patch-2.4.26 linux-2.4.26/arch/ppc/cpm2_io/enet.c

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diff -urN linux-2.4.25/arch/ppc/cpm2_io/enet.c linux-2.4.26/arch/ppc/cpm2_io/enet.c
@@ -0,0 +1,857 @@
+/*
+ * Ethernet driver for Motorola MPC8260.
+ * Copyright (c) 1999 Dan Malek (dmalek@jlc.net)
+ * Copyright (c) 2000 MontaVista Software Inc. (source@mvista.com)
+ *	2.3.99 Updates
+ *
+ * I copied this from the 8xx CPM Ethernet driver, so follow the
+ * credits back through that.
+ *
+ * This version of the driver is somewhat selectable for the different
+ * processor/board combinations.  It works for the boards I know about
+ * now, and should be easily modified to include others.  Some of the
+ * configuration information is contained in <asm/commproc.h> and the
+ * remainder is here.
+ *
+ * Buffer descriptors are kept in the CPM dual port RAM, and the frame
+ * buffers are in the host memory.
+ *
+ * Right now, I am very watseful with the buffers.  I allocate memory
+ * pages and then divide them into 2K frame buffers.  This way I know I
+ * have buffers large enough to hold one frame within one buffer descriptor.
+ * Once I get this working, I will use 64 or 128 byte CPM buffers, which
+ * will be much more memory efficient and will easily handle lots of
+ * small packets.
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/ptrace.h>
+#include <linux/errno.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/spinlock.h>
+
+#include <asm/immap_cpm2.h>
+#include <asm/pgtable.h>
+#include <asm/mpc8260.h>
+#include <asm/bitops.h>
+#include <asm/uaccess.h>
+#include <asm/cpm2.h>
+#include <asm/irq.h>
+
+/*
+ *				Theory of Operation
+ *
+ * The MPC8260 CPM performs the Ethernet processing on an SCC.  It can use
+ * an aribtrary number of buffers on byte boundaries, but must have at
+ * least two receive buffers to prevent constant overrun conditions.
+ *
+ * The buffer descriptors are allocated from the CPM dual port memory
+ * with the data buffers allocated from host memory, just like all other
+ * serial communication protocols.  The host memory buffers are allocated
+ * from the free page pool, and then divided into smaller receive and
+ * transmit buffers.  The size of the buffers should be a power of two,
+ * since that nicely divides the page.  This creates a ring buffer
+ * structure similar to the LANCE and other controllers.
+ *
+ * Like the LANCE driver:
+ * The driver runs as two independent, single-threaded flows of control.  One
+ * is the send-packet routine, which enforces single-threaded use by the
+ * cep->tx_busy flag.  The other thread is the interrupt handler, which is
+ * single threaded by the hardware and other software.
+ */
+
+/* The transmitter timeout
+ */
+#define TX_TIMEOUT	(2*HZ)
+
+/* The number of Tx and Rx buffers.  These are allocated from the page
+ * pool.  The code may assume these are power of two, so it is best
+ * to keep them that size.
+ * We don't need to allocate pages for the transmitter.  We just use
+ * the skbuffer directly.
+ */
+#define CPM_ENET_RX_PAGES	4
+#define CPM_ENET_RX_FRSIZE	2048
+#define CPM_ENET_RX_FRPPG	(PAGE_SIZE / CPM_ENET_RX_FRSIZE)
+#define RX_RING_SIZE		(CPM_ENET_RX_FRPPG * CPM_ENET_RX_PAGES)
+#define TX_RING_SIZE		8	/* Must be power of two */
+#define TX_RING_MOD_MASK	7	/*   for this to work */
+
+/* The CPM stores dest/src/type, data, and checksum for receive packets.
+ */
+#define PKT_MAXBUF_SIZE		1518
+#define PKT_MINBUF_SIZE		64
+#define PKT_MAXBLR_SIZE		1520
+
+/* The CPM buffer descriptors track the ring buffers.  The rx_bd_base and
+ * tx_bd_base always point to the base of the buffer descriptors.  The
+ * cur_rx and cur_tx point to the currently available buffer.
+ * The dirty_tx tracks the current buffer that is being sent by the
+ * controller.  The cur_tx and dirty_tx are equal under both completely
+ * empty and completely full conditions.  The empty/ready indicator in
+ * the buffer descriptor determines the actual condition.
+ */
+struct scc_enet_private {
+	/* The saved address of a sent-in-place packet/buffer, for skfree(). */
+	struct	sk_buff* tx_skbuff[TX_RING_SIZE];
+	ushort	skb_cur;
+	ushort	skb_dirty;
+
+	/* CPM dual port RAM relative addresses.
+	*/
+	cbd_t	*rx_bd_base;		/* Address of Rx and Tx buffers. */
+	cbd_t	*tx_bd_base;
+	cbd_t	*cur_rx, *cur_tx;		/* The next free ring entry */
+	cbd_t	*dirty_tx;	/* The ring entries to be free()ed. */
+	scc_t	*sccp;
+	struct	net_device_stats stats;
+	uint	tx_free;
+	spinlock_t lock;
+};
+
+static int scc_enet_open(struct net_device *dev);
+static int scc_enet_start_xmit(struct sk_buff *skb, struct net_device *dev);
+static int scc_enet_rx(struct net_device *dev);
+static void scc_enet_interrupt(int irq, void * dev_id, struct pt_regs * regs);
+static int scc_enet_close(struct net_device *dev);
+static struct net_device_stats *scc_enet_get_stats(struct net_device *dev);
+static void set_multicast_list(struct net_device *dev);
+
+/* These will be configurable for the SCC choice.
+*/
+#define CPM_ENET_BLOCK	CPM_CR_SCC1_SBLOCK
+#define CPM_ENET_PAGE	CPM_CR_SCC1_PAGE
+#define PROFF_ENET	PROFF_SCC1
+#define SCC_ENET	0
+#define SIU_INT_ENET	SIU_INT_SCC1
+
+/* These are both board and SCC dependent....
+*/
+#define PD_ENET_RXD	((uint)0x00000001)
+#define PD_ENET_TXD	((uint)0x00000002)
+#define PD_ENET_TENA	((uint)0x00000004)
+#define PC_ENET_RENA	((uint)0x00020000)
+#define PC_ENET_CLSN	((uint)0x00000004)
+#define PC_ENET_TXCLK	((uint)0x00000800)
+#define PC_ENET_RXCLK	((uint)0x00000400)
+#define CMX_CLK_ROUTE	((uint)0x25000000)
+#define CMX_CLK_MASK	((uint)0xff000000)
+
+/* Specific to a board.
+*/
+#define PC_EST8260_ENET_LOOPBACK	((uint)0x80000000)
+#define PC_EST8260_ENET_SQE		((uint)0x40000000)
+#define PC_EST8260_ENET_NOTFD		((uint)0x20000000)
+
+static int
+scc_enet_open(struct net_device *dev)
+{
+
+	/* I should reset the ring buffers here, but I don't yet know
+	 * a simple way to do that.
+	 */
+	netif_start_queue(dev);
+	return 0;					/* Always succeed */
+}
+
+static int
+scc_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct scc_enet_private *cep = (struct scc_enet_private *)dev->priv;
+	volatile cbd_t	*bdp;
+
+
+	/* Fill in a Tx ring entry */
+	bdp = cep->cur_tx;
+
+#ifndef final_version
+	if (!cep->tx_free || (bdp->cbd_sc & BD_ENET_TX_READY)) {
+		/* Ooops.  All transmit buffers are full.  Bail out.
+		 * This should not happen, since the tx queue should be stopped.
+		 */
+		printk("%s: tx queue full!.\n", dev->name);
+		return 1;
+	}
+#endif
+
+	/* Clear all of the status flags.
+	 */
+	bdp->cbd_sc &= ~BD_ENET_TX_STATS;
+
+	/* If the frame is short, tell CPM to pad it.
+	*/
+	if (skb->len <= ETH_ZLEN)
+		bdp->cbd_sc |= BD_ENET_TX_PAD;
+	else
+		bdp->cbd_sc &= ~BD_ENET_TX_PAD;
+
+	/* Set buffer length and buffer pointer.
+	*/
+	bdp->cbd_datlen = skb->len;
+	bdp->cbd_bufaddr = __pa(skb->data);
+
+	/* Save skb pointer.
+	*/
+	cep->tx_skbuff[cep->skb_cur] = skb;
+
+	cep->stats.tx_bytes += skb->len;
+	cep->skb_cur = (cep->skb_cur+1) & TX_RING_MOD_MASK;
+
+	spin_lock_irq(&cep->lock);
+
+	/* Send it on its way.  Tell CPM its ready, interrupt when done,
+	 * its the last BD of the frame, and to put the CRC on the end.
+	 */
+	bdp->cbd_sc |= (BD_ENET_TX_READY | BD_ENET_TX_INTR | BD_ENET_TX_LAST | BD_ENET_TX_TC);
+
+	dev->trans_start = jiffies;
+
+	/* If this was the last BD in the ring, start at the beginning again.
+	*/
+	if (bdp->cbd_sc & BD_ENET_TX_WRAP)
+		bdp = cep->tx_bd_base;
+	else
+		bdp++;
+
+	if (!--cep->tx_free)
+		netif_stop_queue(dev);
+
+	cep->cur_tx = (cbd_t *)bdp;
+
+	spin_unlock_irq(&cep->lock);
+
+	return 0;
+}
+
+static void
+scc_enet_timeout(struct net_device *dev)
+{
+	struct scc_enet_private *cep = (struct scc_enet_private *)dev->priv;
+
+	printk("%s: transmit timed out.\n", dev->name);
+	cep->stats.tx_errors++;
+#ifndef final_version
+	{
+		int	i;
+		cbd_t	*bdp;
+		printk(" Ring data dump: cur_tx %p tx_free %d cur_rx %p.\n",
+		       cep->cur_tx, cep->tx_free,
+		       cep->cur_rx);
+		bdp = cep->tx_bd_base;
+		printk(" Tx @base %p :\n", bdp);
+		for (i = 0 ; i < TX_RING_SIZE; i++, bdp++)
+			printk("%04x %04x %08x\n",
+			       bdp->cbd_sc,
+			       bdp->cbd_datlen,
+			       bdp->cbd_bufaddr);
+		bdp = cep->rx_bd_base;
+		printk(" Rx @base %p :\n", bdp);
+		for (i = 0 ; i < RX_RING_SIZE; i++, bdp++)
+			printk("%04x %04x %08x\n",
+			       bdp->cbd_sc,
+			       bdp->cbd_datlen,
+			       bdp->cbd_bufaddr);
+	}
+#endif
+	if (cep->tx_free)
+		netif_wake_queue(dev);
+}
+
+/* The interrupt handler.
+ * This is called from the CPM handler, not the MPC core interrupt.
+ */
+static void
+scc_enet_interrupt(int irq, void * dev_id, struct pt_regs * regs)
+{
+	struct	net_device *dev = dev_id;
+	volatile struct	scc_enet_private *cep;
+	volatile cbd_t	*bdp;
+	ushort	int_events;
+	int	must_restart;
+
+	cep = (struct scc_enet_private *)dev->priv;
+
+	/* Get the interrupt events that caused us to be here.
+	*/
+	int_events = cep->sccp->scc_scce;
+	cep->sccp->scc_scce = int_events;
+	must_restart = 0;
+
+	/* Handle receive event in its own function.
+	*/
+	if (int_events & SCCE_ENET_RXF)
+		scc_enet_rx(dev_id);
+
+	/* Check for a transmit error.  The manual is a little unclear
+	 * about this, so the debug code until I get it figured out.  It
+	 * appears that if TXE is set, then TXB is not set.  However,
+	 * if carrier sense is lost during frame transmission, the TXE
+	 * bit is set, "and continues the buffer transmission normally."
+	 * I don't know if "normally" implies TXB is set when the buffer
+	 * descriptor is closed.....trial and error :-).
+	 */
+
+	/* Transmit OK, or non-fatal error.  Update the buffer descriptors.
+	*/
+	if (int_events & (SCCE_ENET_TXE | SCCE_ENET_TXB)) {
+	    spin_lock(&cep->lock);
+	    bdp = cep->dirty_tx;
+	    while ((bdp->cbd_sc&BD_ENET_TX_READY)==0) {
+		if (cep->tx_free == TX_RING_SIZE)
+		    break;
+
+		if (bdp->cbd_sc & BD_ENET_TX_HB)	/* No heartbeat */
+			cep->stats.tx_heartbeat_errors++;
+		if (bdp->cbd_sc & BD_ENET_TX_LC)	/* Late collision */
+			cep->stats.tx_window_errors++;
+		if (bdp->cbd_sc & BD_ENET_TX_RL)	/* Retrans limit */
+			cep->stats.tx_aborted_errors++;
+		if (bdp->cbd_sc & BD_ENET_TX_UN)	/* Underrun */
+			cep->stats.tx_fifo_errors++;
+		if (bdp->cbd_sc & BD_ENET_TX_CSL)	/* Carrier lost */
+			cep->stats.tx_carrier_errors++;
+
+
+		/* No heartbeat or Lost carrier are not really bad errors.
+		 * The others require a restart transmit command.
+		 */
+		if (bdp->cbd_sc &
+		    (BD_ENET_TX_LC | BD_ENET_TX_RL | BD_ENET_TX_UN)) {
+			must_restart = 1;
+			cep->stats.tx_errors++;
+		}
+
+		cep->stats.tx_packets++;
+
+		/* Deferred means some collisions occurred during transmit,
+		 * but we eventually sent the packet OK.
+		 */
+		if (bdp->cbd_sc & BD_ENET_TX_DEF)
+			cep->stats.collisions++;
+
+		/* Free the sk buffer associated with this last transmit.
+		*/
+		dev_kfree_skb_irq(cep->tx_skbuff[cep->skb_dirty]);
+		cep->skb_dirty = (cep->skb_dirty + 1) & TX_RING_MOD_MASK;
+
+		/* Update pointer to next buffer descriptor to be transmitted.
+		*/
+		if (bdp->cbd_sc & BD_ENET_TX_WRAP)
+			bdp = cep->tx_bd_base;
+		else
+			bdp++;
+
+		/* I don't know if we can be held off from processing these
+		 * interrupts for more than one frame time.  I really hope
+		 * not.  In such a case, we would now want to check the
+		 * currently available BD (cur_tx) and determine if any
+		 * buffers between the dirty_tx and cur_tx have also been
+		 * sent.  We would want to process anything in between that
+		 * does not have BD_ENET_TX_READY set.
+		 */
+
+		/* Since we have freed up a buffer, the ring is no longer
+		 * full.
+		 */
+		if (!cep->tx_free++) {
+			if (netif_queue_stopped(dev)) {
+				netif_wake_queue(dev);
+			}
+		}
+
+		cep->dirty_tx = (cbd_t *)bdp;
+	    }
+
+	    if (must_restart) {
+		volatile cpm_cpm2_t *cp;
+
+		/* Some transmit errors cause the transmitter to shut
+		 * down.  We now issue a restart transmit.  Since the
+		 * errors close the BD and update the pointers, the restart
+		 * _should_ pick up without having to reset any of our
+		 * pointers either.
+		 */
+
+		cp = cpmp;
+		cp->cp_cpcr =
+		    mk_cr_cmd(CPM_ENET_PAGE, CPM_ENET_BLOCK, 0,
+		    			CPM_CR_RESTART_TX) | CPM_CR_FLG;
+		while (cp->cp_cpcr & CPM_CR_FLG);
+	    }
+	    spin_unlock(&cep->lock);
+	}
+
+	/* Check for receive busy, i.e. packets coming but no place to
+	 * put them.
+	 */
+	if (int_events & SCCE_ENET_BSY)
+		cep->stats.rx_dropped++;
+
+	return;
+}
+
+/* During a receive, the cur_rx points to the current incoming buffer.
+ * When we update through the ring, if the next incoming buffer has
+ * not been given to the system, we just set the empty indicator,
+ * effectively tossing the packet.
+ */
+static int
+scc_enet_rx(struct net_device *dev)
+{
+	struct	scc_enet_private *cep;
+	volatile cbd_t	*bdp;
+	struct	sk_buff *skb;
+	ushort	pkt_len;
+
+	cep = (struct scc_enet_private *)dev->priv;
+
+	/* First, grab all of the stats for the incoming packet.
+	 * These get messed up if we get called due to a busy condition.
+	 */
+	bdp = cep->cur_rx;
+
+for (;;) {
+	if (bdp->cbd_sc & BD_ENET_RX_EMPTY)
+		break;
+
+#ifndef final_version
+	/* Since we have allocated space to hold a complete frame, both
+	 * the first and last indicators should be set.
+	 */
+	if ((bdp->cbd_sc & (BD_ENET_RX_FIRST | BD_ENET_RX_LAST)) !=
+		(BD_ENET_RX_FIRST | BD_ENET_RX_LAST))
+			printk("CPM ENET: rcv is not first+last\n");
+#endif
+
+	/* Frame too long or too short.
+	*/
+	if (bdp->cbd_sc & (BD_ENET_RX_LG | BD_ENET_RX_SH))
+		cep->stats.rx_length_errors++;
+	if (bdp->cbd_sc & BD_ENET_RX_NO)	/* Frame alignment */
+		cep->stats.rx_frame_errors++;
+	if (bdp->cbd_sc & BD_ENET_RX_CR)	/* CRC Error */
+		cep->stats.rx_crc_errors++;
+	if (bdp->cbd_sc & BD_ENET_RX_OV)	/* FIFO overrun */
+		cep->stats.rx_crc_errors++;
+
+	/* Report late collisions as a frame error.
+	 * On this error, the BD is closed, but we don't know what we
+	 * have in the buffer.  So, just drop this frame on the floor.
+	 */
+	if (bdp->cbd_sc & BD_ENET_RX_CL) {
+		cep->stats.rx_frame_errors++;
+	}
+	else {
+
+		/* Process the incoming frame.
+		*/
+		cep->stats.rx_packets++;
+		pkt_len = bdp->cbd_datlen;
+		cep->stats.rx_bytes += pkt_len;
+
+		/* This does 16 byte alignment, much more than we need.
+		 * The packet length includes FCS, but we don't want to
+		 * include that when passing upstream as it messes up
+		 * bridging applications.
+		 */
+		skb = dev_alloc_skb(pkt_len-4);
+
+		if (skb == NULL) {
+			printk("%s: Memory squeeze, dropping packet.\n", dev->name);
+			cep->stats.rx_dropped++;
+		}
+		else {
+			skb->dev = dev;
+			skb_put(skb,pkt_len-4);	/* Make room */
+			eth_copy_and_sum(skb,
+				(unsigned char *)__va(bdp->cbd_bufaddr),
+				pkt_len-4, 0);
+			skb->protocol=eth_type_trans(skb,dev);
+			netif_rx(skb);
+		}
+	}
+
+	/* Clear the status flags for this buffer.
+	*/
+	bdp->cbd_sc &= ~BD_ENET_RX_STATS;
+
+	/* Mark the buffer empty.
+	*/
+	bdp->cbd_sc |= BD_ENET_RX_EMPTY;
+
+	/* Update BD pointer to next entry.
+	*/
+	if (bdp->cbd_sc & BD_ENET_RX_WRAP)
+		bdp = cep->rx_bd_base;
+	else
+		bdp++;
+
+   }
+	cep->cur_rx = (cbd_t *)bdp;
+
+	return 0;
+}
+
+static int
+scc_enet_close(struct net_device *dev)
+{
+	/* Don't know what to do yet.
+	*/
+	netif_stop_queue(dev);
+
+	return 0;
+}
+
+static struct net_device_stats *scc_enet_get_stats(struct net_device *dev)
+{
+	struct scc_enet_private *cep = (struct scc_enet_private *)dev->priv;
+
+	return &cep->stats;
+}
+
+/* Set or clear the multicast filter for this adaptor.
+ * Skeleton taken from sunlance driver.
+ * The CPM Ethernet implementation allows Multicast as well as individual
+ * MAC address filtering.  Some of the drivers check to make sure it is
+ * a group multicast address, and discard those that are not.  I guess I
+ * will do the same for now, but just remove the test if you want
+ * individual filtering as well (do the upper net layers want or support
+ * this kind of feature?).
+ */
+
+static void set_multicast_list(struct net_device *dev)
+{
+	struct	scc_enet_private *cep;
+	struct	dev_mc_list *dmi;
+	u_char	*mcptr, *tdptr;
+	volatile scc_enet_t *ep;
+	int	i, j;
+	cep = (struct scc_enet_private *)dev->priv;
+
+	/* Get pointer to SCC area in parameter RAM.
+	*/
+	ep = (scc_enet_t *)dev->base_addr;
+
+	if (dev->flags&IFF_PROMISC) {
+
+		/* Log any net taps. */
+		printk("%s: Promiscuous mode enabled.\n", dev->name);
+		cep->sccp->scc_psmr |= SCC_PSMR_PRO;
+	} else {
+
+		cep->sccp->scc_psmr &= ~SCC_PSMR_PRO;
+
+		if (dev->flags & IFF_ALLMULTI) {
+			/* Catch all multicast addresses, so set the
+			 * filter to all 1's.
+			 */
+			ep->sen_gaddr1 = 0xffff;
+			ep->sen_gaddr2 = 0xffff;
+			ep->sen_gaddr3 = 0xffff;
+			ep->sen_gaddr4 = 0xffff;
+		}
+		else {
+			/* Clear filter and add the addresses in the list.
+			*/
+			ep->sen_gaddr1 = 0;
+			ep->sen_gaddr2 = 0;
+			ep->sen_gaddr3 = 0;
+			ep->sen_gaddr4 = 0;
+
+			dmi = dev->mc_list;
+
+			for (i=0; i<dev->mc_count; i++, dmi = dmi->next) {
+
+				/* Only support group multicast for now.
+				*/
+				if (!(dmi->dmi_addr[0] & 1))
+					continue;
+
+				/* The address in dmi_addr is LSB first,
+				 * and taddr is MSB first.  We have to
+				 * copy bytes MSB first from dmi_addr.
+				 */
+				mcptr = (u_char *)dmi->dmi_addr + 5;
+				tdptr = (u_char *)&ep->sen_taddrh;
+				for (j=0; j<6; j++)
+					*tdptr++ = *mcptr--;
+
+				/* Ask CPM to run CRC and set bit in
+				 * filter mask.
+				 */
+				cpmp->cp_cpcr = mk_cr_cmd(CPM_ENET_PAGE,
+						CPM_ENET_BLOCK, 0,
+						CPM_CR_SET_GADDR) | CPM_CR_FLG;
+				/* this delay is necessary here -- Cort */
+				udelay(10);
+				while (cpmp->cp_cpcr & CPM_CR_FLG);
+			}
+		}
+	}
+}
+
+/* Initialize the CPM Ethernet on SCC.
+ */
+int __init scc_enet_init(void)
+{
+	struct net_device *dev;
+	struct scc_enet_private *cep;
+	int i, j;
+	unsigned char	*eap;
+	unsigned long	mem_addr;
+	bd_t		*bd;
+	volatile	cbd_t		*bdp;
+	volatile	cpm_cpm2_t	*cp;
+	volatile	scc_t		*sccp;
+	volatile	scc_enet_t	*ep;
+	volatile	cpm2_map_t		*immap;
+	volatile	iop_cpm2_t	*io;
+
+	cp = cpmp;	/* Get pointer to Communication Processor */
+
+	immap = (cpm2_map_t *)CPM_MAP_ADDR;	/* and to internal registers */
+	io = &immap->im_ioport;
+
+	bd = (bd_t *)__res;
+
+	/* Allocate some private information.
+	*/
+	cep = (struct scc_enet_private *)kmalloc(sizeof(*cep), GFP_KERNEL);
+	if (cep == NULL)
+		return -ENOMEM;
+
+	__clear_user(cep,sizeof(*cep));
+	spin_lock_init(&cep->lock);
+
+	/* Create an Ethernet device instance.
+	*/
+	dev = init_etherdev(0, 0);
+
+	/* Get pointer to SCC area in parameter RAM.
+	*/
+	ep = (scc_enet_t *)(&immap->im_dprambase[PROFF_ENET]);
+
+	/* And another to the SCC register area.
+	*/
+	sccp = (volatile scc_t *)(&immap->im_scc[SCC_ENET]);
+	cep->sccp = (scc_t *)sccp;		/* Keep the pointer handy */
+
+	/* Disable receive and transmit in case someone left it running.
+	*/
+	sccp->scc_gsmrl &= ~(SCC_GSMRL_ENR | SCC_GSMRL_ENT);
+
+	/* Configure port C and D pins for SCC Ethernet.  This
+	 * won't work for all SCC possibilities....it will be
+	 * board/port specific.
+	 */
+	io->iop_pparc |=
+		(PC_ENET_RENA | PC_ENET_CLSN | PC_ENET_TXCLK | PC_ENET_RXCLK);
+	io->iop_pdirc &=
+		~(PC_ENET_RENA | PC_ENET_CLSN | PC_ENET_TXCLK | PC_ENET_RXCLK);
+	io->iop_psorc &=
+		~(PC_ENET_RENA | PC_ENET_TXCLK | PC_ENET_RXCLK);
+	io->iop_psorc |= PC_ENET_CLSN;
+
+	io->iop_ppard |= (PD_ENET_RXD | PD_ENET_TXD | PD_ENET_TENA);
+	io->iop_pdird |= (PD_ENET_TXD | PD_ENET_TENA);
+	io->iop_pdird &= ~PD_ENET_RXD;
+	io->iop_psord |= PD_ENET_TXD;
+	io->iop_psord &= ~(PD_ENET_RXD | PD_ENET_TENA);
+
+	/* Configure Serial Interface clock routing.
+	 * First, clear all SCC bits to zero, then set the ones we want.
+	 */
+	immap->im_cpmux.cmx_scr &= ~CMX_CLK_MASK;
+	immap->im_cpmux.cmx_scr |= CMX_CLK_ROUTE;
+
+	/* Allocate space for the buffer descriptors in the DP ram.
+	 * These are relative offsets in the DP ram address space.
+	 * Initialize base addresses for the buffer descriptors.
+	 */
+	i = cpm2_dpalloc(sizeof(cbd_t) * RX_RING_SIZE, 8);
+	ep->sen_genscc.scc_rbase = i;
+	cep->rx_bd_base = (cbd_t *)&immap->im_dprambase[i];
+
+	i = cpm2_dpalloc(sizeof(cbd_t) * TX_RING_SIZE, 8);
+	ep->sen_genscc.scc_tbase = i;
+	cep->tx_bd_base = (cbd_t *)&immap->im_dprambase[i];
+
+	cep->dirty_tx = cep->cur_tx = cep->tx_bd_base;
+	cep->tx_free = TX_RING_SIZE;
+	cep->cur_rx = cep->rx_bd_base;
+
+	ep->sen_genscc.scc_rfcr = CPMFCR_GBL | CPMFCR_EB;
+	ep->sen_genscc.scc_tfcr = CPMFCR_GBL | CPMFCR_EB;
+
+	/* Set maximum bytes per receive buffer.
+	 * This appears to be an Ethernet frame size, not the buffer
+	 * fragment size.  It must be a multiple of four.
+	 */
+	ep->sen_genscc.scc_mrblr = PKT_MAXBLR_SIZE;
+
+	/* Set CRC preset and mask.
+	*/
+	ep->sen_cpres = 0xffffffff;
+	ep->sen_cmask = 0xdebb20e3;
+
+	ep->sen_crcec = 0;	/* CRC Error counter */
+	ep->sen_alec = 0;	/* alignment error counter */
+	ep->sen_disfc = 0;	/* discard frame counter */
+
+	ep->sen_pads = 0x8888;	/* Tx short frame pad character */
+	ep->sen_retlim = 15;	/* Retry limit threshold */
+
+	ep->sen_maxflr = PKT_MAXBUF_SIZE;   /* maximum frame length register */
+	ep->sen_minflr = PKT_MINBUF_SIZE;  /* minimum frame length register */
+
+	ep->sen_maxd1 = PKT_MAXBLR_SIZE;	/* maximum DMA1 length */
+	ep->sen_maxd2 = PKT_MAXBLR_SIZE;	/* maximum DMA2 length */
+
+	/* Clear hash tables.
+	*/
+	ep->sen_gaddr1 = 0;
+	ep->sen_gaddr2 = 0;
+	ep->sen_gaddr3 = 0;
+	ep->sen_gaddr4 = 0;
+	ep->sen_iaddr1 = 0;
+	ep->sen_iaddr2 = 0;
+	ep->sen_iaddr3 = 0;
+	ep->sen_iaddr4 = 0;
+
+	/* Set Ethernet station address.
+	 *
+	 * This is supplied in the board information structure, so we
+	 * copy that into the controller.
+	 */
+	eap = (unsigned char *)&(ep->sen_paddrh);
+	for (i=5; i>=0; i--)
+		*eap++ = dev->dev_addr[i] = bd->bi_enetaddr[i];
+
+	ep->sen_pper = 0;	/* 'cause the book says so */
+	ep->sen_taddrl = 0;	/* temp address (LSB) */
+	ep->sen_taddrm = 0;
+	ep->sen_taddrh = 0;	/* temp address (MSB) */
+
+	/* Now allocate the host memory pages and initialize the
+	 * buffer descriptors.
+	 */
+	bdp = cep->tx_bd_base;
+	for (i=0; i<TX_RING_SIZE; i++) {
+
+		/* Initialize the BD for every fragment in the page.
+		*/
+		bdp->cbd_sc = 0;
+		bdp->cbd_bufaddr = 0;
+		bdp++;
+	}
+
+	/* Set the last buffer to wrap.
+	*/
+	bdp--;
+	bdp->cbd_sc |= BD_SC_WRAP;
+
+	bdp = cep->rx_bd_base;
+	for (i=0; i<CPM_ENET_RX_PAGES; i++) {
+
+		/* Allocate a page.
+		*/
+		mem_addr = __get_free_page(GFP_KERNEL);
+
+		/* Initialize the BD for every fragment in the page.
+		*/
+		for (j=0; j<CPM_ENET_RX_FRPPG; j++) {
+			bdp->cbd_sc = BD_ENET_RX_EMPTY | BD_ENET_RX_INTR;
+			bdp->cbd_bufaddr = __pa(mem_addr);
+			mem_addr += CPM_ENET_RX_FRSIZE;
+			bdp++;
+		}
+	}
+
+	/* Set the last buffer to wrap.
+	*/
+	bdp--;
+	bdp->cbd_sc |= BD_SC_WRAP;
+
+	/* Let's re-initialize the channel now.  We have to do it later
+	 * than the manual describes because we have just now finished
+	 * the BD initialization.
+	 */
+	cpmp->cp_cpcr = mk_cr_cmd(CPM_ENET_PAGE, CPM_ENET_BLOCK, 0,
+			CPM_CR_INIT_TRX) | CPM_CR_FLG;
+	while (cp->cp_cpcr & CPM_CR_FLG);
+
+	cep->skb_cur = cep->skb_dirty = 0;
+
+	sccp->scc_scce = 0xffff;	/* Clear any pending events */
+
+	/* Enable interrupts for transmit error, complete frame
+	 * received, and any transmit buffer we have also set the
+	 * interrupt flag.
+	 */
+	sccp->scc_sccm = (SCCE_ENET_TXE | SCCE_ENET_RXF | SCCE_ENET_TXB);
+
+	/* Install our interrupt handler.
+	*/
+	request_irq(SIU_INT_ENET, scc_enet_interrupt, 0, "enet", dev);
+
+	/* Set GSMR_H to enable all normal operating modes.
+	 * Set GSMR_L to enable Ethernet to MC68160.
+	 */
+	sccp->scc_gsmrh = 0;
+	sccp->scc_gsmrl = (SCC_GSMRL_TCI | SCC_GSMRL_TPL_48 | SCC_GSMRL_TPP_10 | SCC_GSMRL_MODE_ENET);
+
+	/* Set sync/delimiters.
+	*/
+	sccp->scc_dsr = 0xd555;
+
+	/* Set processing mode.  Use Ethernet CRC, catch broadcast, and
+	 * start frame search 22 bit times after RENA.
+	 */
+	sccp->scc_psmr = (SCC_PSMR_ENCRC | SCC_PSMR_NIB22);
+
+	/* It is now OK to enable the Ethernet transmitter.
+	 * Unfortunately, there are board implementation differences here.
+	 */
+	io->iop_pparc &= ~(PC_EST8260_ENET_LOOPBACK |
+				PC_EST8260_ENET_SQE | PC_EST8260_ENET_NOTFD);
+	io->iop_psorc &= ~(PC_EST8260_ENET_LOOPBACK |
+				PC_EST8260_ENET_SQE | PC_EST8260_ENET_NOTFD);
+	io->iop_pdirc |= (PC_EST8260_ENET_LOOPBACK |
+				PC_EST8260_ENET_SQE | PC_EST8260_ENET_NOTFD);
+	io->iop_pdatc &= ~(PC_EST8260_ENET_LOOPBACK | PC_EST8260_ENET_SQE);
+	io->iop_pdatc |= PC_EST8260_ENET_NOTFD;
+
+	dev->base_addr = (unsigned long)ep;
+	dev->priv = cep;
+
+	/* The CPM Ethernet specific entries in the device structure. */
+	dev->open = scc_enet_open;
+	dev->hard_start_xmit = scc_enet_start_xmit;
+	dev->tx_timeout = scc_enet_timeout;
+	dev->watchdog_timeo = TX_TIMEOUT;
+	dev->stop = scc_enet_close;
+	dev->get_stats = scc_enet_get_stats;
+	dev->set_multicast_list = set_multicast_list;
+
+	/* And last, enable the transmit and receive processing.
+	*/
+	sccp->scc_gsmrl |= (SCC_GSMRL_ENR | SCC_GSMRL_ENT);
+
+	printk("%s: SCC ENET Version 0.1, ", dev->name);
+	for (i=0; i<5; i++)
+		printk("%02x:", dev->dev_addr[i]);
+	printk("%02x\n", dev->dev_addr[5]);
+
+	return 0;
+}
+
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)