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>

---
 drivers/net/Kconfig  |    7 +
 drivers/net/Makefile |    1 +
 drivers/net/ethoc.c  | 1153 ++++++++++++++++++++++++++++++++++++++++++++++++++
 include/net/ethoc.h  |   22 +
 4 files changed, 1183 insertions(+), 0 deletions(-)

Hi Thierry,

Le Tuesday 24 March 2009 11:18:43 Thierry Reding, vous avez écrit :
> 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.

I am glad someone updated and submitted this driver, excellent work !. Few 
comments below.

> + * Copyright (C) 2007-2008 Avionic Design Development GmbH
> + * Copyright (C) 2008-2009 Avionic Design GmbH

I think there are some other authors like Simon Srot and Tensilica, unless you 
did wrote this completely from scratch and did not look at the uClincu 
open_eth driver at all ?

[snip]

> +/* function prototypes */
> +static int ethoc_set_mac_address(struct net_device *dev, void *addr);
> +static int ethoc_get_mac_address(struct net_device *dev, void *addr);
> +static int ethoc_rx(struct net_device *dev, int budget);
> +static void ethoc_tx(struct net_device *dev);
> +static irqreturn_t ethoc_interrupt(int irq, void *dev_id);

Why do you need these declarations ? Are not your functions properly ordered 
already ?

> +/**
> + * 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;
> +	}

That's what uClinux driver calls SRAM right ?

[snip]

> +	/* setup the net_device structure */
> +	netdev->open = ethoc_open;
> +	netdev->stop = ethoc_stop;
> +	netdev->do_ioctl = ethoc_ioctl;
> +	netdev->set_config = ethoc_config;
> +	netdev->set_mac_address = ethoc_set_mac_address;
> +	netdev->set_multicast_list = ethoc_set_multicast_list;
> +	netdev->change_mtu = ethoc_change_mtu;
> +	netdev->tx_timeout = ethoc_tx_timeout;
> +	netdev->get_stats = ethoc_stats;
> +	netdev->hard_start_xmit = ethoc_start_xmit;
> +	netdev->watchdog_timeo = ETHOC_TIMEOUT;
> +	netdev->features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_HIGHDMA;

Please use netdev_ops.

[snip]

> +#ifndef LINUX_NET_ETHOC_H
> +#define LINUX_NET_ETHOC_H 1
> +
> +struct ethoc_platform_data {
> +	u8 hwaddr[IFHWADDRLEN];
> +	s8 phy_id;

What about allowing platform configuration of the RX/TX buffers size and 
number of them ?

Otherwise

Acked-by: Florian Fainelli <florian@openwrt.org>

On 083, 03 24, 2009 at 11:18:43AM +0100, Thierry Reding wrote:
> 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>
> 
> ---
>  drivers/net/Kconfig  |    7 +
>  drivers/net/Makefile |    1 +
>  drivers/net/ethoc.c  | 1153 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  include/net/ethoc.h  |   22 +
>  4 files changed, 1183 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
> index 62d732a..fab21ca 100644
> --- a/drivers/net/Kconfig
> +++ b/drivers/net/Kconfig
> @@ -963,6 +963,13 @@ 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 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 471baaf..ac3d6f7 100644
> --- a/drivers/net/Makefile
> +++ b/drivers/net/Makefile
> @@ -229,6 +229,7 @@ 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 0000000..05e6bb3
> --- /dev/null
> +++ b/drivers/net/ethoc.c
> @@ -0,0 +1,1153 @@
> +/*
> + * 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/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)
> +
> +/**
> + * struct ethoc -
> + */
> +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;
> +
> +#ifdef CONFIG_MII
> +	struct phy_device *phy;
> +	struct mii_bus *mdio;
> +	s8 phy_id;
> +#endif
> +};
> +
> +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_copy_to_io(void __iomem *dest, struct sk_buff *src)
> +{
> +	size_t size = (src->len & 0x3) ? (src->len & ~0x3) + 4 : src->len;
> +	u8 buffer[ETHOC_BUFSIZ];

Using 1536 bytes of stack is not very nice.

> +	memset(buffer, 0, size);
> +	skb_copy_and_csum_dev(src, buffer);
> +	memcpy(dest, buffer, size);
> +}
> +
> +static void ethoc_copy_from_io(struct sk_buff *dest, const void __iomem *src,
> +		size_t count)
> +{
> +	ssize_t size = (count & 0x3) ? (count & ~0x3) + 4 : count;
> +	u8 buffer[ETHOC_BUFSIZ];

Same here.

> +	memcpy(buffer, src, size);
> +	memcpy(skb_put(dest, count), buffer, count);
> +}
> +
> +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;
> +}
> +
> +/* function prototypes */
> +static int ethoc_set_mac_address(struct net_device *dev, void *addr);
> +static int ethoc_get_mac_address(struct net_device *dev, void *addr);
> +static int ethoc_rx(struct net_device *dev, int budget);
> +static void ethoc_tx(struct net_device *dev);
> +static irqreturn_t ethoc_interrupt(int irq, void *dev_id);
> +
> +#ifdef CONFIG_MII
> +#define	MII_TIMEOUT	(1 + (HZ / 5))
> +
> +static int ethoc_mdio_read(struct mii_bus *bus, int phy, int reg)
> +{
> +	unsigned long timeout = jiffies + 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 + 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, phy->dev.bus_id, &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;
> +}
> +#endif /* CONFIG_MII */
> +
> +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);
> +	}
> +
> +#ifdef CONFIG_MII
> +	phy_start(priv->phy);
> +#endif
> +	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);
> +#ifdef CONFIG_MII
> +	if (priv->phy)
> +		phy_stop(priv->phy);
> +#endif
> +
> +	ethoc_disable_rx_and_tx(priv);
> +	free_irq(dev->irq, dev);
> +
> +	if (!netif_queue_stopped(dev))
> +		netif_stop_queue(dev);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_MII
> +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);
> +}
> +#else
> +static int ethoc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
> +{
> +	return -ENOSYS;
> +}
> +#endif
> +
> +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 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_get_multicast_bit(struct dev_mc_list *mc)
> +{
> +	u32 crc = 0xffffffff;
> +	u32 carry;
> +	int i, j;
> +
> +	for (i = 0; i < mc->dmi_addrlen; i++) {
> +		u8 byte = mc->dmi_addr[i];
> +
> +		for (j = 0; j < 8; j++) {
> +			carry = ((crc & 0x80000000) ? 1 : 0) ^ (byte & 0x1);
> +			byte >>= 1;
> +			crc <<= 1;
> +
> +			if (carry)
> +				crc = (crc ^ 0x04c11db6) | carry;
> +		}
> +	}
> +
> +	return (crc >> 26) & 0x3f;
> +}
> +
> +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) {
> +			int bit = ethoc_get_multicast_bit(mc);
> +			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_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);
> +		netif_rx_complete(napi);
> +	}
> +
> +	return work_done;
> +}
> +
> +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;
> +	ethoc_copy_to_io(dest, skb);
> +
> +	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 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;
> +				ethoc_copy_from_io(skb, 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 (netif_rx_schedule_prep(&priv->napi))
> +			__netif_rx_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;
> +}
> +
> +/**
> + * 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);
> +
> +#ifdef CONFIG_MII
> +	/* 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;
> +	}
> +#endif /* CONFIG_MII */
> +
> +	ether_setup(netdev);
> +
> +	/* setup the net_device structure */
> +	netdev->open = ethoc_open;
> +	netdev->stop = ethoc_stop;
> +	netdev->do_ioctl = ethoc_ioctl;
> +	netdev->set_config = ethoc_config;
> +	netdev->set_mac_address = ethoc_set_mac_address;
> +	netdev->set_multicast_list = ethoc_set_multicast_list;
> +	netdev->change_mtu = ethoc_change_mtu;
> +	netdev->tx_timeout = ethoc_tx_timeout;
> +	netdev->get_stats = ethoc_stats;
> +	netdev->hard_start_xmit = ethoc_start_xmit;
> +	netdev->watchdog_timeo = ETHOC_TIMEOUT;
> +	netdev->features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_HIGHDMA;
> +
> +	/* 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) {
> +#ifdef CONFIG_MII
> +		phy_disconnect(priv->phy);
> +		priv->phy = NULL;
> +
> +		if (priv->mdio) {
> +			mdiobus_unregister(priv->mdio);
> +			kfree(priv->mdio->irq);
> +			mdiobus_free(priv->mdio);
> +		}
> +#endif
> +
> +		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");
> +
> diff --git a/include/net/ethoc.h b/include/net/ethoc.h
> new file mode 100644
> index 0000000..96f3789
> --- /dev/null
> +++ b/include/net/ethoc.h
> @@ -0,0 +1,22 @@
> +/*
> + * linux/include/net/ethoc.h
> + *
> + * 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>
> + */
> +
> +#ifndef LINUX_NET_ETHOC_H
> +#define LINUX_NET_ETHOC_H 1
> +
> +struct ethoc_platform_data {
> +	u8 hwaddr[IFHWADDRLEN];
> +	s8 phy_id;
> +};
> +
> +#endif /* !LINUX_NET_ETHOC_H */
> +
> -- 
> tg: (8e0ee43..) adx/net/ethoc (depends on: adx/master)
> --
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On 083, 03 24, 2009 at 11:18:43AM +0100, Thierry Reding wrote:
> 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>
> 
> ---
>  drivers/net/Kconfig  |    7 +
>  drivers/net/Makefile |    1 +
>  drivers/net/ethoc.c  | 1153 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  include/net/ethoc.h  |   22 +
>  4 files changed, 1183 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
> index 62d732a..fab21ca 100644
> --- a/drivers/net/Kconfig
> +++ b/drivers/net/Kconfig
> @@ -963,6 +963,13 @@ 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 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 471baaf..ac3d6f7 100644
> --- a/drivers/net/Makefile
> +++ b/drivers/net/Makefile
> @@ -229,6 +229,7 @@ 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 0000000..05e6bb3
> --- /dev/null
> +++ b/drivers/net/ethoc.c
> @@ -0,0 +1,1153 @@
> +/*
> + * 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/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)
> +
> +/**
> + * struct ethoc -
> + */
> +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;
> +
> +#ifdef CONFIG_MII
> +	struct phy_device *phy;
> +	struct mii_bus *mdio;
> +	s8 phy_id;
> +#endif
> +};
> +
> +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_copy_to_io(void __iomem *dest, struct sk_buff *src)
> +{
> +	size_t size = (src->len & 0x3) ? (src->len & ~0x3) + 4 : src->len;
> +	u8 buffer[ETHOC_BUFSIZ];
> +
> +	memset(buffer, 0, size);
> +	skb_copy_and_csum_dev(src, buffer);
> +	memcpy(dest, buffer, size);
> +}
> +
> +static void ethoc_copy_from_io(struct sk_buff *dest, const void __iomem *src,
> +		size_t count)
> +{
> +	ssize_t size = (count & 0x3) ? (count & ~0x3) + 4 : count;
> +	u8 buffer[ETHOC_BUFSIZ];
> +
> +	memcpy(buffer, src, size);
> +	memcpy(skb_put(dest, count), buffer, count);
> +}
> +
> +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;
> +}
> +
> +/* function prototypes */
> +static int ethoc_set_mac_address(struct net_device *dev, void *addr);
> +static int ethoc_get_mac_address(struct net_device *dev, void *addr);
> +static int ethoc_rx(struct net_device *dev, int budget);
> +static void ethoc_tx(struct net_device *dev);
> +static irqreturn_t ethoc_interrupt(int irq, void *dev_id);
> +
> +#ifdef CONFIG_MII
> +#define	MII_TIMEOUT	(1 + (HZ / 5))
> +
> +static int ethoc_mdio_read(struct mii_bus *bus, int phy, int reg)
> +{
> +	unsigned long timeout = jiffies + 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 + 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, phy->dev.bus_id, &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;
> +}
> +#endif /* CONFIG_MII */
> +
> +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);
> +	}
> +
> +#ifdef CONFIG_MII
> +	phy_start(priv->phy);
> +#endif
> +	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);
> +#ifdef CONFIG_MII
> +	if (priv->phy)
> +		phy_stop(priv->phy);
> +#endif
> +
> +	ethoc_disable_rx_and_tx(priv);
> +	free_irq(dev->irq, dev);
> +
> +	if (!netif_queue_stopped(dev))
> +		netif_stop_queue(dev);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_MII
> +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);
> +}
> +#else
> +static int ethoc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
> +{
> +	return -ENOSYS;
> +}
> +#endif
> +
> +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 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_get_multicast_bit(struct dev_mc_list *mc)
> +{
> +	u32 crc = 0xffffffff;
> +	u32 carry;
> +	int i, j;
> +
> +	for (i = 0; i < mc->dmi_addrlen; i++) {
> +		u8 byte = mc->dmi_addr[i];
> +
> +		for (j = 0; j < 8; j++) {
> +			carry = ((crc & 0x80000000) ? 1 : 0) ^ (byte & 0x1);
> +			byte >>= 1;
> +			crc <<= 1;
> +
> +			if (carry)
> +				crc = (crc ^ 0x04c11db6) | carry;
> +		}
> +	}

This looks like yet another crc32 implementation, consider using ether_crc_le()

> +
> +	return (crc >> 26) & 0x3f;
> +}
> +
> +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) {
> +			int bit = ethoc_get_multicast_bit(mc);
> +			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_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);
> +		netif_rx_complete(napi);
> +	}
> +
> +	return work_done;
> +}
> +
> +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;
> +	ethoc_copy_to_io(dest, skb);
> +
> +	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 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;
> +				ethoc_copy_from_io(skb, 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 (netif_rx_schedule_prep(&priv->napi))
> +			__netif_rx_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;
> +}
> +
> +/**
> + * 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);
> +
> +#ifdef CONFIG_MII
> +	/* 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;
> +	}
> +#endif /* CONFIG_MII */
> +
> +	ether_setup(netdev);
> +
> +	/* setup the net_device structure */
> +	netdev->open = ethoc_open;
> +	netdev->stop = ethoc_stop;
> +	netdev->do_ioctl = ethoc_ioctl;
> +	netdev->set_config = ethoc_config;
> +	netdev->set_mac_address = ethoc_set_mac_address;
> +	netdev->set_multicast_list = ethoc_set_multicast_list;
> +	netdev->change_mtu = ethoc_change_mtu;
> +	netdev->tx_timeout = ethoc_tx_timeout;
> +	netdev->get_stats = ethoc_stats;
> +	netdev->hard_start_xmit = ethoc_start_xmit;
> +	netdev->watchdog_timeo = ETHOC_TIMEOUT;
> +	netdev->features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_HIGHDMA;
> +
> +	/* 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) {
> +#ifdef CONFIG_MII
> +		phy_disconnect(priv->phy);
> +		priv->phy = NULL;
> +
> +		if (priv->mdio) {
> +			mdiobus_unregister(priv->mdio);
> +			kfree(priv->mdio->irq);
> +			mdiobus_free(priv->mdio);
> +		}
> +#endif
> +
> +		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");
> +
> diff --git a/include/net/ethoc.h b/include/net/ethoc.h
> new file mode 100644
> index 0000000..96f3789
> --- /dev/null
> +++ b/include/net/ethoc.h
> @@ -0,0 +1,22 @@
> +/*
> + * linux/include/net/ethoc.h
> + *
> + * 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>
> + */
> +
> +#ifndef LINUX_NET_ETHOC_H
> +#define LINUX_NET_ETHOC_H 1
> +
> +struct ethoc_platform_data {
> +	u8 hwaddr[IFHWADDRLEN];
> +	s8 phy_id;
> +};
> +
> +#endif /* !LINUX_NET_ETHOC_H */
> +
> -- 
> tg: (8e0ee43..) adx/net/ethoc (depends on: adx/master)
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From: Andrey Panin <pazke@donpac.ru>
Date: Tue, 24 Mar 2009 14:13:59 +0300

> On 083, 03 24, 2009 at 11:18:43AM +0100, Thierry Reding wrote:
> > +static void ethoc_copy_to_io(void __iomem *dest, struct sk_buff *src)
> > +{
> > +	size_t size = (src->len & 0x3) ? (src->len & ~0x3) + 4 : src->len;
> > +	u8 buffer[ETHOC_BUFSIZ];
> 
> Using 1536 bytes of stack is not very nice.

Agreed, this stuff must be fixed.

You could use skb_copy_and_csum_dev() directly into your buffer, then
pad out the end of the buffer with a memset() call, if necessary.

Actually, no you can't...

You should not be using memcpy() to store things into I/O memory.
That's what memcpy_io() is for.

I think because of all of these special padding cases and the use
of I/O memory instead of DMA, there is no real gain by using
skb_copy_and_csum_dev() in this driver.  Just let the network
stack checksum the packet, and use memcpy_io() here which is
the currect interface for copying data into I/O memory.
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* Florian Fainelli wrote:
> Hi Thierry,
> 
> Le Tuesday 24 March 2009 11:18:43 Thierry Reding, vous avez écrit :
> > 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.
> 
> I am glad someone updated and submitted this driver, excellent work !. Few 
> comments below.
> 
> > + * Copyright (C) 2007-2008 Avionic Design Development GmbH
> > + * Copyright (C) 2008-2009 Avionic Design GmbH
> 
> I think there are some other authors like Simon Srot and Tensilica, unless you 
> did wrote this completely from scratch and did not look at the uClincu 
> open_eth driver at all ?

I did look at the uClinux driver at some point, but decided to rewrite it-
from scratch. But to be honest it's been quite some time since I started work
on this and I'm not a 100% certain that one part or another may not be
borrowed from it.

Would it be enough to mention that it is loosely based on the uClinux driver?

> > +/* function prototypes */
> > +static int ethoc_set_mac_address(struct net_device *dev, void *addr);
> > +static int ethoc_get_mac_address(struct net_device *dev, void *addr);
> > +static int ethoc_rx(struct net_device *dev, int budget);
> > +static void ethoc_tx(struct net_device *dev);
> > +static irqreturn_t ethoc_interrupt(int irq, void *dev_id);
> 
> Why do you need these declarations ? Are not your functions properly ordered 
> already ?

I'll reply to the first patch with an updated version shortly.

> > +/**
> > + * 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;
> > +	}
> 
> That's what uClinux driver calls SRAM right ?

Right.

> > +	/* setup the net_device structure */
> > +	netdev->open = ethoc_open;
> > +	netdev->stop = ethoc_stop;
> > +	netdev->do_ioctl = ethoc_ioctl;
> > +	netdev->set_config = ethoc_config;
> > +	netdev->set_mac_address = ethoc_set_mac_address;
> > +	netdev->set_multicast_list = ethoc_set_multicast_list;
> > +	netdev->change_mtu = ethoc_change_mtu;
> > +	netdev->tx_timeout = ethoc_tx_timeout;
> > +	netdev->get_stats = ethoc_stats;
> > +	netdev->hard_start_xmit = ethoc_start_xmit;
> > +	netdev->watchdog_timeo = ETHOC_TIMEOUT;
> > +	netdev->features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_HIGHDMA;
> 
> Please use netdev_ops.

Done.

> > +#ifndef LINUX_NET_ETHOC_H
> > +#define LINUX_NET_ETHOC_H 1
> > +
> > +struct ethoc_platform_data {
> > +	u8 hwaddr[IFHWADDRLEN];
> > +	s8 phy_id;
> 
> What about allowing platform configuration of the RX/TX buffers size and 
> number of them ?

I think this is a good idea, but I'm not quite sure about how this should be
implemented. The total number of buffers is dependent on the total buffer size
as defined by the second IORESOURCE_MEM resource. That really only leaves the
option for allowing the individual buffer size to be defined by the platform
configuration. Furthermore the network controller can only handle fixed-sized
buffers (at least for reception), so perhaps defining some kind of RX/TX
buffer number ratio would be useful. Or perhaps defining a minimum or maximum
number of TX buffers and leaving the rest up for RX for instance.

Any suggestions?

Cheers,
Thierry

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* David Miller wrote:
> From: Andrey Panin <pazke@donpac.ru>
> Date: Tue, 24 Mar 2009 14:13:59 +0300
> 
> > On 083, 03 24, 2009 at 11:18:43AM +0100, Thierry Reding wrote:
> > > +static void ethoc_copy_to_io(void __iomem *dest, struct sk_buff *src)
> > > +{
> > > +	size_t size = (src->len & 0x3) ? (src->len & ~0x3) + 4 : src->len;
> > > +	u8 buffer[ETHOC_BUFSIZ];
> > 
> > Using 1536 bytes of stack is not very nice.
> 
> Agreed, this stuff must be fixed.
> 
> You could use skb_copy_and_csum_dev() directly into your buffer, then
> pad out the end of the buffer with a memset() call, if necessary.
>-
> Actually, no you can't...
> 
> You should not be using memcpy() to store things into I/O memory.
> That's what memcpy_io() is for.
> 
> I think because of all of these special padding cases and the use
> of I/O memory instead of DMA, there is no real gain by using
> skb_copy_and_csum_dev() in this driver.

Actually these special padding cases are only necessary for the FPGA interface
we use and have nothing to do with the OpenCores Ethernet MAC itself. The ARM
memcpy_{to,from}io() functions don't work correctly with my setup because our
VLIO bridge implementation apparently doesn't handle byte-wise accesses very
well.

I can work around that by implementing the memcpy_{to,from}io() functions
differently, though. That may however break anything else using those
functions.

> Just let the network stack checksum the packet, and use memcpy_io() here
> which is the currect interface for copying data into I/O memory.

See follow-up patch in reply to the first patch.

Cheers,
Thierry

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* Andrey Panin wrote:
> On 083, 03 24, 2009 at 11:18:43AM +0100, Thierry Reding wrote:
[snip]
> > +static int ethoc_get_multicast_bit(struct dev_mc_list *mc)
> > +{
> > +	u32 crc = 0xffffffff;
> > +	u32 carry;
> > +	int i, j;
> > +
> > +	for (i = 0; i < mc->dmi_addrlen; i++) {
> > +		u8 byte = mc->dmi_addr[i];
> > +
> > +		for (j = 0; j < 8; j++) {
> > +			carry = ((crc & 0x80000000) ? 1 : 0) ^ (byte & 0x1);
> > +			byte >>= 1;
> > +			crc <<= 1;
> > +
> > +			if (carry)
> > +				crc = (crc ^ 0x04c11db6) | carry;
> > +		}
> > +	}
> 
> This looks like yet another crc32 implementation, consider using ether_crc_le()
[snip]

Yes, ether_crc() does the trick. See follow-up patch. Thanks.

Cheers,
Thierry

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Hello Thierry,

Le Wednesday 25 March 2009 15:43:10 Thierry Reding, vous avez écrit :
> I did look at the uClinux driver at some point, but decided to rewrite it-
> from scratch. But to be honest it's been quite some time since I started
> work on this and I'm not a 100% certain that one part or another may not be
> borrowed from it.

Sure my concern was more about the original authors somehow claiming copyright 
on this sooner or later. That's fine with me.

>
> Would it be enough to mention that it is loosely based on the uClinux
> driver?
>
> > > +/* function prototypes */
> > > +static int ethoc_set_mac_address(struct net_device *dev, void *addr);
> > > +static int ethoc_get_mac_address(struct net_device *dev, void *addr);
> > > +static int ethoc_rx(struct net_device *dev, int budget);
> > > +static void ethoc_tx(struct net_device *dev);
> > > +static irqreturn_t ethoc_interrupt(int irq, void *dev_id);
> >
> > Why do you need these declarations ? Are not your functions properly
> > ordered already ?
>
> I'll reply to the first patch with an updated version shortly.
>
> > > +/**
> > > + * 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;
> > > +	}
> >
> > That's what uClinux driver calls SRAM right ?
>
> Right.
>
> > > +	/* setup the net_device structure */
> > > +	netdev->open = ethoc_open;
> > > +	netdev->stop = ethoc_stop;
> > > +	netdev->do_ioctl = ethoc_ioctl;
> > > +	netdev->set_config = ethoc_config;
> > > +	netdev->set_mac_address = ethoc_set_mac_address;
> > > +	netdev->set_multicast_list = ethoc_set_multicast_list;
> > > +	netdev->change_mtu = ethoc_change_mtu;
> > > +	netdev->tx_timeout = ethoc_tx_timeout;
> > > +	netdev->get_stats = ethoc_stats;
> > > +	netdev->hard_start_xmit = ethoc_start_xmit;
> > > +	netdev->watchdog_timeo = ETHOC_TIMEOUT;
> > > +	netdev->features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_HIGHDMA;
> >
> > Please use netdev_ops.
>
> Done.
>
> > > +#ifndef LINUX_NET_ETHOC_H
> > > +#define LINUX_NET_ETHOC_H 1
> > > +
> > > +struct ethoc_platform_data {
> > > +	u8 hwaddr[IFHWADDRLEN];
> > > +	s8 phy_id;
> >
> > What about allowing platform configuration of the RX/TX buffers size and
> > number of them ?
>
> I think this is a good idea, but I'm not quite sure about how this should
> be implemented. The total number of buffers is dependent on the total
> buffer size as defined by the second IORESOURCE_MEM resource. That really
> only leaves the option for allowing the individual buffer size to be
> defined by the platform configuration. Furthermore the network controller
> can only handle fixed-sized buffers (at least for reception), so perhaps
> defining some kind of RX/TX buffer number ratio would be useful. Or perhaps
> defining a minimum or maximum number of TX buffers and leaving the rest up
> for RX for instance.

I like the idea of defining ratios but for now let's just stick to what you 
proposed and we can later agree on getting more parameters being passed to 
the driver using platform_data I am not sure yet how I will tune these 
parameters on my design.