1/*
2 * Ethernet driver for Motorola MPC8260.
3 * Copyright (c) 1999 Dan Malek (dmalek@jlc.net)
4 * Copyright (c) 2000 MontaVista Software Inc. (source@mvista.com)
5 *	2.3.99 Updates
6 *
7 * I copied this from the 8xx CPM Ethernet driver, so follow the
8 * credits back through that.
9 *
10 * This version of the driver is somewhat selectable for the different
11 * processor/board combinations.  It works for the boards I know about
12 * now, and should be easily modified to include others.  Some of the
13 * configuration information is contained in <asm/commproc.h> and the
14 * remainder is here.
15 *
16 * Buffer descriptors are kept in the CPM dual port RAM, and the frame
17 * buffers are in the host memory.
18 *
19 * Right now, I am very watseful with the buffers.  I allocate memory
20 * pages and then divide them into 2K frame buffers.  This way I know I
21 * have buffers large enough to hold one frame within one buffer descriptor.
22 * Once I get this working, I will use 64 or 128 byte CPM buffers, which
23 * will be much more memory efficient and will easily handle lots of
24 * small packets.
25 *
26 */
27#include <linux/kernel.h>
28#include <linux/sched.h>
29#include <linux/string.h>
30#include <linux/ptrace.h>
31#include <linux/errno.h>
32#include <linux/ioport.h>
33#include <linux/slab.h>
34#include <linux/interrupt.h>
35#include <linux/init.h>
36#include <linux/delay.h>
37#include <linux/netdevice.h>
38#include <linux/etherdevice.h>
39#include <linux/skbuff.h>
40#include <linux/spinlock.h>
41#include <linux/bitops.h>
42
43#include <asm/immap_cpm2.h>
44#include <asm/pgtable.h>
45#include <asm/mpc8260.h>
46#include <asm/uaccess.h>
47#include <asm/cpm2.h>
48#include <asm/irq.h>
49
50/*
51 *				Theory of Operation
52 *
53 * The MPC8260 CPM performs the Ethernet processing on an SCC.  It can use
54 * an aribtrary number of buffers on byte boundaries, but must have at
55 * least two receive buffers to prevent constant overrun conditions.
56 *
57 * The buffer descriptors are allocated from the CPM dual port memory
58 * with the data buffers allocated from host memory, just like all other
59 * serial communication protocols.  The host memory buffers are allocated
60 * from the free page pool, and then divided into smaller receive and
61 * transmit buffers.  The size of the buffers should be a power of two,
62 * since that nicely divides the page.  This creates a ring buffer
63 * structure similar to the LANCE and other controllers.
64 *
65 * Like the LANCE driver:
66 * The driver runs as two independent, single-threaded flows of control.  One
67 * is the send-packet routine, which enforces single-threaded use by the
68 * cep->tx_busy flag.  The other thread is the interrupt handler, which is
69 * single threaded by the hardware and other software.
70 */
71
72/* The transmitter timeout
73 */
74#define TX_TIMEOUT	(2*HZ)
75
76/* The number of Tx and Rx buffers.  These are allocated from the page
77 * pool.  The code may assume these are power of two, so it is best
78 * to keep them that size.
79 * We don't need to allocate pages for the transmitter.  We just use
80 * the skbuffer directly.
81 */
82#define CPM_ENET_RX_PAGES	4
83#define CPM_ENET_RX_FRSIZE	2048
84#define CPM_ENET_RX_FRPPG	(PAGE_SIZE / CPM_ENET_RX_FRSIZE)
85#define RX_RING_SIZE		(CPM_ENET_RX_FRPPG * CPM_ENET_RX_PAGES)
86#define TX_RING_SIZE		8	/* Must be power of two */
87#define TX_RING_MOD_MASK	7	/*   for this to work */
88
89/* The CPM stores dest/src/type, data, and checksum for receive packets.
90 */
91#define PKT_MAXBUF_SIZE		1518
92#define PKT_MINBUF_SIZE		64
93#define PKT_MAXBLR_SIZE		1520
94
95/* The CPM buffer descriptors track the ring buffers.  The rx_bd_base and
96 * tx_bd_base always point to the base of the buffer descriptors.  The
97 * cur_rx and cur_tx point to the currently available buffer.
98 * The dirty_tx tracks the current buffer that is being sent by the
99 * controller.  The cur_tx and dirty_tx are equal under both completely
100 * empty and completely full conditions.  The empty/ready indicator in
101 * the buffer descriptor determines the actual condition.
102 */
103struct scc_enet_private {
104	/* The saved address of a sent-in-place packet/buffer, for skfree(). */
105	struct	sk_buff* tx_skbuff[TX_RING_SIZE];
106	ushort	skb_cur;
107	ushort	skb_dirty;
108
109	/* CPM dual port RAM relative addresses.
110	*/
111	cbd_t	*rx_bd_base;		/* Address of Rx and Tx buffers. */
112	cbd_t	*tx_bd_base;
113	cbd_t	*cur_rx, *cur_tx;		/* The next free ring entry */
114	cbd_t	*dirty_tx;	/* The ring entries to be free()ed. */
115	scc_t	*sccp;
116	struct	net_device_stats stats;
117	uint	tx_full;
118	spinlock_t lock;
119};
120
121static int scc_enet_open(struct net_device *dev);
122static int scc_enet_start_xmit(struct sk_buff *skb, struct net_device *dev);
123static int scc_enet_rx(struct net_device *dev);
124static irqreturn_t scc_enet_interrupt(int irq, void *dev_id);
125static int scc_enet_close(struct net_device *dev);
126static struct net_device_stats *scc_enet_get_stats(struct net_device *dev);
127static void set_multicast_list(struct net_device *dev);
128
129/* These will be configurable for the SCC choice.
130*/
131#define CPM_ENET_BLOCK	CPM_CR_SCC1_SBLOCK
132#define CPM_ENET_PAGE	CPM_CR_SCC1_PAGE
133#define PROFF_ENET	PROFF_SCC1
134#define SCC_ENET	0
135#define SIU_INT_ENET	SIU_INT_SCC1
136
137/* These are both board and SCC dependent....
138*/
139#define PD_ENET_RXD	((uint)0x00000001)
140#define PD_ENET_TXD	((uint)0x00000002)
141#define PD_ENET_TENA	((uint)0x00000004)
142#define PC_ENET_RENA	((uint)0x00020000)
143#define PC_ENET_CLSN	((uint)0x00000004)
144#define PC_ENET_TXCLK	((uint)0x00000800)
145#define PC_ENET_RXCLK	((uint)0x00000400)
146#define CMX_CLK_ROUTE	((uint)0x25000000)
147#define CMX_CLK_MASK	((uint)0xff000000)
148
149/* Specific to a board.
150*/
151#define PC_EST8260_ENET_LOOPBACK	((uint)0x80000000)
152#define PC_EST8260_ENET_SQE		((uint)0x40000000)
153#define PC_EST8260_ENET_NOTFD		((uint)0x20000000)
154
155static int
156scc_enet_open(struct net_device *dev)
157{
158
159	/* I should reset the ring buffers here, but I don't yet know
160	 * a simple way to do that.
161	 */
162	netif_start_queue(dev);
163	return 0;					/* Always succeed */
164}
165
166static int
167scc_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
168{
169	struct scc_enet_private *cep = (struct scc_enet_private *)dev->priv;
170	volatile cbd_t	*bdp;
171
172
173	/* Fill in a Tx ring entry */
174	bdp = cep->cur_tx;
175
176#ifndef final_version
177	if (bdp->cbd_sc & BD_ENET_TX_READY) {
178		/* Ooops.  All transmit buffers are full.  Bail out.
179		 * This should not happen, since cep->tx_full should be set.
180		 */
181		printk("%s: tx queue full!.\n", dev->name);
182		return 1;
183	}
184#endif
185
186	/* Clear all of the status flags.
187	 */
188	bdp->cbd_sc &= ~BD_ENET_TX_STATS;
189
190	/* If the frame is short, tell CPM to pad it.
191	*/
192	if (skb->len <= ETH_ZLEN)
193		bdp->cbd_sc |= BD_ENET_TX_PAD;
194	else
195		bdp->cbd_sc &= ~BD_ENET_TX_PAD;
196
197	/* Set buffer length and buffer pointer.
198	*/
199	bdp->cbd_datlen = skb->len;
200	bdp->cbd_bufaddr = __pa(skb->data);
201
202	/* Save skb pointer.
203	*/
204	cep->tx_skbuff[cep->skb_cur] = skb;
205
206	cep->stats.tx_bytes += skb->len;
207	cep->skb_cur = (cep->skb_cur+1) & TX_RING_MOD_MASK;
208
209	spin_lock_irq(&cep->lock);
210
211	/* Send it on its way.  Tell CPM its ready, interrupt when done,
212	 * its the last BD of the frame, and to put the CRC on the end.
213	 */
214	bdp->cbd_sc |= (BD_ENET_TX_READY | BD_ENET_TX_INTR | BD_ENET_TX_LAST | BD_ENET_TX_TC);
215
216	dev->trans_start = jiffies;
217
218	/* If this was the last BD in the ring, start at the beginning again.
219	*/
220	if (bdp->cbd_sc & BD_ENET_TX_WRAP)
221		bdp = cep->tx_bd_base;
222	else
223		bdp++;
224
225	if (bdp->cbd_sc & BD_ENET_TX_READY) {
226		netif_stop_queue(dev);
227		cep->tx_full = 1;
228	}
229
230	cep->cur_tx = (cbd_t *)bdp;
231
232	spin_unlock_irq(&cep->lock);
233
234	return 0;
235}
236
237static void
238scc_enet_timeout(struct net_device *dev)
239{
240	struct scc_enet_private *cep = (struct scc_enet_private *)dev->priv;
241
242	printk("%s: transmit timed out.\n", dev->name);
243	cep->stats.tx_errors++;
244#ifndef final_version
245	{
246		int	i;
247		cbd_t	*bdp;
248		printk(" Ring data dump: cur_tx %p%s cur_rx %p.\n",
249		       cep->cur_tx, cep->tx_full ? " (full)" : "",
250		       cep->cur_rx);
251		bdp = cep->tx_bd_base;
252		printk(" Tx @base %p :\n", bdp);
253		for (i = 0 ; i < TX_RING_SIZE; i++, bdp++)
254			printk("%04x %04x %08x\n",
255			       bdp->cbd_sc,
256			       bdp->cbd_datlen,
257			       bdp->cbd_bufaddr);
258		bdp = cep->rx_bd_base;
259		printk(" Rx @base %p :\n", bdp);
260		for (i = 0 ; i < RX_RING_SIZE; i++, bdp++)
261			printk("%04x %04x %08x\n",
262			       bdp->cbd_sc,
263			       bdp->cbd_datlen,
264			       bdp->cbd_bufaddr);
265	}
266#endif
267	if (!cep->tx_full)
268		netif_wake_queue(dev);
269}
270
271/* The interrupt handler.
272 * This is called from the CPM handler, not the MPC core interrupt.
273 */
274static irqreturn_t
275scc_enet_interrupt(int irq, void * dev_id)
276{
277	struct	net_device *dev = dev_id;
278	volatile struct	scc_enet_private *cep;
279	volatile cbd_t	*bdp;
280	ushort	int_events;
281	int	must_restart;
282
283	cep = (struct scc_enet_private *)dev->priv;
284
285	/* Get the interrupt events that caused us to be here.
286	*/
287	int_events = cep->sccp->scc_scce;
288	cep->sccp->scc_scce = int_events;
289	must_restart = 0;
290
291	/* Handle receive event in its own function.
292	*/
293	if (int_events & SCCE_ENET_RXF)
294		scc_enet_rx(dev_id);
295
296	/* Check for a transmit error.  The manual is a little unclear
297	 * about this, so the debug code until I get it figured out.  It
298	 * appears that if TXE is set, then TXB is not set.  However,
299	 * if carrier sense is lost during frame transmission, the TXE
300	 * bit is set, "and continues the buffer transmission normally."
301	 * I don't know if "normally" implies TXB is set when the buffer
302	 * descriptor is closed.....trial and error :-).
303	 */
304
305	/* Transmit OK, or non-fatal error.  Update the buffer descriptors.
306	*/
307	if (int_events & (SCCE_ENET_TXE | SCCE_ENET_TXB)) {
308	    spin_lock(&cep->lock);
309	    bdp = cep->dirty_tx;
310	    while ((bdp->cbd_sc&BD_ENET_TX_READY)==0) {
311		if ((bdp==cep->cur_tx) && (cep->tx_full == 0))
312		    break;
313
314		if (bdp->cbd_sc & BD_ENET_TX_HB)	/* No heartbeat */
315			cep->stats.tx_heartbeat_errors++;
316		if (bdp->cbd_sc & BD_ENET_TX_LC)	/* Late collision */
317			cep->stats.tx_window_errors++;
318		if (bdp->cbd_sc & BD_ENET_TX_RL)	/* Retrans limit */
319			cep->stats.tx_aborted_errors++;
320		if (bdp->cbd_sc & BD_ENET_TX_UN)	/* Underrun */
321			cep->stats.tx_fifo_errors++;
322		if (bdp->cbd_sc & BD_ENET_TX_CSL)	/* Carrier lost */
323			cep->stats.tx_carrier_errors++;
324
325
326		/* No heartbeat or Lost carrier are not really bad errors.
327		 * The others require a restart transmit command.
328		 */
329		if (bdp->cbd_sc &
330		    (BD_ENET_TX_LC | BD_ENET_TX_RL | BD_ENET_TX_UN)) {
331			must_restart = 1;
332			cep->stats.tx_errors++;
333		}
334
335		cep->stats.tx_packets++;
336
337		/* Deferred means some collisions occurred during transmit,
338		 * but we eventually sent the packet OK.
339		 */
340		if (bdp->cbd_sc & BD_ENET_TX_DEF)
341			cep->stats.collisions++;
342
343		/* Free the sk buffer associated with this last transmit.
344		*/
345		dev_kfree_skb_irq(cep->tx_skbuff[cep->skb_dirty]);
346		cep->skb_dirty = (cep->skb_dirty + 1) & TX_RING_MOD_MASK;
347
348		/* Update pointer to next buffer descriptor to be transmitted.
349		*/
350		if (bdp->cbd_sc & BD_ENET_TX_WRAP)
351			bdp = cep->tx_bd_base;
352		else
353			bdp++;
354
355		/* I don't know if we can be held off from processing these
356		 * interrupts for more than one frame time.  I really hope
357		 * not.  In such a case, we would now want to check the
358		 * currently available BD (cur_tx) and determine if any
359		 * buffers between the dirty_tx and cur_tx have also been
360		 * sent.  We would want to process anything in between that
361		 * does not have BD_ENET_TX_READY set.
362		 */
363
364		/* Since we have freed up a buffer, the ring is no longer
365		 * full.
366		 */
367		if (cep->tx_full) {
368			cep->tx_full = 0;
369			if (netif_queue_stopped(dev)) {
370				netif_wake_queue(dev);
371			}
372		}
373
374		cep->dirty_tx = (cbd_t *)bdp;
375	    }
376
377	    if (must_restart) {
378		volatile cpm_cpm2_t *cp;
379
380		/* Some transmit errors cause the transmitter to shut
381		 * down.  We now issue a restart transmit.  Since the
382		 * errors close the BD and update the pointers, the restart
383		 * _should_ pick up without having to reset any of our
384		 * pointers either.
385		 */
386
387		cp = cpmp;
388		cp->cp_cpcr =
389		    mk_cr_cmd(CPM_ENET_PAGE, CPM_ENET_BLOCK, 0,
390		    			CPM_CR_RESTART_TX) | CPM_CR_FLG;
391		while (cp->cp_cpcr & CPM_CR_FLG);
392	    }
393	    spin_unlock(&cep->lock);
394	}
395
396	/* Check for receive busy, i.e. packets coming but no place to
397	 * put them.  This "can't happen" because the receive interrupt
398	 * is tossing previous frames.
399	 */
400	if (int_events & SCCE_ENET_BSY) {
401		cep->stats.rx_dropped++;
402		printk("SCC ENET: BSY can't happen.\n");
403	}
404
405	return IRQ_HANDLED;
406}
407
408/* During a receive, the cur_rx points to the current incoming buffer.
409 * When we update through the ring, if the next incoming buffer has
410 * not been given to the system, we just set the empty indicator,
411 * effectively tossing the packet.
412 */
413static int
414scc_enet_rx(struct net_device *dev)
415{
416	struct	scc_enet_private *cep;
417	volatile cbd_t	*bdp;
418	struct	sk_buff *skb;
419	ushort	pkt_len;
420
421	cep = (struct scc_enet_private *)dev->priv;
422
423	/* First, grab all of the stats for the incoming packet.
424	 * These get messed up if we get called due to a busy condition.
425	 */
426	bdp = cep->cur_rx;
427
428for (;;) {
429	if (bdp->cbd_sc & BD_ENET_RX_EMPTY)
430		break;
431
432#ifndef final_version
433	/* Since we have allocated space to hold a complete frame, both
434	 * the first and last indicators should be set.
435	 */
436	if ((bdp->cbd_sc & (BD_ENET_RX_FIRST | BD_ENET_RX_LAST)) !=
437		(BD_ENET_RX_FIRST | BD_ENET_RX_LAST))
438			printk("CPM ENET: rcv is not first+last\n");
439#endif
440
441	/* Frame too long or too short.
442	*/
443	if (bdp->cbd_sc & (BD_ENET_RX_LG | BD_ENET_RX_SH))
444		cep->stats.rx_length_errors++;
445	if (bdp->cbd_sc & BD_ENET_RX_NO)	/* Frame alignment */
446		cep->stats.rx_frame_errors++;
447	if (bdp->cbd_sc & BD_ENET_RX_CR)	/* CRC Error */
448		cep->stats.rx_crc_errors++;
449	if (bdp->cbd_sc & BD_ENET_RX_OV)	/* FIFO overrun */
450		cep->stats.rx_crc_errors++;
451
452	/* Report late collisions as a frame error.
453	 * On this error, the BD is closed, but we don't know what we
454	 * have in the buffer.  So, just drop this frame on the floor.
455	 */
456	if (bdp->cbd_sc & BD_ENET_RX_CL) {
457		cep->stats.rx_frame_errors++;
458	}
459	else {
460
461		/* Process the incoming frame.
462		*/
463		cep->stats.rx_packets++;
464		pkt_len = bdp->cbd_datlen;
465		cep->stats.rx_bytes += pkt_len;
466
467		/* This does 16 byte alignment, much more than we need.
468		 * The packet length includes FCS, but we don't want to
469		 * include that when passing upstream as it messes up
470		 * bridging applications.
471		 */
472		skb = dev_alloc_skb(pkt_len-4);
473
474		if (skb == NULL) {
475			printk("%s: Memory squeeze, dropping packet.\n", dev->name);
476			cep->stats.rx_dropped++;
477		}
478		else {
479			skb_put(skb,pkt_len-4);	/* Make room */
480			eth_copy_and_sum(skb,
481				(unsigned char *)__va(bdp->cbd_bufaddr),
482				pkt_len-4, 0);
483			skb->protocol=eth_type_trans(skb,dev);
484			netif_rx(skb);
485		}
486	}
487
488	/* Clear the status flags for this buffer.
489	*/
490	bdp->cbd_sc &= ~BD_ENET_RX_STATS;
491
492	/* Mark the buffer empty.
493	*/
494	bdp->cbd_sc |= BD_ENET_RX_EMPTY;
495
496	/* Update BD pointer to next entry.
497	*/
498	if (bdp->cbd_sc & BD_ENET_RX_WRAP)
499		bdp = cep->rx_bd_base;
500	else
501		bdp++;
502
503   }
504	cep->cur_rx = (cbd_t *)bdp;
505
506	return 0;
507}
508
509static int
510scc_enet_close(struct net_device *dev)
511{
512	/* Don't know what to do yet.
513	*/
514	netif_stop_queue(dev);
515
516	return 0;
517}
518
519static struct net_device_stats *scc_enet_get_stats(struct net_device *dev)
520{
521	struct scc_enet_private *cep = (struct scc_enet_private *)dev->priv;
522
523	return &cep->stats;
524}
525
526/* Set or clear the multicast filter for this adaptor.
527 * Skeleton taken from sunlance driver.
528 * The CPM Ethernet implementation allows Multicast as well as individual
529 * MAC address filtering.  Some of the drivers check to make sure it is
530 * a group multicast address, and discard those that are not.  I guess I
531 * will do the same for now, but just remove the test if you want
532 * individual filtering as well (do the upper net layers want or support
533 * this kind of feature?).
534 */
535
536static void set_multicast_list(struct net_device *dev)
537{
538	struct	scc_enet_private *cep;
539	struct	dev_mc_list *dmi;
540	u_char	*mcptr, *tdptr;
541	volatile scc_enet_t *ep;
542	int	i, j;
543	cep = (struct scc_enet_private *)dev->priv;
544
545	/* Get pointer to SCC area in parameter RAM.
546	*/
547	ep = (scc_enet_t *)dev->base_addr;
548
549	if (dev->flags&IFF_PROMISC) {
550
551		/* Log any net taps. */
552		printk("%s: Promiscuous mode enabled.\n", dev->name);
553		cep->sccp->scc_psmr |= SCC_PSMR_PRO;
554	} else {
555
556		cep->sccp->scc_psmr &= ~SCC_PSMR_PRO;
557
558		if (dev->flags & IFF_ALLMULTI) {
559			/* Catch all multicast addresses, so set the
560			 * filter to all 1's.
561			 */
562			ep->sen_gaddr1 = 0xffff;
563			ep->sen_gaddr2 = 0xffff;
564			ep->sen_gaddr3 = 0xffff;
565			ep->sen_gaddr4 = 0xffff;
566		}
567		else {
568			/* Clear filter and add the addresses in the list.
569			*/
570			ep->sen_gaddr1 = 0;
571			ep->sen_gaddr2 = 0;
572			ep->sen_gaddr3 = 0;
573			ep->sen_gaddr4 = 0;
574
575			dmi = dev->mc_list;
576
577			for (i=0; i<dev->mc_count; i++) {
578
579				/* Only support group multicast for now.
580				*/
581				if (!(dmi->dmi_addr[0] & 1))
582					continue;
583
584				/* The address in dmi_addr is LSB first,
585				 * and taddr is MSB first.  We have to
586				 * copy bytes MSB first from dmi_addr.
587				 */
588				mcptr = (u_char *)dmi->dmi_addr + 5;
589				tdptr = (u_char *)&ep->sen_taddrh;
590				for (j=0; j<6; j++)
591					*tdptr++ = *mcptr--;
592
593				/* Ask CPM to run CRC and set bit in
594				 * filter mask.
595				 */
596				cpmp->cp_cpcr = mk_cr_cmd(CPM_ENET_PAGE,
597						CPM_ENET_BLOCK, 0,
598						CPM_CR_SET_GADDR) | CPM_CR_FLG;
599				/* this delay is necessary here -- Cort */
600				udelay(10);
601				while (cpmp->cp_cpcr & CPM_CR_FLG);
602			}
603		}
604	}
605}
606
607/* Initialize the CPM Ethernet on SCC.
608 */
609static int __init scc_enet_init(void)
610{
611	struct net_device *dev;
612	struct scc_enet_private *cep;
613	int i, j, err;
614	uint dp_offset;
615	unsigned char	*eap;
616	unsigned long	mem_addr;
617	bd_t		*bd;
618	volatile	cbd_t		*bdp;
619	volatile	cpm_cpm2_t	*cp;
620	volatile	scc_t		*sccp;
621	volatile	scc_enet_t	*ep;
622	volatile	cpm2_map_t		*immap;
623	volatile	iop_cpm2_t	*io;
624
625	cp = cpmp;	/* Get pointer to Communication Processor */
626
627	immap = (cpm2_map_t *)CPM_MAP_ADDR;	/* and to internal registers */
628	io = &immap->im_ioport;
629
630	bd = (bd_t *)__res;
631
632	/* Create an Ethernet device instance.
633	*/
634	dev = alloc_etherdev(sizeof(*cep));
635	if (!dev)
636		return -ENOMEM;
637
638	cep = dev->priv;
639	spin_lock_init(&cep->lock);
640
641	/* Get pointer to SCC area in parameter RAM.
642	*/
643	ep = (scc_enet_t *)(&immap->im_dprambase[PROFF_ENET]);
644
645	/* And another to the SCC register area.
646	*/
647	sccp = (volatile scc_t *)(&immap->im_scc[SCC_ENET]);
648	cep->sccp = (scc_t *)sccp;		/* Keep the pointer handy */
649
650	/* Disable receive and transmit in case someone left it running.
651	*/
652	sccp->scc_gsmrl &= ~(SCC_GSMRL_ENR | SCC_GSMRL_ENT);
653
654	/* Configure port C and D pins for SCC Ethernet.  This
655	 * won't work for all SCC possibilities....it will be
656	 * board/port specific.
657	 */
658	io->iop_pparc |=
659		(PC_ENET_RENA | PC_ENET_CLSN | PC_ENET_TXCLK | PC_ENET_RXCLK);
660	io->iop_pdirc &=
661		~(PC_ENET_RENA | PC_ENET_CLSN | PC_ENET_TXCLK | PC_ENET_RXCLK);
662	io->iop_psorc &=
663		~(PC_ENET_RENA | PC_ENET_TXCLK | PC_ENET_RXCLK);
664	io->iop_psorc |= PC_ENET_CLSN;
665
666	io->iop_ppard |= (PD_ENET_RXD | PD_ENET_TXD | PD_ENET_TENA);
667	io->iop_pdird |= (PD_ENET_TXD | PD_ENET_TENA);
668	io->iop_pdird &= ~PD_ENET_RXD;
669	io->iop_psord |= PD_ENET_TXD;
670	io->iop_psord &= ~(PD_ENET_RXD | PD_ENET_TENA);
671
672	/* Configure Serial Interface clock routing.
673	 * First, clear all SCC bits to zero, then set the ones we want.
674	 */
675	immap->im_cpmux.cmx_scr &= ~CMX_CLK_MASK;
676	immap->im_cpmux.cmx_scr |= CMX_CLK_ROUTE;
677
678	/* Allocate space for the buffer descriptors in the DP ram.
679	 * These are relative offsets in the DP ram address space.
680	 * Initialize base addresses for the buffer descriptors.
681	 */
682	dp_offset = cpm_dpalloc(sizeof(cbd_t) * RX_RING_SIZE, 8);
683	ep->sen_genscc.scc_rbase = dp_offset;
684	cep->rx_bd_base = (cbd_t *)cpm_dpram_addr(dp_offset);
685
686	dp_offset = cpm_dpalloc(sizeof(cbd_t) * TX_RING_SIZE, 8);
687	ep->sen_genscc.scc_tbase = dp_offset;
688	cep->tx_bd_base = (cbd_t *)cpm_dpram_addr(dp_offset);
689
690	cep->dirty_tx = cep->cur_tx = cep->tx_bd_base;
691	cep->cur_rx = cep->rx_bd_base;
692
693	ep->sen_genscc.scc_rfcr = CPMFCR_GBL | CPMFCR_EB;
694	ep->sen_genscc.scc_tfcr = CPMFCR_GBL | CPMFCR_EB;
695
696	/* Set maximum bytes per receive buffer.
697	 * This appears to be an Ethernet frame size, not the buffer
698	 * fragment size.  It must be a multiple of four.
699	 */
700	ep->sen_genscc.scc_mrblr = PKT_MAXBLR_SIZE;
701
702	/* Set CRC preset and mask.
703	*/
704	ep->sen_cpres = 0xffffffff;
705	ep->sen_cmask = 0xdebb20e3;
706
707	ep->sen_crcec = 0;	/* CRC Error counter */
708	ep->sen_alec = 0;	/* alignment error counter */
709	ep->sen_disfc = 0;	/* discard frame counter */
710
711	ep->sen_pads = 0x8888;	/* Tx short frame pad character */
712	ep->sen_retlim = 15;	/* Retry limit threshold */
713
714	ep->sen_maxflr = PKT_MAXBUF_SIZE;   /* maximum frame length register */
715	ep->sen_minflr = PKT_MINBUF_SIZE;  /* minimum frame length register */
716
717	ep->sen_maxd1 = PKT_MAXBLR_SIZE;	/* maximum DMA1 length */
718	ep->sen_maxd2 = PKT_MAXBLR_SIZE;	/* maximum DMA2 length */
719
720	/* Clear hash tables.
721	*/
722	ep->sen_gaddr1 = 0;
723	ep->sen_gaddr2 = 0;
724	ep->sen_gaddr3 = 0;
725	ep->sen_gaddr4 = 0;
726	ep->sen_iaddr1 = 0;
727	ep->sen_iaddr2 = 0;
728	ep->sen_iaddr3 = 0;
729	ep->sen_iaddr4 = 0;
730
731	/* Set Ethernet station address.
732	 *
733	 * This is supplied in the board information structure, so we
734	 * copy that into the controller.
735	 */
736	eap = (unsigned char *)&(ep->sen_paddrh);
737	for (i=5; i>=0; i--)
738		*eap++ = dev->dev_addr[i] = bd->bi_enetaddr[i];
739
740	ep->sen_pper = 0;	/* 'cause the book says so */
741	ep->sen_taddrl = 0;	/* temp address (LSB) */
742	ep->sen_taddrm = 0;
743	ep->sen_taddrh = 0;	/* temp address (MSB) */
744
745	/* Now allocate the host memory pages and initialize the
746	 * buffer descriptors.
747	 */
748	bdp = cep->tx_bd_base;
749	for (i=0; i<TX_RING_SIZE; i++) {
750
751		/* Initialize the BD for every fragment in the page.
752		*/
753		bdp->cbd_sc = 0;
754		bdp->cbd_bufaddr = 0;
755		bdp++;
756	}
757
758	/* Set the last buffer to wrap.
759	*/
760	bdp--;
761	bdp->cbd_sc |= BD_SC_WRAP;
762
763	bdp = cep->rx_bd_base;
764	for (i=0; i<CPM_ENET_RX_PAGES; i++) {
765
766		/* Allocate a page.
767		*/
768		mem_addr = __get_free_page(GFP_KERNEL);
769		/* BUG: no check for failure */
770
771		/* Initialize the BD for every fragment in the page.
772		*/
773		for (j=0; j<CPM_ENET_RX_FRPPG; j++) {
774			bdp->cbd_sc = BD_ENET_RX_EMPTY | BD_ENET_RX_INTR;
775			bdp->cbd_bufaddr = __pa(mem_addr);
776			mem_addr += CPM_ENET_RX_FRSIZE;
777			bdp++;
778		}
779	}
780
781	/* Set the last buffer to wrap.
782	*/
783	bdp--;
784	bdp->cbd_sc |= BD_SC_WRAP;
785
786	/* Let's re-initialize the channel now.  We have to do it later
787	 * than the manual describes because we have just now finished
788	 * the BD initialization.
789	 */
790	cpmp->cp_cpcr = mk_cr_cmd(CPM_ENET_PAGE, CPM_ENET_BLOCK, 0,
791			CPM_CR_INIT_TRX) | CPM_CR_FLG;
792	while (cp->cp_cpcr & CPM_CR_FLG);
793
794	cep->skb_cur = cep->skb_dirty = 0;
795
796	sccp->scc_scce = 0xffff;	/* Clear any pending events */
797
798	/* Enable interrupts for transmit error, complete frame
799	 * received, and any transmit buffer we have also set the
800	 * interrupt flag.
801	 */
802	sccp->scc_sccm = (SCCE_ENET_TXE | SCCE_ENET_RXF | SCCE_ENET_TXB);
803
804	/* Install our interrupt handler.
805	*/
806	request_irq(SIU_INT_ENET, scc_enet_interrupt, 0, "enet", dev);
807	/* BUG: no check for failure */
808
809	/* Set GSMR_H to enable all normal operating modes.
810	 * Set GSMR_L to enable Ethernet to MC68160.
811	 */
812	sccp->scc_gsmrh = 0;
813	sccp->scc_gsmrl = (SCC_GSMRL_TCI | SCC_GSMRL_TPL_48 | SCC_GSMRL_TPP_10 | SCC_GSMRL_MODE_ENET);
814
815	/* Set sync/delimiters.
816	*/
817	sccp->scc_dsr = 0xd555;
818
819	/* Set processing mode.  Use Ethernet CRC, catch broadcast, and
820	 * start frame search 22 bit times after RENA.
821	 */
822	sccp->scc_psmr = (SCC_PSMR_ENCRC | SCC_PSMR_NIB22);
823
824	/* It is now OK to enable the Ethernet transmitter.
825	 * Unfortunately, there are board implementation differences here.
826	 */
827	io->iop_pparc &= ~(PC_EST8260_ENET_LOOPBACK |
828				PC_EST8260_ENET_SQE | PC_EST8260_ENET_NOTFD);
829	io->iop_psorc &= ~(PC_EST8260_ENET_LOOPBACK |
830				PC_EST8260_ENET_SQE | PC_EST8260_ENET_NOTFD);
831	io->iop_pdirc |= (PC_EST8260_ENET_LOOPBACK |
832				PC_EST8260_ENET_SQE | PC_EST8260_ENET_NOTFD);
833	io->iop_pdatc &= ~(PC_EST8260_ENET_LOOPBACK | PC_EST8260_ENET_SQE);
834	io->iop_pdatc |= PC_EST8260_ENET_NOTFD;
835
836	dev->base_addr = (unsigned long)ep;
837
838	/* The CPM Ethernet specific entries in the device structure. */
839	dev->open = scc_enet_open;
840	dev->hard_start_xmit = scc_enet_start_xmit;
841	dev->tx_timeout = scc_enet_timeout;
842	dev->watchdog_timeo = TX_TIMEOUT;
843	dev->stop = scc_enet_close;
844	dev->get_stats = scc_enet_get_stats;
845	dev->set_multicast_list = set_multicast_list;
846
847	/* And last, enable the transmit and receive processing.
848	*/
849	sccp->scc_gsmrl |= (SCC_GSMRL_ENR | SCC_GSMRL_ENT);
850
851	err = register_netdev(dev);
852	if (err) {
853		free_netdev(dev);
854		return err;
855	}
856
857	printk("%s: SCC ENET Version 0.1, ", dev->name);
858	for (i=0; i<5; i++)
859		printk("%02x:", dev->dev_addr[i]);
860	printk("%02x\n", dev->dev_addr[5]);
861
862	return 0;
863}
864
865module_init(scc_enet_init);
866