ethoc: Move the Avionic driver

Move the Avionic driver into drivers/net/ethernet/ and make the
necessary Kconfig and Makefile changes.

CC: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

3 files changed, 1215 insertions, 0 deletions

diff --git a/drivers/net/ethernet/Kconfig b/drivers/net/ethernet/Kconfig
index a9117536f11..e89bb279085 100644
--- a/drivers/net/ethernet/Kconfig
+++ b/drivers/net/ethernet/Kconfig
@@ -103,6 +103,17 @@ source "drivers/net/ethernet/nuvoton/Kconfig"
 source "drivers/net/ethernet/nvidia/Kconfig"
 source "drivers/net/ethernet/octeon/Kconfig"
 source "drivers/net/ethernet/oki-semi/Kconfig"
+
+config ETHOC
+	tristate "OpenCores 10/100 Mbps Ethernet MAC support"
+	depends on HAS_IOMEM && HAS_DMA
+	select MII
+	select PHYLIB
+	select CRC32
+	select BITREVERSE
+	---help---
+	  Say Y here if you want to use the OpenCores 10/100 Mbps Ethernet MAC.
+
 source "drivers/net/ethernet/packetengines/Kconfig"
 source "drivers/net/ethernet/pasemi/Kconfig"
 source "drivers/net/ethernet/qlogic/Kconfig"
diff --git a/drivers/net/ethernet/Makefile b/drivers/net/ethernet/Makefile
index 51542912afd..5ef1218a6e8 100644
--- a/drivers/net/ethernet/Makefile
+++ b/drivers/net/ethernet/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_NET_VENDOR_NUVOTON) += nuvoton/
 obj-$(CONFIG_NET_VENDOR_NVIDIA) += nvidia/
 obj-$(CONFIG_OCTEON_MGMT_ETHERNET) += octeon/
 obj-$(CONFIG_NET_VENDOR_OKI) += oki-semi/
+obj-$(CONFIG_ETHOC) += ethoc.o
 obj-$(CONFIG_NET_PACKET_ENGINE) += packetengines/
 obj-$(CONFIG_NET_VENDOR_PASEMI) += pasemi/
 obj-$(CONFIG_NET_VENDOR_QLOGIC) += qlogic/
diff --git a/drivers/net/ethernet/ethoc.c b/drivers/net/ethernet/ethoc.c
new file mode 100644
index 00000000000..8abbe1d8282
--- /dev/null
+++ b/drivers/net/ethernet/ethoc.c
@@ -0,0 +1,1203 @@
+/*
+ * 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/dma-mapping.h>
+#include <linux/etherdevice.h>
+#include <linux/crc32.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mii.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <net/ethoc.h>
+
+static int buffer_size = 0x8000; /* 32 KBytes */
+module_param(buffer_size, int, 0);
+MODULE_PARM_DESC(buffer_size, "DMA buffer allocation size");
+
+/* 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
+ * @dma_alloc:	dma allocated buffer size
+ * @io_region_size:	I/O memory region size
+ * @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
+ * @vma:        pointer to array of virtual memory addresses for buffers
+ * @netdev:	pointer to network device structure
+ * @napi:	NAPI structure
+ * @msg_enable:	device state flags
+ * @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;
+	int dma_alloc;
+	resource_size_t io_region_size;
+
+	unsigned int num_tx;
+	unsigned int cur_tx;
+	unsigned int dty_tx;
+
+	unsigned int num_rx;
+	unsigned int cur_rx;
+
+	void** vma;
+
+	struct net_device *netdev;
+	struct napi_struct napi;
+	u32 msg_enable;
+
+	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 inline u32 ethoc_read(struct ethoc *dev, loff_t offset)
+{
+	return ioread32(dev->iobase + offset);
+}
+
+static inline void ethoc_write(struct ethoc *dev, loff_t offset, u32 data)
+{
+	iowrite32(data, dev->iobase + offset);
+}
+
+static inline 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 inline 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 inline 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 inline 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 inline void ethoc_ack_irq(struct ethoc *dev, u32 mask)
+{
+	ethoc_write(dev, INT_SOURCE, mask);
+}
+
+static inline 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 inline 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, unsigned long mem_start)
+{
+	struct ethoc_bd bd;
+	int i;
+	void* vma;
+
+	dev->cur_tx = 0;
+	dev->dty_tx = 0;
+	dev->cur_rx = 0;
+
+	ethoc_write(dev, TX_BD_NUM, dev->num_tx);
+
+	/* setup transmission buffers */
+	bd.addr = mem_start;
+	bd.stat = TX_BD_IRQ | TX_BD_CRC;
+	vma = dev->membase;
+
+	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;
+
+		dev->vma[i] = vma;
+		vma += 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;
+
+		dev->vma[dev->num_tx + i] = vma;
+		vma += 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");
+		netdev->stats.rx_length_errors++;
+		ret++;
+	}
+
+	if (bd->stat & RX_BD_SF) {
+		dev_err(&netdev->dev, "RX: frame too short\n");
+		netdev->stats.rx_length_errors++;
+		ret++;
+	}
+
+	if (bd->stat & RX_BD_DN) {
+		dev_err(&netdev->dev, "RX: dribble nibble\n");
+		netdev->stats.rx_frame_errors++;
+	}
+
+	if (bd->stat & RX_BD_CRC) {
+		dev_err(&netdev->dev, "RX: wrong CRC\n");
+		netdev->stats.rx_crc_errors++;
+		ret++;
+	}
+
+	if (bd->stat & RX_BD_OR) {
+		dev_err(&netdev->dev, "RX: overrun\n");
+		netdev->stats.rx_over_errors++;
+		ret++;
+	}
+
+	if (bd->stat & RX_BD_MISS)
+		netdev->stats.rx_missed_errors++;
+
+	if (bd->stat & RX_BD_LC) {
+		dev_err(&netdev->dev, "RX: late collision\n");
+		netdev->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;
+		ethoc_read_bd(priv, entry, &bd);
+		if (bd.stat & RX_BD_EMPTY) {
+			ethoc_ack_irq(priv, INT_MASK_RX);
+			/* If packet (interrupt) came in between checking
+			 * BD_EMTPY and clearing the interrupt source, then we
+			 * risk missing the packet as the RX interrupt won't
+			 * trigger right away when we reenable it; hence, check
+			 * BD_EMTPY here again to make sure there isn't such a
+			 * packet waiting for us...
+			 */
+			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;
+
+			size -= 4; /* strip the CRC */
+			skb = netdev_alloc_skb_ip_align(dev, size);
+
+			if (likely(skb)) {
+				void *src = priv->vma[entry];
+				memcpy_fromio(skb_put(skb, size), src, size);
+				skb->protocol = eth_type_trans(skb, dev);
+				dev->stats.rx_packets++;
+				dev->stats.rx_bytes += size;
+				netif_receive_skb(skb);
+			} else {
+				if (net_ratelimit())
+					dev_warn(&dev->dev, "low on memory - "
+							"packet dropped\n");
+
+				dev->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);
+		if (++priv->cur_rx == priv->num_rx)
+			priv->cur_rx = 0;
+	}
+
+	return count;
+}
+
+static void 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");
+		netdev->stats.tx_window_errors++;
+	}
+
+	if (bd->stat & TX_BD_RL) {
+		dev_err(&netdev->dev, "TX: retransmit limit\n");
+		netdev->stats.tx_aborted_errors++;
+	}
+
+	if (bd->stat & TX_BD_UR) {
+		dev_err(&netdev->dev, "TX: underrun\n");
+		netdev->stats.tx_fifo_errors++;
+	}
+
+	if (bd->stat & TX_BD_CS) {
+		dev_err(&netdev->dev, "TX: carrier sense lost\n");
+		netdev->stats.tx_carrier_errors++;
+	}
+
+	if (bd->stat & TX_BD_STATS)
+		netdev->stats.tx_errors++;
+
+	netdev->stats.collisions += (bd->stat >> 4) & 0xf;
+	netdev->stats.tx_bytes += bd->stat >> 16;
+	netdev->stats.tx_packets++;
+}
+
+static int ethoc_tx(struct net_device *dev, int limit)
+{
+	struct ethoc *priv = netdev_priv(dev);
+	int count;
+	struct ethoc_bd bd;
+
+	for (count = 0; count < limit; ++count) {
+		unsigned int entry;
+
+		entry = priv->dty_tx & (priv->num_tx-1);
+
+		ethoc_read_bd(priv, entry, &bd);
+
+		if (bd.stat & TX_BD_READY || (priv->dty_tx == priv->cur_tx)) {
+			ethoc_ack_irq(priv, INT_MASK_TX);
+			/* If interrupt came in between reading in the BD
+			 * and clearing the interrupt source, then we risk
+			 * missing the event as the TX interrupt won't trigger
+			 * right away when we reenable it; hence, check
+			 * BD_EMPTY here again to make sure there isn't such an
+			 * event pending...
+			 */
+			ethoc_read_bd(priv, entry, &bd);
+			if (bd.stat & TX_BD_READY ||
+			    (priv->dty_tx == priv->cur_tx))
+				break;
+		}
+
+		ethoc_update_tx_stats(priv, &bd);
+		priv->dty_tx++;
+	}
+
+	if ((priv->cur_tx - priv->dty_tx) <= (priv->num_tx / 2))
+		netif_wake_queue(dev);
+
+	return count;
+}
+
+static irqreturn_t ethoc_interrupt(int irq, void *dev_id)
+{
+	struct net_device *dev = dev_id;
+	struct ethoc *priv = netdev_priv(dev);
+	u32 pending;
+	u32 mask;
+
+	/* Figure out what triggered the interrupt...
+	 * The tricky bit here is that the interrupt source bits get
+	 * set in INT_SOURCE for an event regardless of whether that
+	 * event is masked or not.  Thus, in order to figure out what
+	 * triggered the interrupt, we need to remove the sources
+	 * for all events that are currently masked.  This behaviour
+	 * is not particularly well documented but reasonable...
+	 */
+	mask = ethoc_read(priv, INT_MASK);
+	pending = ethoc_read(priv, INT_SOURCE);
+	pending &= mask;
+
+	if (unlikely(pending == 0)) {
+		return IRQ_NONE;
+	}
+
+	ethoc_ack_irq(priv, pending);
+
+	/* We always handle the dropped packet interrupt */
+	if (pending & INT_MASK_BUSY) {
+		dev_err(&dev->dev, "packet dropped\n");
+		dev->stats.rx_dropped++;
+	}
+
+	/* Handle receive/transmit event by switching to polling */
+	if (pending & (INT_MASK_TX | INT_MASK_RX)) {
+		ethoc_disable_irq(priv, INT_MASK_TX | INT_MASK_RX);
+		napi_schedule(&priv->napi);
+	}
+
+	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 rx_work_done = 0;
+	int tx_work_done = 0;
+
+	rx_work_done = ethoc_rx(priv->netdev, budget);
+	tx_work_done = ethoc_tx(priv->netdev, budget);
+
+	if (rx_work_done < budget && tx_work_done < budget) {
+		napi_complete(napi);
+		ethoc_enable_irq(priv, INT_MASK_TX | INT_MASK_RX);
+	}
+
+	return rx_work_done;
+}
+
+static int ethoc_mdio_read(struct mii_bus *bus, int phy, int reg)
+{
+	struct ethoc *priv = bus->priv;
+	int i;
+
+	ethoc_write(priv, MIIADDRESS, MIIADDRESS_ADDR(phy, reg));
+	ethoc_write(priv, MIICOMMAND, MIICOMMAND_READ);
+
+	for (i=0; i < 5; i++) {
+		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;
+		}
+		usleep_range(100,200);
+	}
+
+	return -EBUSY;
+}
+
+static int ethoc_mdio_write(struct mii_bus *bus, int phy, int reg, u16 val)
+{
+	struct ethoc *priv = bus->priv;
+	int i;
+
+	ethoc_write(priv, MIIADDRESS, MIIADDRESS_ADDR(phy, reg));
+	ethoc_write(priv, MIITX_DATA, val);
+	ethoc_write(priv, MIICOMMAND, MIICOMMAND_WRITE);
+
+	for (i=0; i < 5; i++) {
+		u32 stat = ethoc_read(priv, MIISTATUS);
+		if (!(stat & MIISTATUS_BUSY)) {
+			/* reset MII command register */
+			ethoc_write(priv, MIICOMMAND, 0);
+			return 0;
+		}
+		usleep_range(100,200);
+	}
+
+	return -EBUSY;
+}
+
+static int ethoc_mdio_reset(struct mii_bus *bus)
+{
+	return 0;
+}
+
+static void ethoc_mdio_poll(struct net_device *dev)
+{
+}
+
+static int __devinit ethoc_mdio_probe(struct net_device *dev)
+{
+	struct ethoc *priv = netdev_priv(dev);
+	struct phy_device *phy;
+	int err;
+
+	if (priv->phy_id != -1) {
+		phy = priv->mdio->phy_map[priv->phy_id];
+	} else {
+		phy = phy_find_first(priv->mdio);
+	}
+
+	if (!phy) {
+		dev_err(&dev->dev, "no PHY found\n");
+		return -ENXIO;
+	}
+
+	err = phy_connect_direct(dev, phy, ethoc_mdio_poll, 0,
+			PHY_INTERFACE_MODE_GMII);
+	if (err) {
+		dev_err(&dev->dev, "could not attach to PHY\n");
+		return err;
+	}
+
+	priv->phy = phy;
+	return 0;
+}
+
+static int ethoc_open(struct net_device *dev)
+{
+	struct ethoc *priv = netdev_priv(dev);
+	int ret;
+
+	ret = request_irq(dev->irq, ethoc_interrupt, IRQF_SHARED,
+			dev->name, dev);
+	if (ret)
+		return ret;
+
+	ethoc_init_ring(priv, dev->mem_start);
+	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, ifr, 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 netdev_hw_addr *ha;
+	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 {
+		netdev_for_each_mc_addr(ha, dev) {
+			u32 crc = ether_crc(ETH_ALEN, ha->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 netdev_tx_t 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)) {
+		dev->stats.tx_errors++;
+		goto out;
+	}
+
+	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->vma[entry];
+	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);
+	}
+
+	spin_unlock_irq(&priv->lock);
+	skb_tx_timestamp(skb);
+out:
+	dev_kfree_skb(skb);
+	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_start_xmit = ethoc_start_xmit,
+};
+
+/**
+ * ethoc_probe() - initialize OpenCores ethernet MAC
+ * pdev:	platform device
+ */
+static int __devinit 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 num_bd;
+	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,
+			resource_size(res), res->name);
+	if (!mmio) {
+		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) {
+		mem = devm_request_mem_region(&pdev->dev, res->start,
+			resource_size(res), 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->dma_alloc = 0;
+	priv->io_region_size = resource_size(mmio);
+
+	priv->iobase = devm_ioremap_nocache(&pdev->dev, netdev->base_addr,
+			resource_size(mmio));
+	if (!priv->iobase) {
+		dev_err(&pdev->dev, "cannot remap I/O memory space\n");
+		ret = -ENXIO;
+		goto error;
+	}
+
+	if (netdev->mem_end) {
+		priv->membase = devm_ioremap_nocache(&pdev->dev,
+			netdev->mem_start, resource_size(mem));
+		if (!priv->membase) {
+			dev_err(&pdev->dev, "cannot remap memory space\n");
+			ret = -ENXIO;
+			goto error;
+		}
+	} else {
+		/* Allocate buffer memory */
+		priv->membase = dmam_alloc_coherent(&pdev->dev,
+			buffer_size, (void *)&netdev->mem_start,
+			GFP_KERNEL);
+		if (!priv->membase) {
+			dev_err(&pdev->dev, "cannot allocate %dB buffer\n",
+				buffer_size);
+			ret = -ENOMEM;
+			goto error;
+		}
+		netdev->mem_end = netdev->mem_start + buffer_size;
+		priv->dma_alloc = buffer_size;
+	}
+
+	/* calculate the number of TX/RX buffers, maximum 128 supported */
+	num_bd = min_t(unsigned int,
+		128, (netdev->mem_end - netdev->mem_start + 1) / ETHOC_BUFSIZ);
+	if (num_bd < 4) {
+		ret = -ENODEV;
+		goto error;
+	}
+	/* num_tx must be a power of two */
+	priv->num_tx = rounddown_pow_of_two(num_bd >> 1);
+	priv->num_rx = num_bd - priv->num_tx;
+
+	dev_dbg(&pdev->dev, "ethoc: num_tx: %d num_rx: %d\n",
+		priv->num_tx, priv->num_rx);
+
+	priv->vma = devm_kzalloc(&pdev->dev, num_bd*sizeof(void*), GFP_KERNEL);
+	if (!priv->vma) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	/* Allow the platform setup code to pass in a MAC address. */
+	if (pdev->dev.platform_data) {
+		struct ethoc_platform_data *pdata = pdev->dev.platform_data;
+		memcpy(netdev->dev_addr, pdata->hwaddr, IFHWADDRLEN);
+		priv->phy_id = pdata->phy_id;
+	} else {
+		priv->phy_id = -1;
+
+#ifdef CONFIG_OF
+		{
+		const uint8_t* mac;
+
+		mac = of_get_property(pdev->dev.of_node,
+				      "local-mac-address",
+				      NULL);
+		if (mac)
+			memcpy(netdev->dev_addr, mac, IFHWADDRLEN);
+		}
+#endif
+	}
+
+	/* 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 */
+	netif_napi_add(netdev, &priv->napi, ethoc_poll, 64);
+
+	spin_lock_init(&priv->lock);
+
+	ret = register_netdev(netdev);
+	if (ret < 0) {
+		dev_err(&netdev->dev, "failed to register interface\n");
+		goto error2;
+	}
+
+	goto out;
+
+error2:
+	netif_napi_del(&priv->napi);
+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 __devexit 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) {
+		netif_napi_del(&priv->napi);
+		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 of_device_id ethoc_match[] = {
+	{ .compatible = "opencores,ethoc", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ethoc_match);
+
+static struct platform_driver ethoc_driver = {
+	.probe   = ethoc_probe,
+	.remove  = __devexit_p(ethoc_remove),
+	.suspend = ethoc_suspend,
+	.resume  = ethoc_resume,
+	.driver  = {
+		.name = "ethoc",
+		.owner = THIS_MODULE,
+		.of_match_table = ethoc_match,
+	},
+};
+
+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");
+