[U-Boot-Users] [PATCH 7/13] SPARC: Added GRETH Ethernet 10/100/1000 support for LEON3

[Daniel Hellstrom <daniel@gaisler.com>]

Hello Wolfgang,

GRETH is an Ethernet 10/100 or 10/100/1000 MAC with out without
a debug link (EDCL). The GRETH core is documented in GRIP.pdf
available at www.gaisler.com.

If the GRETH has GigaBit support (GBIT, Scatter gather, checksum
offloading etc.) can be determined by a bit in the control register.
The GBIT MAC is supported by operating in GRTEH 10/100 legacy mode.

This patch is also available at 
ftp://ftp.gaisler.com/gaisler.com/u-boot/patches.

Best Regards,
Daniel Hellstrom



 drivers/net/Makefile |    1 +
 drivers/net/greth.c  |  661 
++++++++++++++++++++++++++++++++++++++++++++++++++
 drivers/net/greth.h  |   97 ++++++++
 net/eth.c            |    4 +
 4 files changed, 763 insertions(+), 0 deletions(-)


diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 320dc3e..eafd267 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -35,6 +35,7 @@ COBJS-y += e1000.o
 COBJS-y += eepro100.o
 COBJS-y += enc28j60.o
 COBJS-y += fsl_mcdmafec.o
+COBJS-$(CONFIG_GRETH) += greth.o
 COBJS-y += inca-ip_sw.o
 COBJS-y += ks8695eth.o
 COBJS-y += lan91c96.o
diff --git a/drivers/net/greth.c b/drivers/net/greth.c
new file mode 100644
index 0000000..76ece59
--- /dev/null
+++ b/drivers/net/greth.c
@@ -0,0 +1,661 @@
+/* Gaisler.com GRETH 10/100/1000 Ethernet MAC driver
+ *
+ * Driver use polling mode (no Interrupt)
+ *
+ * (C) Copyright 2007
+ * Daniel Hellstrom, Gaisler Research, daniel at gaisler.com
+ *
+ * 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
+ */
+
+#include <common.h>
+#include <command.h>
+#include <net.h>
+#include <malloc.h>
+#include <asm/processor.h>
+#include <ambapp.h>
+#include <asm/leon.h>
+
+/* #define DEBUG */
+
+#include "greth.h"
+
+/* Default to 3s timeout on autonegotiation */
+#ifndef GRETH_PHY_TIMEOUT_MS
+#define GRETH_PHY_TIMEOUT_MS 3000
+#endif
+
+/* ByPass Cache when reading regs */
+#define GRETH_REGLOAD(addr)        SPARC_NOCACHE_READ(addr)
+/* Write-through cache ==> no bypassing needed on writes */
+#define GRETH_REGSAVE(addr,data)    (*(unsigned int *)(addr) = (data))
+#define GRETH_REGORIN(addr,data) 
GRETH_REGSAVE(addr,GRETH_REGLOAD(addr)|data)
+#define GRETH_REGANDIN(addr,data) 
GRETH_REGSAVE(addr,GRETH_REGLOAD(addr)&data)
+
+#define GRETH_RXBD_CNT 4
+#define GRETH_TXBD_CNT 1
+
+#define GRETH_RXBUF_SIZE 1540
+#define GRETH_BUF_ALIGN 4
+#define GRETH_RXBUF_EFF_SIZE \
+    ( (GRETH_RXBUF_SIZE&~(GRETH_BUF_ALIGN-1))+GRETH_BUF_ALIGN )
+
+typedef struct {
+    greth_regs *regs;
+    int irq;
+    struct eth_device *dev;
+
+    /* Hardware info */
+    unsigned char phyaddr;
+    int gbit_mac;
+
+    /* Current operating Mode */
+    int gb;            /* GigaBit */
+    int fd;            /* Full Duplex */
+    int sp;            /* 10/100Mbps speed (1=100,0=10) */
+    int auto_neg;        /* Auto negotiate done */
+
+    unsigned char hwaddr[6];    /* MAC Address */
+
+    /* Descriptors */
+    greth_bd *rxbd_base, *rxbd_max;
+    greth_bd *txbd_base, *txbd_max;
+
+    greth_bd *rxbd_curr;
+
+    /* rx buffers in rx descriptors */
+    void *rxbuf_base;    /* (GRETH_RXBUF_SIZE+ALIGNBYTES) * 
GRETH_RXBD_CNT */
+
+    /* unused for gbit_mac, temp buffer for sending packets with unligned
+     * start.
+     * Pointer to packet allocated with malloc.
+     */
+    void *txbuf;
+
+    struct {
+        /* rx status */
+        unsigned int rx_packets,
+            rx_crc_errors, rx_frame_errors, rx_length_errors, rx_errors;
+
+        /* tx stats */
+        unsigned int tx_packets,
+            tx_latecol_errors,
+            tx_underrun_errors, tx_limit_errors, tx_errors;
+    } stats;
+} greth_priv;
+
+/* Read MII register 'addr' from core 'regs' */
+static int read_mii(int addr, volatile greth_regs * regs)
+{
+    while (GRETH_REGLOAD(&regs->mdio) & GRETH_MII_BUSY) {
+    }
+
+    GRETH_REGSAVE(&regs->mdio, (0 << 11) | ((addr & 0x1F) << 6) | 2);
+
+    while (GRETH_REGLOAD(&regs->mdio) & GRETH_MII_BUSY) {
+    }
+
+    if (!(GRETH_REGLOAD(&regs->mdio) & GRETH_MII_NVALID)) {
+        return (GRETH_REGLOAD(&regs->mdio) >> 16) & 0xFFFF;
+    } else {
+        return -1;
+    }
+}
+
+static void write_mii(int addr, int data, volatile greth_regs * regs)
+{
+    while (GRETH_REGLOAD(&regs->mdio) & GRETH_MII_BUSY) {
+    }
+
+    GRETH_REGSAVE(&regs->mdio,
+              ((data & 0xFFFF) << 16) | (0 << 11) | ((addr & 0x1F) << 6)
+              | 1);
+
+    while (GRETH_REGLOAD(&regs->mdio) & GRETH_MII_BUSY) {
+    }
+
+}
+
+/* init/start hardware and allocate descriptor buffers for rx side
+ *
+ */
+int greth_init(struct eth_device *dev, bd_t * bis)
+{
+    int i;
+
+    greth_priv *greth = dev->priv;
+    greth_regs *regs = greth->regs;
+#ifdef DEBUG
+    printf("greth_init\n");
+#endif
+
+    GRETH_REGSAVE(&regs->control, 0);
+
+    if (!greth->rxbd_base) {
+
+        /* allocate descriptors */
+        greth->rxbd_base = (greth_bd *)
+            memalign(0x1000, GRETH_RXBD_CNT * sizeof(greth_bd));
+        greth->txbd_base = (greth_bd *)
+            memalign(0x1000, GRETH_RXBD_CNT * sizeof(greth_bd));
+
+        /* allocate buffers to all descriptors  */
+        greth->rxbuf_base =
+            malloc(GRETH_RXBUF_EFF_SIZE * GRETH_RXBD_CNT);
+    }
+
+    /* initate rx decriptors */
+    for (i = 0; i < GRETH_RXBD_CNT; i++) {
+        greth->rxbd_base[i].addr = (unsigned int)
+            greth->rxbuf_base + (GRETH_RXBUF_EFF_SIZE * i);
+        /* enable desciptor & set wrap bit if last descriptor */
+        if (i >= (GRETH_RXBD_CNT - 1)) {
+            greth->rxbd_base[i].stat = GRETH_BD_EN | GRETH_BD_WR;
+        } else {
+            greth->rxbd_base[i].stat = GRETH_BD_EN;
+        }
+    }
+
+    /* initiate indexes */
+    greth->rxbd_curr = greth->rxbd_base;
+    greth->rxbd_max = greth->rxbd_base + (GRETH_RXBD_CNT - 1);
+    greth->txbd_max = greth->txbd_base + (GRETH_TXBD_CNT - 1);
+    /*
+     * greth->txbd_base->addr = 0;
+     * greth->txbd_base->stat = GRETH_BD_WR;
+     */
+
+    /* initate tx decriptors */
+    for (i = 0; i < GRETH_TXBD_CNT; i++) {
+        greth->txbd_base[i].addr = 0;
+        /* enable desciptor & set wrap bit if last descriptor */
+        if (i >= (GRETH_RXBD_CNT - 1)) {
+            greth->txbd_base[i].stat = GRETH_BD_WR;
+        } else {
+            greth->txbd_base[i].stat = 0;
+        }
+    }
+
+    /**** SET HARDWARE REGS ****/
+
+    /* Set pointer to tx/rx descriptor areas */
+    GRETH_REGSAVE(&regs->rx_desc_p, (unsigned int)&greth->rxbd_base[0]);
+    GRETH_REGSAVE(&regs->tx_desc_p, (unsigned int)&greth->txbd_base[0]);
+
+    /* Enable Transmitter, GRETH will now scan descriptors for packets
+     * to transmitt */
+#ifdef DEBUG
+    printf("greth_init: enabling receiver\n");
+#endif
+    GRETH_REGORIN(&regs->control, GRETH_RXEN);
+
+    return 0;
+}
+
+/* Initiate PHY to a relevant speed
+ * return:
+ *  - 0 = success
+ *  - 1 = timeout/fail
+ */
+int greth_init_phy(greth_priv * dev, bd_t * bis)
+{
+    greth_regs *regs = dev->regs;
+    int tmp, tmp1, tmp2, i;
+    unsigned int start, timeout;
+
+    /* X msecs to ticks */
+    timeout = usec2ticks(GRETH_PHY_TIMEOUT_MS * 1000);
+
+    /* Get system timer0 current value
+     * Total timeout is 5s
+     */
+    start = get_timer(0);
+
+    /* get phy control register default values */
+
+    while ((tmp = read_mii(0, regs)) & 0x8000) {
+        if (get_timer(start) > timeout)
+            return 1;    /* Fail */
+    }
+
+    /* reset PHY and wait for completion */
+    write_mii(0, 0x8000 | tmp, regs);
+
+    while (((tmp = read_mii(0, regs))) & 0x8000) {
+        if (get_timer(start) > timeout)
+            return 1;    /* Fail */
+    }
+
+    /* Check if PHY is autoneg capable and then determine operating
+     * mode, otherwise force it to 10 Mbit halfduplex
+     */
+    dev->gb = 0;
+    dev->fd = 0;
+    dev->sp = 0;
+    dev->auto_neg = 0;
+    if (!((tmp >> 12) & 1)) {
+        write_mii(0, 0, regs);
+    } else {
+        /* wait for auto negotiation to complete and then check 
operating mode */
+        dev->auto_neg = 1;
+        i = 0;
+        while (!(((tmp = read_mii(1, regs)) >> 5) & 1)) {
+            if (get_timer(start) > timeout) {
+                printf("Auto negotiation timed out. "
+                       "Selecting default config\n");
+                tmp = read_mii(0, regs);
+                dev->gb = ((tmp >> 6) & 1)
+                    && !((tmp >> 13) & 1);
+                dev->sp = !((tmp >> 6) & 1)
+                    && ((tmp >> 13) & 1);
+                dev->fd = (tmp >> 8) & 1;
+                goto auto_neg_done;
+            }
+        }
+        if ((tmp >> 8) & 1) {
+            tmp1 = read_mii(9, regs);
+            tmp2 = read_mii(10, regs);
+            if ((tmp1 & GRETH_MII_EXTADV_1000FD) &&
+                (tmp2 & GRETH_MII_EXTPRT_1000FD)) {
+                dev->gb = 1;
+                dev->fd = 1;
+            }
+            if ((tmp1 & GRETH_MII_EXTADV_1000HD) &&
+                (tmp2 & GRETH_MII_EXTPRT_1000HD)) {
+                dev->gb = 1;
+                dev->fd = 0;
+            }
+        }
+        if ((dev->gb == 0) || ((dev->gb == 1) && (dev->gbit_mac == 0))) {
+            tmp1 = read_mii(4, regs);
+            tmp2 = read_mii(5, regs);
+            if ((tmp1 & GRETH_MII_100TXFD) &&
+                (tmp2 & GRETH_MII_100TXFD)) {
+                dev->sp = 1;
+                dev->fd = 1;
+            }
+            if ((tmp1 & GRETH_MII_100TXHD) &&
+                (tmp2 & GRETH_MII_100TXHD)) {
+                dev->sp = 1;
+                dev->fd = 0;
+            }
+            if ((tmp1 & GRETH_MII_10FD) && (tmp2 & GRETH_MII_10FD)) {
+                dev->fd = 1;
+            }
+            if ((dev->gb == 1) && (dev->gbit_mac == 0)) {
+                dev->gb = 0;
+                dev->fd = 0;
+                write_mii(0, dev->sp << 13, regs);
+            }
+        }
+
+    }
+      auto_neg_done:
+#ifdef DEBUG
+    printf("%s GRETH Ethermac@[0x%x] irq %d. Running \
+        %d Mbps %s duplex\n", dev->gbit_mac ? "10/100/1000" : "10/100", 
(unsigned int)(regs), (unsigned int)(dev->irq), dev->gb ? 1000 : 
(dev->sp ? 100 : 10), dev->fd ? "full" : "half");
+#endif
+    /* Read out PHY info if extended registers are available */
+    if (tmp & 1) {
+        tmp1 = read_mii(2, regs);
+        tmp2 = read_mii(3, regs);
+        tmp1 = (tmp1 << 6) | ((tmp2 >> 10) & 0x3F);
+        tmp = tmp2 & 0xF;
+
+        tmp2 = (tmp2 >> 4) & 0x3F;
+#ifdef DEBUG
+        printf("PHY: Vendor %x   Device %x    Revision %d\n", tmp1,
+               tmp2, tmp);
+#endif
+    } else {
+        printf("PHY info not available\n");
+    }
+
+    /* set speed and duplex bits in control register */
+    GRETH_REGORIN(&regs->control,
+              (dev->gb << 8) | (dev->sp << 7) | (dev->fd << 4));
+
+    return 0;
+}
+
+void greth_halt(struct eth_device *dev)
+{
+    greth_priv *greth;
+    greth_regs *regs;
+    int i;
+#ifdef DEBUG
+    printf("greth_halt\n");
+#endif
+    if (!dev || !dev->priv)
+        return;
+
+    greth = dev->priv;
+    regs = greth->regs;
+
+    if (!regs)
+        return;
+
+    /* disable receiver/transmitter by clearing the enable bits */
+    GRETH_REGANDIN(&regs->control, ~(GRETH_RXEN | GRETH_TXEN));
+
+    /* reset rx/tx descriptors */
+    if (greth->rxbd_base) {
+        for (i = 0; i < GRETH_RXBD_CNT; i++) {
+            greth->rxbd_base[i].stat =
+                (i >= (GRETH_RXBD_CNT - 1)) ? GRETH_BD_WR : 0;
+        }
+    }
+
+    if (greth->txbd_base) {
+        for (i = 0; i < GRETH_TXBD_CNT; i++) {
+            greth->txbd_base[i].stat =
+                (i >= (GRETH_TXBD_CNT - 1)) ? GRETH_BD_WR : 0;
+        }
+    }
+}
+
+int greth_send(struct eth_device *dev, volatile void *eth_data, int 
data_length)
+{
+    greth_priv *greth = dev->priv;
+    greth_regs *regs = greth->regs;
+    greth_bd *txbd;
+    void *txbuf;
+    unsigned int status;
+#ifdef DEBUG
+    printf("greth_send\n");
+#endif
+    /* send data, wait for data to be sent, then return */
+    if (((unsigned int)eth_data & (GRETH_BUF_ALIGN - 1))
+        && !greth->gbit_mac) {
+        /* data not aligned as needed by GRETH 10/100, solve this by 
allocating 4 byte aligned buffer
+         * and copy data to before giving it to GRETH.
+         */
+        if (!greth->txbuf) {
+            greth->txbuf = malloc(GRETH_RXBUF_SIZE);
+#ifdef DEBUG
+            printf("GRETH: allocated aligned tx-buf\n");
+#endif
+        }
+
+        txbuf = greth->txbuf;
+
+        /* copy data info buffer */
+        memcpy((char *)txbuf, (char *)eth_data, data_length);
+
+        /* keep buffer to next time */
+    } else {
+        txbuf = (void *)eth_data;
+    }
+    /* get descriptor to use, only 1 supported... hehe easy */
+    txbd = greth->txbd_base;
+
+    /* setup descriptor to wrap around to it self */
+    txbd->addr = (unsigned int)txbuf;
+    txbd->stat = GRETH_BD_EN | GRETH_BD_WR | data_length;
+
+    /* Remind Core which descriptor to use when sending */
+    GRETH_REGSAVE(&regs->tx_desc_p, (unsigned int)txbd);
+
+    /* initate send by enabling transmitter */
+    GRETH_REGORIN(&regs->control, GRETH_TXEN);
+
+    /* Wait for data to be sent */
+    while ((status = GRETH_REGLOAD(&txbd->stat)) & GRETH_BD_EN) {
+        ;
+    }
+
+    /* was the packet transmitted succesfully? */
+    if (status & GRETH_TXBD_ERR_AL) {
+        greth->stats.tx_limit_errors++;
+    }
+
+    if (status & GRETH_TXBD_ERR_UE) {
+        greth->stats.tx_underrun_errors++;
+    }
+
+    if (status & GRETH_TXBD_ERR_LC) {
+        greth->stats.tx_latecol_errors++;
+    }
+
+    if (status &
+        (GRETH_TXBD_ERR_LC | GRETH_TXBD_ERR_UE | GRETH_TXBD_ERR_AL)) {
+        /* any error */
+        greth->stats.tx_errors++;
+        return -1;
+    }
+
+    /* bump tx packet counter */
+    greth->stats.tx_packets++;
+
+    /* return succefully */
+    return 0;
+}
+
+int greth_recv(struct eth_device *dev)
+{
+    greth_priv *greth = dev->priv;
+    greth_regs *regs = greth->regs;
+    greth_bd *rxbd;
+    unsigned int status, len = 0, bad;
+    unsigned char *d;
+    int enable = 0;
+    int i;
+#ifdef DEBUG
+/*    printf("greth_recv\n"); */
+#endif
+    /* Receive One packet only, but clear as many error packets as 
there are
+     * available.
+     */
+    {
+        /* current receive descriptor */
+        rxbd = greth->rxbd_curr;
+
+        /* get status of next received packet */
+        status = GRETH_REGLOAD(&rxbd->stat);
+
+        bad = 0;
+
+        /* stop if no more packets received */
+        if (status & GRETH_BD_EN) {
+            goto done;
+        }
+#ifdef DEBUG
+        printf("greth_recv: packet 0x%lx, 0x%lx, len: %d\n",
+               (unsigned int)rxbd, status, status & GRETH_BD_LEN);
+#endif
+
+        /* Check status for errors.
+         */
+        if (status & GRETH_RXBD_ERR_FT) {
+            greth->stats.rx_length_errors++;
+            bad = 1;
+        }
+        if (status & (GRETH_RXBD_ERR_AE | GRETH_RXBD_ERR_OE)) {
+            greth->stats.rx_frame_errors++;
+            bad = 1;
+        }
+        if (status & GRETH_RXBD_ERR_CRC) {
+            greth->stats.rx_crc_errors++;
+            bad = 1;
+        }
+        if (bad) {
+            greth->stats.rx_errors++;
+            printf
+                ("greth_recv: Bad packet (%d, %d, %d, 0x%08x, %d)\n",
+                 greth->stats.rx_length_errors,
+                 greth->stats.rx_frame_errors,
+                 greth->stats.rx_crc_errors, status,
+                 greth->stats.rx_packets);
+            /* print all rx descriptors */
+            for (i = 0; i < GRETH_RXBD_CNT; i++) {
+                printf("[%d]: Stat=0x%lx, Addr=0x%lx\n", i,
+                       GRETH_REGLOAD(&greth->rxbd_base[i].stat),
+                       GRETH_REGLOAD(&greth->rxbd_base[i].
+                             addr));
+            }
+        } else {
+            /* Process the incoming packet. */
+            len = status & GRETH_BD_LEN;
+            d = (char *)rxbd->addr;
+#ifdef DEBUG
+            printf
+                ("greth_recv: new packet, length: %d. data: %x %x %x %x 
%x %x %x %x\n",
+                 len, d[0], d[1], d[2], d[3], d[4], d[5], d[6],
+                 d[7]);
+#endif
+            /* flush all data cache to make sure we're not reading old 
packet data */
+            sparc_dcache_flush_all();
+
+            /* pass packet on to network subsystem */
+            NetReceive((void *)d, len);
+
+            /* bump stats counters */
+            greth->stats.rx_packets++;
+
+            /* bad is now 0 ==> will stop loop */
+        }
+
+        /* reenable descriptor to receive more packet with this 
descriptor, wrap around if needed */
+        rxbd->stat =
+            GRETH_BD_EN |
+            (((unsigned int)greth->rxbd_curr >=
+              (unsigned int)greth->rxbd_max) ? GRETH_BD_WR : 0);
+        enable = 1;
+
+        /* increase index */
+        greth->rxbd_curr =
+            ((unsigned int)greth->rxbd_curr >=
+             (unsigned int)greth->rxbd_max) ? greth->
+            rxbd_base : (greth->rxbd_curr + 1);
+
+    };
+
+    if (enable) {
+        GRETH_REGORIN(&regs->control, GRETH_RXEN);
+    }
+      done:
+    /* return positive length of packet or 0 if non recieved */
+    return len;
+}
+
+void greth_set_hwaddr(greth_priv * greth, unsigned char *mac)
+{
+    /* save new MAC address */
+    greth->dev->enetaddr[0] = greth->hwaddr[0] = mac[0];
+    greth->dev->enetaddr[1] = greth->hwaddr[1] = mac[1];
+    greth->dev->enetaddr[2] = greth->hwaddr[2] = mac[2];
+    greth->dev->enetaddr[3] = greth->hwaddr[3] = mac[3];
+    greth->dev->enetaddr[4] = greth->hwaddr[4] = mac[4];
+    greth->dev->enetaddr[5] = greth->hwaddr[5] = mac[5];
+    greth->regs->esa_msb = (mac[0] << 8) | mac[1];
+    greth->regs->esa_lsb =
+        (mac[2] << 24) | (mac[3] << 16) | (mac[4] << 8) | mac[5];
+#ifdef DEBUG
+    printf("GRETH: New MAC address: %02x:%02x:%02x:%02x:%02x:%02x\n",
+           mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+#endif
+}
+
+int greth_initialize(bd_t * bis)
+{
+    greth_priv *greth;
+    ambapp_apbdev apbdev;
+    struct eth_device *dev;
+    int i;
+    char *addr_str, *end;
+    unsigned char addr[6];
+#ifdef DEBUG
+    printf("Scanning for GRETH\n");
+#endif
+    /* Find Device & IRQ via AMBA Plug&Play information */
+    if (ambapp_apb_first(VENDOR_GAISLER, GAISLER_ETHMAC, &apbdev) != 1) {
+        return -1;    /* GRETH not found */
+    }
+
+    greth = (greth_priv *) malloc(sizeof(greth_priv));
+    dev = (struct eth_device *)malloc(sizeof(struct eth_device));
+    memset(dev, 0, sizeof(struct eth_device));
+    memset(greth, 0, sizeof(greth_priv));
+
+    greth->regs = (greth_regs *) apbdev.address;
+    greth->irq = apbdev.irq;
+#ifdef DEBUG
+    printf("Found GRETH at 0x%lx, irq %d\n", greth->regs, greth->irq);
+#endif
+    dev->priv = (void *)greth;
+    dev->iobase = (unsigned int)greth->regs;
+    dev->init = greth_init;
+    dev->halt = greth_halt;
+    dev->send = greth_send;
+    dev->recv = greth_recv;
+    greth->dev = dev;
+
+    /* Reset Core */
+    GRETH_REGSAVE(&greth->regs->control, GRETH_RESET);
+
+    /* Wait for core to finish reset cycle */
+    while (GRETH_REGLOAD(&greth->regs->control) & GRETH_RESET) ;
+
+    /* Get the phy address which assumed to have been set
+       correctly with the reset value in hardware */
+    greth->phyaddr = (GRETH_REGLOAD(&greth->regs->mdio) >> 11) & 0x1F;
+
+    /* Check if mac is gigabit capable */
+    greth->gbit_mac = (GRETH_REGLOAD(&greth->regs->control) >> 27) & 1;
+
+    /* Make descriptor string */
+    if (greth->gbit_mac) {
+        sprintf(dev->name, "GRETH 10/100/GB");
+    } else {
+        sprintf(dev->name, "GRETH 10/100");
+    }
+
+    /* initiate PHY, select speed/duplex depending on connected PHY */
+    if (greth_init_phy(greth, bis)) {
+        /* Failed to init PHY (timedout) */
+        return -1;
+    }
+
+    /* Register Device to EtherNet subsystem  */
+    eth_register(dev);
+
+    /* Get MAC address */
+    if ((addr_str = getenv("ethaddr")) != NULL) {
+        for (i = 0; i < 6; i++) {
+            addr[i] =
+                addr_str ? simple_strtoul(addr_str, &end, 16) : 0;
+            if (addr_str) {
+                addr_str = (*end) ? end + 1 : end;
+            }
+        }
+    } else {
+        /* HW Address not found in environment, Set default HW address */
+        addr[0] = GRETH_HWADDR_0;    /* MSB */
+        addr[1] = GRETH_HWADDR_1;
+        addr[2] = GRETH_HWADDR_2;
+        addr[3] = GRETH_HWADDR_3;
+        addr[4] = GRETH_HWADDR_4;
+        addr[5] = GRETH_HWADDR_5;    /* LSB */
+    }
+
+    /* set and remember MAC address */
+    greth_set_hwaddr(greth, addr);
+
+    return 1;
+}
diff --git a/drivers/net/greth.h b/drivers/net/greth.h
new file mode 100644
index 0000000..7d5fbd3
--- /dev/null
+++ b/drivers/net/greth.h
@@ -0,0 +1,97 @@
+/* Gaisler.com GRETH 10/100/1000 Ethernet MAC driver
+ *
+ * (C) Copyright 2007
+ * Daniel Hellstrom, Gaisler Research, daniel@gaisler.com
+ *
+ * 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
+ */
+
+#define GRETH_FD 0x10
+#define GRETH_RESET 0x40
+#define GRETH_MII_BUSY 0x8
+#define GRETH_MII_NVALID 0x10
+
+/* MII registers */
+#define GRETH_MII_EXTADV_1000FD 0x00000200
+#define GRETH_MII_EXTADV_1000HD 0x00000100
+#define GRETH_MII_EXTPRT_1000FD 0x00000800
+#define GRETH_MII_EXTPRT_1000HD 0x00000400
+
+#define GRETH_MII_100T4 0x00000200
+#define GRETH_MII_100TXFD 0x00000100
+#define GRETH_MII_100TXHD 0x00000080
+#define GRETH_MII_10FD 0x00000040
+#define GRETH_MII_10HD 0x00000020
+
+#define GRETH_BD_EN 0x800
+#define GRETH_BD_WR 0x1000
+#define GRETH_BD_IE 0x2000
+#define GRETH_BD_LEN 0x7FF
+
+#define GRETH_TXEN 0x1
+#define GRETH_INT_TX 0x8
+#define GRETH_TXI 0x4
+#define GRETH_TXBD_STATUS 0x0001C000
+#define GRETH_TXBD_MORE 0x20000
+#define GRETH_TXBD_IPCS 0x40000
+#define GRETH_TXBD_TCPCS 0x80000
+#define GRETH_TXBD_UDPCS 0x100000
+#define GRETH_TXBD_ERR_LC 0x10000
+#define GRETH_TXBD_ERR_UE 0x4000
+#define GRETH_TXBD_ERR_AL 0x8000
+#define GRETH_TXBD_NUM 128
+#define GRETH_TXBD_NUM_MASK (GRETH_TXBD_NUM-1)
+#define GRETH_TX_BUF_SIZE 2048
+
+#define GRETH_INT_RX         0x4
+#define GRETH_RXEN           0x2
+#define GRETH_RXI            0x8
+#define GRETH_RXBD_STATUS    0xFFFFC000
+#define GRETH_RXBD_ERR_AE    0x4000
+#define GRETH_RXBD_ERR_FT    0x8000
+#define GRETH_RXBD_ERR_CRC   0x10000
+#define GRETH_RXBD_ERR_OE    0x20000
+#define GRETH_RXBD_ERR_LE    0x40000
+#define GRETH_RXBD_IP_DEC    0x80000
+#define GRETH_RXBD_IP_CSERR  0x100000
+#define GRETH_RXBD_UDP_DEC   0x200000
+#define GRETH_RXBD_UDP_CSERR 0x400000
+#define GRETH_RXBD_TCP_DEC   0x800000
+#define GRETH_RXBD_TCP_CSERR 0x1000000
+
+#define GRETH_RXBD_NUM 128
+#define GRETH_RXBD_NUM_MASK (GRETH_RXBD_NUM-1)
+#define GRETH_RX_BUF_SIZE 2048
+
+/* Ethernet configuration registers */
+typedef struct _greth_regs {
+    volatile unsigned int control;
+    volatile unsigned int status;
+    volatile unsigned int esa_msb;
+    volatile unsigned int esa_lsb;
+    volatile unsigned int mdio;
+    volatile unsigned int tx_desc_p;
+    volatile unsigned int rx_desc_p;
+} greth_regs;
+
+/* Ethernet buffer descriptor */
+typedef struct _greth_bd {
+    volatile unsigned int stat;
+    unsigned int addr;    /* Buffer address not changed by HW */
+} greth_bd;
diff --git a/net/eth.c b/net/eth.c
index 16a6dcb..3b86f87 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -60,6 +60,7 @@ extern int npe_initialize(bd_t *);
 extern int uec_initialize(int);
 extern int bfin_EMAC_initialize(bd_t *);
 extern int atstk1000_eth_initialize(bd_t *);
+extern int greth_initialize(bd_t *);
 extern int atngw100_eth_initialize(bd_t *);
 extern int mcffec_initialize(bd_t*);
 extern int mcdmafec_initialize(bd_t*);
@@ -275,6 +276,9 @@ int eth_initialize(bd_t *bis)
 #if defined(CONFIG_ATSTK1000)
     atstk1000_eth_initialize(bis);
 #endif
+#if defined(CONFIG_GRETH)
+    greth_initialize(bis);
+#endif
 #if defined(CONFIG_ATNGW100)
     atngw100_eth_initialize(bis);
 #endif