[PATCH] AT91RM9200 Ethernet driver

This patch adds support for the Ethernet controller integrated in the
Atmel AT91RM9200 SoC processor.

Changes since the previous submission (01/02/2006) are:
  - Make use of the clk.h clock infrastructure.
  - The multicast hash function is not crc32. [Patch by Pedro Perez]

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 1110 insertions, 0 deletions

diff --git a/drivers/net/arm/at91_ether.c b/drivers/net/arm/at91_ether.c
new file mode 100644
index 0000000..5503dc8
--- /dev/null
+++ b/drivers/net/arm/at91_ether.c
@@ -0,0 +1,1110 @@
+/*
+ * Ethernet driver for the Atmel AT91RM9200 (Thunder)
+ *
+ *  Copyright (C) 2003 SAN People (Pty) Ltd
+ *
+ * Based on an earlier Atmel EMAC macrocell driver by Atmel and Lineo Inc.
+ * Initial version by Rick Bronson 01/11/2003
+ *
+ * Intel LXT971A PHY support by Christopher Bahns & David Knickerbocker
+ *   (Polaroid Corporation)
+ *
+ * Realtek RTL8201(B)L PHY support by Roman Avramenko <roman@imsystems.ru>
+ *
+ * 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/module.h>
+#include <linux/init.h>
+#include <linux/config.h>
+#include <linux/mii.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/dma-mapping.h>
+#include <linux/ethtool.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/mach-types.h>
+
+#include <asm/arch/at91rm9200_emac.h>
+#include <asm/arch/gpio.h>
+#include <asm/arch/board.h>
+
+#include "at91_ether.h"
+
+#define DRV_NAME	"at91_ether"
+#define DRV_VERSION	"1.0"
+
+static struct net_device *at91_dev;
+static struct clk *ether_clk;
+
+/* ..................................................................... */
+
+/*
+ * Read from a EMAC register.
+ */
+static inline unsigned long at91_emac_read(unsigned int reg)
+{
+	void __iomem *emac_base = (void __iomem *)AT91_VA_BASE_EMAC;
+
+	return __raw_readl(emac_base + reg);
+}
+
+/*
+ * Write to a EMAC register.
+ */
+static inline void at91_emac_write(unsigned int reg, unsigned long value)
+{
+	void __iomem *emac_base = (void __iomem *)AT91_VA_BASE_EMAC;
+
+	__raw_writel(value, emac_base + reg);
+}
+
+/* ........................... PHY INTERFACE ........................... */
+
+/*
+ * Enable the MDIO bit in MAC control register
+ * When not called from an interrupt-handler, access to the PHY must be
+ *  protected by a spinlock.
+ */
+static void enable_mdi(void)
+{
+	unsigned long ctl;
+
+	ctl = at91_emac_read(AT91_EMAC_CTL);
+	at91_emac_write(AT91_EMAC_CTL, ctl | AT91_EMAC_MPE);	/* enable management port */
+}
+
+/*
+ * Disable the MDIO bit in the MAC control register
+ */
+static void disable_mdi(void)
+{
+	unsigned long ctl;
+
+	ctl = at91_emac_read(AT91_EMAC_CTL);
+	at91_emac_write(AT91_EMAC_CTL, ctl & ~AT91_EMAC_MPE);	/* disable management port */
+}
+
+/*
+ * Wait until the PHY operation is complete.
+ */
+static inline void at91_phy_wait(void) {
+	unsigned long timeout = jiffies + 2;
+
+	while (!(at91_emac_read(AT91_EMAC_SR) & AT91_EMAC_SR_IDLE)) {
+		if (time_after(jiffies, timeout)) {
+			printk("at91_ether: MIO timeout\n");
+			break;
+		}
+		cpu_relax();
+	}
+}
+
+/*
+ * Write value to the a PHY register
+ * Note: MDI interface is assumed to already have been enabled.
+ */
+static void write_phy(unsigned char phy_addr, unsigned char address, unsigned int value)
+{
+	at91_emac_write(AT91_EMAC_MAN, AT91_EMAC_MAN_802_3 | AT91_EMAC_RW_W
+		| ((phy_addr & 0x1f) << 23) | (address << 18) | (value & AT91_EMAC_DATA));
+
+	/* Wait until IDLE bit in Network Status register is cleared */
+	at91_phy_wait();
+}
+
+/*
+ * Read value stored in a PHY register.
+ * Note: MDI interface is assumed to already have been enabled.
+ */
+static void read_phy(unsigned char phy_addr, unsigned char address, unsigned int *value)
+{
+	at91_emac_write(AT91_EMAC_MAN, AT91_EMAC_MAN_802_3 | AT91_EMAC_RW_R
+		| ((phy_addr & 0x1f) << 23) | (address << 18));
+
+	/* Wait until IDLE bit in Network Status register is cleared */
+	at91_phy_wait();
+
+	*value = at91_emac_read(AT91_EMAC_MAN) & AT91_EMAC_DATA;
+}
+
+/* ........................... PHY MANAGEMENT .......................... */
+
+/*
+ * Access the PHY to determine the current link speed and mode, and update the
+ * MAC accordingly.
+ * If no link or auto-negotiation is busy, then no changes are made.
+ */
+static void update_linkspeed(struct net_device *dev)
+{
+	struct at91_private *lp = (struct at91_private *) dev->priv;
+	unsigned int bmsr, bmcr, lpa, mac_cfg;
+	unsigned int speed, duplex;
+
+	if (!mii_link_ok(&lp->mii)) {		/* no link */
+		netif_carrier_off(dev);
+		printk(KERN_INFO "%s: Link down.\n", dev->name);
+		return;
+	}
+
+	/* Link up, or auto-negotiation still in progress */
+	read_phy(lp->phy_address, MII_BMSR, &bmsr);
+	read_phy(lp->phy_address, MII_BMCR, &bmcr);
+	if (bmcr & BMCR_ANENABLE) {				/* AutoNegotiation is enabled */
+		if (!(bmsr & BMSR_ANEGCOMPLETE))
+			return;			/* Do nothing - another interrupt generated when negotiation complete */
+
+		read_phy(lp->phy_address, MII_LPA, &lpa);
+		if ((lpa & LPA_100FULL) || (lpa & LPA_100HALF)) speed = SPEED_100;
+		else speed = SPEED_10;
+		if ((lpa & LPA_100FULL) || (lpa & LPA_10FULL)) duplex = DUPLEX_FULL;
+		else duplex = DUPLEX_HALF;
+	} else {
+		speed = (bmcr & BMCR_SPEED100) ? SPEED_100 : SPEED_10;
+		duplex = (bmcr & BMCR_FULLDPLX) ? DUPLEX_FULL : DUPLEX_HALF;
+	}
+
+	/* Update the MAC */
+	mac_cfg = at91_emac_read(AT91_EMAC_CFG) & ~(AT91_EMAC_SPD | AT91_EMAC_FD);
+	if (speed == SPEED_100) {
+		if (duplex == DUPLEX_FULL)		/* 100 Full Duplex */
+			mac_cfg |= AT91_EMAC_SPD | AT91_EMAC_FD;
+		else					/* 100 Half Duplex */
+			mac_cfg |= AT91_EMAC_SPD;
+	} else {
+		if (duplex == DUPLEX_FULL)		/* 10 Full Duplex */
+			mac_cfg |= AT91_EMAC_FD;
+		else {}					/* 10 Half Duplex */
+	}
+	at91_emac_write(AT91_EMAC_CFG, mac_cfg);
+
+	printk(KERN_INFO "%s: Link now %i-%s\n", dev->name, speed, (duplex == DUPLEX_FULL) ? "FullDuplex" : "HalfDuplex");
+	netif_carrier_on(dev);
+}
+
+/*
+ * Handle interrupts from the PHY
+ */
+static irqreturn_t at91ether_phy_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct net_device *dev = (struct net_device *) dev_id;
+	struct at91_private *lp = (struct at91_private *) dev->priv;
+	unsigned int phy;
+
+	/*
+	 * This hander is triggered on both edges, but the PHY chips expect
+	 * level-triggering.  We therefore have to check if the PHY actually has
+	 * an IRQ pending.
+	 */
+	enable_mdi();
+	if ((lp->phy_type == MII_DM9161_ID) || (lp->phy_type == MII_DM9161A_ID)) {
+		read_phy(lp->phy_address, MII_DSINTR_REG, &phy);	/* ack interrupt in Davicom PHY */
+		if (!(phy & (1 << 0)))
+			goto done;
+	}
+	else if (lp->phy_type == MII_LXT971A_ID) {
+		read_phy(lp->phy_address, MII_ISINTS_REG, &phy);	/* ack interrupt in Intel PHY */
+		if (!(phy & (1 << 2)))
+			goto done;
+	}
+	else if (lp->phy_type == MII_BCM5221_ID) {
+		read_phy(lp->phy_address, MII_BCMINTR_REG, &phy);	/* ack interrupt in Broadcom PHY */
+		if (!(phy & (1 << 0)))
+			goto done;
+	}
+	else if (lp->phy_type == MII_KS8721_ID) {
+		read_phy(lp->phy_address, MII_TPISTATUS, &phy);		/* ack interrupt in Micrel PHY */
+		if (!(phy & ((1 << 2) | 1)))
+			goto done;
+	}
+
+	update_linkspeed(dev);
+
+done:
+	disable_mdi();
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Initialize and enable the PHY interrupt for link-state changes
+ */
+static void enable_phyirq(struct net_device *dev)
+{
+	struct at91_private *lp = (struct at91_private *) dev->priv;
+	unsigned int dsintr, irq_number;
+	int status;
+
+	if (lp->phy_type == MII_RTL8201_ID)	/* RTL8201 does not have an interrupt */
+		return;
+	if (lp->phy_type == MII_DP83847_ID)	/* DP83847 does not have an interrupt */
+		return;
+	if (lp->phy_type == MII_AC101L_ID)	/* AC101L interrupt not supported yet */
+		return;
+
+	irq_number = lp->board_data.phy_irq_pin;
+	status = request_irq(irq_number, at91ether_phy_interrupt, 0, dev->name, dev);
+	if (status) {
+		printk(KERN_ERR "at91_ether: PHY IRQ %d request failed - status %d!\n", irq_number, status);
+		return;
+	}
+
+	spin_lock_irq(&lp->lock);
+	enable_mdi();
+
+	if ((lp->phy_type == MII_DM9161_ID) || (lp->phy_type == MII_DM9161A_ID)) {	/* for Davicom PHY */
+		read_phy(lp->phy_address, MII_DSINTR_REG, &dsintr);
+		dsintr = dsintr & ~0xf00;		/* clear bits 8..11 */
+		write_phy(lp->phy_address, MII_DSINTR_REG, dsintr);
+	}
+	else if (lp->phy_type == MII_LXT971A_ID) {	/* for Intel PHY */
+		read_phy(lp->phy_address, MII_ISINTE_REG, &dsintr);
+		dsintr = dsintr | 0xf2;			/* set bits 1, 4..7 */
+		write_phy(lp->phy_address, MII_ISINTE_REG, dsintr);
+	}
+	else if (lp->phy_type == MII_BCM5221_ID) {	/* for Broadcom PHY */
+		dsintr = (1 << 15) | ( 1 << 14);
+		write_phy(lp->phy_address, MII_BCMINTR_REG, dsintr);
+	}
+	else if (lp->phy_type == MII_KS8721_ID) {	/* for Micrel PHY */
+		dsintr = (1 << 10) | ( 1 << 8);
+		write_phy(lp->phy_address, MII_TPISTATUS, dsintr);
+	}
+
+	disable_mdi();
+	spin_unlock_irq(&lp->lock);
+}
+
+/*
+ * Disable the PHY interrupt
+ */
+static void disable_phyirq(struct net_device *dev)
+{
+	struct at91_private *lp = (struct at91_private *) dev->priv;
+	unsigned int dsintr;
+	unsigned int irq_number;
+
+	if (lp->phy_type == MII_RTL8201_ID) 	/* RTL8201 does not have an interrupt */
+		return;
+	if (lp->phy_type == MII_DP83847_ID)	/* DP83847 does not have an interrupt */
+		return;
+	if (lp->phy_type == MII_AC101L_ID)	/* AC101L interrupt not supported yet */
+		return;
+
+	spin_lock_irq(&lp->lock);
+	enable_mdi();
+
+	if ((lp->phy_type == MII_DM9161_ID) || (lp->phy_type == MII_DM9161A_ID)) {	/* for Davicom PHY */
+		read_phy(lp->phy_address, MII_DSINTR_REG, &dsintr);
+		dsintr = dsintr | 0xf00;			/* set bits 8..11 */
+		write_phy(lp->phy_address, MII_DSINTR_REG, dsintr);
+	}
+	else if (lp->phy_type == MII_LXT971A_ID) {	/* for Intel PHY */
+		read_phy(lp->phy_address, MII_ISINTE_REG, &dsintr);
+		dsintr = dsintr & ~0xf2;			/* clear bits 1, 4..7 */
+		write_phy(lp->phy_address, MII_ISINTE_REG, dsintr);
+	}
+	else if (lp->phy_type == MII_BCM5221_ID) {	/* for Broadcom PHY */
+		read_phy(lp->phy_address, MII_BCMINTR_REG, &dsintr);
+		dsintr = ~(1 << 14);
+		write_phy(lp->phy_address, MII_BCMINTR_REG, dsintr);
+	}
+	else if (lp->phy_type == MII_KS8721_ID) {	/* for Micrel PHY */
+		read_phy(lp->phy_address, MII_TPISTATUS, &dsintr);
+		dsintr = ~((1 << 10) | (1 << 8));
+		write_phy(lp->phy_address, MII_TPISTATUS, dsintr);
+	}
+
+	disable_mdi();
+	spin_unlock_irq(&lp->lock);
+
+	irq_number = lp->board_data.phy_irq_pin;
+	free_irq(irq_number, dev);			/* Free interrupt handler */
+}
+
+/*
+ * Perform a software reset of the PHY.
+ */
+#if 0
+static void reset_phy(struct net_device *dev)
+{
+	struct at91_private *lp = (struct at91_private *) dev->priv;
+	unsigned int bmcr;
+
+	spin_lock_irq(&lp->lock);
+	enable_mdi();
+
+	/* Perform PHY reset */
+	write_phy(lp->phy_address, MII_BMCR, BMCR_RESET);
+
+	/* Wait until PHY reset is complete */
+	do {
+		read_phy(lp->phy_address, MII_BMCR, &bmcr);
+	} while (!(bmcr && BMCR_RESET));
+
+	disable_mdi();
+	spin_unlock_irq(&lp->lock);
+}
+#endif
+
+/* ......................... ADDRESS MANAGEMENT ........................ */
+
+/*
+ * NOTE: Your bootloader must always set the MAC address correctly before
+ * booting into Linux.
+ *
+ * - It must always set the MAC address after reset, even if it doesn't
+ *   happen to access the Ethernet while it's booting.  Some versions of
+ *   U-Boot on the AT91RM9200-DK do not do this.
+ *
+ * - Likewise it must store the addresses in the correct byte order.
+ *   MicroMonitor (uMon) on the CSB337 does this incorrectly (and
+ *   continues to do so, for bug-compatibility).
+ */
+
+static short __init unpack_mac_address(struct net_device *dev, unsigned int hi, unsigned int lo)
+{
+	char addr[6];
+
+	if (machine_is_csb337()) {
+		addr[5] = (lo & 0xff);			/* The CSB337 bootloader stores the MAC the wrong-way around */
+		addr[4] = (lo & 0xff00) >> 8;
+		addr[3] = (lo & 0xff0000) >> 16;
+		addr[2] = (lo & 0xff000000) >> 24;
+		addr[1] = (hi & 0xff);
+		addr[0] = (hi & 0xff00) >> 8;
+	}
+	else {
+		addr[0] = (lo & 0xff);
+		addr[1] = (lo & 0xff00) >> 8;
+		addr[2] = (lo & 0xff0000) >> 16;
+		addr[3] = (lo & 0xff000000) >> 24;
+		addr[4] = (hi & 0xff);
+		addr[5] = (hi & 0xff00) >> 8;
+	}
+
+	if (is_valid_ether_addr(addr)) {
+		memcpy(dev->dev_addr, &addr, 6);
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * Set the ethernet MAC address in dev->dev_addr
+ */
+static void __init get_mac_address(struct net_device *dev)
+{
+	/* Check Specific-Address 1 */
+	if (unpack_mac_address(dev, at91_emac_read(AT91_EMAC_SA1H), at91_emac_read(AT91_EMAC_SA1L)))
+		return;
+	/* Check Specific-Address 2 */
+	if (unpack_mac_address(dev, at91_emac_read(AT91_EMAC_SA2H), at91_emac_read(AT91_EMAC_SA2L)))
+		return;
+	/* Check Specific-Address 3 */
+	if (unpack_mac_address(dev, at91_emac_read(AT91_EMAC_SA3H), at91_emac_read(AT91_EMAC_SA3L)))
+		return;
+	/* Check Specific-Address 4 */
+	if (unpack_mac_address(dev, at91_emac_read(AT91_EMAC_SA4H), at91_emac_read(AT91_EMAC_SA4L)))
+		return;
+
+	printk(KERN_ERR "at91_ether: Your bootloader did not configure a MAC address.\n");
+}
+
+/*
+ * Program the hardware MAC address from dev->dev_addr.
+ */
+static void update_mac_address(struct net_device *dev)
+{
+	at91_emac_write(AT91_EMAC_SA1L, (dev->dev_addr[3] << 24) | (dev->dev_addr[2] << 16) | (dev->dev_addr[1] << 8) | (dev->dev_addr[0]));
+	at91_emac_write(AT91_EMAC_SA1H, (dev->dev_addr[5] << 8) | (dev->dev_addr[4]));
+
+	at91_emac_write(AT91_EMAC_SA2L, 0);
+	at91_emac_write(AT91_EMAC_SA2H, 0);
+}
+
+/*
+ * Store the new hardware address in dev->dev_addr, and update the MAC.
+ */
+static int set_mac_address(struct net_device *dev, void* addr)
+{
+	struct sockaddr *address = addr;
+
+	if (!is_valid_ether_addr(address->sa_data))
+		return -EADDRNOTAVAIL;
+
+	memcpy(dev->dev_addr, address->sa_data, dev->addr_len);
+	update_mac_address(dev);
+
+	printk("%s: Setting MAC address to %02x:%02x:%02x:%02x:%02x:%02x\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]);
+
+	return 0;
+}
+
+static int inline hash_bit_value(int bitnr, __u8 *addr)
+{
+	if (addr[bitnr / 8] & (1 << (bitnr % 8)))
+		return 1;
+	return 0;
+}
+
+/*
+ * The hash address register is 64 bits long and takes up two locations in the memory map.
+ * The least significant bits are stored in EMAC_HSL and the most significant
+ * bits in EMAC_HSH.
+ *
+ * The unicast hash enable and the multicast hash enable bits in the network configuration
+ *  register enable the reception of hash matched frames. The destination address is
+ *  reduced to a 6 bit index into the 64 bit hash register using the following hash function.
+ * The hash function is an exclusive or of every sixth bit of the destination address.
+ *   hash_index[5] = da[5] ^ da[11] ^ da[17] ^ da[23] ^ da[29] ^ da[35] ^ da[41] ^ da[47]
+ *   hash_index[4] = da[4] ^ da[10] ^ da[16] ^ da[22] ^ da[28] ^ da[34] ^ da[40] ^ da[46]
+ *   hash_index[3] = da[3] ^ da[09] ^ da[15] ^ da[21] ^ da[27] ^ da[33] ^ da[39] ^ da[45]
+ *   hash_index[2] = da[2] ^ da[08] ^ da[14] ^ da[20] ^ da[26] ^ da[32] ^ da[38] ^ da[44]
+ *   hash_index[1] = da[1] ^ da[07] ^ da[13] ^ da[19] ^ da[25] ^ da[31] ^ da[37] ^ da[43]
+ *   hash_index[0] = da[0] ^ da[06] ^ da[12] ^ da[18] ^ da[24] ^ da[30] ^ da[36] ^ da[42]
+ * da[0] represents the least significant bit of the first byte received, that is, the multicast/
+ *  unicast indicator, and da[47] represents the most significant bit of the last byte
+ *  received.
+ * If the hash index points to a bit that is set in the hash register then the frame will be
+ *  matched according to whether the frame is multicast or unicast.
+ * A multicast match will be signalled if the multicast hash enable bit is set, da[0] is 1 and
+ *  the hash index points to a bit set in the hash register.
+ * A unicast match will be signalled if the unicast hash enable bit is set, da[0] is 0 and the
+ *  hash index points to a bit set in the hash register.
+ * To receive all multicast frames, the hash register should be set with all ones and the
+ *  multicast hash enable bit should be set in the network configuration register.
+ */
+
+/*
+ * Return the hash index value for the specified address.
+ */
+static int hash_get_index(__u8 *addr)
+{
+	int i, j, bitval;
+	int hash_index = 0;
+
+	for (j = 0; j < 6; j++) {
+		for (i = 0, bitval = 0; i < 8; i++)
+			bitval ^= hash_bit_value(i*6 + j, addr);
+
+		hash_index |= (bitval << j);
+	}
+
+        return hash_index;
+}
+
+/*
+ * Add multicast addresses to the internal multicast-hash table.
+ */
+static void at91ether_sethashtable(struct net_device *dev)
+{
+	struct dev_mc_list *curr;
+	unsigned long mc_filter[2];
+	unsigned int i, bitnr;
+
+	mc_filter[0] = mc_filter[1] = 0;
+
+	curr = dev->mc_list;
+	for (i = 0; i < dev->mc_count; i++, curr = curr->next) {
+		if (!curr) break;	/* unexpected end of list */
+
+		bitnr = hash_get_index(curr->dmi_addr);
+		mc_filter[bitnr >> 5] |= 1 << (bitnr & 31);
+	}
+
+	at91_emac_write(AT91_EMAC_HSH, mc_filter[0]);
+	at91_emac_write(AT91_EMAC_HSL, mc_filter[1]);
+}
+
+/*
+ * Enable/Disable promiscuous and multicast modes.
+ */
+static void at91ether_set_rx_mode(struct net_device *dev)
+{
+	unsigned long cfg;
+
+	cfg = at91_emac_read(AT91_EMAC_CFG);
+
+	if (dev->flags & IFF_PROMISC)			/* Enable promiscuous mode */
+		cfg |= AT91_EMAC_CAF;
+	else if (dev->flags & (~IFF_PROMISC))		/* Disable promiscuous mode */
+		cfg &= ~AT91_EMAC_CAF;
+
+	if (dev->flags & IFF_ALLMULTI) {		/* Enable all multicast mode */
+		at91_emac_write(AT91_EMAC_HSH, -1);
+		at91_emac_write(AT91_EMAC_HSL, -1);
+		cfg |= AT91_EMAC_MTI;
+	} else if (dev->mc_count > 0) {			/* Enable specific multicasts */
+		at91ether_sethashtable(dev);
+		cfg |= AT91_EMAC_MTI;
+	} else if (dev->flags & (~IFF_ALLMULTI)) {	/* Disable all multicast mode */
+		at91_emac_write(AT91_EMAC_HSH, 0);
+		at91_emac_write(AT91_EMAC_HSL, 0);
+		cfg &= ~AT91_EMAC_MTI;
+	}
+
+	at91_emac_write(AT91_EMAC_CFG, cfg);
+}
+
+
+/* ......................... ETHTOOL SUPPORT ........................... */
+
+
+static int mdio_read(struct net_device *dev, int phy_id, int location)
+{
+	unsigned int value;
+
+	read_phy(phy_id, location, &value);
+	return value;
+}
+
+static void mdio_write(struct net_device *dev, int phy_id, int location, int value)
+{
+	write_phy(phy_id, location, value);
+}
+
+static int at91ether_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+	struct at91_private *lp = (struct at91_private *) dev->priv;
+	int ret;
+
+	spin_lock_irq(&lp->lock);
+	enable_mdi();
+
+	ret = mii_ethtool_gset(&lp->mii, cmd);
+
+	disable_mdi();
+	spin_unlock_irq(&lp->lock);
+
+	if (lp->phy_media == PORT_FIBRE) {		/* override media type since mii.c doesn't know */
+		cmd->supported = SUPPORTED_FIBRE;
+		cmd->port = PORT_FIBRE;
+	}
+
+	return ret;
+}
+
+static int at91ether_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+	struct at91_private *lp = (struct at91_private *) dev->priv;
+	int ret;
+
+	spin_lock_irq(&lp->lock);
+	enable_mdi();
+
+	ret = mii_ethtool_sset(&lp->mii, cmd);
+
+	disable_mdi();
+	spin_unlock_irq(&lp->lock);
+
+	return ret;
+}
+
+static int at91ether_nwayreset(struct net_device *dev)
+{
+	struct at91_private *lp = (struct at91_private *) dev->priv;
+	int ret;
+
+	spin_lock_irq(&lp->lock);
+	enable_mdi();
+
+	ret = mii_nway_restart(&lp->mii);
+
+	disable_mdi();
+	spin_unlock_irq(&lp->lock);
+
+	return ret;
+}
+
+static void at91ether_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
+{
+	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
+	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
+	strlcpy(info->bus_info, dev->class_dev.dev->bus_id, sizeof(info->bus_info));
+}
+
+static struct ethtool_ops at91ether_ethtool_ops = {
+	.get_settings	= at91ether_get_settings,
+	.set_settings	= at91ether_set_settings,
+	.get_drvinfo	= at91ether_get_drvinfo,
+	.nway_reset	= at91ether_nwayreset,
+	.get_link	= ethtool_op_get_link,
+};
+
+
+/* ................................ MAC ................................ */
+
+/*
+ * Initialize and start the Receiver and Transmit subsystems
+ */
+static void at91ether_start(struct net_device *dev)
+{
+	struct at91_private *lp = (struct at91_private *) dev->priv;
+	struct recv_desc_bufs *dlist, *dlist_phys;
+	int i;
+	unsigned long ctl;
+
+	dlist = lp->dlist;
+	dlist_phys = lp->dlist_phys;
+
+	for (i = 0; i < MAX_RX_DESCR; i++) {
+		dlist->descriptors[i].addr = (unsigned int) &dlist_phys->recv_buf[i][0];
+		dlist->descriptors[i].size = 0;
+	}
+
+	/* Set the Wrap bit on the last descriptor */
+	dlist->descriptors[i-1].addr |= EMAC_DESC_WRAP;
+
+	/* Reset buffer index */
+	lp->rxBuffIndex = 0;
+
+	/* Program address of descriptor list in Rx Buffer Queue register */
+	at91_emac_write(AT91_EMAC_RBQP, (unsigned long) dlist_phys);
+
+	/* Enable Receive and Transmit */
+	ctl = at91_emac_read(AT91_EMAC_CTL);
+	at91_emac_write(AT91_EMAC_CTL, ctl | AT91_EMAC_RE | AT91_EMAC_TE);
+}
+
+/*
+ * Open the ethernet interface
+ */
+static int at91ether_open(struct net_device *dev)
+{
+	struct at91_private *lp = (struct at91_private *) dev->priv;
+	unsigned long ctl;
+
+        if (!is_valid_ether_addr(dev->dev_addr))
+        	return -EADDRNOTAVAIL;
+
+	clk_enable(ether_clk);			/* Re-enable Peripheral clock */
+
+	/* Clear internal statistics */
+	ctl = at91_emac_read(AT91_EMAC_CTL);
+	at91_emac_write(AT91_EMAC_CTL, ctl | AT91_EMAC_CSR);
+
+	/* Update the MAC address (incase user has changed it) */
+	update_mac_address(dev);
+
+	/* Enable PHY interrupt */
+	enable_phyirq(dev);
+
+	/* Enable MAC interrupts */
+	at91_emac_write(AT91_EMAC_IER, AT91_EMAC_RCOM | AT91_EMAC_RBNA
+				| AT91_EMAC_TUND | AT91_EMAC_RTRY | AT91_EMAC_TCOM
+				| AT91_EMAC_ROVR | AT91_EMAC_ABT);
+
+	/* Determine current link speed */
+	spin_lock_irq(&lp->lock);
+	enable_mdi();
+	update_linkspeed(dev);
+	disable_mdi();
+	spin_unlock_irq(&lp->lock);
+
+	at91ether_start(dev);
+	netif_start_queue(dev);
+	return 0;
+}
+
+/*
+ * Close the interface
+ */
+static int at91ether_close(struct net_device *dev)
+{
+	unsigned long ctl;
+
+	/* Disable Receiver and Transmitter */
+	ctl = at91_emac_read(AT91_EMAC_CTL);
+	at91_emac_write(AT91_EMAC_CTL, ctl & ~(AT91_EMAC_TE | AT91_EMAC_RE));
+
+	/* Disable PHY interrupt */
+	disable_phyirq(dev);
+
+	/* Disable MAC interrupts */
+	at91_emac_write(AT91_EMAC_IDR, AT91_EMAC_RCOM | AT91_EMAC_RBNA
+				| AT91_EMAC_TUND | AT91_EMAC_RTRY | AT91_EMAC_TCOM
+				| AT91_EMAC_ROVR | AT91_EMAC_ABT);
+
+	netif_stop_queue(dev);
+
+	clk_disable(ether_clk);			/* Disable Peripheral clock */
+
+	return 0;
+}
+
+/*
+ * Transmit packet.
+ */
+static int at91ether_tx(struct sk_buff *skb, struct net_device *dev)
+{
+	struct at91_private *lp = (struct at91_private *) dev->priv;
+
+	if (at91_emac_read(AT91_EMAC_TSR) & AT91_EMAC_TSR_BNQ) {
+		netif_stop_queue(dev);
+
+		/* Store packet information (to free when Tx completed) */
+		lp->skb = skb;
+		lp->skb_length = skb->len;
+		lp->skb_physaddr = dma_map_single(NULL, skb->data, skb->len, DMA_TO_DEVICE);
+		lp->stats.tx_bytes += skb->len;
+
+		/* Set address of the data in the Transmit Address register */
+		at91_emac_write(AT91_EMAC_TAR, lp->skb_physaddr);
+		/* Set length of the packet in the Transmit Control register */
+		at91_emac_write(AT91_EMAC_TCR, skb->len);
+
+		dev->trans_start = jiffies;
+	} else {
+		printk(KERN_ERR "at91_ether.c: at91ether_tx() called, but device is busy!\n");
+		return 1;	/* if we return anything but zero, dev.c:1055 calls kfree_skb(skb)
+				on this skb, he also reports -ENETDOWN and printk's, so either
+				we free and return(0) or don't free and return 1 */
+	}
+
+	return 0;
+}
+
+/*
+ * Update the current statistics from the internal statistics registers.
+ */
+static struct net_device_stats *at91ether_stats(struct net_device *dev)
+{
+	struct at91_private *lp = (struct at91_private *) dev->priv;
+	int ale, lenerr, seqe, lcol, ecol;
+
+	if (netif_running(dev)) {
+		lp->stats.rx_packets += at91_emac_read(AT91_EMAC_OK);		/* Good frames received */
+		ale = at91_emac_read(AT91_EMAC_ALE);
+		lp->stats.rx_frame_errors += ale;				/* Alignment errors */
+		lenerr = at91_emac_read(AT91_EMAC_ELR) + at91_emac_read(AT91_EMAC_USF);
+		lp->stats.rx_length_errors += lenerr;				/* Excessive Length or Undersize Frame error */
+		seqe = at91_emac_read(AT91_EMAC_SEQE);
+		lp->stats.rx_crc_errors += seqe;				/* CRC error */
+		lp->stats.rx_fifo_errors += at91_emac_read(AT91_EMAC_DRFC);	/* Receive buffer not available */
+		lp->stats.rx_errors += (ale + lenerr + seqe
+			+ at91_emac_read(AT91_EMAC_CDE) + at91_emac_read(AT91_EMAC_RJB));
+
+		lp->stats.tx_packets += at91_emac_read(AT91_EMAC_FRA);		/* Frames successfully transmitted */
+		lp->stats.tx_fifo_errors += at91_emac_read(AT91_EMAC_TUE);	/* Transmit FIFO underruns */
+		lp->stats.tx_carrier_errors += at91_emac_read(AT91_EMAC_CSE);	/* Carrier Sense errors */
+		lp->stats.tx_heartbeat_errors += at91_emac_read(AT91_EMAC_SQEE);/* Heartbeat error */
+
+		lcol = at91_emac_read(AT91_EMAC_LCOL);
+		ecol = at91_emac_read(AT91_EMAC_ECOL);
+		lp->stats.tx_window_errors += lcol;			/* Late collisions */
+		lp->stats.tx_aborted_errors += ecol;			/* 16 collisions */
+
+		lp->stats.collisions += (at91_emac_read(AT91_EMAC_SCOL) + at91_emac_read(AT91_EMAC_MCOL) + lcol + ecol);
+	}
+	return &lp->stats;
+}
+
+/*
+ * Extract received frame from buffer descriptors and sent to upper layers.
+ * (Called from interrupt context)
+ */
+static void at91ether_rx(struct net_device *dev)
+{
+	struct at91_private *lp = (struct at91_private *) dev->priv;
+	struct recv_desc_bufs *dlist;
+	unsigned char *p_recv;
+	struct sk_buff *skb;
+	unsigned int pktlen;
+
+	dlist = lp->dlist;
+	while (dlist->descriptors[lp->rxBuffIndex].addr & EMAC_DESC_DONE) {
+		p_recv = dlist->recv_buf[lp->rxBuffIndex];
+		pktlen = dlist->descriptors[lp->rxBuffIndex].size & 0x7ff;	/* Length of frame including FCS */
+		skb = alloc_skb(pktlen + 2, GFP_ATOMIC);
+		if (skb != NULL) {
+			skb_reserve(skb, 2);
+			memcpy(skb_put(skb, pktlen), p_recv, pktlen);
+
+			skb->dev = dev;
+			skb->protocol = eth_type_trans(skb, dev);
+			skb->len = pktlen;
+			dev->last_rx = jiffies;
+			lp->stats.rx_bytes += pktlen;
+			netif_rx(skb);
+		}
+		else {
+			lp->stats.rx_dropped += 1;
+			printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n", dev->name);
+		}
+
+		if (dlist->descriptors[lp->rxBuffIndex].size & EMAC_MULTICAST)
+			lp->stats.multicast++;
+
+		dlist->descriptors[lp->rxBuffIndex].addr &= ~EMAC_DESC_DONE;	/* reset ownership bit */
+		if (lp->rxBuffIndex == MAX_RX_DESCR-1)				/* wrap after last buffer */
+			lp->rxBuffIndex = 0;
+		else
+			lp->rxBuffIndex++;
+	}
+}
+
+/*
+ * MAC interrupt handler
+ */
+static irqreturn_t at91ether_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct net_device *dev = (struct net_device *) dev_id;
+	struct at91_private *lp = (struct at91_private *) dev->priv;
+	unsigned long intstatus, ctl;
+
+	/* MAC Interrupt Status register indicates what interrupts are pending.
+	   It is automatically cleared once read. */
+	intstatus = at91_emac_read(AT91_EMAC_ISR);
+
+	if (intstatus & AT91_EMAC_RCOM)		/* Receive complete */
+		at91ether_rx(dev);
+
+	if (intstatus & AT91_EMAC_TCOM) {		/* Transmit complete */
+		/* The TCOM bit is set even if the transmission failed. */
+		if (intstatus & (AT91_EMAC_TUND | AT91_EMAC_RTRY))
+			lp->stats.tx_errors += 1;
+
+		if (lp->skb) {
+			dev_kfree_skb_irq(lp->skb);
+			lp->skb = NULL;
+			dma_unmap_single(NULL, lp->skb_physaddr, lp->skb_length, DMA_TO_DEVICE);
+		}
+		netif_wake_queue(dev);
+	}
+
+	/* Work-around for Errata #11 */
+	if (intstatus & AT91_EMAC_RBNA) {
+		ctl = at91_emac_read(AT91_EMAC_CTL);
+		at91_emac_write(AT91_EMAC_CTL, ctl & ~AT91_EMAC_RE);
+		at91_emac_write(AT91_EMAC_CTL, ctl | AT91_EMAC_RE);
+	}
+
+	if (intstatus & AT91_EMAC_ROVR)
+		printk("%s: ROVR error\n", dev->name);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Initialize the ethernet interface
+ */
+static int __init at91ether_setup(unsigned long phy_type, unsigned short phy_address, struct platform_device *pdev)
+{
+	struct at91_eth_data *board_data = pdev->dev.platform_data;
+	struct net_device *dev;
+	struct at91_private *lp;
+	unsigned int val;
+	int res;
+
+	if (at91_dev)			/* already initialized */
+		return 0;
+
+	dev = alloc_etherdev(sizeof(struct at91_private));
+	if (!dev)
+		return -ENOMEM;
+
+	dev->base_addr = AT91_VA_BASE_EMAC;
+	dev->irq = AT91_ID_EMAC;
+	SET_MODULE_OWNER(dev);
+
+	/* Install the interrupt handler */
+	if (request_irq(dev->irq, at91ether_interrupt, 0, dev->name, dev)) {
+		free_netdev(dev);
+		return -EBUSY;
+	}
+
+	/* Allocate memory for DMA Receive descriptors */
+	lp = (struct at91_private *)dev->priv;
+	lp->dlist = (struct recv_desc_bufs *) dma_alloc_coherent(NULL, sizeof(struct recv_desc_bufs), (dma_addr_t *) &lp->dlist_phys, GFP_KERNEL);
+	if (lp->dlist == NULL) {
+		free_irq(dev->irq, dev);
+		free_netdev(dev);
+		return -ENOMEM;
+	}
+	lp->board_data = *board_data;
+	platform_set_drvdata(pdev, dev);
+
+	spin_lock_init(&lp->lock);
+
+	ether_setup(dev);
+	dev->open = at91ether_open;
+	dev->stop = at91ether_close;
+	dev->hard_start_xmit = at91ether_tx;
+	dev->get_stats = at91ether_stats;
+	dev->set_multicast_list = at91ether_set_rx_mode;
+	dev->set_mac_address = set_mac_address;
+	dev->ethtool_ops = &at91ether_ethtool_ops;
+
+	SET_NETDEV_DEV(dev, &pdev->dev);
+
+	get_mac_address(dev);		/* Get ethernet address and store it in dev->dev_addr */
+	update_mac_address(dev);	/* Program ethernet address into MAC */
+
+	at91_emac_write(AT91_EMAC_CTL, 0);
+
+	if (lp->board_data.is_rmii)
+		at91_emac_write(AT91_EMAC_CFG, AT91_EMAC_CLK_DIV32 | AT91_EMAC_BIG | AT91_EMAC_RMII);
+	else
+		at91_emac_write(AT91_EMAC_CFG, AT91_EMAC_CLK_DIV32 | AT91_EMAC_BIG);
+
+	/* Perform PHY-specific initialization */
+	spin_lock_irq(&lp->lock);
+	enable_mdi();
+	if ((phy_type == MII_DM9161_ID) || (lp->phy_type == MII_DM9161A_ID)) {
+		read_phy(phy_address, MII_DSCR_REG, &val);
+		if ((val & (1 << 10)) == 0)			/* DSCR bit 10 is 0 -- fiber mode */
+			lp->phy_media = PORT_FIBRE;
+	} else if (machine_is_csb337()) {
+		/* mix link activity status into LED2 link state */
+		write_phy(phy_address, MII_LEDCTRL_REG, 0x0d22);
+	}
+	disable_mdi();
+	spin_unlock_irq(&lp->lock);
+
+	lp->mii.dev = dev;		/* Support for ethtool */
+	lp->mii.mdio_read = mdio_read;
+	lp->mii.mdio_write = mdio_write;
+
+	lp->phy_type = phy_type;	/* Type of PHY connected */
+	lp->phy_address = phy_address;	/* MDI address of PHY */
+
+	/* Register the network interface */
+	res = register_netdev(dev);
+	if (res) {
+		free_irq(dev->irq, dev);
+		free_netdev(dev);
+		dma_free_coherent(NULL, sizeof(struct recv_desc_bufs), lp->dlist, (dma_addr_t)lp->dlist_phys);
+		return res;
+	}
+	at91_dev = dev;
+
+	/* Determine current link speed */
+	spin_lock_irq(&lp->lock);
+	enable_mdi();
+	update_linkspeed(dev);
+	disable_mdi();
+	spin_unlock_irq(&lp->lock);
+	netif_carrier_off(dev);		/* will be enabled in open() */
+
+	/* Display ethernet banner */
+	printk(KERN_INFO "%s: AT91 ethernet at 0x%08x int=%d %s%s (%02x:%02x:%02x:%02x:%02x:%02x)\n",
+		dev->name, (uint) dev->base_addr, dev->irq,
+		at91_emac_read(AT91_EMAC_CFG) & AT91_EMAC_SPD ? "100-" : "10-",
+		at91_emac_read(AT91_EMAC_CFG) & AT91_EMAC_FD ? "FullDuplex" : "HalfDuplex",
+		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 ((phy_type == MII_DM9161_ID) || (lp->phy_type == MII_DM9161A_ID))
+		printk(KERN_INFO "%s: Davicom 9196 PHY %s\n", dev->name, (lp->phy_media == PORT_FIBRE) ? "(Fiber)" : "(Copper)");
+	else if (phy_type == MII_LXT971A_ID)
+		printk(KERN_INFO "%s: Intel LXT971A PHY\n", dev->name);
+	else if (phy_type == MII_RTL8201_ID)
+		printk(KERN_INFO "%s: Realtek RTL8201(B)L PHY\n", dev->name);
+	else if (phy_type == MII_BCM5221_ID)
+		printk(KERN_INFO "%s: Broadcom BCM5221 PHY\n", dev->name);
+	else if (phy_type == MII_DP83847_ID)
+		printk(KERN_INFO "%s: National Semiconductor DP83847 PHY\n", dev->name);
+	else if (phy_type == MII_AC101L_ID)
+		printk(KERN_INFO "%s: Altima AC101L PHY\n", dev->name);
+	else if (phy_type == MII_KS8721_ID)
+		printk(KERN_INFO "%s: Micrel KS8721 PHY\n", dev->name);
+
+	return 0;
+}
+
+/*
+ * Detect MAC and PHY and perform initialization
+ */
+static int __init at91ether_probe(struct platform_device *pdev)
+{
+	unsigned int phyid1, phyid2;
+	int detected = -1;
+	unsigned long phy_id;
+	unsigned short phy_address = 0;
+
+	ether_clk = clk_get(&pdev->dev, "ether_clk");
+	if (!ether_clk) {
+		printk(KERN_ERR "at91_ether: no clock defined\n");
+		return -ENODEV;
+	}
+	clk_enable(ether_clk);					/* Enable Peripheral clock */
+
+	while ((detected != 0) && (phy_address < 32)) {
+		/* Read the PHY ID registers */
+		enable_mdi();
+		read_phy(phy_address, MII_PHYSID1, &phyid1);
+		read_phy(phy_address, MII_PHYSID2, &phyid2);
+		disable_mdi();
+
+		phy_id = (phyid1 << 16) | (phyid2 & 0xfff0);
+		switch (phy_id) {
+			case MII_DM9161_ID:		/* Davicom 9161: PHY_ID1 = 0x181, PHY_ID2 = B881 */
+			case MII_DM9161A_ID:		/* Davicom 9161A: PHY_ID1 = 0x181, PHY_ID2 = B8A0 */
+			case MII_LXT971A_ID:		/* Intel LXT971A: PHY_ID1 = 0x13, PHY_ID2 = 78E0 */
+			case MII_RTL8201_ID:		/* Realtek RTL8201: PHY_ID1 = 0, PHY_ID2 = 0x8201 */
+			case MII_BCM5221_ID:		/* Broadcom BCM5221: PHY_ID1 = 0x40, PHY_ID2 = 0x61e0 */
+			case MII_DP83847_ID:		/* National Semiconductor DP83847:  */
+			case MII_AC101L_ID:		/* Altima AC101L: PHY_ID1 = 0x22, PHY_ID2 = 0x5520 */
+			case MII_KS8721_ID:		/* Micrel KS8721: PHY_ID1 = 0x22, PHY_ID2 = 0x1610 */
+				detected = at91ether_setup(phy_id, phy_address, pdev);
+				break;
+		}
+
+		phy_address++;
+	}
+
+	clk_disable(ether_clk);					/* Disable Peripheral clock */
+
+	return detected;
+}
+
+static int __devexit at91ether_remove(struct platform_device *pdev)
+{
+	struct at91_private *lp = (struct at91_private *) at91_dev->priv;
+
+	unregister_netdev(at91_dev);
+	free_irq(at91_dev->irq, at91_dev);
+	dma_free_coherent(NULL, sizeof(struct recv_desc_bufs), lp->dlist, (dma_addr_t)lp->dlist_phys);
+	clk_put(ether_clk);
+
+	free_netdev(at91_dev);
+	at91_dev = NULL;
+	return 0;
+}
+
+static struct platform_driver at91ether_driver = {
+	.probe		= at91ether_probe,
+	.remove		= __devexit_p(at91ether_remove),
+	/* FIXME:  support suspend and resume */
+	.driver		= {
+		.name	= DRV_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init at91ether_init(void)
+{
+	return platform_driver_register(&at91ether_driver);
+}
+
+static void __exit at91ether_exit(void)
+{
+	platform_driver_unregister(&at91ether_driver);
+}
+
+module_init(at91ether_init)
+module_exit(at91ether_exit)
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("AT91RM9200 EMAC Ethernet driver");
+MODULE_AUTHOR("Andrew Victor");