[PATCH] Cirrus Logic ep93xx ethernet driver

The Cirrus Logic ep93xx is an ARM SoC that includes an ethernet MAC
-- this patch adds a driver for that ethernet MAC.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

3 files changed, 952 insertions, 0 deletions

diff --git a/drivers/net/arm/Kconfig b/drivers/net/arm/Kconfig
index 77fe20db..678e4f4 100644
--- a/drivers/net/arm/Kconfig
+++ b/drivers/net/arm/Kconfig
@@ -39,3 +39,10 @@ config ARM_AT91_ETHER
 	help
 	  If you wish to compile a kernel for the AT91RM9200 and enable
 	  ethernet support, then you should always answer Y to this.
+
+config EP93XX_ETH
+	tristate "EP93xx Ethernet support"
+	depends on NET_ETHERNET && ARM && ARCH_EP93XX
+	help
+	  This is a driver for the ethernet hardware included in EP93xx CPUs.
+	  Say Y if you are building a kernel for EP93xx based devices.
diff --git a/drivers/net/arm/Makefile b/drivers/net/arm/Makefile
index 42c95b7..a4c8682 100644
--- a/drivers/net/arm/Makefile
+++ b/drivers/net/arm/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_ARM_ETHERH)	+= etherh.o
 obj-$(CONFIG_ARM_ETHER3)	+= ether3.o
 obj-$(CONFIG_ARM_ETHER1)	+= ether1.o
 obj-$(CONFIG_ARM_AT91_ETHER)	+= at91_ether.o
+obj-$(CONFIG_EP93XX_ETH)	+= ep93xx_eth.o
diff --git a/drivers/net/arm/ep93xx_eth.c b/drivers/net/arm/ep93xx_eth.c
new file mode 100644
index 0000000..cef0074
--- /dev/null
+++ b/drivers/net/arm/ep93xx_eth.c
@@ -0,0 +1,944 @@
+/*
+ * EP93xx ethernet network device driver
+ * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
+ * Dedicated to Marija Kulikova.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/dma-mapping.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/mii.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <asm/arch/ep93xx-regs.h>
+#include <asm/arch/platform.h>
+#include <asm/io.h>
+
+#define DRV_MODULE_NAME		"ep93xx-eth"
+#define DRV_MODULE_VERSION	"0.1"
+
+#define RX_QUEUE_ENTRIES	64
+#define TX_QUEUE_ENTRIES	8
+
+#define MAX_PKT_SIZE		2044
+#define PKT_BUF_SIZE		2048
+
+#define REG_RXCTL		0x0000
+#define  REG_RXCTL_DEFAULT	0x00073800
+#define REG_TXCTL		0x0004
+#define  REG_TXCTL_ENABLE	0x00000001
+#define REG_MIICMD		0x0010
+#define  REG_MIICMD_READ	0x00008000
+#define  REG_MIICMD_WRITE	0x00004000
+#define REG_MIIDATA		0x0014
+#define REG_MIISTS		0x0018
+#define  REG_MIISTS_BUSY	0x00000001
+#define REG_SELFCTL		0x0020
+#define  REG_SELFCTL_RESET	0x00000001
+#define REG_INTEN		0x0024
+#define  REG_INTEN_TX		0x00000008
+#define  REG_INTEN_RX		0x00000007
+#define REG_INTSTSP		0x0028
+#define  REG_INTSTS_TX		0x00000008
+#define  REG_INTSTS_RX		0x00000004
+#define REG_INTSTSC		0x002c
+#define REG_AFP			0x004c
+#define REG_INDAD0		0x0050
+#define REG_INDAD1		0x0051
+#define REG_INDAD2		0x0052
+#define REG_INDAD3		0x0053
+#define REG_INDAD4		0x0054
+#define REG_INDAD5		0x0055
+#define REG_GIINTMSK		0x0064
+#define  REG_GIINTMSK_ENABLE	0x00008000
+#define REG_BMCTL		0x0080
+#define  REG_BMCTL_ENABLE_TX	0x00000100
+#define  REG_BMCTL_ENABLE_RX	0x00000001
+#define REG_BMSTS		0x0084
+#define  REG_BMSTS_RX_ACTIVE	0x00000008
+#define REG_RXDQBADD		0x0090
+#define REG_RXDQBLEN		0x0094
+#define REG_RXDCURADD		0x0098
+#define REG_RXDENQ		0x009c
+#define REG_RXSTSQBADD		0x00a0
+#define REG_RXSTSQBLEN		0x00a4
+#define REG_RXSTSQCURADD	0x00a8
+#define REG_RXSTSENQ		0x00ac
+#define REG_TXDQBADD		0x00b0
+#define REG_TXDQBLEN		0x00b4
+#define REG_TXDQCURADD		0x00b8
+#define REG_TXDENQ		0x00bc
+#define REG_TXSTSQBADD		0x00c0
+#define REG_TXSTSQBLEN		0x00c4
+#define REG_TXSTSQCURADD	0x00c8
+#define REG_MAXFRMLEN		0x00e8
+
+struct ep93xx_rdesc
+{
+	u32	buf_addr;
+	u32	rdesc1;
+};
+
+#define RDESC1_NSOF		0x80000000
+#define RDESC1_BUFFER_INDEX	0x7fff0000
+#define RDESC1_BUFFER_LENGTH	0x0000ffff
+
+struct ep93xx_rstat
+{
+	u32	rstat0;
+	u32	rstat1;
+};
+
+#define RSTAT0_RFP		0x80000000
+#define RSTAT0_RWE		0x40000000
+#define RSTAT0_EOF		0x20000000
+#define RSTAT0_EOB		0x10000000
+#define RSTAT0_AM		0x00c00000
+#define RSTAT0_RX_ERR		0x00200000
+#define RSTAT0_OE		0x00100000
+#define RSTAT0_FE		0x00080000
+#define RSTAT0_RUNT		0x00040000
+#define RSTAT0_EDATA		0x00020000
+#define RSTAT0_CRCE		0x00010000
+#define RSTAT0_CRCI		0x00008000
+#define RSTAT0_HTI		0x00003f00
+#define RSTAT1_RFP		0x80000000
+#define RSTAT1_BUFFER_INDEX	0x7fff0000
+#define RSTAT1_FRAME_LENGTH	0x0000ffff
+
+struct ep93xx_tdesc
+{
+	u32	buf_addr;
+	u32	tdesc1;
+};
+
+#define TDESC1_EOF		0x80000000
+#define TDESC1_BUFFER_INDEX	0x7fff0000
+#define TDESC1_BUFFER_ABORT	0x00008000
+#define TDESC1_BUFFER_LENGTH	0x00000fff
+
+struct ep93xx_tstat
+{
+	u32	tstat0;
+};
+
+#define TSTAT0_TXFP		0x80000000
+#define TSTAT0_TXWE		0x40000000
+#define TSTAT0_FA		0x20000000
+#define TSTAT0_LCRS		0x10000000
+#define TSTAT0_OW		0x04000000
+#define TSTAT0_TXU		0x02000000
+#define TSTAT0_ECOLL		0x01000000
+#define TSTAT0_NCOLL		0x001f0000
+#define TSTAT0_BUFFER_INDEX	0x00007fff
+
+struct ep93xx_descs
+{
+	struct ep93xx_rdesc	rdesc[RX_QUEUE_ENTRIES];
+	struct ep93xx_tdesc	tdesc[TX_QUEUE_ENTRIES];
+	struct ep93xx_rstat	rstat[RX_QUEUE_ENTRIES];
+	struct ep93xx_tstat	tstat[TX_QUEUE_ENTRIES];
+};
+
+struct ep93xx_priv
+{
+	struct resource		*res;
+	void			*base_addr;
+	int			irq;
+
+	struct ep93xx_descs	*descs;
+	dma_addr_t		descs_dma_addr;
+
+	void			*rx_buf[RX_QUEUE_ENTRIES];
+	void			*tx_buf[TX_QUEUE_ENTRIES];
+
+	spinlock_t		rx_lock;
+	unsigned int		rx_pointer;
+	unsigned int		tx_clean_pointer;
+	unsigned int		tx_pointer;
+	spinlock_t		tx_pending_lock;
+	unsigned int		tx_pending;
+
+	struct net_device_stats	stats;
+
+	struct mii_if_info	mii;
+	u8			mdc_divisor;
+};
+
+#define rdb(ep, off)		__raw_readb((ep)->base_addr + (off))
+#define rdw(ep, off)		__raw_readw((ep)->base_addr + (off))
+#define rdl(ep, off)		__raw_readl((ep)->base_addr + (off))
+#define wrb(ep, off, val)	__raw_writeb((val), (ep)->base_addr + (off))
+#define wrw(ep, off, val)	__raw_writew((val), (ep)->base_addr + (off))
+#define wrl(ep, off, val)	__raw_writel((val), (ep)->base_addr + (off))
+
+static int ep93xx_mdio_read(struct net_device *dev, int phy_id, int reg);
+
+static struct net_device_stats *ep93xx_get_stats(struct net_device *dev)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	return &(ep->stats);
+}
+
+static int ep93xx_rx(struct net_device *dev, int *budget)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	int tail_offset;
+	int rx_done;
+	int processed;
+
+	tail_offset = rdl(ep, REG_RXSTSQCURADD) - ep->descs_dma_addr;
+
+	rx_done = 0;
+	processed = 0;
+	while (*budget > 0) {
+		int entry;
+		struct ep93xx_rstat *rstat;
+		u32 rstat0;
+		u32 rstat1;
+		int length;
+		struct sk_buff *skb;
+
+		entry = ep->rx_pointer;
+		rstat = ep->descs->rstat + entry;
+		if ((void *)rstat - (void *)ep->descs == tail_offset) {
+			rx_done = 1;
+			break;
+		}
+
+		rstat0 = rstat->rstat0;
+		rstat1 = rstat->rstat1;
+		rstat->rstat0 = 0;
+		rstat->rstat1 = 0;
+
+		if (!(rstat0 & RSTAT0_RFP))
+			printk(KERN_CRIT "ep93xx_rx: buffer not done "
+					 " %.8x %.8x\n", rstat0, rstat1);
+		if (!(rstat0 & RSTAT0_EOF))
+			printk(KERN_CRIT "ep93xx_rx: not end-of-frame "
+					 " %.8x %.8x\n", rstat0, rstat1);
+		if (!(rstat0 & RSTAT0_EOB))
+			printk(KERN_CRIT "ep93xx_rx: not end-of-buffer "
+					 " %.8x %.8x\n", rstat0, rstat1);
+		if (!(rstat1 & RSTAT1_RFP))
+			printk(KERN_CRIT "ep93xx_rx: buffer1 not done "
+					 " %.8x %.8x\n", rstat0, rstat1);
+		if ((rstat1 & RSTAT1_BUFFER_INDEX) >> 16 != entry)
+			printk(KERN_CRIT "ep93xx_rx: entry mismatch "
+					 " %.8x %.8x\n", rstat0, rstat1);
+
+		if (!(rstat0 & RSTAT0_RWE)) {
+			printk(KERN_NOTICE "ep93xx_rx: receive error "
+					 " %.8x %.8x\n", rstat0, rstat1);
+
+			ep->stats.rx_errors++;
+			if (rstat0 & RSTAT0_OE)
+				ep->stats.rx_fifo_errors++;
+			if (rstat0 & RSTAT0_FE)
+				ep->stats.rx_frame_errors++;
+			if (rstat0 & (RSTAT0_RUNT | RSTAT0_EDATA))
+				ep->stats.rx_length_errors++;
+			if (rstat0 & RSTAT0_CRCE)
+				ep->stats.rx_crc_errors++;
+			goto err;
+		}
+
+		length = rstat1 & RSTAT1_FRAME_LENGTH;
+		if (length > MAX_PKT_SIZE) {
+			printk(KERN_NOTICE "ep93xx_rx: invalid length "
+					 " %.8x %.8x\n", rstat0, rstat1);
+			goto err;
+		}
+
+		/* Strip FCS.  */
+		if (rstat0 & RSTAT0_CRCI)
+			length -= 4;
+
+		skb = dev_alloc_skb(length + 2);
+		if (likely(skb != NULL)) {
+			skb->dev = dev;
+			skb_reserve(skb, 2);
+			dma_sync_single(NULL, ep->descs->rdesc[entry].buf_addr,
+						length, DMA_FROM_DEVICE);
+			eth_copy_and_sum(skb, ep->rx_buf[entry], length, 0);
+			skb_put(skb, length);
+			skb->protocol = eth_type_trans(skb, dev);
+
+			dev->last_rx = jiffies;
+
+			netif_receive_skb(skb);
+
+			ep->stats.rx_packets++;
+			ep->stats.rx_bytes += length;
+		} else {
+			ep->stats.rx_dropped++;
+		}
+
+err:
+		ep->rx_pointer = (entry + 1) & (RX_QUEUE_ENTRIES - 1);
+		processed++;
+		dev->quota--;
+		(*budget)--;
+	}
+
+	if (processed) {
+		wrw(ep, REG_RXDENQ, processed);
+		wrw(ep, REG_RXSTSENQ, processed);
+	}
+
+	return !rx_done;
+}
+
+static int ep93xx_have_more_rx(struct ep93xx_priv *ep)
+{
+	struct ep93xx_rstat *rstat;
+	int tail_offset;
+
+	rstat = ep->descs->rstat + ep->rx_pointer;
+	tail_offset = rdl(ep, REG_RXSTSQCURADD) - ep->descs_dma_addr;
+
+	return !((void *)rstat - (void *)ep->descs == tail_offset);
+}
+
+static int ep93xx_poll(struct net_device *dev, int *budget)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+
+	/*
+	 * @@@ Have to stop polling if device is downed while we
+	 * are polling.
+	 */
+
+poll_some_more:
+	if (ep93xx_rx(dev, budget))
+		return 1;
+
+	netif_rx_complete(dev);
+
+	spin_lock_irq(&ep->rx_lock);
+	wrl(ep, REG_INTEN, REG_INTEN_TX | REG_INTEN_RX);
+	if (ep93xx_have_more_rx(ep)) {
+		wrl(ep, REG_INTEN, REG_INTEN_TX);
+		wrl(ep, REG_INTSTSP, REG_INTSTS_RX);
+		spin_unlock_irq(&ep->rx_lock);
+
+		if (netif_rx_reschedule(dev, 0))
+			goto poll_some_more;
+
+		return 0;
+	}
+	spin_unlock_irq(&ep->rx_lock);
+
+	return 0;
+}
+
+static int ep93xx_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	int entry;
+
+	if (unlikely(skb->len) > MAX_PKT_SIZE) {
+		ep->stats.tx_dropped++;
+		dev_kfree_skb(skb);
+		return NETDEV_TX_OK;
+	}
+
+	entry = ep->tx_pointer;
+	ep->tx_pointer = (ep->tx_pointer + 1) & (TX_QUEUE_ENTRIES - 1);
+
+	ep->descs->tdesc[entry].tdesc1 =
+		TDESC1_EOF | (entry << 16) | (skb->len & 0xfff);
+	skb_copy_and_csum_dev(skb, ep->tx_buf[entry]);
+	dma_sync_single(NULL, ep->descs->tdesc[entry].buf_addr,
+				skb->len, DMA_TO_DEVICE);
+	dev_kfree_skb(skb);
+
+	dev->trans_start = jiffies;
+
+	spin_lock_irq(&ep->tx_pending_lock);
+	ep->tx_pending++;
+	if (ep->tx_pending == TX_QUEUE_ENTRIES)
+		netif_stop_queue(dev);
+	spin_unlock_irq(&ep->tx_pending_lock);
+
+	wrl(ep, REG_TXDENQ, 1);
+
+	return NETDEV_TX_OK;
+}
+
+static void ep93xx_tx_complete(struct net_device *dev)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	int tail_offset;
+	int wake;
+
+	tail_offset = rdl(ep, REG_TXSTSQCURADD) - ep->descs_dma_addr;
+	wake = 0;
+
+	spin_lock(&ep->tx_pending_lock);
+	while (1) {
+		int entry;
+		struct ep93xx_tstat *tstat;
+		u32 tstat0;
+
+		entry = ep->tx_clean_pointer;
+		tstat = ep->descs->tstat + entry;
+		if ((void *)tstat - (void *)ep->descs == tail_offset)
+			break;
+
+		tstat0 = tstat->tstat0;
+		tstat->tstat0 = 0;
+
+		if (!(tstat0 & TSTAT0_TXFP))
+			printk(KERN_CRIT "ep93xx_tx_complete: buffer not done "
+					 " %.8x\n", tstat0);
+		if (tstat0 & TSTAT0_FA)
+			printk(KERN_CRIT "ep93xx_tx_complete: frame aborted "
+					 " %.8x\n", tstat0);
+		if ((tstat0 & TSTAT0_BUFFER_INDEX) != entry)
+			printk(KERN_CRIT "ep93xx_tx_complete: entry mismatch "
+					 " %.8x\n", tstat0);
+
+		if (tstat0 & TSTAT0_TXWE) {
+			int length = ep->descs->tdesc[entry].tdesc1 & 0xfff;
+
+			ep->stats.tx_packets++;
+			ep->stats.tx_bytes += length;
+		} else {
+			ep->stats.tx_errors++;
+		}
+
+		if (tstat0 & TSTAT0_OW)
+			ep->stats.tx_window_errors++;
+		if (tstat0 & TSTAT0_TXU)
+			ep->stats.tx_fifo_errors++;
+		ep->stats.collisions += (tstat0 >> 16) & 0x1f;
+
+		ep->tx_clean_pointer = (entry + 1) & (TX_QUEUE_ENTRIES - 1);
+		if (ep->tx_pending == TX_QUEUE_ENTRIES)
+			wake = 1;
+		ep->tx_pending--;
+	}
+	spin_unlock(&ep->tx_pending_lock);
+
+	if (wake)
+		netif_wake_queue(dev);
+}
+
+static irqreturn_t ep93xx_irq(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct net_device *dev = dev_id;
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	u32 status;
+
+	status = rdl(ep, REG_INTSTSC);
+	if (status == 0)
+		return IRQ_NONE;
+
+	if (status & REG_INTSTS_RX) {
+		spin_lock(&ep->rx_lock);
+		if (likely(__netif_rx_schedule_prep(dev))) {
+			wrl(ep, REG_INTEN, REG_INTEN_TX);
+			__netif_rx_schedule(dev);
+		}
+		spin_unlock(&ep->rx_lock);
+	}
+
+	if (status & REG_INTSTS_TX)
+		ep93xx_tx_complete(dev);
+
+	return IRQ_HANDLED;
+}
+
+static void ep93xx_free_buffers(struct ep93xx_priv *ep)
+{
+	int i;
+
+	for (i = 0; i < RX_QUEUE_ENTRIES; i += 2) {
+		dma_addr_t d;
+
+		d = ep->descs->rdesc[i].buf_addr;
+		if (d)
+			dma_unmap_single(NULL, d, PAGE_SIZE, DMA_FROM_DEVICE);
+
+		if (ep->rx_buf[i] != NULL)
+			free_page((unsigned long)ep->rx_buf[i]);
+	}
+
+	for (i = 0; i < TX_QUEUE_ENTRIES; i += 2) {
+		dma_addr_t d;
+
+		d = ep->descs->tdesc[i].buf_addr;
+		if (d)
+			dma_unmap_single(NULL, d, PAGE_SIZE, DMA_TO_DEVICE);
+
+		if (ep->tx_buf[i] != NULL)
+			free_page((unsigned long)ep->tx_buf[i]);
+	}
+
+	dma_free_coherent(NULL, sizeof(struct ep93xx_descs), ep->descs,
+							ep->descs_dma_addr);
+}
+
+/*
+ * The hardware enforces a sub-2K maximum packet size, so we put
+ * two buffers on every hardware page.
+ */
+static int ep93xx_alloc_buffers(struct ep93xx_priv *ep)
+{
+	int i;
+
+	ep->descs = dma_alloc_coherent(NULL, sizeof(struct ep93xx_descs),
+				&ep->descs_dma_addr, GFP_KERNEL | GFP_DMA);
+	if (ep->descs == NULL)
+		return 1;
+
+	for (i = 0; i < RX_QUEUE_ENTRIES; i += 2) {
+		void *page;
+		dma_addr_t d;
+
+		page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
+		if (page == NULL)
+			goto err;
+
+		d = dma_map_single(NULL, page, PAGE_SIZE, DMA_FROM_DEVICE);
+		if (dma_mapping_error(d)) {
+			free_page((unsigned long)page);
+			goto err;
+		}
+
+		ep->rx_buf[i] = page;
+		ep->descs->rdesc[i].buf_addr = d;
+		ep->descs->rdesc[i].rdesc1 = (i << 16) | PKT_BUF_SIZE;
+
+		ep->rx_buf[i + 1] = page + PKT_BUF_SIZE;
+		ep->descs->rdesc[i + 1].buf_addr = d + PKT_BUF_SIZE;
+		ep->descs->rdesc[i + 1].rdesc1 = ((i + 1) << 16) | PKT_BUF_SIZE;
+	}
+
+	for (i = 0; i < TX_QUEUE_ENTRIES; i += 2) {
+		void *page;
+		dma_addr_t d;
+
+		page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
+		if (page == NULL)
+			goto err;
+
+		d = dma_map_single(NULL, page, PAGE_SIZE, DMA_TO_DEVICE);
+		if (dma_mapping_error(d)) {
+			free_page((unsigned long)page);
+			goto err;
+		}
+
+		ep->tx_buf[i] = page;
+		ep->descs->tdesc[i].buf_addr = d;
+
+		ep->tx_buf[i + 1] = page + PKT_BUF_SIZE;
+		ep->descs->tdesc[i + 1].buf_addr = d + PKT_BUF_SIZE;
+	}
+
+	return 0;
+
+err:
+	ep93xx_free_buffers(ep);
+	return 1;
+}
+
+static int ep93xx_start_hw(struct net_device *dev)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	unsigned long addr;
+	int i;
+
+	wrl(ep, REG_SELFCTL, REG_SELFCTL_RESET);
+	for (i = 0; i < 10; i++) {
+		if ((rdl(ep, REG_SELFCTL) & REG_SELFCTL_RESET) == 0)
+			break;
+		msleep(1);
+	}
+
+	if (i == 10) {
+		printk(KERN_CRIT DRV_MODULE_NAME ": hw failed to reset\n");
+		return 1;
+	}
+
+	wrl(ep, REG_SELFCTL, ((ep->mdc_divisor - 1) << 9));
+
+	/* Does the PHY support preamble suppress?  */
+	if ((ep93xx_mdio_read(dev, ep->mii.phy_id, MII_BMSR) & 0x0040) != 0)
+		wrl(ep, REG_SELFCTL, ((ep->mdc_divisor - 1) << 9) | (1 << 8));
+
+	/* Receive descriptor ring.  */
+	addr = ep->descs_dma_addr + offsetof(struct ep93xx_descs, rdesc);
+	wrl(ep, REG_RXDQBADD, addr);
+	wrl(ep, REG_RXDCURADD, addr);
+	wrw(ep, REG_RXDQBLEN, RX_QUEUE_ENTRIES * sizeof(struct ep93xx_rdesc));
+
+	/* Receive status ring.  */
+	addr = ep->descs_dma_addr + offsetof(struct ep93xx_descs, rstat);
+	wrl(ep, REG_RXSTSQBADD, addr);
+	wrl(ep, REG_RXSTSQCURADD, addr);
+	wrw(ep, REG_RXSTSQBLEN, RX_QUEUE_ENTRIES * sizeof(struct ep93xx_rstat));
+
+	/* Transmit descriptor ring.  */
+	addr = ep->descs_dma_addr + offsetof(struct ep93xx_descs, tdesc);
+	wrl(ep, REG_TXDQBADD, addr);
+	wrl(ep, REG_TXDQCURADD, addr);
+	wrw(ep, REG_TXDQBLEN, TX_QUEUE_ENTRIES * sizeof(struct ep93xx_tdesc));
+
+	/* Transmit status ring.  */
+	addr = ep->descs_dma_addr + offsetof(struct ep93xx_descs, tstat);
+	wrl(ep, REG_TXSTSQBADD, addr);
+	wrl(ep, REG_TXSTSQCURADD, addr);
+	wrw(ep, REG_TXSTSQBLEN, TX_QUEUE_ENTRIES * sizeof(struct ep93xx_tstat));
+
+	wrl(ep, REG_BMCTL, REG_BMCTL_ENABLE_TX | REG_BMCTL_ENABLE_RX);
+	wrl(ep, REG_INTEN, REG_INTEN_TX | REG_INTEN_RX);
+	wrl(ep, REG_GIINTMSK, 0);
+
+	for (i = 0; i < 10; i++) {
+		if ((rdl(ep, REG_BMSTS) & REG_BMSTS_RX_ACTIVE) != 0)
+			break;
+		msleep(1);
+	}
+
+	if (i == 10) {
+		printk(KERN_CRIT DRV_MODULE_NAME ": hw failed to start\n");
+		return 1;
+	}
+
+	wrl(ep, REG_RXDENQ, RX_QUEUE_ENTRIES);
+	wrl(ep, REG_RXSTSENQ, RX_QUEUE_ENTRIES);
+
+	wrb(ep, REG_INDAD0, dev->dev_addr[0]);
+	wrb(ep, REG_INDAD1, dev->dev_addr[1]);
+	wrb(ep, REG_INDAD2, dev->dev_addr[2]);
+	wrb(ep, REG_INDAD3, dev->dev_addr[3]);
+	wrb(ep, REG_INDAD4, dev->dev_addr[4]);
+	wrb(ep, REG_INDAD5, dev->dev_addr[5]);
+	wrl(ep, REG_AFP, 0);
+
+	wrl(ep, REG_MAXFRMLEN, (MAX_PKT_SIZE << 16) | MAX_PKT_SIZE);
+
+	wrl(ep, REG_RXCTL, REG_RXCTL_DEFAULT);
+	wrl(ep, REG_TXCTL, REG_TXCTL_ENABLE);
+
+	return 0;
+}
+
+static void ep93xx_stop_hw(struct net_device *dev)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	int i;
+
+	wrl(ep, REG_SELFCTL, REG_SELFCTL_RESET);
+	for (i = 0; i < 10; i++) {
+		if ((rdl(ep, REG_SELFCTL) & REG_SELFCTL_RESET) == 0)
+			break;
+		msleep(1);
+	}
+
+	if (i == 10)
+		printk(KERN_CRIT DRV_MODULE_NAME ": hw failed to reset\n");
+}
+
+static int ep93xx_open(struct net_device *dev)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	int err;
+
+	if (ep93xx_alloc_buffers(ep))
+		return -ENOMEM;
+
+	if (is_zero_ether_addr(dev->dev_addr)) {
+		random_ether_addr(dev->dev_addr);
+		printk(KERN_INFO "%s: generated random MAC address "
+			"%.2x:%.2x:%.2x:%.2x:%.2x:%.2x.\n", dev->name,
+			dev->dev_addr[0], dev->dev_addr[1],
+			dev->dev_addr[2], dev->dev_addr[3],
+			dev->dev_addr[4], dev->dev_addr[5]);
+	}
+
+	if (ep93xx_start_hw(dev)) {
+		ep93xx_free_buffers(ep);
+		return -EIO;
+	}
+
+	spin_lock_init(&ep->rx_lock);
+	ep->rx_pointer = 0;
+	ep->tx_clean_pointer = 0;
+	ep->tx_pointer = 0;
+	spin_lock_init(&ep->tx_pending_lock);
+	ep->tx_pending = 0;
+
+	err = request_irq(ep->irq, ep93xx_irq, IRQF_SHARED, dev->name, dev);
+	if (err) {
+		ep93xx_stop_hw(dev);
+		ep93xx_free_buffers(ep);
+		return err;
+	}
+
+	wrl(ep, REG_GIINTMSK, REG_GIINTMSK_ENABLE);
+
+	netif_start_queue(dev);
+
+	return 0;
+}
+
+static int ep93xx_close(struct net_device *dev)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+
+	netif_stop_queue(dev);
+
+	wrl(ep, REG_GIINTMSK, 0);
+	free_irq(ep->irq, dev);
+	ep93xx_stop_hw(dev);
+	ep93xx_free_buffers(ep);
+
+	return 0;
+}
+
+static int ep93xx_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	struct mii_ioctl_data *data = if_mii(ifr);
+
+	return generic_mii_ioctl(&ep->mii, data, cmd, NULL);
+}
+
+static int ep93xx_mdio_read(struct net_device *dev, int phy_id, int reg)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	int data;
+	int i;
+
+	wrl(ep, REG_MIICMD, REG_MIICMD_READ | (phy_id << 5) | reg);
+
+	for (i = 0; i < 10; i++) {
+		if ((rdl(ep, REG_MIISTS) & REG_MIISTS_BUSY) == 0)
+			break;
+		msleep(1);
+	}
+
+	if (i == 10) {
+		printk(KERN_INFO DRV_MODULE_NAME ": mdio read timed out\n");
+		data = 0xffff;
+	} else {
+		data = rdl(ep, REG_MIIDATA);
+	}
+
+	return data;
+}
+
+static void ep93xx_mdio_write(struct net_device *dev, int phy_id, int reg, int data)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	int i;
+
+	wrl(ep, REG_MIIDATA, data);
+	wrl(ep, REG_MIICMD, REG_MIICMD_WRITE | (phy_id << 5) | reg);
+
+	for (i = 0; i < 10; i++) {
+		if ((rdl(ep, REG_MIISTS) & REG_MIISTS_BUSY) == 0)
+			break;
+		msleep(1);
+	}
+
+	if (i == 10)
+		printk(KERN_INFO DRV_MODULE_NAME ": mdio write timed out\n");
+}
+
+static void ep93xx_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
+{
+	strcpy(info->driver, DRV_MODULE_NAME);
+	strcpy(info->version, DRV_MODULE_VERSION);
+}
+
+static int ep93xx_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	return mii_ethtool_gset(&ep->mii, cmd);
+}
+
+static int ep93xx_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	return mii_ethtool_sset(&ep->mii, cmd);
+}
+
+static int ep93xx_nway_reset(struct net_device *dev)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	return mii_nway_restart(&ep->mii);
+}
+
+static u32 ep93xx_get_link(struct net_device *dev)
+{
+	struct ep93xx_priv *ep = netdev_priv(dev);
+	return mii_link_ok(&ep->mii);
+}
+
+static struct ethtool_ops ep93xx_ethtool_ops = {
+	.get_drvinfo		= ep93xx_get_drvinfo,
+	.get_settings		= ep93xx_get_settings,
+	.set_settings		= ep93xx_set_settings,
+	.nway_reset		= ep93xx_nway_reset,
+	.get_link		= ep93xx_get_link,
+};
+
+struct net_device *ep93xx_dev_alloc(struct ep93xx_eth_data *data)
+{
+	struct net_device *dev;
+	struct ep93xx_priv *ep;
+
+	dev = alloc_etherdev(sizeof(struct ep93xx_priv));
+	if (dev == NULL)
+		return NULL;
+	ep = netdev_priv(dev);
+
+	memcpy(dev->dev_addr, data->dev_addr, ETH_ALEN);
+
+	dev->get_stats = ep93xx_get_stats;
+	dev->ethtool_ops = &ep93xx_ethtool_ops;
+	dev->poll = ep93xx_poll;
+	dev->hard_start_xmit = ep93xx_xmit;
+	dev->open = ep93xx_open;
+	dev->stop = ep93xx_close;
+	dev->do_ioctl = ep93xx_ioctl;
+
+	dev->features |= NETIF_F_SG | NETIF_F_HW_CSUM;
+	dev->weight = 64;
+
+	return dev;
+}
+
+
+static int ep93xx_eth_remove(struct platform_device *pdev)
+{
+	struct net_device *dev;
+	struct ep93xx_priv *ep;
+
+	dev = platform_get_drvdata(pdev);
+	if (dev == NULL)
+		return 0;
+	platform_set_drvdata(pdev, NULL);
+
+	ep = netdev_priv(dev);
+
+	/* @@@ Force down.  */
+	unregister_netdev(dev);
+	ep93xx_free_buffers(ep);
+
+	if (ep->base_addr != NULL)
+		iounmap(ep->base_addr);
+
+	if (ep->res != NULL) {
+		release_resource(ep->res);
+		kfree(ep->res);
+	}
+
+	free_netdev(dev);
+
+	return 0;
+}
+
+static int ep93xx_eth_probe(struct platform_device *pdev)
+{
+	struct ep93xx_eth_data *data;
+	struct net_device *dev;
+	struct ep93xx_priv *ep;
+	int err;
+
+	data = pdev->dev.platform_data;
+	if (pdev == NULL)
+		return -ENODEV;
+
+	dev = ep93xx_dev_alloc(data);
+	if (dev == NULL) {
+		err = -ENOMEM;
+		goto err_out;
+	}
+	ep = netdev_priv(dev);
+
+	platform_set_drvdata(pdev, dev);
+
+	ep->res = request_mem_region(pdev->resource[0].start,
+			pdev->resource[0].end - pdev->resource[0].start + 1,
+			pdev->dev.bus_id);
+	if (ep->res == NULL) {
+		dev_err(&pdev->dev, "Could not reserve memory region\n");
+		err = -ENOMEM;
+		goto err_out;
+	}
+
+	ep->base_addr = ioremap(pdev->resource[0].start,
+			pdev->resource[0].end - pdev->resource[0].start);
+	if (ep->base_addr == NULL) {
+		dev_err(&pdev->dev, "Failed to ioremap ethernet registers\n");
+		err = -EIO;
+		goto err_out;
+	}
+	ep->irq = pdev->resource[1].start;
+
+	ep->mii.phy_id = data->phy_id;
+	ep->mii.phy_id_mask = 0x1f;
+	ep->mii.reg_num_mask = 0x1f;
+	ep->mii.dev = dev;
+	ep->mii.mdio_read = ep93xx_mdio_read;
+	ep->mii.mdio_write = ep93xx_mdio_write;
+	ep->mdc_divisor = 40;	/* Max HCLK 100 MHz, min MDIO clk 2.5 MHz.  */
+
+	err = register_netdev(dev);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to register netdev\n");
+		goto err_out;
+	}
+
+	printk(KERN_INFO "%s: ep93xx on-chip ethernet, IRQ %d, "
+			 "%.2x:%.2x:%.2x:%.2x:%.2x:%.2x.\n", dev->name,
+			ep->irq, data->dev_addr[0], data->dev_addr[1],
+			data->dev_addr[2], data->dev_addr[3],
+			data->dev_addr[4], data->dev_addr[5]);
+
+	return 0;
+
+err_out:
+	ep93xx_eth_remove(pdev);
+	return err;
+}
+
+
+static struct platform_driver ep93xx_eth_driver = {
+	.probe		= ep93xx_eth_probe,
+	.remove		= ep93xx_eth_remove,
+	.driver		= {
+		.name	= "ep93xx-eth",
+	},
+};
+
+static int __init ep93xx_eth_init_module(void)
+{
+	printk(KERN_INFO DRV_MODULE_NAME " version " DRV_MODULE_VERSION " loading\n");
+	return platform_driver_register(&ep93xx_eth_driver);
+}
+
+static void __exit ep93xx_eth_cleanup_module(void)
+{
+	platform_driver_unregister(&ep93xx_eth_driver);
+}
+
+module_init(ep93xx_eth_init_module);
+module_exit(ep93xx_eth_cleanup_module);
+MODULE_LICENSE("GPL");