XMIT_PAUSE_MASK 0x00002000UL /* Transmit pause pkt
+ * received */
+
+/*
+ * EMAC Control Register (ECR)
+ */
+#define XEM_ECR_FULL_DUPLEX_MASK 0x80000000UL /* Full duplex mode */
+#define XEM_ECR_XMIT_RESET_MASK 0x40000000UL /* Reset transmitter */
+#define XEM_ECR_XMIT_ENABLE_MASK 0x20000000UL /* Enable transmitter */
+#define XEM_ECR_RECV_RESET_MASK 0x10000000UL /* Reset receiver */
+#define XEM_ECR_RECV_ENABLE_MASK 0x08000000UL /* Enable receiver */
+#define XEM_ECR_PHY_ENABLE_MASK 0x04000000UL /* Enable PHY */
+#define XEM_ECR_XMIT_PAD_ENABLE_MASK 0x02000000UL /* Enable xmit pad
+ * insert */
+#define XEM_ECR_XMIT_FCS_ENABLE_MASK 0x01000000UL /* Enable xmit FCS
+ * insert */
+#define XEM_ECR_UNICAST_ENABLE_MASK 0x00020000UL /* Enable unicast
+ * addr */
+#define XEM_ECR_BROAD_ENABLE_MASK 0x00008000UL /* Enable broadcast
+ * addr */
+
+/* Transmit Status Register (TSR) */
+#define XEM_TSR_EXCESS_DEFERRAL_MASK 0x80000000UL /* Transmit excess deferral */
+#define XEM_TSR_LATE_COLLISION_MASK 0x01000000UL /* Transmit late collision */