Blackfin ethernet driver: on chip ethernet MAC controller driver

This patch implements the driver necessary use the Analog Devices
Blackfin processor's on-chip ethernet MAC controller.

[try#2]
 - add timeout control
 - kill dma_config_reg bitfields
 - some trivial cleanup

[try#3]
 - add endianess check
 - add DRV_NAME, DRV_VERSION... driver information string
 - add some comments for silicon anomaly and dma API confusion
 - some code trivial cleanup

[try#4]
 - add Blackfin latest GPIO pin mux opertion with Michael Hennerich's
  help and Dan's review
 - rewrite the DMA descriptor list operation in a more readable way
  by Joe's review

[try#5]
 - cleanup some coding style by Joe's review.

[try#6]
 - 1.1 version fix a bug when set up multicast list pointed by Mr. yoshfuji
 - rearrange the desc_list_free function.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Mike Frysinger <vapier.adi@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dan Williams <dcbw@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 1009 insertions, 0 deletions

diff --git a/drivers/net/bfin_mac.c b/drivers/net/bfin_mac.c
new file mode 100644
index 00000000000..9a08d656f1c
--- /dev/null
+++ b/drivers/net/bfin_mac.c
@@ -0,0 +1,1009 @@
+/*
+ * File:	drivers/net/bfin_mac.c
+ * Based on:
+ * Maintainer:
+ * 		Bryan Wu <bryan.wu@analog.com>
+ *
+ * Original author:
+ * 		Luke Yang <luke.yang@analog.com>
+ *
+ * Created:
+ * Description:
+ *
+ * Modified:
+ *		Copyright 2004-2006 Analog Devices Inc.
+ *
+ * Bugs:	Enter bugs at http://blackfin.uclinux.org/
+ *
+ * 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, or (at your option)
+ * any later version.
+ *
+ * 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 ;  see the file COPYING.
+ * If not, write to the Free Software Foundation,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/timer.h>
+#include <linux/errno.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/crc32.h>
+#include <linux/device.h>
+#include <linux/spinlock.h>
+#include <linux/ethtool.h>
+#include <linux/mii.h>
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+
+#include <linux/platform_device.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+
+#include <asm/dma.h>
+#include <linux/dma-mapping.h>
+
+#include <asm/blackfin.h>
+#include <asm/cacheflush.h>
+#include <asm/portmux.h>
+
+#include "bfin_mac.h"
+
+#define DRV_NAME	"bfin_mac"
+#define DRV_VERSION	"1.1"
+#define DRV_AUTHOR	"Bryan Wu, Luke Yang"
+#define DRV_DESC	"Blackfin BF53[67] on-chip Ethernet MAC driver"
+
+MODULE_AUTHOR(DRV_AUTHOR);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION(DRV_DESC);
+
+#if defined(CONFIG_BFIN_MAC_USE_L1)
+# define bfin_mac_alloc(dma_handle, size)  l1_data_sram_zalloc(size)
+# define bfin_mac_free(dma_handle, ptr)    l1_data_sram_free(ptr)
+#else
+# define bfin_mac_alloc(dma_handle, size) \
+	dma_alloc_coherent(NULL, size, dma_handle, GFP_KERNEL)
+# define bfin_mac_free(dma_handle, ptr) \
+	dma_free_coherent(NULL, sizeof(*ptr), ptr, dma_handle)
+#endif
+
+#define PKT_BUF_SZ 1580
+
+#define MAX_TIMEOUT_CNT	500
+
+/* pointers to maintain transmit list */
+static struct net_dma_desc_tx *tx_list_head;
+static struct net_dma_desc_tx *tx_list_tail;
+static struct net_dma_desc_rx *rx_list_head;
+static struct net_dma_desc_rx *rx_list_tail;
+static struct net_dma_desc_rx *current_rx_ptr;
+static struct net_dma_desc_tx *current_tx_ptr;
+static struct net_dma_desc_tx *tx_desc;
+static struct net_dma_desc_rx *rx_desc;
+
+static void desc_list_free(void)
+{
+	struct net_dma_desc_rx *r;
+	struct net_dma_desc_tx *t;
+	int i;
+#if !defined(CONFIG_BFIN_MAC_USE_L1)
+	dma_addr_t dma_handle = 0;
+#endif
+
+	if (tx_desc) {
+		t = tx_list_head;
+		for (i = 0; i < CONFIG_BFIN_TX_DESC_NUM; i++) {
+			if (t) {
+				if (t->skb) {
+					dev_kfree_skb(t->skb);
+					t->skb = NULL;
+				}
+				t = t->next;
+			}
+		}
+		bfin_mac_free(dma_handle, tx_desc);
+	}
+
+	if (rx_desc) {
+		r = rx_list_head;
+		for (i = 0; i < CONFIG_BFIN_RX_DESC_NUM; i++) {
+			if (r) {
+				if (r->skb) {
+					dev_kfree_skb(r->skb);
+					r->skb = NULL;
+				}
+				r = r->next;
+			}
+		}
+		bfin_mac_free(dma_handle, rx_desc);
+	}
+}
+
+static int desc_list_init(void)
+{
+	int i;
+	struct sk_buff *new_skb;
+#if !defined(CONFIG_BFIN_MAC_USE_L1)
+	/*
+	 * This dma_handle is useless in Blackfin dma_alloc_coherent().
+	 * The real dma handler is the return value of dma_alloc_coherent().
+	 */
+	dma_addr_t dma_handle;
+#endif
+
+	tx_desc = bfin_mac_alloc(&dma_handle,
+				sizeof(struct net_dma_desc_tx) *
+				CONFIG_BFIN_TX_DESC_NUM);
+	if (tx_desc == NULL)
+		goto init_error;
+
+	rx_desc = bfin_mac_alloc(&dma_handle,
+				sizeof(struct net_dma_desc_rx) *
+				CONFIG_BFIN_RX_DESC_NUM);
+	if (rx_desc == NULL)
+		goto init_error;
+
+	/* init tx_list */
+	tx_list_head = tx_list_tail = tx_desc;
+
+	for (i = 0; i < CONFIG_BFIN_TX_DESC_NUM; i++) {
+		struct net_dma_desc_tx *t = tx_desc + i;
+		struct dma_descriptor *a = &(t->desc_a);
+		struct dma_descriptor *b = &(t->desc_b);
+
+		/*
+		 * disable DMA
+		 * read from memory WNR = 0
+		 * wordsize is 32 bits
+		 * 6 half words is desc size
+		 * large desc flow
+		 */
+		a->config = WDSIZE_32 | NDSIZE_6 | DMAFLOW_LARGE;
+		a->start_addr = (unsigned long)t->packet;
+		a->x_count = 0;
+		a->next_dma_desc = b;
+
+		/*
+		 * enabled DMA
+		 * write to memory WNR = 1
+		 * wordsize is 32 bits
+		 * disable interrupt
+		 * 6 half words is desc size
+		 * large desc flow
+		 */
+		b->config = DMAEN | WNR | WDSIZE_32 | NDSIZE_6 | DMAFLOW_LARGE;
+		b->start_addr = (unsigned long)(&(t->status));
+		b->x_count = 0;
+
+		t->skb = NULL;
+		tx_list_tail->desc_b.next_dma_desc = a;
+		tx_list_tail->next = t;
+		tx_list_tail = t;
+	}
+	tx_list_tail->next = tx_list_head;	/* tx_list is a circle */
+	tx_list_tail->desc_b.next_dma_desc = &(tx_list_head->desc_a);
+	current_tx_ptr = tx_list_head;
+
+	/* init rx_list */
+	rx_list_head = rx_list_tail = rx_desc;
+
+	for (i = 0; i < CONFIG_BFIN_RX_DESC_NUM; i++) {
+		struct net_dma_desc_rx *r = rx_desc + i;
+		struct dma_descriptor *a = &(r->desc_a);
+		struct dma_descriptor *b = &(r->desc_b);
+
+		/* allocate a new skb for next time receive */
+		new_skb = dev_alloc_skb(PKT_BUF_SZ + 2);
+		if (!new_skb) {
+			printk(KERN_NOTICE DRV_NAME
+			       ": init: low on mem - packet dropped\n");
+			goto init_error;
+		}
+		skb_reserve(new_skb, 2);
+		r->skb = new_skb;
+
+		/*
+		 * enabled DMA
+		 * write to memory WNR = 1
+		 * wordsize is 32 bits
+		 * disable interrupt
+		 * 6 half words is desc size
+		 * large desc flow
+		 */
+		a->config = DMAEN | WNR | WDSIZE_32 | NDSIZE_6 | DMAFLOW_LARGE;
+		/* since RXDWA is enabled */
+		a->start_addr = (unsigned long)new_skb->data - 2;
+		a->x_count = 0;
+		a->next_dma_desc = b;
+
+		/*
+		 * enabled DMA
+		 * write to memory WNR = 1
+		 * wordsize is 32 bits
+		 * enable interrupt
+		 * 6 half words is desc size
+		 * large desc flow
+		 */
+		b->config = DMAEN | WNR | WDSIZE_32 | DI_EN |
+				NDSIZE_6 | DMAFLOW_LARGE;
+		b->start_addr = (unsigned long)(&(r->status));
+		b->x_count = 0;
+
+		rx_list_tail->desc_b.next_dma_desc = a;
+		rx_list_tail->next = r;
+		rx_list_tail = r;
+	}
+	rx_list_tail->next = rx_list_head;	/* rx_list is a circle */
+	rx_list_tail->desc_b.next_dma_desc = &(rx_list_head->desc_a);
+	current_rx_ptr = rx_list_head;
+
+	return 0;
+
+init_error:
+	desc_list_free();
+	printk(KERN_ERR DRV_NAME ": kmalloc failed\n");
+	return -ENOMEM;
+}
+
+
+/*---PHY CONTROL AND CONFIGURATION-----------------------------------------*/
+
+/* Set FER regs to MUX in Ethernet pins */
+static int setup_pin_mux(int action)
+{
+#if defined(CONFIG_BFIN_MAC_RMII)
+	u16 pin_req[] = P_RMII0;
+#else
+	u16 pin_req[] = P_MII0;
+#endif
+
+	if (action) {
+		if (peripheral_request_list(pin_req, DRV_NAME)) {
+			printk(KERN_ERR DRV_NAME
+			": Requesting Peripherals failed\n");
+			return -EFAULT;
+		}
+	} else
+		peripheral_free_list(pin_req);
+
+	return 0;
+}
+
+/* Wait until the previous MDC/MDIO transaction has completed */
+static void poll_mdc_done(void)
+{
+	int timeout_cnt = MAX_TIMEOUT_CNT;
+
+	/* poll the STABUSY bit */
+	while ((bfin_read_EMAC_STAADD()) & STABUSY) {
+		mdelay(10);
+		if (timeout_cnt-- < 0) {
+			printk(KERN_ERR DRV_NAME
+			": wait MDC/MDIO transaction to complete timeout\n");
+			break;
+		}
+	}
+}
+
+/* Read an off-chip register in a PHY through the MDC/MDIO port */
+static u16 read_phy_reg(u16 PHYAddr, u16 RegAddr)
+{
+	poll_mdc_done();
+	/* read mode */
+	bfin_write_EMAC_STAADD(SET_PHYAD(PHYAddr) |
+				SET_REGAD(RegAddr) |
+				STABUSY);
+	poll_mdc_done();
+
+	return (u16) bfin_read_EMAC_STADAT();
+}
+
+/* Write an off-chip register in a PHY through the MDC/MDIO port */
+static void raw_write_phy_reg(u16 PHYAddr, u16 RegAddr, u32 Data)
+{
+	bfin_write_EMAC_STADAT(Data);
+
+	/* write mode */
+	bfin_write_EMAC_STAADD(SET_PHYAD(PHYAddr) |
+				SET_REGAD(RegAddr) |
+				STAOP |
+				STABUSY);
+
+	poll_mdc_done();
+}
+
+static void write_phy_reg(u16 PHYAddr, u16 RegAddr, u32 Data)
+{
+	poll_mdc_done();
+	raw_write_phy_reg(PHYAddr, RegAddr, Data);
+}
+
+/* set up the phy */
+static void bf537mac_setphy(struct net_device *dev)
+{
+	u16 phydat;
+	struct bf537mac_local *lp = netdev_priv(dev);
+
+	/* Program PHY registers */
+	pr_debug("start setting up phy\n");
+
+	/* issue a reset */
+	raw_write_phy_reg(lp->PhyAddr, PHYREG_MODECTL, 0x8000);
+
+	/* wait half a second */
+	msleep(500);
+
+	phydat = read_phy_reg(lp->PhyAddr, PHYREG_MODECTL);
+
+	/* advertise flow control supported */
+	phydat = read_phy_reg(lp->PhyAddr, PHYREG_ANAR);
+	phydat |= (1 << 10);
+	write_phy_reg(lp->PhyAddr, PHYREG_ANAR, phydat);
+
+	phydat = 0;
+	if (lp->Negotiate)
+		phydat |= 0x1000;	/* enable auto negotiation */
+	else {
+		if (lp->FullDuplex)
+			phydat |= (1 << 8);	/* full duplex */
+		else
+			phydat &= (~(1 << 8));	/* half duplex */
+
+		if (!lp->Port10)
+			phydat |= (1 << 13);	/* 100 Mbps */
+		else
+			phydat &= (~(1 << 13));	/* 10 Mbps */
+	}
+
+	if (lp->Loopback)
+		phydat |= (1 << 14);	/* enable TX->RX loopback */
+
+	write_phy_reg(lp->PhyAddr, PHYREG_MODECTL, phydat);
+	msleep(500);
+
+	phydat = read_phy_reg(lp->PhyAddr, PHYREG_MODECTL);
+	/* check for SMSC PHY */
+	if ((read_phy_reg(lp->PhyAddr, PHYREG_PHYID1) == 0x7) &&
+	((read_phy_reg(lp->PhyAddr, PHYREG_PHYID2) & 0xfff0) == 0xC0A0)) {
+		/*
+		 * we have SMSC PHY so reqest interrupt
+		 * on link down condition
+		 */
+
+		/* enable interrupts */
+		write_phy_reg(lp->PhyAddr, 30, 0x0ff);
+	}
+}
+
+/**************************************************************************/
+void setup_system_regs(struct net_device *dev)
+{
+	int phyaddr;
+	unsigned short sysctl, phydat;
+	u32 opmode;
+	struct bf537mac_local *lp = netdev_priv(dev);
+	int count = 0;
+
+	phyaddr = lp->PhyAddr;
+
+	/* Enable PHY output */
+	if (!(bfin_read_VR_CTL() & PHYCLKOE))
+		bfin_write_VR_CTL(bfin_read_VR_CTL() | PHYCLKOE);
+
+	/* MDC  = 2.5 MHz */
+	sysctl = SET_MDCDIV(24);
+	/* Odd word alignment for Receive Frame DMA word */
+	/* Configure checksum support and rcve frame word alignment */
+#if defined(BFIN_MAC_CSUM_OFFLOAD)
+	sysctl |= RXDWA | RXCKS;
+#else
+	sysctl |= RXDWA;
+#endif
+	bfin_write_EMAC_SYSCTL(sysctl);
+	/* auto negotiation on  */
+	/* full duplex          */
+	/* 100 Mbps             */
+	phydat = PHY_ANEG_EN | PHY_DUPLEX | PHY_SPD_SET;
+	write_phy_reg(phyaddr, PHYREG_MODECTL, phydat);
+
+	/* test if full duplex supported */
+	do {
+		msleep(100);
+		phydat = read_phy_reg(phyaddr, PHYREG_MODESTAT);
+		if (count > 30) {
+			printk(KERN_NOTICE DRV_NAME ": Link is down\n");
+			printk(KERN_NOTICE DRV_NAME
+				 "please check your network connection\n");
+			break;
+		}
+		count++;
+	} while (!(phydat & 0x0004));
+
+	phydat = read_phy_reg(phyaddr, PHYREG_ANLPAR);
+
+	if ((phydat & 0x0100) || (phydat & 0x0040)) {
+		opmode = FDMODE;
+	} else {
+		opmode = 0;
+		printk(KERN_INFO DRV_NAME
+			": Network is set to half duplex\n");
+	}
+
+#if defined(CONFIG_BFIN_MAC_RMII)
+	opmode |= RMII; /* For Now only 100MBit are supported */
+#endif
+
+	bfin_write_EMAC_OPMODE(opmode);
+
+	bfin_write_EMAC_MMC_CTL(RSTC | CROLL);
+
+	/* Initialize the TX DMA channel registers */
+	bfin_write_DMA2_X_COUNT(0);
+	bfin_write_DMA2_X_MODIFY(4);
+	bfin_write_DMA2_Y_COUNT(0);
+	bfin_write_DMA2_Y_MODIFY(0);
+
+	/* Initialize the RX DMA channel registers */
+	bfin_write_DMA1_X_COUNT(0);
+	bfin_write_DMA1_X_MODIFY(4);
+	bfin_write_DMA1_Y_COUNT(0);
+	bfin_write_DMA1_Y_MODIFY(0);
+}
+
+void setup_mac_addr(u8 * mac_addr)
+{
+	u32 addr_low = le32_to_cpu(*(__le32 *) & mac_addr[0]);
+	u16 addr_hi = le16_to_cpu(*(__le16 *) & mac_addr[4]);
+
+	/* this depends on a little-endian machine */
+	bfin_write_EMAC_ADDRLO(addr_low);
+	bfin_write_EMAC_ADDRHI(addr_hi);
+}
+
+static void adjust_tx_list(void)
+{
+	int timeout_cnt = MAX_TIMEOUT_CNT;
+
+	if (tx_list_head->status.status_word != 0
+	    && current_tx_ptr != tx_list_head) {
+		goto adjust_head;	/* released something, just return; */
+	}
+
+	/*
+	 * if nothing released, check wait condition
+	 * current's next can not be the head,
+	 * otherwise the dma will not stop as we want
+	 */
+	if (current_tx_ptr->next->next == tx_list_head) {
+		while (tx_list_head->status.status_word == 0) {
+			mdelay(10);
+			if (tx_list_head->status.status_word != 0
+			    || !(bfin_read_DMA2_IRQ_STATUS() & 0x08)) {
+				goto adjust_head;
+			}
+			if (timeout_cnt-- < 0) {
+				printk(KERN_ERR DRV_NAME
+				": wait for adjust tx list head timeout\n");
+				break;
+			}
+		}
+		if (tx_list_head->status.status_word != 0) {
+			goto adjust_head;
+		}
+	}
+
+	return;
+
+adjust_head:
+	do {
+		tx_list_head->desc_a.config &= ~DMAEN;
+		tx_list_head->status.status_word = 0;
+		if (tx_list_head->skb) {
+			dev_kfree_skb(tx_list_head->skb);
+			tx_list_head->skb = NULL;
+		} else {
+			printk(KERN_ERR DRV_NAME
+			       ": no sk_buff in a transmitted frame!\n");
+		}
+		tx_list_head = tx_list_head->next;
+	} while (tx_list_head->status.status_word != 0
+		 && current_tx_ptr != tx_list_head);
+	return;
+
+}
+
+static int bf537mac_hard_start_xmit(struct sk_buff *skb,
+				struct net_device *dev)
+{
+	struct bf537mac_local *lp = netdev_priv(dev);
+	unsigned int data;
+
+	current_tx_ptr->skb = skb;
+
+	/*
+	 * Is skb->data always 16-bit aligned?
+	 * Do we need to memcpy((char *)(tail->packet + 2), skb->data, len)?
+	 */
+	if ((((unsigned int)(skb->data)) & 0x02) == 2) {
+		/* move skb->data to current_tx_ptr payload */
+		data = (unsigned int)(skb->data) - 2;
+		*((unsigned short *)data) = (unsigned short)(skb->len);
+		current_tx_ptr->desc_a.start_addr = (unsigned long)data;
+		/* this is important! */
+		blackfin_dcache_flush_range(data, (data + (skb->len)) + 2);
+
+	} else {
+		*((unsigned short *)(current_tx_ptr->packet)) =
+		    (unsigned short)(skb->len);
+		memcpy((char *)(current_tx_ptr->packet + 2), skb->data,
+		       (skb->len));
+		current_tx_ptr->desc_a.start_addr =
+		    (unsigned long)current_tx_ptr->packet;
+		if (current_tx_ptr->status.status_word != 0)
+			current_tx_ptr->status.status_word = 0;
+		blackfin_dcache_flush_range((unsigned int)current_tx_ptr->
+					    packet,
+					    (unsigned int)(current_tx_ptr->
+							   packet + skb->len) +
+					    2);
+	}
+
+	/* enable this packet's dma */
+	current_tx_ptr->desc_a.config |= DMAEN;
+
+	/* tx dma is running, just return */
+	if (bfin_read_DMA2_IRQ_STATUS() & 0x08)
+		goto out;
+
+	/* tx dma is not running */
+	bfin_write_DMA2_NEXT_DESC_PTR(&(current_tx_ptr->desc_a));
+	/* dma enabled, read from memory, size is 6 */
+	bfin_write_DMA2_CONFIG(current_tx_ptr->desc_a.config);
+	/* Turn on the EMAC tx */
+	bfin_write_EMAC_OPMODE(bfin_read_EMAC_OPMODE() | TE);
+
+out:
+	adjust_tx_list();
+	current_tx_ptr = current_tx_ptr->next;
+	dev->trans_start = jiffies;
+	lp->stats.tx_packets++;
+	lp->stats.tx_bytes += (skb->len);
+	return 0;
+}
+
+static void bf537mac_rx(struct net_device *dev)
+{
+	struct sk_buff *skb, *new_skb;
+	struct bf537mac_local *lp = netdev_priv(dev);
+	unsigned short len;
+
+	/* allocate a new skb for next time receive */
+	skb = current_rx_ptr->skb;
+	new_skb = dev_alloc_skb(PKT_BUF_SZ + 2);
+	if (!new_skb) {
+		printk(KERN_NOTICE DRV_NAME
+		       ": rx: low on mem - packet dropped\n");
+		lp->stats.rx_dropped++;
+		goto out;
+	}
+	/* reserve 2 bytes for RXDWA padding */
+	skb_reserve(new_skb, 2);
+	current_rx_ptr->skb = new_skb;
+	current_rx_ptr->desc_a.start_addr = (unsigned long)new_skb->data - 2;
+
+	len = (unsigned short)((current_rx_ptr->status.status_word) & RX_FRLEN);
+	skb_put(skb, len);
+	blackfin_dcache_invalidate_range((unsigned long)skb->head,
+					 (unsigned long)skb->tail);
+
+	dev->last_rx = jiffies;
+	skb->dev = dev;
+	skb->protocol = eth_type_trans(skb, dev);
+#if defined(BFIN_MAC_CSUM_OFFLOAD)
+	skb->csum = current_rx_ptr->status.ip_payload_csum;
+	skb->ip_summed = CHECKSUM_PARTIAL;
+#endif
+
+	netif_rx(skb);
+	lp->stats.rx_packets++;
+	lp->stats.rx_bytes += len;
+	current_rx_ptr->status.status_word = 0x00000000;
+	current_rx_ptr = current_rx_ptr->next;
+
+out:
+	return;
+}
+
+/* interrupt routine to handle rx and error signal */
+static irqreturn_t bf537mac_interrupt(int irq, void *dev_id)
+{
+	struct net_device *dev = dev_id;
+	int number = 0;
+
+get_one_packet:
+	if (current_rx_ptr->status.status_word == 0) {
+		/* no more new packet received */
+		if (number == 0) {
+			if (current_rx_ptr->next->status.status_word != 0) {
+				current_rx_ptr = current_rx_ptr->next;
+				goto real_rx;
+			}
+		}
+		bfin_write_DMA1_IRQ_STATUS(bfin_read_DMA1_IRQ_STATUS() |
+					   DMA_DONE | DMA_ERR);
+		return IRQ_HANDLED;
+	}
+
+real_rx:
+	bf537mac_rx(dev);
+	number++;
+	goto get_one_packet;
+}
+
+#ifdef CONFIG_NET_POLL_CONTROLLER
+static void bf537mac_poll(struct net_device *dev)
+{
+	disable_irq(IRQ_MAC_RX);
+	bf537mac_interrupt(IRQ_MAC_RX, dev);
+	enable_irq(IRQ_MAC_RX);
+}
+#endif				/* CONFIG_NET_POLL_CONTROLLER */
+
+static void bf537mac_reset(void)
+{
+	unsigned int opmode;
+
+	opmode = bfin_read_EMAC_OPMODE();
+	opmode &= (~RE);
+	opmode &= (~TE);
+	/* Turn off the EMAC */
+	bfin_write_EMAC_OPMODE(opmode);
+}
+
+/*
+ * Enable Interrupts, Receive, and Transmit
+ */
+static int bf537mac_enable(struct net_device *dev)
+{
+	u32 opmode;
+
+	pr_debug("%s: %s\n", dev->name, __FUNCTION__);
+
+	/* Set RX DMA */
+	bfin_write_DMA1_NEXT_DESC_PTR(&(rx_list_head->desc_a));
+	bfin_write_DMA1_CONFIG(rx_list_head->desc_a.config);
+
+	/* Wait MII done */
+	poll_mdc_done();
+
+	/* We enable only RX here */
+	/* ASTP   : Enable Automatic Pad Stripping
+	   PR     : Promiscuous Mode for test
+	   PSF    : Receive frames with total length less than 64 bytes.
+	   FDMODE : Full Duplex Mode
+	   LB     : Internal Loopback for test
+	   RE     : Receiver Enable */
+	opmode = bfin_read_EMAC_OPMODE();
+	if (opmode & FDMODE)
+		opmode |= PSF;
+	else
+		opmode |= DRO | DC | PSF;
+	opmode |= RE;
+
+#if defined(CONFIG_BFIN_MAC_RMII)
+	opmode |= RMII; /* For Now only 100MBit are supported */
+#ifdef CONFIG_BF_REV_0_2
+	opmode |= TE;
+#endif
+#endif
+	/* Turn on the EMAC rx */
+	bfin_write_EMAC_OPMODE(opmode);
+
+	return 0;
+}
+
+/* Our watchdog timed out. Called by the networking layer */
+static void bf537mac_timeout(struct net_device *dev)
+{
+	pr_debug("%s: %s\n", dev->name, __FUNCTION__);
+
+	bf537mac_reset();
+
+	/* reset tx queue */
+	tx_list_tail = tx_list_head->next;
+
+	bf537mac_enable(dev);
+
+	/* We can accept TX packets again */
+	dev->trans_start = jiffies;
+	netif_wake_queue(dev);
+}
+
+/*
+ * Get the current statistics.
+ * This may be called with the card open or closed.
+ */
+static struct net_device_stats *bf537mac_query_statistics(struct net_device
+							  *dev)
+{
+	struct bf537mac_local *lp = netdev_priv(dev);
+
+	pr_debug("%s: %s\n", dev->name, __FUNCTION__);
+
+	return &lp->stats;
+}
+
+/*
+ * This routine will, depending on the values passed to it,
+ * either make it accept multicast packets, go into
+ * promiscuous mode (for TCPDUMP and cousins) or accept
+ * a select set of multicast packets
+ */
+static void bf537mac_set_multicast_list(struct net_device *dev)
+{
+	u32 sysctl;
+
+	if (dev->flags & IFF_PROMISC) {
+		printk(KERN_INFO "%s: set to promisc mode\n", dev->name);
+		sysctl = bfin_read_EMAC_OPMODE();
+		sysctl |= RAF;
+		bfin_write_EMAC_OPMODE(sysctl);
+	} else if (dev->flags & IFF_ALLMULTI || dev->mc_count) {
+		/* accept all multicast */
+		sysctl = bfin_read_EMAC_OPMODE();
+		sysctl |= PAM;
+		bfin_write_EMAC_OPMODE(sysctl);
+	} else {
+		/* clear promisc or multicast mode */
+		sysctl = bfin_read_EMAC_OPMODE();
+		sysctl &= ~(RAF | PAM);
+		bfin_write_EMAC_OPMODE(sysctl);
+	}
+}
+
+/*
+ * this puts the device in an inactive state
+ */
+static void bf537mac_shutdown(struct net_device *dev)
+{
+	/* Turn off the EMAC */
+	bfin_write_EMAC_OPMODE(0x00000000);
+	/* Turn off the EMAC RX DMA */
+	bfin_write_DMA1_CONFIG(0x0000);
+	bfin_write_DMA2_CONFIG(0x0000);
+}
+
+/*
+ * Open and Initialize the interface
+ *
+ * Set up everything, reset the card, etc..
+ */
+static int bf537mac_open(struct net_device *dev)
+{
+	pr_debug("%s: %s\n", dev->name, __FUNCTION__);
+
+	/*
+	 * Check that the address is valid.  If its not, refuse
+	 * to bring the device up.  The user must specify an
+	 * address using ifconfig eth0 hw ether xx:xx:xx:xx:xx:xx
+	 */
+	if (!is_valid_ether_addr(dev->dev_addr)) {
+		printk(KERN_WARNING DRV_NAME ": no valid ethernet hw addr\n");
+		return -EINVAL;
+	}
+
+	/* initial rx and tx list */
+	desc_list_init();
+
+	bf537mac_setphy(dev);
+	setup_system_regs(dev);
+	bf537mac_reset();
+	bf537mac_enable(dev);
+
+	pr_debug("hardware init finished\n");
+	netif_start_queue(dev);
+	netif_carrier_on(dev);
+
+	return 0;
+}
+
+/*
+ *
+ * this makes the board clean up everything that it can
+ * and not talk to the outside world.   Caused by
+ * an 'ifconfig ethX down'
+ */
+static int bf537mac_close(struct net_device *dev)
+{
+	pr_debug("%s: %s\n", dev->name, __FUNCTION__);
+
+	netif_stop_queue(dev);
+	netif_carrier_off(dev);
+
+	/* clear everything */
+	bf537mac_shutdown(dev);
+
+	/* free the rx/tx buffers */
+	desc_list_free();
+
+	return 0;
+}
+
+static int __init bf537mac_probe(struct net_device *dev)
+{
+	struct bf537mac_local *lp = netdev_priv(dev);
+	int retval;
+
+	/* Grab the MAC address in the MAC */
+	*(__le32 *) (&(dev->dev_addr[0])) = cpu_to_le32(bfin_read_EMAC_ADDRLO());
+	*(__le16 *) (&(dev->dev_addr[4])) = cpu_to_le16((u16) bfin_read_EMAC_ADDRHI());
+
+	/* probe mac */
+	/*todo: how to proble? which is revision_register */
+	bfin_write_EMAC_ADDRLO(0x12345678);
+	if (bfin_read_EMAC_ADDRLO() != 0x12345678) {
+		pr_debug("can't detect bf537 mac!\n");
+		retval = -ENODEV;
+		goto err_out;
+	}
+
+	/* set the GPIO pins to Ethernet mode */
+	retval = setup_pin_mux(1);
+
+	if (retval)
+		return retval;
+
+	/*Is it valid? (Did bootloader initialize it?) */
+	if (!is_valid_ether_addr(dev->dev_addr)) {
+		/* Grab the MAC from the board somehow - this is done in the
+		   arch/blackfin/mach-bf537/boards/eth_mac.c */
+		get_bf537_ether_addr(dev->dev_addr);
+	}
+
+	/* If still not valid, get a random one */
+	if (!is_valid_ether_addr(dev->dev_addr)) {
+		random_ether_addr(dev->dev_addr);
+	}
+
+	setup_mac_addr(dev->dev_addr);
+
+	/* Fill in the fields of the device structure with ethernet values. */
+	ether_setup(dev);
+
+	dev->open = bf537mac_open;
+	dev->stop = bf537mac_close;
+	dev->hard_start_xmit = bf537mac_hard_start_xmit;
+	dev->tx_timeout = bf537mac_timeout;
+	dev->get_stats = bf537mac_query_statistics;
+	dev->set_multicast_list = bf537mac_set_multicast_list;
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	dev->poll_controller = bf537mac_poll;
+#endif
+
+	/* fill in some of the fields */
+	lp->version = 1;
+	lp->PhyAddr = 0x01;
+	lp->CLKIN = 25;
+	lp->FullDuplex = 0;
+	lp->Negotiate = 1;
+	lp->FlowControl = 0;
+	spin_lock_init(&lp->lock);
+
+	/* now, enable interrupts */
+	/* register irq handler */
+	if (request_irq
+	    (IRQ_MAC_RX, bf537mac_interrupt, IRQF_DISABLED | IRQF_SHARED,
+	     "BFIN537_MAC_RX", dev)) {
+		printk(KERN_WARNING DRV_NAME
+		       ": Unable to attach BlackFin MAC RX interrupt\n");
+		return -EBUSY;
+	}
+
+	/* Enable PHY output early */
+	if (!(bfin_read_VR_CTL() & PHYCLKOE))
+		bfin_write_VR_CTL(bfin_read_VR_CTL() | PHYCLKOE);
+
+	retval = register_netdev(dev);
+	if (retval == 0) {
+		/* now, print out the card info, in a short format.. */
+		printk(KERN_INFO "%s: Version %s, %s\n",
+			 DRV_NAME, DRV_VERSION, DRV_DESC);
+	}
+
+err_out:
+	return retval;
+}
+
+static int bfin_mac_probe(struct platform_device *pdev)
+{
+	struct net_device *ndev;
+
+	ndev = alloc_etherdev(sizeof(struct bf537mac_local));
+	if (!ndev) {
+		printk(KERN_WARNING DRV_NAME ": could not allocate device\n");
+		return -ENOMEM;
+	}
+
+	SET_MODULE_OWNER(ndev);
+	SET_NETDEV_DEV(ndev, &pdev->dev);
+
+	platform_set_drvdata(pdev, ndev);
+
+	if (bf537mac_probe(ndev) != 0) {
+		platform_set_drvdata(pdev, NULL);
+		free_netdev(ndev);
+		printk(KERN_WARNING DRV_NAME ": not found\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int bfin_mac_remove(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	unregister_netdev(ndev);
+
+	free_irq(IRQ_MAC_RX, ndev);
+
+	free_netdev(ndev);
+
+	setup_pin_mux(0);
+
+	return 0;
+}
+
+static int bfin_mac_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	return 0;
+}
+
+static int bfin_mac_resume(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static struct platform_driver bfin_mac_driver = {
+	.probe = bfin_mac_probe,
+	.remove = bfin_mac_remove,
+	.resume = bfin_mac_resume,
+	.suspend = bfin_mac_suspend,
+	.driver = {
+		   .name = DRV_NAME,
+		   },
+};
+
+static int __init bfin_mac_init(void)
+{
+	return platform_driver_register(&bfin_mac_driver);
+}
+
+module_init(bfin_mac_init);
+
+static void __exit bfin_mac_cleanup(void)
+{
+	platform_driver_unregister(&bfin_mac_driver);
+}
+
+module_exit(bfin_mac_cleanup);