/*
 *   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.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, see <http://www.gnu.org/licenses/>.
 *
 *   Copyright (C) 2011 John Crispin <blogic@openwrt.org>
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/uaccess.h>
#include <linux/in.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/phy.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/skbuff.h>
#include <linux/mm.h>
#include <linux/platform_device.h>
#include <linux/ethtool.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>

#include <asm/checksum.h>

#include <lantiq_soc.h>
#include <xway_dma.h>
#include <lantiq_platform.h>

#define LTQ_ETOP_MDIO		0x11804
#define MDIO_REQUEST		0x80000000
#define MDIO_READ		0x40000000
#define MDIO_ADDR_MASK		0x1f
#define MDIO_ADDR_OFFSET	0x15
#define MDIO_REG_MASK		0x1f
#define MDIO_REG_OFFSET		0x10
#define MDIO_VAL_MASK		0xffff

#define PPE32_CGEN		0x800
#define LQ_PPE32_ENET_MAC_CFG	0x1840

#define LTQ_ETOP_ENETS0		0x11850
#define LTQ_ETOP_MAC_DA0	0x1186C
#define LTQ_ETOP_MAC_DA1	0x11870
#define LTQ_ETOP_CFG		0x16020
#define LTQ_ETOP_IGPLEN		0x16080

#define MAX_DMA_CHAN		0x8
#define MAX_DMA_CRC_LEN		0x4
#define MAX_DMA_DATA_LEN	0x600

#define ETOP_FTCU		BIT(28)
#define ETOP_MII_MASK		0xf
#define ETOP_MII_NORMAL		0xd
#define ETOP_MII_REVERSE	0xe
#define ETOP_PLEN_UNDER		0x40
#define ETOP_CGEN		0x800

/* use 2 static channels for TX/RX */
#define LTQ_ETOP_TX_CHANNEL	1
#define LTQ_ETOP_RX_CHANNEL	6
#define IS_TX(x)		(x == LTQ_ETOP_TX_CHANNEL)
#define IS_RX(x)		(x == LTQ_ETOP_RX_CHANNEL)

#define ltq_etop_r32(x)		ltq_r32(ltq_etop_membase + (x))
#define ltq_etop_w32(x, y)	ltq_w32(x, ltq_etop_membase + (y))
#define ltq_etop_w32_mask(x, y, z)	\
		ltq_w32_mask(x, y, ltq_etop_membase + (z))

#define DRV_VERSION	"1.0"

static void __iomem *ltq_etop_membase;

struct ltq_etop_chan {
	int idx;
	int tx_free;
	struct net_device *netdev;
	struct napi_struct napi;
	struct ltq_dma_channel dma;
	struct sk_buff *skb[LTQ_DESC_NUM];
};

struct ltq_etop_priv {
	struct net_device *netdev;
	struct platform_device *pdev;
	struct ltq_eth_data *pldata;
	struct resource *res;

	struct mii_bus *mii_bus;
	struct phy_device *phydev;

	struct ltq_etop_chan ch[MAX_DMA_CHAN];
	int tx_free[MAX_DMA_CHAN >> 1];

	spinlock_t lock;
};

static int
ltq_etop_alloc_skb(struct ltq_etop_chan *ch)
{
	ch->skb[ch->dma.desc] = netdev_alloc_skb(ch->netdev, MAX_DMA_DATA_LEN);
	if (!ch->skb[ch->dma.desc])
		return -ENOMEM;
	ch->dma.desc_base[ch->dma.desc].addr = dma_map_single(NULL,
		ch->skb[ch->dma.desc]->data, MAX_DMA_DATA_LEN,
		DMA_FROM_DEVICE);
	ch->dma.desc_base[ch->dma.desc].addr =
		CPHYSADDR(ch->skb[ch->dma.desc]->data);
	ch->dma.desc_base[ch->dma.desc].ctl =
		LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
		MAX_DMA_DATA_LEN;
	skb_reserve(ch->skb[ch->dma.desc], NET_IP_ALIGN);
	return 0;
}

static void
ltq_etop_hw_receive(struct ltq_etop_chan *ch)
{
	struct ltq_etop_priv *priv = netdev_priv(ch->netdev);
	struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
	struct sk_buff *skb = ch->skb[ch->dma.desc];
	int len = (desc->ctl & LTQ_DMA_SIZE_MASK) - MAX_DMA_CRC_LEN;
	unsigned long flags;

	spin_lock_irqsave(&priv->lock, flags);
	if (ltq_etop_alloc_skb(ch)) {
		netdev_err(ch->netdev,
			"failed to allocate new rx buffer, stopping DMA\n");
		ltq_dma_close(&ch->dma);
	}
	ch->dma.desc++;
	ch->dma.desc %= LTQ_DESC_NUM;
	spin_unlock_irqrestore(&priv->lock, flags);

	skb_put(skb, len);
	skb->protocol = eth_type_trans(skb, ch->netdev);
	netif_receive_skb(skb);
}

static int
ltq_etop_poll_rx(struct napi_struct *napi, int budget)
{
	struct ltq_etop_chan *ch = container_of(napi,
				struct ltq_etop_chan, napi);
	int rx = 0;
	int complete = 0;

	while ((rx < budget) && !complete) {
		struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];

		if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) {
			ltq_etop_hw_receive(ch);
			rx++;
		} else {
			complete = 1;
		}
	}
	if (complete || !rx) {
		napi_complete(&ch->napi);
		ltq_dma_ack_irq(&ch->dma);
	}
	return rx;
}

static int
ltq_etop_poll_tx(struct napi_struct *napi, int budget)
{
	struct ltq_etop_chan *ch =
		container_of(napi, struct ltq_etop_chan, napi);
	struct ltq_etop_priv *priv = netdev_priv(ch->netdev);
	struct netdev_queue *txq =
		netdev_get_tx_queue(ch->netdev, ch->idx >> 1);
	unsigned long flags;

	spin_lock_irqsave(&priv->lock, flags);
	while ((ch->dma.desc_base[ch->tx_free].ctl &
			(LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) {
		dev_kfree_skb_any(ch->skb[ch->tx_free]);
		ch->skb[ch->tx_free] = NULL;
		memset(&ch->dma.desc_base[ch->tx_free], 0,
			sizeof(struct ltq_dma_desc));
		ch->tx_free++;
		ch->tx_free %= LTQ_DESC_NUM;
	}
	spin_unlock_irqrestore(&priv->lock, flags);

	if (netif_tx_queue_stopped(txq))
		netif_tx_start_queue(txq);
	napi_complete(&ch->napi);
	ltq_dma_ack_irq(&ch->dma);
	return 1;
}

static irqreturn_t
ltq_etop_dma_irq(int irq, void *_priv)
{
	struct ltq_etop_priv *priv = _priv;
	int ch = irq - LTQ_DMA_CH0_INT;

	napi_schedule(&priv->ch[ch].napi);
	return IRQ_HANDLED;
}

static void
ltq_etop_free_channel(struct net_device *dev, struct ltq_etop_chan *ch)
{
	struct ltq_etop_priv *priv = netdev_priv(dev);

	ltq_dma_free(&ch->dma);
	if (ch->dma.irq)
		free_irq(ch->dma.irq, priv);
	if (IS_RX(ch->idx)) {
		int desc;
		for (desc = 0; desc < LTQ_DESC_NUM; desc++)
			dev_kfree_skb_any(ch->skb[ch->dma.desc]);
	}
}

static void
ltq_etop_hw_exit(struct net_device *dev)
{
	struct ltq_etop_priv *priv = netdev_priv(dev);
	int i;

	ltq_pmu_disable(PMU_PPE);
	for (i = 0; i < MAX_DMA_CHAN; i++)
		if (IS_TX(i) || IS_RX(i))
			ltq_etop_free_channel(dev, &priv->ch[i]);
}

static int
ltq_etop_hw_init(struct net_device *dev)
{
	struct ltq_etop_priv *priv = netdev_priv(dev);
	int i;

	ltq_pmu_enable(PMU_PPE);

	switch (priv->pldata->mii_mode) {
	case PHY_INTERFACE_MODE_RMII:
		ltq_etop_w32_mask(ETOP_MII_MASK,
			ETOP_MII_REVERSE, LTQ_ETOP_CFG);
		break;

	case PHY_INTERFACE_MODE_MII:
		ltq_etop_w32_mask(ETOP_MII_MASK,
			ETOP_MII_NORMAL, LTQ_ETOP_CFG);
		break;

	default:
		netdev_err(dev, "unknown mii mode %d\n",
			priv->pldata->mii_mode);
		return -ENOTSUPP;
	}

	/* enable crc generation */
	ltq_etop_w32(PPE32_CGEN, LQ_PPE32_ENET_MAC_CFG);

	ltq_dma_init_port(DMA_PORT_ETOP);

	for (i = 0; i < MAX_DMA_CHAN; i++) {
		int irq = LTQ_DMA_CH0_INT + i;
		struct ltq_etop_chan *ch = &priv->ch[i];

		ch->idx = ch->dma.nr = i;

		if (IS_TX(i)) {
			ltq_dma_alloc_tx(&ch->dma);
			request_irq(irq, ltq_etop_dma_irq, 0, "etop_tx", priv);
		} else if (IS_RX(i)) {
			ltq_dma_alloc_rx(&ch->dma);
			for (ch->dma.desc = 0; ch->dma.desc < LTQ_DESC_NUM;
					ch->dma.desc++)
				if (ltq_etop_alloc_skb(ch))
					return -ENOMEM;
			ch->dma.desc = 0;
			request_irq(irq, ltq_etop_dma_irq, 0, "etop_rx", priv);
		}
		ch->dma.irq = irq;
	}
	return 0;
}

static void
ltq_etop_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
{
	strlcpy(info->driver, "Lantiq ETOP", sizeof(info->driver));
	strlcpy(info->bus_info, "internal", sizeof(info->bus_info));
	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
}

static int
ltq_etop_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
	struct ltq_etop_priv *priv = netdev_priv(dev);

	return phy_ethtool_gset(priv->phydev, cmd);
}

static int
ltq_etop_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
	struct ltq_etop_priv *priv = netdev_priv(dev);

	return phy_ethtool_sset(priv->phydev, cmd);
}

static int
ltq_etop_nway_reset(struct net_device *dev)
{
	struct ltq_etop_priv *priv = netdev_priv(dev);

	return phy_start_aneg(priv->phydev);
}

static const struct ethtool_ops ltq_etop_ethtool_ops = {
	.get_drvinfo = ltq_etop_get_drvinfo,
	.get_settings = ltq_etop_get_settings,
	.set_settings = ltq_etop_set_settings,
	.nway_reset = ltq_etop_nway_reset,
};

static int
ltq_etop_mdio_wr(struct mii_bus *bus, int phy_addr, int phy_reg, u16 phy_data)
{
	u32 val = MDIO_REQUEST |
		((phy_addr & MDIO_ADDR_MASK) << MDIO_ADDR_OFFSET) |
		((phy_reg & MDIO_REG_MASK) << MDIO_REG_OFFSET) |
		phy_data;

	while (ltq_etop_r32(LTQ_ETOP_MDIO) & MDIO_REQUEST)
		;
	ltq_etop_w32(val, LTQ_ETOP_MDIO);
	return 0;
}

static int
ltq_etop_mdio_rd(struct mii_bus *bus, int phy_addr, int phy_reg)
{
	u32 val = MDIO_REQUEST | MDIO_READ |
		((phy_addr & MDIO_ADDR_MASK) << MDIO_ADDR_OFFSET) |
		((phy_reg & MDIO_REG_MASK) << MDIO_REG_OFFSET);

	while (ltq_etop_r32(LTQ_ETOP_MDIO) & MDIO_REQUEST)
		;
	ltq_etop_w32(val, LTQ_ETOP_MDIO);
	while (ltq_etop_r32(LTQ_ETOP_MDIO) & MDIO_REQUEST)
		;
	val = ltq_etop_r32(LTQ_ETOP_MDIO) & MDIO_VAL_MASK;
	return val;
}

static void
ltq_etop_mdio_link(struct net_device *dev)
{
	/* nothing to do  */
}

static int
ltq_etop_mdio_probe(struct net_device *dev)
{
	struct ltq_etop_priv *priv = netdev_priv(dev);
	struct phy_device *phydev = NULL;
	int phy_addr;

	for (phy_addr = 0; phy_addr < PHY_MAX_ADDR; phy_addr++) {
		if (priv->mii_bus->phy_map[phy_addr]) {
			phydev = priv->mii_bus->phy_map[phy_addr];
			break;
		}
	}

	if (!phydev) {
		netdev_err(dev, "no PHY found\n");
		return -ENODEV;
	}

	phydev = phy_connect(dev, dev_name(&phydev->dev),
			     &ltq_etop_mdio_link, priv->pldata->mii_mode);

	if (IS_ERR(phydev)) {
		netdev_err(dev, "Could not attach to PHY\n");
		return PTR_ERR(phydev);
	}

	phydev->supported &= (SUPPORTED_10baseT_Half
			      | SUPPORTED_10baseT_Full
			      | SUPPORTED_100baseT_Half
			      | SUPPORTED_100baseT_Full
			      | SUPPORTED_Autoneg
			      | SUPPORTED_MII
			      | SUPPORTED_TP);

	phydev->advertising = phydev->supported;
	priv->phydev = phydev;
	pr_info("%s: attached PHY [%s] (phy_addr=%s, irq=%d)\n",
	       dev->name, phydev->drv->name,
	       dev_name(&phydev->dev), phydev->irq);

	return 0;
}

static int
ltq_etop_mdio_init(struct net_device *dev)
{
	struct ltq_etop_priv *priv = netdev_priv(dev);
	int i;
	int err;

	priv->mii_bus = mdiobus_alloc();
	if (!priv->mii_bus) {
		netdev_err(dev, "failed to allocate mii bus\n");
		err = -ENOMEM;
		goto err_out;
	}

	priv->mii_bus->priv = dev;
	priv->mii_bus->read = ltq_etop_mdio_rd;
	priv->mii_bus->write = ltq_etop_mdio_wr;
	priv->mii_bus->name = "ltq_mii";
	snprintf(priv->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
		priv->pdev->name, priv->pdev->id);
	priv->mii_bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
	if (!priv->mii_bus->irq) {
		err = -ENOMEM;
		goto err_out_free_mdiobus;
	}

	for (i = 0; i < PHY_MAX_ADDR; ++i)
		priv->mii_bus->irq[i] = PHY_POLL;

	if (mdiobus_register(priv->mii_bus)) {
		err = -ENXIO;
		goto err_out_free_mdio_irq;
	}

	if (ltq_etop_mdio_probe(dev)) {
		err = -ENXIO;
		goto err_out_unregister_bus;
	}
	return 0;

err_out_unregister_bus:
	mdiobus_unregister(priv->mii_bus);
err_out_free_mdio_irq:
	kfree(priv->mii_bus->irq);
err_out_free_mdiobus:
	mdiobus_free(priv->mii_bus);
err_out:
	return err;
}

static void
ltq_etop_mdio_cleanup(struct net_device *dev)
{
	struct ltq_etop_priv *priv = netdev_priv(dev);

	phy_disconnect(priv->phydev);
	mdiobus_unregister(priv->mii_bus);
	kfree(priv->mii_bus->irq);
	mdiobus_free(priv->mii_bus);
}

static int
ltq_etop_open(struct net_device *dev)
{
	struct ltq_etop_priv *priv = netdev_priv(dev);
	int i;

	for (i = 0; i < MAX_DMA_CHAN; i++) {
		struct ltq_etop_chan *ch = &priv->ch[i];

		if (!IS_TX(i) && (!IS_RX(i)))
			continue;
		ltq_dma_open(&ch->dma);
		napi_enable(&ch->napi);
	}
	phy_start(priv->phydev);
	netif_tx_start_all_queues(dev);
	return 0;
}

static int
ltq_etop_stop(struct net_device *dev)
{
	struct ltq_etop_priv *priv = netdev_priv(dev);
	int i;

	netif_tx_stop_all_queues(dev);
	phy_stop(priv->phydev);
	for (i = 0; i < MAX_DMA_CHAN; i++) {
		struct ltq_etop_chan *ch = &priv->ch[i];

		if (!IS_RX(i) && !IS_TX(i))
			continue;
		napi_disable(&ch->napi);
		ltq_dma_close(&ch->dma);
	}
	return 0;
}

static int
ltq_etop_tx(struct sk_buff *skb, struct net_device *dev)
{
	int queue = skb_get_queue_mapping(skb);
	struct netdev_queue *txq = netdev_get_tx_queue(dev, queue);
	struct ltq_etop_priv *priv = netdev_priv(dev);
	struct ltq_etop_chan *ch = &priv->ch[(queue << 1) | 1];
	struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
	int len;
	unsigned long flags;
	u32 byte_offset;

	len = skb->len < ETH_ZLEN ? ETH_ZLEN : skb->len;

	if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) || ch->skb[ch->dma.desc]) {
		dev_kfree_skb_any(skb);
		netdev_err(dev, "tx ring full\n");
		netif_tx_stop_queue(txq);
		return NETDEV_TX_BUSY;
	}

	/* dma needs to start on a 16 byte aligned address */
	byte_offset = CPHYSADDR(skb->data) % 16;
	ch->skb[ch->dma.desc] = skb;

	dev->trans_start = jiffies;

	spin_lock_irqsave(&priv->lock, flags);
	desc->addr = ((unsigned int) dma_map_single(NULL, skb->data, len,
						DMA_TO_DEVICE)) - byte_offset;
	wmb();
	desc->ctl = LTQ_DMA_OWN | LTQ_DMA_SOP | LTQ_DMA_EOP |
		LTQ_DMA_TX_OFFSET(byte_offset) | (len & LTQ_DMA_SIZE_MASK);
	ch->dma.desc++;
	ch->dma.desc %= LTQ_DESC_NUM;
	spin_unlock_irqrestore(&priv->lock, flags);

	if (ch->dma.desc_base[ch->dma.desc].ctl & LTQ_DMA_OWN)
		netif_tx_stop_queue(txq);

	return NETDEV_TX_OK;
}

static int
ltq_etop_change_mtu(struct net_device *dev, int new_mtu)
{
	int ret = eth_change_mtu(dev, new_mtu);

	if (!ret) {
		struct ltq_etop_priv *priv = netdev_priv(dev);
		unsigned long flags;

		spin_lock_irqsave(&priv->lock, flags);
		ltq_etop_w32((ETOP_PLEN_UNDER << 16) | new_mtu,
			LTQ_ETOP_IGPLEN);
		spin_unlock_irqrestore(&priv->lock, flags);
	}
	return ret;
}

static int
ltq_etop_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
	struct ltq_etop_priv *priv = netdev_priv(dev);

	/* TODO: mii-toll reports "No MII transceiver present!." ?!*/
	return phy_mii_ioctl(priv->phydev, rq, cmd);
}

static int
ltq_etop_set_mac_address(struct net_device *dev, void *p)
{
	int ret = eth_mac_addr(dev, p);

	if (!ret) {
		struct ltq_etop_priv *priv = netdev_priv(dev);
		unsigned long flags;

		/* store the mac for the unicast filter */
		spin_lock_irqsave(&priv->lock, flags);
		ltq_etop_w32(*((u32 *)dev->dev_addr), LTQ_ETOP_MAC_DA0);
		ltq_etop_w32(*((u16 *)&dev->dev_addr[4]) << 16,
			LTQ_ETOP_MAC_DA1);
		spin_unlock_irqrestore(&priv->lock, flags);
	}
	return ret;
}

static void
ltq_etop_set_multicast_list(struct net_device *dev)
{
	struct ltq_etop_priv *priv = netdev_priv(dev);
	unsigned long flags;

	/* ensure that the unicast filter is not enabled in promiscious mode */
	spin_lock_irqsave(&priv->lock, flags);
	if ((dev->flags & IFF_PROMISC) || (dev->flags & IFF_ALLMULTI))
		ltq_etop_w32_mask(ETOP_FTCU, 0, LTQ_ETOP_ENETS0);
	else
		ltq_etop_w32_mask(0, ETOP_FTCU, LTQ_ETOP_ENETS0);
	spin_unlock_irqrestore(&priv->lock, flags);
}

static u16
ltq_etop_select_queue(struct net_device *dev, struct sk_buff *skb,
		      void *accel_priv, select_queue_fallback_t fallback)
{
	/* we are currently only using the first queue */
	return 0;
}

static int
ltq_etop_init(struct net_device *dev)
{
	struct ltq_etop_priv *priv = netdev_priv(dev);
	struct sockaddr mac;
	int err;
	bool random_mac = false;

	dev->watchdog_timeo = 10 * HZ;
	err = ltq_etop_hw_init(dev);
	if (err)
		goto err_hw;
	ltq_etop_change_mtu(dev, 1500);

	memcpy(&mac, &priv->pldata->mac, sizeof(struct sockaddr));
	if (!is_valid_ether_addr(mac.sa_data)) {
		pr_warn("etop: invalid MAC, using random\n");
		eth_random_addr(mac.sa_data);
		random_mac = true;
	}

	err = ltq_etop_set_mac_address(dev, &mac);
	if (err)
		goto err_netdev;

	/* Set addr_assign_type here, ltq_etop_set_mac_address would reset it. */
	if (random_mac)
		dev->addr_assign_type = NET_ADDR_RANDOM;

	ltq_etop_set_multicast_list(dev);
	err = ltq_etop_mdio_init(dev);
	if (err)
		goto err_netdev;
	return 0;

err_netdev:
	unregister_netdev(dev);
	free_netdev(dev);
err_hw:
	ltq_etop_hw_exit(dev);
	return err;
}

static void
ltq_etop_tx_timeout(struct net_device *dev)
{
	int err;

	ltq_etop_hw_exit(dev);
	err = ltq_etop_hw_init(dev);
	if (err)
		goto err_hw;
	dev->trans_start = jiffies;
	netif_wake_queue(dev);
	return;

err_hw:
	ltq_etop_hw_exit(dev);
	netdev_err(dev, "failed to restart etop after TX timeout\n");
}

static const struct net_device_ops ltq_eth_netdev_ops = {
	.ndo_open = ltq_etop_open,
	.ndo_stop = ltq_etop_stop,
	.ndo_start_xmit = ltq_etop_tx,
	.ndo_change_mtu = ltq_etop_change_mtu,
	.ndo_do_ioctl = ltq_etop_ioctl,
	.ndo_set_mac_address = ltq_etop_set_mac_address,
	.ndo_validate_addr = eth_validate_addr,
	.ndo_set_rx_mode = ltq_etop_set_multicast_list,
	.ndo_select_queue = ltq_etop_select_queue,
	.ndo_init = ltq_etop_init,
	.ndo_tx_timeout = ltq_etop_tx_timeout,
};

static int __init
ltq_etop_probe(struct platform_device *pdev)
{
	struct net_device *dev;
	struct ltq_etop_priv *priv;
	struct resource *res;
	int err;
	int i;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(&pdev->dev, "failed to get etop resource\n");
		err = -ENOENT;
		goto err_out;
	}

	res = devm_request_mem_region(&pdev->dev, res->start,
		resource_size(res), dev_name(&pdev->dev));
	if (!res) {
		dev_err(&pdev->dev, "failed to request etop resource\n");
		err = -EBUSY;
		goto err_out;
	}

	ltq_etop_membase = devm_ioremap_nocache(&pdev->dev,
		res->start, resource_size(res));
	if (!ltq_etop_membase) {
		dev_err(&pdev->dev, "failed to remap etop engine %d\n",
			pdev->id);
		err = -ENOMEM;
		goto err_out;
	}

	dev = alloc_etherdev_mq(sizeof(struct ltq_etop_priv), 4);
	if (!dev) {
		err = -ENOMEM;
		goto err_out;
	}
	strcpy(dev->name, "eth%d");
	dev->netdev_ops = &ltq_eth_netdev_ops;
	dev->ethtool_ops = &ltq_etop_ethtool_ops;
	priv = netdev_priv(dev);
	priv->res = res;
	priv->pdev = pdev;
	priv->pldata = dev_get_platdata(&pdev->dev);
	priv->netdev = dev;
	spin_lock_init(&priv->lock);

	for (i = 0; i < MAX_DMA_CHAN; i++) {
		if (IS_TX(i))
			netif_napi_add(dev, &priv->ch[i].napi,
				ltq_etop_poll_tx, 8);
		else if (IS_RX(i))
			netif_napi_add(dev, &priv->ch[i].napi,
				ltq_etop_poll_rx, 32);
		priv->ch[i].netdev = dev;
	}

	err = register_netdev(dev);
	if (err)
		goto err_free;

	platform_set_drvdata(pdev, dev);
	return 0;

err_free:
	free_netdev(dev);
err_out:
	return err;
}

static int
ltq_etop_remove(struct platform_device *pdev)
{
	struct net_device *dev = platform_get_drvdata(pdev);

	if (dev) {
		netif_tx_stop_all_queues(dev);
		ltq_etop_hw_exit(dev);
		ltq_etop_mdio_cleanup(dev);
		unregister_netdev(dev);
	}
	return 0;
}

static struct platform_driver ltq_mii_driver = {
	.remove = ltq_etop_remove,
	.driver = {
		.name = "ltq_etop",
	},
};

int __init
init_ltq_etop(void)
{
	int ret = platform_driver_probe(&ltq_mii_driver, ltq_etop_probe);

	if (ret)
		pr_err("ltq_etop: Error registering platform driver!");
	return ret;
}

static void __exit
exit_ltq_etop(void)
{
	platform_driver_unregister(&ltq_mii_driver);
}

module_init(init_ltq_etop);
module_exit(exit_ltq_etop);

MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
MODULE_DESCRIPTION("Lantiq SoC ETOP");
MODULE_LICENSE("GPL");