MIPS: Lantiq: Add ethernet driver

This patch adds the driver for the ETOP Packet Processing Engine (PPE32)
found inside the XWAY family of Lantiq MIPS SoCs. This driver makes 100MBit
ethernet work. Support for all 8 dma channels, gbit and the embedded switch
found on the ar9/vr9 still needs to be implemented.

Signed-off-by: John Crispin <[e-mail]>
Signed-off-by: Ralph Hempel <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Patchwork: https://patchwork.linux-mips.org/patch/2357/
Acked-by: David S. Miller <[e-mail]>
Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/include/asm/mach-lantiq/lantiq_platform.h

···
 #define _LANTIQ_PLATFORM_H__
 
 #include <linux/mtd/partitions.h>
+#include <linux/socket.h>
 
 /* struct used to pass info to the pci core */
 enum {
···
 	int clock;
 	int gpio;
 	int irq[16];
+};
+
+/* struct used to pass info to network drivers */
+struct ltq_eth_data {
+	struct sockaddr mac;
+	int mii_mode;
 };
 
 #endif

arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h

···
 #define PMU_SWITCH		0x10000000
 
 /* ETOP - ethernet */
-#define LTQ_PPE32_BASE_ADDR	0xBE180000
-#define LTQ_PPE32_SIZE		0x40000
+#define LTQ_ETOP_BASE_ADDR	0x1E180000
+#define LTQ_ETOP_SIZE		0x40000
 
 /* DMA */
 #define LTQ_DMA_BASE_ADDR	0x1E104100

arch/mips/lantiq/xway/devices.c

···
 	platform_device_register_simple("ltq_asc", 0,
 		ltq_ase_asc_resources, ARRAY_SIZE(ltq_ase_asc_resources));
 }
+
+/* ethernet */
+static struct resource ltq_etop_resources = {
+	.name	= "etop",
+	.start	= LTQ_ETOP_BASE_ADDR,
+	.end	= LTQ_ETOP_BASE_ADDR + LTQ_ETOP_SIZE - 1,
+	.flags	= IORESOURCE_MEM,
+};
+
+static struct platform_device ltq_etop = {
+	.name		= "ltq_etop",
+	.resource	= &ltq_etop_resources,
+	.num_resources	= 1,
+};
+
+void __init
+ltq_register_etop(struct ltq_eth_data *eth)
+{
+	if (eth) {
+		ltq_etop.dev.platform_data = eth;
+		platform_device_register(&ltq_etop);
+	}
+}

arch/mips/lantiq/xway/devices.h

···
 extern void ltq_register_gpio(void);
 extern void ltq_register_gpio_stp(void);
 extern void ltq_register_ase_asc(void);
+extern void ltq_register_etop(struct ltq_eth_data *eth);
 
 #endif

drivers/net/Kconfig

···
 	  from Faraday. It is used on Faraday A320, Andes AG101 and some
 	  other ARM/NDS32 SoC's.
 
+config LANTIQ_ETOP
+	tristate "Lantiq SoC ETOP driver"
+	depends on SOC_TYPE_XWAY
+	help
+	  Support for the MII0 inside the Lantiq SoC
+
+
 source "drivers/net/fs_enet/Kconfig"
 
 source "drivers/net/octeon/Kconfig"

drivers/net/Makefile

···
 obj-$(CONFIG_ENC28J60) += enc28j60.o
 obj-$(CONFIG_ETHOC) += ethoc.o
 obj-$(CONFIG_GRETH) += greth.o
+obj-$(CONFIG_LANTIQ_ETOP) += lantiq_etop.o
 
 obj-$(CONFIG_XTENSA_XT2000_SONIC) += xtsonic.o
 

drivers/net/lantiq_etop.c

···
+/*
+ *   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, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ *
+ *   Copyright (C) 2011 John Crispin <[e-mail]>
+ */
+
+#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 <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 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] = dev_alloc_skb(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->dev = ch->netdev;
+	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, IRQF_DISABLED,
+				"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, IRQF_DISABLED,
+				"etop_rx", priv);
+		}
+		ch->dma.irq = irq;
+	}
+	return 0;
+}
+
+static void
+ltq_etop_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
+{
+	strcpy(info->driver, "Lantiq ETOP");
+	strcpy(info->bus_info, "internal");
+	strcpy(info->version, DRV_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,
+			0, 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, "%x", 0);
+	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)
+{
+	/* 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;
+
+	ether_setup(dev);
+	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");
+		random_ether_addr(mac.sa_data);
+	}
+
+	err = ltq_etop_set_mac_address(dev, &mac);
+	if (err)
+		goto err_netdev;
+	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_multicast_list = 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);
+	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->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:
+	kfree(dev);
+err_out:
+	return err;
+}
+
+static int __devexit
+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 = __devexit_p(ltq_etop_remove),
+	.driver = {
+		.name = "ltq_etop",
+		.owner = THIS_MODULE,
+	},
+};
+
+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 platfom 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 <[e-mail]>");
+MODULE_DESCRIPTION("Lantiq SoC ETOP");
+MODULE_LICENSE("GPL");