microblaze: add Emac ethernet driver
diff --git a/drivers/net/xilinx_emac.c b/drivers/net/xilinx_emac.c
new file mode 100644
index 0000000..c7f1a2a
--- /dev/null
+++ b/drivers/net/xilinx_emac.c
@@ -0,0 +1,462 @@
+/******************************************************************************
+ *
+ * XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
+ * AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
+ * SOLUTIONS FOR XILINX DEVICES. BY PROVIDING THIS DESIGN, CODE,
+ * OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
+ * APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION
+ * THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
+ * AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE
+ * FOR YOUR IMPLEMENTATION. XILINX EXPRESSLY DISCLAIMS ANY
+ * WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
+ * IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
+ * REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
+ * INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE.
+ *
+ * (C) Copyright 2007-2008 Michal Simek
+ * Michal SIMEK <monstr@monstr.eu>
+ *
+ * (c) Copyright 2003 Xilinx Inc.
+ * All rights reserved.
+ *
+ ******************************************************************************/
+
+#include <config.h>
+#include <common.h>
+#include <net.h>
+#include <asm/io.h>
+
+#include <asm/asm.h>
+
+#undef DEBUG
+
+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
+/* Tx registers */
+#define XEM_PFIFO_TXREG_OFFSET	(XEM_PFIFO_OFFSET + 0x0)
+/* Rx registers */
+#define XEM_PFIFO_RXREG_OFFSET	(XEM_PFIFO_OFFSET + 0x10)
+/* Tx keyhole */
+#define XEM_PFIFO_TXDATA_OFFSET	(XEM_PFIFO_OFFSET + 0x100)
+/* Rx keyhole */
+#define XEM_PFIFO_RXDATA_OFFSET	(XEM_PFIFO_OFFSET + 0x200)
+
+/*
+ * 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)
+
+/* Xmit complete */
+#define XEM_EIR_XMIT_DONE_MASK		0x00000001UL
+/* Recv complete */
+#define XEM_EIR_RECV_DONE_MASK		0x00000002UL
+/* Xmit error */
+#define XEM_EIR_XMIT_ERROR_MASK		0x00000004UL
+/* Recv error */
+#define XEM_EIR_RECV_ERROR_MASK		0x00000008UL
+/* Xmit status fifo empty */
+#define XEM_EIR_XMIT_SFIFO_EMPTY_MASK	0x00000010UL
+/* Recv length fifo empty */
+#define XEM_EIR_RECV_LFIFO_EMPTY_MASK	0x00000020UL
+/* Xmit length fifo full */
+#define XEM_EIR_XMIT_LFIFO_FULL_MASK	0x00000040UL
+/* Recv length fifo overrun */
+#define XEM_EIR_RECV_LFIFO_OVER_MASK	0x00000080UL
+/* Recv length fifo underrun */
+#define XEM_EIR_RECV_LFIFO_UNDER_MASK	0x00000100UL
+/* Xmit status fifo overrun */
+#define XEM_EIR_XMIT_SFIFO_OVER_MASK	0x00000200UL
+/* Transmit status fifo underrun */
+#define XEM_EIR_XMIT_SFIFO_UNDER_MASK	0x00000400UL
+/* Transmit length fifo overrun */
+#define XEM_EIR_XMIT_LFIFO_OVER_MASK	0x00000800UL
+/* Transmit length fifo underrun */
+#define XEM_EIR_XMIT_LFIFO_UNDER_MASK	0x00001000UL
+/* Transmit pause pkt received */
+#define XEM_EIR_XMIT_PAUSE_MASK		0x00002000UL
+
+/*
+ * EMAC Control Register (ECR)
+ */
+/* Full duplex mode */
+#define XEM_ECR_FULL_DUPLEX_MASK	0x80000000UL
+/* Reset transmitter */
+#define XEM_ECR_XMIT_RESET_MASK		0x40000000UL
+/* Enable transmitter */
+#define XEM_ECR_XMIT_ENABLE_MASK	0x20000000UL
+/* Reset receiver */
+#define XEM_ECR_RECV_RESET_MASK		0x10000000UL
+/* Enable receiver */
+#define XEM_ECR_RECV_ENABLE_MASK	0x08000000UL
+/* Enable PHY */
+#define XEM_ECR_PHY_ENABLE_MASK		0x04000000UL
+/* Enable xmit pad insert */
+#define XEM_ECR_XMIT_PAD_ENABLE_MASK	0x02000000UL
+/* Enable xmit FCS insert */
+#define XEM_ECR_XMIT_FCS_ENABLE_MASK	0x01000000UL
+/* Enable unicast addr */
+#define XEM_ECR_UNICAST_ENABLE_MASK	0x00020000UL
+/* Enable broadcast addr */
+#define XEM_ECR_BROAD_ENABLE_MASK	0x00008000UL
+
+/*
+ * Transmit Status Register (TSR)
+ */
+/* Transmit excess deferral */
+#define XEM_TSR_EXCESS_DEFERRAL_MASK	0x80000000UL
+/* Transmit late collision */
+#define XEM_TSR_LATE_COLLISION_MASK	0x01000000UL
+
+#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)
+{
+	debug ("eth_halt\n");
+}
+
+int eth_init(bd_t * bis)
+{
+	u32 helpreg;
+	debug ("EMAC Initialization Started\n\r");
+
+	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)) {
+		debug ("Transmitting overrun error\n");
+		return 0;
+	} else if (intrstatus & (XEM_EIR_XMIT_SFIFO_UNDER_MASK |
+			XEM_EIR_XMIT_LFIFO_UNDER_MASK)) {
+		debug ("Transmitting underrun error\n");
+		return 0;
+	} else if (in_be32 (emac.sendfifo.regbaseaddress +
+			XPF_COUNT_STATUS_REG_OFFSET) & XPF_DEADLOCK_MASK) {
+		debug ("Transmitting fifo error\n");
+		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);
+		debug ("Fifo is full\n");
+		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) {
+		debug ("Sending packet is larger then size of FIFO\n");
+		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)) {
+		debug ("Transmitting overrun error\n");
+		return 0;
+	} else if (intrstatus & (XEM_EIR_XMIT_SFIFO_UNDER_MASK |
+					XEM_EIR_XMIT_LFIFO_UNDER_MASK)) {
+		debug ("Transmitting underrun error\n");
+		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)) {
+		debug ("Transmitting collision error\n");
+		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);
+		debug ("Receiving FIFO deadlock\n");
+		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)) {
+		/* debug ("Receiving FIFO is empty\n"); */
+		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) {
+		debug ("Receiving FIFO is smaller than packet size.\n");
+		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;
+}