net: Add support for the OpenCores 10/100 Mbps Ethernet MAC.

This patch adds a platform device driver that supports the OpenCores 10/100
Mbps Ethernet MAC.

The driver expects three resources: one IORESOURCE_MEM resource defines the
memory region for the core's memory-mapped registers while a second
IORESOURCE_MEM resource defines the network packet buffer space. The third
resource, of type IORESOURCE_IRQ, associates an interrupt with the driver.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 1121 insertions, 0 deletions

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index e5ffc1c606c1..f062b424704e 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -972,6 +972,14 @@ config ENC28J60_WRITEVERIFY
 	  Enable the verify after the buffer write useful for debugging purpose.
 	  If unsure, say N.
 
+config ETHOC
+	tristate "OpenCores 10/100 Mbps Ethernet MAC support"
+	depends on NET_ETHERNET
+	select MII
+	select PHYLIB
+	help
+	  Say Y here if you want to use the OpenCores 10/100 Mbps Ethernet MAC.
+
 config SMC911X
 	tristate "SMSC LAN911[5678] support"
 	select CRC32
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 758ecdf4c820..98409c9dd445 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -230,6 +230,7 @@ obj-$(CONFIG_PASEMI_MAC) += pasemi_mac_driver.o
 pasemi_mac_driver-objs := pasemi_mac.o pasemi_mac_ethtool.o
 obj-$(CONFIG_MLX4_CORE) += mlx4/
 obj-$(CONFIG_ENC28J60) += enc28j60.o
+obj-$(CONFIG_ETHOC) += ethoc.o
 
 obj-$(CONFIG_XTENSA_XT2000_SONIC) += xtsonic.o
 
diff --git a/drivers/net/ethoc.c b/drivers/net/ethoc.c
new file mode 100644
index 000000000000..91a9b1a33764
--- /dev/null
+++ b/drivers/net/ethoc.c
@@ -0,0 +1,1112 @@
+/*
+ * linux/drivers/net/ethoc.c
+ *
+ * Copyright (C) 2007-2008 Avionic Design Development GmbH
+ * Copyright (C) 2008-2009 Avionic Design GmbH
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Written by Thierry Reding <thierry.reding@avionic-design.de>
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/crc32.h>
+#include <linux/io.h>
+#include <linux/mii.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <net/ethoc.h>
+
+/* register offsets */
+#define	MODER		0x00
+#define	INT_SOURCE	0x04
+#define	INT_MASK	0x08
+#define	IPGT		0x0c
+#define	IPGR1		0x10
+#define	IPGR2		0x14
+#define	PACKETLEN	0x18
+#define	COLLCONF	0x1c
+#define	TX_BD_NUM	0x20
+#define	CTRLMODER	0x24
+#define	MIIMODER	0x28
+#define	MIICOMMAND	0x2c
+#define	MIIADDRESS	0x30
+#define	MIITX_DATA	0x34
+#define	MIIRX_DATA	0x38
+#define	MIISTATUS	0x3c
+#define	MAC_ADDR0	0x40
+#define	MAC_ADDR1	0x44
+#define	ETH_HASH0	0x48
+#define	ETH_HASH1	0x4c
+#define	ETH_TXCTRL	0x50
+
+/* mode register */
+#define	MODER_RXEN	(1 <<  0) /* receive enable */
+#define	MODER_TXEN	(1 <<  1) /* transmit enable */
+#define	MODER_NOPRE	(1 <<  2) /* no preamble */
+#define	MODER_BRO	(1 <<  3) /* broadcast address */
+#define	MODER_IAM	(1 <<  4) /* individual address mode */
+#define	MODER_PRO	(1 <<  5) /* promiscuous mode */
+#define	MODER_IFG	(1 <<  6) /* interframe gap for incoming frames */
+#define	MODER_LOOP	(1 <<  7) /* loopback */
+#define	MODER_NBO	(1 <<  8) /* no back-off */
+#define	MODER_EDE	(1 <<  9) /* excess defer enable */
+#define	MODER_FULLD	(1 << 10) /* full duplex */
+#define	MODER_RESET	(1 << 11) /* FIXME: reset (undocumented) */
+#define	MODER_DCRC	(1 << 12) /* delayed CRC enable */
+#define	MODER_CRC	(1 << 13) /* CRC enable */
+#define	MODER_HUGE	(1 << 14) /* huge packets enable */
+#define	MODER_PAD	(1 << 15) /* padding enabled */
+#define	MODER_RSM	(1 << 16) /* receive small packets */
+
+/* interrupt source and mask registers */
+#define	INT_MASK_TXF	(1 << 0) /* transmit frame */
+#define	INT_MASK_TXE	(1 << 1) /* transmit error */
+#define	INT_MASK_RXF	(1 << 2) /* receive frame */
+#define	INT_MASK_RXE	(1 << 3) /* receive error */
+#define	INT_MASK_BUSY	(1 << 4)
+#define	INT_MASK_TXC	(1 << 5) /* transmit control frame */
+#define	INT_MASK_RXC	(1 << 6) /* receive control frame */
+
+#define	INT_MASK_TX	(INT_MASK_TXF | INT_MASK_TXE)
+#define	INT_MASK_RX	(INT_MASK_RXF | INT_MASK_RXE)
+
+#define	INT_MASK_ALL ( \
+		INT_MASK_TXF | INT_MASK_TXE | \
+		INT_MASK_RXF | INT_MASK_RXE | \
+		INT_MASK_TXC | INT_MASK_RXC | \
+		INT_MASK_BUSY \
+	)
+
+/* packet length register */
+#define	PACKETLEN_MIN(min)		(((min) & 0xffff) << 16)
+#define	PACKETLEN_MAX(max)		(((max) & 0xffff) <<  0)
+#define	PACKETLEN_MIN_MAX(min, max)	(PACKETLEN_MIN(min) | \
+					PACKETLEN_MAX(max))
+
+/* transmit buffer number register */
+#define	TX_BD_NUM_VAL(x)	(((x) <= 0x80) ? (x) : 0x80)
+
+/* control module mode register */
+#define	CTRLMODER_PASSALL	(1 << 0) /* pass all receive frames */
+#define	CTRLMODER_RXFLOW	(1 << 1) /* receive control flow */
+#define	CTRLMODER_TXFLOW	(1 << 2) /* transmit control flow */
+
+/* MII mode register */
+#define	MIIMODER_CLKDIV(x)	((x) & 0xfe) /* needs to be an even number */
+#define	MIIMODER_NOPRE		(1 << 8) /* no preamble */
+
+/* MII command register */
+#define	MIICOMMAND_SCAN		(1 << 0) /* scan status */
+#define	MIICOMMAND_READ		(1 << 1) /* read status */
+#define	MIICOMMAND_WRITE	(1 << 2) /* write control data */
+
+/* MII address register */
+#define	MIIADDRESS_FIAD(x)		(((x) & 0x1f) << 0)
+#define	MIIADDRESS_RGAD(x)		(((x) & 0x1f) << 8)
+#define	MIIADDRESS_ADDR(phy, reg)	(MIIADDRESS_FIAD(phy) | \
+					MIIADDRESS_RGAD(reg))
+
+/* MII transmit data register */
+#define	MIITX_DATA_VAL(x)	((x) & 0xffff)
+
+/* MII receive data register */
+#define	MIIRX_DATA_VAL(x)	((x) & 0xffff)
+
+/* MII status register */
+#define	MIISTATUS_LINKFAIL	(1 << 0)
+#define	MIISTATUS_BUSY		(1 << 1)
+#define	MIISTATUS_INVALID	(1 << 2)
+
+/* TX buffer descriptor */
+#define	TX_BD_CS		(1 <<  0) /* carrier sense lost */
+#define	TX_BD_DF		(1 <<  1) /* defer indication */
+#define	TX_BD_LC		(1 <<  2) /* late collision */
+#define	TX_BD_RL		(1 <<  3) /* retransmission limit */
+#define	TX_BD_RETRY_MASK	(0x00f0)
+#define	TX_BD_RETRY(x)		(((x) & 0x00f0) >>  4)
+#define	TX_BD_UR		(1 <<  8) /* transmitter underrun */
+#define	TX_BD_CRC		(1 << 11) /* TX CRC enable */
+#define	TX_BD_PAD		(1 << 12) /* pad enable for short packets */
+#define	TX_BD_WRAP		(1 << 13)
+#define	TX_BD_IRQ		(1 << 14) /* interrupt request enable */
+#define	TX_BD_READY		(1 << 15) /* TX buffer ready */
+#define	TX_BD_LEN(x)		(((x) & 0xffff) << 16)
+#define	TX_BD_LEN_MASK		(0xffff << 16)
+
+#define	TX_BD_STATS		(TX_BD_CS | TX_BD_DF | TX_BD_LC | \
+				TX_BD_RL | TX_BD_RETRY_MASK | TX_BD_UR)
+
+/* RX buffer descriptor */
+#define	RX_BD_LC	(1 <<  0) /* late collision */
+#define	RX_BD_CRC	(1 <<  1) /* RX CRC error */
+#define	RX_BD_SF	(1 <<  2) /* short frame */
+#define	RX_BD_TL	(1 <<  3) /* too long */
+#define	RX_BD_DN	(1 <<  4) /* dribble nibble */
+#define	RX_BD_IS	(1 <<  5) /* invalid symbol */
+#define	RX_BD_OR	(1 <<  6) /* receiver overrun */
+#define	RX_BD_MISS	(1 <<  7)
+#define	RX_BD_CF	(1 <<  8) /* control frame */
+#define	RX_BD_WRAP	(1 << 13)
+#define	RX_BD_IRQ	(1 << 14) /* interrupt request enable */
+#define	RX_BD_EMPTY	(1 << 15)
+#define	RX_BD_LEN(x)	(((x) & 0xffff) << 16)
+
+#define	RX_BD_STATS	(RX_BD_LC | RX_BD_CRC | RX_BD_SF | RX_BD_TL | \
+			RX_BD_DN | RX_BD_IS | RX_BD_OR | RX_BD_MISS)
+
+#define	ETHOC_BUFSIZ		1536
+#define	ETHOC_ZLEN		64
+#define	ETHOC_BD_BASE		0x400
+#define	ETHOC_TIMEOUT		(HZ / 2)
+#define	ETHOC_MII_TIMEOUT	(1 + (HZ / 5))
+
+/**
+ * struct ethoc - driver-private device structure
+ * @iobase:	pointer to I/O memory region
+ * @membase:	pointer to buffer memory region
+ * @num_tx:	number of send buffers
+ * @cur_tx:	last send buffer written
+ * @dty_tx:	last buffer actually sent
+ * @num_rx:	number of receive buffers
+ * @cur_rx:	current receive buffer
+ * @netdev:	pointer to network device structure
+ * @napi:	NAPI structure
+ * @stats:	network device statistics
+ * @msg_enable:	device state flags
+ * @rx_lock:	receive lock
+ * @lock:	device lock
+ * @phy:	attached PHY
+ * @mdio:	MDIO bus for PHY access
+ * @phy_id:	address of attached PHY
+ */
+struct ethoc {
+	void __iomem *iobase;
+	void __iomem *membase;
+
+	unsigned int num_tx;
+	unsigned int cur_tx;
+	unsigned int dty_tx;
+
+	unsigned int num_rx;
+	unsigned int cur_rx;
+
+	struct net_device *netdev;
+	struct napi_struct napi;
+	struct net_device_stats stats;
+	u32 msg_enable;
+
+	spinlock_t rx_lock;
+	spinlock_t lock;
+
+	struct phy_device *phy;
+	struct mii_bus *mdio;
+	s8 phy_id;
+};
+
+/**
+ * struct ethoc_bd - buffer descriptor
+ * @stat:	buffer statistics
+ * @addr:	physical memory address
+ */
+struct ethoc_bd {
+	u32 stat;
+	u32 addr;
+};
+
+static u32 ethoc_read(struct ethoc *dev, loff_t offset)
+{
+	return ioread32(dev->iobase + offset);
+}
+
+static void ethoc_write(struct ethoc *dev, loff_t offset, u32 data)
+{
+	iowrite32(data, dev->iobase + offset);
+}
+
+static void ethoc_read_bd(struct ethoc *dev, int index, struct ethoc_bd *bd)
+{
+	loff_t offset = ETHOC_BD_BASE + (index * sizeof(struct ethoc_bd));
+	bd->stat = ethoc_read(dev, offset + 0);
+	bd->addr = ethoc_read(dev, offset + 4);
+}
+
+static void ethoc_write_bd(struct ethoc *dev, int index,
+		const struct ethoc_bd *bd)
+{
+	loff_t offset = ETHOC_BD_BASE + (index * sizeof(struct ethoc_bd));
+	ethoc_write(dev, offset + 0, bd->stat);
+	ethoc_write(dev, offset + 4, bd->addr);
+}
+
+static void ethoc_enable_irq(struct ethoc *dev, u32 mask)
+{
+	u32 imask = ethoc_read(dev, INT_MASK);
+	imask |= mask;
+	ethoc_write(dev, INT_MASK, imask);
+}
+
+static void ethoc_disable_irq(struct ethoc *dev, u32 mask)
+{
+	u32 imask = ethoc_read(dev, INT_MASK);
+	imask &= ~mask;
+	ethoc_write(dev, INT_MASK, imask);
+}
+
+static void ethoc_ack_irq(struct ethoc *dev, u32 mask)
+{
+	ethoc_write(dev, INT_SOURCE, mask);
+}
+
+static void ethoc_enable_rx_and_tx(struct ethoc *dev)
+{
+	u32 mode = ethoc_read(dev, MODER);
+	mode |= MODER_RXEN | MODER_TXEN;
+	ethoc_write(dev, MODER, mode);
+}
+
+static void ethoc_disable_rx_and_tx(struct ethoc *dev)
+{
+	u32 mode = ethoc_read(dev, MODER);
+	mode &= ~(MODER_RXEN | MODER_TXEN);
+	ethoc_write(dev, MODER, mode);
+}
+
+static int ethoc_init_ring(struct ethoc *dev)
+{
+	struct ethoc_bd bd;
+	int i;
+
+	dev->cur_tx = 0;
+	dev->dty_tx = 0;
+	dev->cur_rx = 0;
+
+	/* setup transmission buffers */
+	bd.addr = 0;
+	bd.stat = TX_BD_IRQ | TX_BD_CRC;
+
+	for (i = 0; i < dev->num_tx; i++) {
+		if (i == dev->num_tx - 1)
+			bd.stat |= TX_BD_WRAP;
+
+		ethoc_write_bd(dev, i, &bd);
+		bd.addr += ETHOC_BUFSIZ;
+	}
+
+	bd.addr = dev->num_tx * ETHOC_BUFSIZ;
+	bd.stat = RX_BD_EMPTY | RX_BD_IRQ;
+
+	for (i = 0; i < dev->num_rx; i++) {
+		if (i == dev->num_rx - 1)
+			bd.stat |= RX_BD_WRAP;
+
+		ethoc_write_bd(dev, dev->num_tx + i, &bd);
+		bd.addr += ETHOC_BUFSIZ;
+	}
+
+	return 0;
+}
+
+static int ethoc_reset(struct ethoc *dev)
+{
+	u32 mode;
+
+	/* TODO: reset controller? */
+
+	ethoc_disable_rx_and_tx(dev);
+
+	/* TODO: setup registers */
+
+	/* enable FCS generation and automatic padding */
+	mode = ethoc_read(dev, MODER);
+	mode |= MODER_CRC | MODER_PAD;
+	ethoc_write(dev, MODER, mode);
+
+	/* set full-duplex mode */
+	mode = ethoc_read(dev, MODER);
+	mode |= MODER_FULLD;
+	ethoc_write(dev, MODER, mode);
+	ethoc_write(dev, IPGT, 0x15);
+
+	ethoc_ack_irq(dev, INT_MASK_ALL);
+	ethoc_enable_irq(dev, INT_MASK_ALL);
+	ethoc_enable_rx_and_tx(dev);
+	return 0;
+}
+
+static unsigned int ethoc_update_rx_stats(struct ethoc *dev,
+		struct ethoc_bd *bd)
+{
+	struct net_device *netdev = dev->netdev;
+	unsigned int ret = 0;
+
+	if (bd->stat & RX_BD_TL) {
+		dev_err(&netdev->dev, "RX: frame too long\n");
+		dev->stats.rx_length_errors++;
+		ret++;
+	}
+
+	if (bd->stat & RX_BD_SF) {
+		dev_err(&netdev->dev, "RX: frame too short\n");
+		dev->stats.rx_length_errors++;
+		ret++;
+	}
+
+	if (bd->stat & RX_BD_DN) {
+		dev_err(&netdev->dev, "RX: dribble nibble\n");
+		dev->stats.rx_frame_errors++;
+	}
+
+	if (bd->stat & RX_BD_CRC) {
+		dev_err(&netdev->dev, "RX: wrong CRC\n");
+		dev->stats.rx_crc_errors++;
+		ret++;
+	}
+
+	if (bd->stat & RX_BD_OR) {
+		dev_err(&netdev->dev, "RX: overrun\n");
+		dev->stats.rx_over_errors++;
+		ret++;
+	}
+
+	if (bd->stat & RX_BD_MISS)
+		dev->stats.rx_missed_errors++;
+
+	if (bd->stat & RX_BD_LC) {
+		dev_err(&netdev->dev, "RX: late collision\n");
+		dev->stats.collisions++;
+		ret++;
+	}
+
+	return ret;
+}
+
+static int ethoc_rx(struct net_device *dev, int limit)
+{
+	struct ethoc *priv = netdev_priv(dev);
+	int count;
+
+	for (count = 0; count < limit; ++count) {
+		unsigned int entry;
+		struct ethoc_bd bd;
+
+		entry = priv->num_tx + (priv->cur_rx % priv->num_rx);
+		ethoc_read_bd(priv, entry, &bd);
+		if (bd.stat & RX_BD_EMPTY)
+			break;
+
+		if (ethoc_update_rx_stats(priv, &bd) == 0) {
+			int size = bd.stat >> 16;
+			struct sk_buff *skb = netdev_alloc_skb(dev, size);
+			if (likely(skb)) {
+				void *src = priv->membase + bd.addr;
+				memcpy_fromio(skb_put(skb, size), src, size);
+				skb->protocol = eth_type_trans(skb, dev);
+				dev->last_rx = jiffies;
+				priv->stats.rx_packets++;
+				priv->stats.rx_bytes += size;
+				netif_receive_skb(skb);
+			} else {
+				if (net_ratelimit())
+					dev_warn(&dev->dev, "low on memory - "
+							"packet dropped\n");
+
+				priv->stats.rx_dropped++;
+				break;
+			}
+		}
+
+		/* clear the buffer descriptor so it can be reused */
+		bd.stat &= ~RX_BD_STATS;
+		bd.stat |=  RX_BD_EMPTY;
+		ethoc_write_bd(priv, entry, &bd);
+		priv->cur_rx++;
+	}
+
+	return count;
+}
+
+static int ethoc_update_tx_stats(struct ethoc *dev, struct ethoc_bd *bd)
+{
+	struct net_device *netdev = dev->netdev;
+
+	if (bd->stat & TX_BD_LC) {
+		dev_err(&netdev->dev, "TX: late collision\n");
+		dev->stats.tx_window_errors++;
+	}
+
+	if (bd->stat & TX_BD_RL) {
+		dev_err(&netdev->dev, "TX: retransmit limit\n");
+		dev->stats.tx_aborted_errors++;
+	}
+
+	if (bd->stat & TX_BD_UR) {
+		dev_err(&netdev->dev, "TX: underrun\n");
+		dev->stats.tx_fifo_errors++;
+	}
+
+	if (bd->stat & TX_BD_CS) {
+		dev_err(&netdev->dev, "TX: carrier sense lost\n");
+		dev->stats.tx_carrier_errors++;
+	}
+
+	if (bd->stat & TX_BD_STATS)
+		dev->stats.tx_errors++;
+
+	dev->stats.collisions += (bd->stat >> 4) & 0xf;
+	dev->stats.tx_bytes += bd->stat >> 16;
+	dev->stats.tx_packets++;
+	return 0;
+}
+
+static void ethoc_tx(struct net_device *dev)
+{
+	struct ethoc *priv = netdev_priv(dev);
+
+	spin_lock(&priv->lock);
+
+	while (priv->dty_tx != priv->cur_tx) {
+		unsigned int entry = priv->dty_tx % priv->num_tx;
+		struct ethoc_bd bd;
+
+		ethoc_read_bd(priv, entry, &bd);
+		if (bd.stat & TX_BD_READY)
+			break;
+
+		entry = (++priv->dty_tx) % priv->num_tx;
+		(void)ethoc_update_tx_stats(priv, &bd);
+	}
+
+	if ((priv->cur_tx - priv->dty_tx) <= (priv->num_tx / 2))
+		netif_wake_queue(dev);
+
+	ethoc_ack_irq(priv, INT_MASK_TX);
+	spin_unlock(&priv->lock);
+}
+
+static irqreturn_t ethoc_interrupt(int irq, void *dev_id)
+{
+	struct net_device *dev = (struct net_device *)dev_id;
+	struct ethoc *priv = netdev_priv(dev);
+	u32 pending;
+
+	ethoc_disable_irq(priv, INT_MASK_ALL);
+	pending = ethoc_read(priv, INT_SOURCE);
+	if (unlikely(pending == 0)) {
+		ethoc_enable_irq(priv, INT_MASK_ALL);
+		return IRQ_NONE;
+	}
+
+	ethoc_ack_irq(priv, INT_MASK_ALL);
+
+	if (pending & INT_MASK_BUSY) {
+		dev_err(&dev->dev, "packet dropped\n");
+		priv->stats.rx_dropped++;
+	}
+
+	if (pending & INT_MASK_RX) {
+		if (napi_schedule_prep(&priv->napi))
+			__napi_schedule(&priv->napi);
+	} else {
+		ethoc_enable_irq(priv, INT_MASK_RX);
+	}
+
+	if (pending & INT_MASK_TX)
+		ethoc_tx(dev);
+
+	ethoc_enable_irq(priv, INT_MASK_ALL & ~INT_MASK_RX);
+	return IRQ_HANDLED;
+}
+
+static int ethoc_get_mac_address(struct net_device *dev, void *addr)
+{
+	struct ethoc *priv = netdev_priv(dev);
+	u8 *mac = (u8 *)addr;
+	u32 reg;
+
+	reg = ethoc_read(priv, MAC_ADDR0);
+	mac[2] = (reg >> 24) & 0xff;
+	mac[3] = (reg >> 16) & 0xff;
+	mac[4] = (reg >>  8) & 0xff;
+	mac[5] = (reg >>  0) & 0xff;
+
+	reg = ethoc_read(priv, MAC_ADDR1);
+	mac[0] = (reg >>  8) & 0xff;
+	mac[1] = (reg >>  0) & 0xff;
+
+	return 0;
+}
+
+static int ethoc_poll(struct napi_struct *napi, int budget)
+{
+	struct ethoc *priv = container_of(napi, struct ethoc, napi);
+	int work_done = 0;
+
+	work_done = ethoc_rx(priv->netdev, budget);
+	if (work_done < budget) {
+		ethoc_enable_irq(priv, INT_MASK_RX);
+		napi_complete(napi);
+	}
+
+	return work_done;
+}
+
+static int ethoc_mdio_read(struct mii_bus *bus, int phy, int reg)
+{
+	unsigned long timeout = jiffies + ETHOC_MII_TIMEOUT;
+	struct ethoc *priv = bus->priv;
+
+	ethoc_write(priv, MIIADDRESS, MIIADDRESS_ADDR(phy, reg));
+	ethoc_write(priv, MIICOMMAND, MIICOMMAND_READ);
+
+	while (time_before(jiffies, timeout)) {
+		u32 status = ethoc_read(priv, MIISTATUS);
+		if (!(status & MIISTATUS_BUSY)) {
+			u32 data = ethoc_read(priv, MIIRX_DATA);
+			/* reset MII command register */
+			ethoc_write(priv, MIICOMMAND, 0);
+			return data;
+		}
+
+		schedule();
+	}
+
+	return -EBUSY;
+}
+
+static int ethoc_mdio_write(struct mii_bus *bus, int phy, int reg, u16 val)
+{
+	unsigned long timeout = jiffies + ETHOC_MII_TIMEOUT;
+	struct ethoc *priv = bus->priv;
+
+	ethoc_write(priv, MIIADDRESS, MIIADDRESS_ADDR(phy, reg));
+	ethoc_write(priv, MIITX_DATA, val);
+	ethoc_write(priv, MIICOMMAND, MIICOMMAND_WRITE);
+
+	while (time_before(jiffies, timeout)) {
+		u32 stat = ethoc_read(priv, MIISTATUS);
+		if (!(stat & MIISTATUS_BUSY))
+			return 0;
+
+		schedule();
+	}
+
+	return -EBUSY;
+}
+
+static int ethoc_mdio_reset(struct mii_bus *bus)
+{
+	return 0;
+}
+
+static void ethoc_mdio_poll(struct net_device *dev)
+{
+}
+
+static int ethoc_mdio_probe(struct net_device *dev)
+{
+	struct ethoc *priv = netdev_priv(dev);
+	struct phy_device *phy;
+	int i;
+
+	for (i = 0; i < PHY_MAX_ADDR; i++) {
+		phy = priv->mdio->phy_map[i];
+		if (phy) {
+			if (priv->phy_id != -1) {
+				/* attach to specified PHY */
+				if (priv->phy_id == phy->addr)
+					break;
+			} else {
+				/* autoselect PHY if none was specified */
+				if (phy->addr != 0)
+					break;
+			}
+		}
+	}
+
+	if (!phy) {
+		dev_err(&dev->dev, "no PHY found\n");
+		return -ENXIO;
+	}
+
+	phy = phy_connect(dev, dev_name(&phy->dev), &ethoc_mdio_poll, 0,
+			PHY_INTERFACE_MODE_GMII);
+	if (IS_ERR(phy)) {
+		dev_err(&dev->dev, "could not attach to PHY\n");
+		return PTR_ERR(phy);
+	}
+
+	priv->phy = phy;
+	return 0;
+}
+
+static int ethoc_open(struct net_device *dev)
+{
+	struct ethoc *priv = netdev_priv(dev);
+	unsigned int min_tx = 2;
+	unsigned int num_bd;
+	int ret;
+
+	ret = request_irq(dev->irq, ethoc_interrupt, IRQF_SHARED,
+			dev->name, dev);
+	if (ret)
+		return ret;
+
+	/* calculate the number of TX/RX buffers */
+	num_bd = (dev->mem_end - dev->mem_start + 1) / ETHOC_BUFSIZ;
+	priv->num_tx = min(min_tx, num_bd / 4);
+	priv->num_rx = num_bd - priv->num_tx;
+	ethoc_write(priv, TX_BD_NUM, priv->num_tx);
+
+	ethoc_init_ring(priv);
+	ethoc_reset(priv);
+
+	if (netif_queue_stopped(dev)) {
+		dev_dbg(&dev->dev, " resuming queue\n");
+		netif_wake_queue(dev);
+	} else {
+		dev_dbg(&dev->dev, " starting queue\n");
+		netif_start_queue(dev);
+	}
+
+	phy_start(priv->phy);
+	napi_enable(&priv->napi);
+
+	if (netif_msg_ifup(priv)) {
+		dev_info(&dev->dev, "I/O: %08lx Memory: %08lx-%08lx\n",
+				dev->base_addr, dev->mem_start, dev->mem_end);
+	}
+
+	return 0;
+}
+
+static int ethoc_stop(struct net_device *dev)
+{
+	struct ethoc *priv = netdev_priv(dev);
+
+	napi_disable(&priv->napi);
+
+	if (priv->phy)
+		phy_stop(priv->phy);
+
+	ethoc_disable_rx_and_tx(priv);
+	free_irq(dev->irq, dev);
+
+	if (!netif_queue_stopped(dev))
+		netif_stop_queue(dev);
+
+	return 0;
+}
+
+static int ethoc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+	struct ethoc *priv = netdev_priv(dev);
+	struct mii_ioctl_data *mdio = if_mii(ifr);
+	struct phy_device *phy = NULL;
+
+	if (!netif_running(dev))
+		return -EINVAL;
+
+	if (cmd != SIOCGMIIPHY) {
+		if (mdio->phy_id >= PHY_MAX_ADDR)
+			return -ERANGE;
+
+		phy = priv->mdio->phy_map[mdio->phy_id];
+		if (!phy)
+			return -ENODEV;
+	} else {
+		phy = priv->phy;
+	}
+
+	return phy_mii_ioctl(phy, mdio, cmd);
+}
+
+static int ethoc_config(struct net_device *dev, struct ifmap *map)
+{
+	return -ENOSYS;
+}
+
+static int ethoc_set_mac_address(struct net_device *dev, void *addr)
+{
+	struct ethoc *priv = netdev_priv(dev);
+	u8 *mac = (u8 *)addr;
+
+	ethoc_write(priv, MAC_ADDR0, (mac[2] << 24) | (mac[3] << 16) |
+				     (mac[4] <<  8) | (mac[5] <<  0));
+	ethoc_write(priv, MAC_ADDR1, (mac[0] <<  8) | (mac[1] <<  0));
+
+	return 0;
+}
+
+static void ethoc_set_multicast_list(struct net_device *dev)
+{
+	struct ethoc *priv = netdev_priv(dev);
+	u32 mode = ethoc_read(priv, MODER);
+	struct dev_mc_list *mc = NULL;
+	u32 hash[2] = { 0, 0 };
+
+	/* set loopback mode if requested */
+	if (dev->flags & IFF_LOOPBACK)
+		mode |=  MODER_LOOP;
+	else
+		mode &= ~MODER_LOOP;
+
+	/* receive broadcast frames if requested */
+	if (dev->flags & IFF_BROADCAST)
+		mode &= ~MODER_BRO;
+	else
+		mode |=  MODER_BRO;
+
+	/* enable promiscuous mode if requested */
+	if (dev->flags & IFF_PROMISC)
+		mode |=  MODER_PRO;
+	else
+		mode &= ~MODER_PRO;
+
+	ethoc_write(priv, MODER, mode);
+
+	/* receive multicast frames */
+	if (dev->flags & IFF_ALLMULTI) {
+		hash[0] = 0xffffffff;
+		hash[1] = 0xffffffff;
+	} else {
+		for (mc = dev->mc_list; mc; mc = mc->next) {
+			u32 crc = ether_crc(mc->dmi_addrlen, mc->dmi_addr);
+			int bit = (crc >> 26) & 0x3f;
+			hash[bit >> 5] |= 1 << (bit & 0x1f);
+		}
+	}
+
+	ethoc_write(priv, ETH_HASH0, hash[0]);
+	ethoc_write(priv, ETH_HASH1, hash[1]);
+}
+
+static int ethoc_change_mtu(struct net_device *dev, int new_mtu)
+{
+	return -ENOSYS;
+}
+
+static void ethoc_tx_timeout(struct net_device *dev)
+{
+	struct ethoc *priv = netdev_priv(dev);
+	u32 pending = ethoc_read(priv, INT_SOURCE);
+	if (likely(pending))
+		ethoc_interrupt(dev->irq, dev);
+}
+
+static struct net_device_stats *ethoc_stats(struct net_device *dev)
+{
+	struct ethoc *priv = netdev_priv(dev);
+	return &priv->stats;
+}
+
+static int ethoc_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct ethoc *priv = netdev_priv(dev);
+	struct ethoc_bd bd;
+	unsigned int entry;
+	void *dest;
+
+	if (unlikely(skb->len > ETHOC_BUFSIZ)) {
+		priv->stats.tx_errors++;
+		return -EMSGSIZE;
+	}
+
+	entry = priv->cur_tx % priv->num_tx;
+	spin_lock_irq(&priv->lock);
+	priv->cur_tx++;
+
+	ethoc_read_bd(priv, entry, &bd);
+	if (unlikely(skb->len < ETHOC_ZLEN))
+		bd.stat |=  TX_BD_PAD;
+	else
+		bd.stat &= ~TX_BD_PAD;
+
+	dest = priv->membase + bd.addr;
+	memcpy_toio(dest, skb->data, skb->len);
+
+	bd.stat &= ~(TX_BD_STATS | TX_BD_LEN_MASK);
+	bd.stat |= TX_BD_LEN(skb->len);
+	ethoc_write_bd(priv, entry, &bd);
+
+	bd.stat |= TX_BD_READY;
+	ethoc_write_bd(priv, entry, &bd);
+
+	if (priv->cur_tx == (priv->dty_tx + priv->num_tx)) {
+		dev_dbg(&dev->dev, "stopping queue\n");
+		netif_stop_queue(dev);
+	}
+
+	dev->trans_start = jiffies;
+	dev_kfree_skb(skb);
+
+	spin_unlock_irq(&priv->lock);
+	return NETDEV_TX_OK;
+}
+
+static const struct net_device_ops ethoc_netdev_ops = {
+	.ndo_open = ethoc_open,
+	.ndo_stop = ethoc_stop,
+	.ndo_do_ioctl = ethoc_ioctl,
+	.ndo_set_config = ethoc_config,
+	.ndo_set_mac_address = ethoc_set_mac_address,
+	.ndo_set_multicast_list = ethoc_set_multicast_list,
+	.ndo_change_mtu = ethoc_change_mtu,
+	.ndo_tx_timeout = ethoc_tx_timeout,
+	.ndo_get_stats = ethoc_stats,
+	.ndo_start_xmit = ethoc_start_xmit,
+};
+
+/**
+ * ethoc_probe() - initialize OpenCores ethernet MAC
+ * pdev:	platform device
+ */
+static int ethoc_probe(struct platform_device *pdev)
+{
+	struct net_device *netdev = NULL;
+	struct resource *res = NULL;
+	struct resource *mmio = NULL;
+	struct resource *mem = NULL;
+	struct ethoc *priv = NULL;
+	unsigned int phy;
+	int ret = 0;
+
+	/* allocate networking device */
+	netdev = alloc_etherdev(sizeof(struct ethoc));
+	if (!netdev) {
+		dev_err(&pdev->dev, "cannot allocate network device\n");
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	SET_NETDEV_DEV(netdev, &pdev->dev);
+	platform_set_drvdata(pdev, netdev);
+
+	/* obtain I/O memory space */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "cannot obtain I/O memory space\n");
+		ret = -ENXIO;
+		goto free;
+	}
+
+	mmio = devm_request_mem_region(&pdev->dev, res->start,
+			res->end - res->start + 1, res->name);
+	if (!res) {
+		dev_err(&pdev->dev, "cannot request I/O memory space\n");
+		ret = -ENXIO;
+		goto free;
+	}
+
+	netdev->base_addr = mmio->start;
+
+	/* obtain buffer memory space */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res) {
+		dev_err(&pdev->dev, "cannot obtain memory space\n");
+		ret = -ENXIO;
+		goto free;
+	}
+
+	mem = devm_request_mem_region(&pdev->dev, res->start,
+			res->end - res->start + 1, res->name);
+	if (!mem) {
+		dev_err(&pdev->dev, "cannot request memory space\n");
+		ret = -ENXIO;
+		goto free;
+	}
+
+	netdev->mem_start = mem->start;
+	netdev->mem_end   = mem->end;
+
+	/* obtain device IRQ number */
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "cannot obtain IRQ\n");
+		ret = -ENXIO;
+		goto free;
+	}
+
+	netdev->irq = res->start;
+
+	/* setup driver-private data */
+	priv = netdev_priv(netdev);
+	priv->netdev = netdev;
+
+	priv->iobase = devm_ioremap_nocache(&pdev->dev, netdev->base_addr,
+			mmio->end - mmio->start + 1);
+	if (!priv->iobase) {
+		dev_err(&pdev->dev, "cannot remap I/O memory space\n");
+		ret = -ENXIO;
+		goto error;
+	}
+
+	priv->membase = devm_ioremap_nocache(&pdev->dev, netdev->mem_start,
+			mem->end - mem->start + 1);
+	if (!priv->membase) {
+		dev_err(&pdev->dev, "cannot remap memory space\n");
+		ret = -ENXIO;
+		goto error;
+	}
+
+	/* Allow the platform setup code to pass in a MAC address. */
+	if (pdev->dev.platform_data) {
+		struct ethoc_platform_data *pdata =
+			(struct ethoc_platform_data *)pdev->dev.platform_data;
+		memcpy(netdev->dev_addr, pdata->hwaddr, IFHWADDRLEN);
+		priv->phy_id = pdata->phy_id;
+	}
+
+	/* Check that the given MAC address is valid. If it isn't, read the
+	 * current MAC from the controller. */
+	if (!is_valid_ether_addr(netdev->dev_addr))
+		ethoc_get_mac_address(netdev, netdev->dev_addr);
+
+	/* Check the MAC again for validity, if it still isn't choose and
+	 * program a random one. */
+	if (!is_valid_ether_addr(netdev->dev_addr))
+		random_ether_addr(netdev->dev_addr);
+
+	ethoc_set_mac_address(netdev, netdev->dev_addr);
+
+	/* register MII bus */
+	priv->mdio = mdiobus_alloc();
+	if (!priv->mdio) {
+		ret = -ENOMEM;
+		goto free;
+	}
+
+	priv->mdio->name = "ethoc-mdio";
+	snprintf(priv->mdio->id, MII_BUS_ID_SIZE, "%s-%d",
+			priv->mdio->name, pdev->id);
+	priv->mdio->read = ethoc_mdio_read;
+	priv->mdio->write = ethoc_mdio_write;
+	priv->mdio->reset = ethoc_mdio_reset;
+	priv->mdio->priv = priv;
+
+	priv->mdio->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
+	if (!priv->mdio->irq) {
+		ret = -ENOMEM;
+		goto free_mdio;
+	}
+
+	for (phy = 0; phy < PHY_MAX_ADDR; phy++)
+		priv->mdio->irq[phy] = PHY_POLL;
+
+	ret = mdiobus_register(priv->mdio);
+	if (ret) {
+		dev_err(&netdev->dev, "failed to register MDIO bus\n");
+		goto free_mdio;
+	}
+
+	ret = ethoc_mdio_probe(netdev);
+	if (ret) {
+		dev_err(&netdev->dev, "failed to probe MDIO bus\n");
+		goto error;
+	}
+
+	ether_setup(netdev);
+
+	/* setup the net_device structure */
+	netdev->netdev_ops = &ethoc_netdev_ops;
+	netdev->watchdog_timeo = ETHOC_TIMEOUT;
+	netdev->features |= 0;
+
+	/* setup NAPI */
+	memset(&priv->napi, 0, sizeof(priv->napi));
+	netif_napi_add(netdev, &priv->napi, ethoc_poll, 64);
+
+	spin_lock_init(&priv->rx_lock);
+	spin_lock_init(&priv->lock);
+
+	ret = register_netdev(netdev);
+	if (ret < 0) {
+		dev_err(&netdev->dev, "failed to register interface\n");
+		goto error;
+	}
+
+	goto out;
+
+error:
+	mdiobus_unregister(priv->mdio);
+free_mdio:
+	kfree(priv->mdio->irq);
+	mdiobus_free(priv->mdio);
+free:
+	free_netdev(netdev);
+out:
+	return ret;
+}
+
+/**
+ * ethoc_remove() - shutdown OpenCores ethernet MAC
+ * @pdev:	platform device
+ */
+static int ethoc_remove(struct platform_device *pdev)
+{
+	struct net_device *netdev = platform_get_drvdata(pdev);
+	struct ethoc *priv = netdev_priv(netdev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	if (netdev) {
+		phy_disconnect(priv->phy);
+		priv->phy = NULL;
+
+		if (priv->mdio) {
+			mdiobus_unregister(priv->mdio);
+			kfree(priv->mdio->irq);
+			mdiobus_free(priv->mdio);
+		}
+
+		unregister_netdev(netdev);
+		free_netdev(netdev);
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int ethoc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	return -ENOSYS;
+}
+
+static int ethoc_resume(struct platform_device *pdev)
+{
+	return -ENOSYS;
+}
+#else
+# define ethoc_suspend NULL
+# define ethoc_resume  NULL
+#endif
+
+static struct platform_driver ethoc_driver = {
+	.probe   = ethoc_probe,
+	.remove  = ethoc_remove,
+	.suspend = ethoc_suspend,
+	.resume  = ethoc_resume,
+	.driver  = {
+		.name = "ethoc",
+	},
+};
+
+static int __init ethoc_init(void)
+{
+	return platform_driver_register(&ethoc_driver);
+}
+
+static void __exit ethoc_exit(void)
+{
+	platform_driver_unregister(&ethoc_driver);
+}
+
+module_init(ethoc_init);
+module_exit(ethoc_exit);
+
+MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
+MODULE_DESCRIPTION("OpenCores Ethernet MAC driver");
+MODULE_LICENSE("GPL v2");
+