1 /*
2  * Combined Ethernet driver for Motorola MPC8xx and MPC82xx.
3  *
4  * Copyright (c) 2003 Intracom S.A.
5  *  by Pantelis Antoniou <panto@intracom.gr>
6  *
7  * 2005 (c) MontaVista Software, Inc.
8  * Vitaly Bordug <vbordug@ru.mvista.com>
9  *
10  * Heavily based on original FEC driver by Dan Malek <dan@embeddededge.com>
11  * and modifications by Joakim Tjernlund <joakim.tjernlund@lumentis.se>
12  *
13  * This file is licensed under the terms of the GNU General Public License
14  * version 2. This program is licensed "as is" without any warranty of any
15  * kind, whether express or implied.
16  */
17 
18 #include <linux/module.h>
19 #include <linux/kernel.h>
20 #include <linux/types.h>
21 #include <linux/string.h>
22 #include <linux/ptrace.h>
23 #include <linux/errno.h>
24 #include <linux/ioport.h>
25 #include <linux/slab.h>
26 #include <linux/interrupt.h>
27 #include <linux/delay.h>
28 #include <linux/netdevice.h>
29 #include <linux/etherdevice.h>
30 #include <linux/skbuff.h>
31 #include <linux/spinlock.h>
32 #include <linux/mii.h>
33 #include <linux/ethtool.h>
34 #include <linux/bitops.h>
35 #include <linux/fs.h>
36 #include <linux/platform_device.h>
37 #include <linux/phy.h>
38 #include <linux/of.h>
39 #include <linux/of_mdio.h>
40 #include <linux/of_platform.h>
41 #include <linux/of_gpio.h>
42 #include <linux/of_net.h>
43 
44 #include <linux/vmalloc.h>
45 #include <asm/pgtable.h>
46 #include <asm/irq.h>
47 #include <asm/uaccess.h>
48 
49 #include "fs_enet.h"
50 
51 /*************************************************/
52 
53 MODULE_AUTHOR("Pantelis Antoniou <panto@intracom.gr>");
54 MODULE_DESCRIPTION("Freescale Ethernet Driver");
55 MODULE_LICENSE("GPL");
56 MODULE_VERSION(DRV_MODULE_VERSION);
57 
58 static int fs_enet_debug = -1; /* -1 == use FS_ENET_DEF_MSG_ENABLE as value */
59 module_param(fs_enet_debug, int, 0);
60 MODULE_PARM_DESC(fs_enet_debug,
61 		 "Freescale bitmapped debugging message enable value");
62 
63 #ifdef CONFIG_NET_POLL_CONTROLLER
64 static void fs_enet_netpoll(struct net_device *dev);
65 #endif
66 
67 static void fs_set_multicast_list(struct net_device *dev)
68 {
69 	struct fs_enet_private *fep = netdev_priv(dev);
70 
71 	(*fep->ops->set_multicast_list)(dev);
72 }
73 
74 static void skb_align(struct sk_buff *skb, int align)
75 {
76 	int off = ((unsigned long)skb->data) & (align - 1);
77 
78 	if (off)
79 		skb_reserve(skb, align - off);
80 }
81 
82 /* NAPI receive function */
83 static int fs_enet_rx_napi(struct napi_struct *napi, int budget)
84 {
85 	struct fs_enet_private *fep = container_of(napi, struct fs_enet_private, napi);
86 	struct net_device *dev = fep->ndev;
87 	const struct fs_platform_info *fpi = fep->fpi;
88 	cbd_t __iomem *bdp;
89 	struct sk_buff *skb, *skbn, *skbt;
90 	int received = 0;
91 	u16 pkt_len, sc;
92 	int curidx;
93 
94 	/*
95 	 * First, grab all of the stats for the incoming packet.
96 	 * These get messed up if we get called due to a busy condition.
97 	 */
98 	bdp = fep->cur_rx;
99 
100 	/* clear RX status bits for napi*/
101 	(*fep->ops->napi_clear_rx_event)(dev);
102 
103 	while (((sc = CBDR_SC(bdp)) & BD_ENET_RX_EMPTY) == 0) {
104 		curidx = bdp - fep->rx_bd_base;
105 
106 		/*
107 		 * Since we have allocated space to hold a complete frame,
108 		 * the last indicator should be set.
109 		 */
110 		if ((sc & BD_ENET_RX_LAST) == 0)
111 			dev_warn(fep->dev, "rcv is not +last\n");
112 
113 		/*
114 		 * Check for errors.
115 		 */
116 		if (sc & (BD_ENET_RX_LG | BD_ENET_RX_SH | BD_ENET_RX_CL |
117 			  BD_ENET_RX_NO | BD_ENET_RX_CR | BD_ENET_RX_OV)) {
118 			fep->stats.rx_errors++;
119 			/* Frame too long or too short. */
120 			if (sc & (BD_ENET_RX_LG | BD_ENET_RX_SH))
121 				fep->stats.rx_length_errors++;
122 			/* Frame alignment */
123 			if (sc & (BD_ENET_RX_NO | BD_ENET_RX_CL))
124 				fep->stats.rx_frame_errors++;
125 			/* CRC Error */
126 			if (sc & BD_ENET_RX_CR)
127 				fep->stats.rx_crc_errors++;
128 			/* FIFO overrun */
129 			if (sc & BD_ENET_RX_OV)
130 				fep->stats.rx_crc_errors++;
131 
132 			skb = fep->rx_skbuff[curidx];
133 
134 			dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp),
135 				L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
136 				DMA_FROM_DEVICE);
137 
138 			skbn = skb;
139 
140 		} else {
141 			skb = fep->rx_skbuff[curidx];
142 
143 			dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp),
144 				L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
145 				DMA_FROM_DEVICE);
146 
147 			/*
148 			 * Process the incoming frame.
149 			 */
150 			fep->stats.rx_packets++;
151 			pkt_len = CBDR_DATLEN(bdp) - 4;	/* remove CRC */
152 			fep->stats.rx_bytes += pkt_len + 4;
153 
154 			if (pkt_len <= fpi->rx_copybreak) {
155 				/* +2 to make IP header L1 cache aligned */
156 				skbn = netdev_alloc_skb(dev, pkt_len + 2);
157 				if (skbn != NULL) {
158 					skb_reserve(skbn, 2);	/* align IP header */
159 					skb_copy_from_linear_data(skb,
160 						      skbn->data, pkt_len);
161 					/* swap */
162 					skbt = skb;
163 					skb = skbn;
164 					skbn = skbt;
165 				}
166 			} else {
167 				skbn = netdev_alloc_skb(dev, ENET_RX_FRSIZE);
168 
169 				if (skbn)
170 					skb_align(skbn, ENET_RX_ALIGN);
171 			}
172 
173 			if (skbn != NULL) {
174 				skb_put(skb, pkt_len);	/* Make room */
175 				skb->protocol = eth_type_trans(skb, dev);
176 				received++;
177 				netif_receive_skb(skb);
178 			} else {
179 				fep->stats.rx_dropped++;
180 				skbn = skb;
181 			}
182 		}
183 
184 		fep->rx_skbuff[curidx] = skbn;
185 		CBDW_BUFADDR(bdp, dma_map_single(fep->dev, skbn->data,
186 			     L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
187 			     DMA_FROM_DEVICE));
188 		CBDW_DATLEN(bdp, 0);
189 		CBDW_SC(bdp, (sc & ~BD_ENET_RX_STATS) | BD_ENET_RX_EMPTY);
190 
191 		/*
192 		 * Update BD pointer to next entry.
193 		 */
194 		if ((sc & BD_ENET_RX_WRAP) == 0)
195 			bdp++;
196 		else
197 			bdp = fep->rx_bd_base;
198 
199 		(*fep->ops->rx_bd_done)(dev);
200 
201 		if (received >= budget)
202 			break;
203 	}
204 
205 	fep->cur_rx = bdp;
206 
207 	if (received < budget) {
208 		/* done */
209 		napi_complete(napi);
210 		(*fep->ops->napi_enable_rx)(dev);
211 	}
212 	return received;
213 }
214 
215 /* non NAPI receive function */
216 static int fs_enet_rx_non_napi(struct net_device *dev)
217 {
218 	struct fs_enet_private *fep = netdev_priv(dev);
219 	const struct fs_platform_info *fpi = fep->fpi;
220 	cbd_t __iomem *bdp;
221 	struct sk_buff *skb, *skbn, *skbt;
222 	int received = 0;
223 	u16 pkt_len, sc;
224 	int curidx;
225 	/*
226 	 * First, grab all of the stats for the incoming packet.
227 	 * These get messed up if we get called due to a busy condition.
228 	 */
229 	bdp = fep->cur_rx;
230 
231 	while (((sc = CBDR_SC(bdp)) & BD_ENET_RX_EMPTY) == 0) {
232 
233 		curidx = bdp - fep->rx_bd_base;
234 
235 		/*
236 		 * Since we have allocated space to hold a complete frame,
237 		 * the last indicator should be set.
238 		 */
239 		if ((sc & BD_ENET_RX_LAST) == 0)
240 			dev_warn(fep->dev, "rcv is not +last\n");
241 
242 		/*
243 		 * Check for errors.
244 		 */
245 		if (sc & (BD_ENET_RX_LG | BD_ENET_RX_SH | BD_ENET_RX_CL |
246 			  BD_ENET_RX_NO | BD_ENET_RX_CR | BD_ENET_RX_OV)) {
247 			fep->stats.rx_errors++;
248 			/* Frame too long or too short. */
249 			if (sc & (BD_ENET_RX_LG | BD_ENET_RX_SH))
250 				fep->stats.rx_length_errors++;
251 			/* Frame alignment */
252 			if (sc & (BD_ENET_RX_NO | BD_ENET_RX_CL))
253 				fep->stats.rx_frame_errors++;
254 			/* CRC Error */
255 			if (sc & BD_ENET_RX_CR)
256 				fep->stats.rx_crc_errors++;
257 			/* FIFO overrun */
258 			if (sc & BD_ENET_RX_OV)
259 				fep->stats.rx_crc_errors++;
260 
261 			skb = fep->rx_skbuff[curidx];
262 
263 			dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp),
264 				L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
265 				DMA_FROM_DEVICE);
266 
267 			skbn = skb;
268 
269 		} else {
270 
271 			skb = fep->rx_skbuff[curidx];
272 
273 			dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp),
274 				L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
275 				DMA_FROM_DEVICE);
276 
277 			/*
278 			 * Process the incoming frame.
279 			 */
280 			fep->stats.rx_packets++;
281 			pkt_len = CBDR_DATLEN(bdp) - 4;	/* remove CRC */
282 			fep->stats.rx_bytes += pkt_len + 4;
283 
284 			if (pkt_len <= fpi->rx_copybreak) {
285 				/* +2 to make IP header L1 cache aligned */
286 				skbn = netdev_alloc_skb(dev, pkt_len + 2);
287 				if (skbn != NULL) {
288 					skb_reserve(skbn, 2);	/* align IP header */
289 					skb_copy_from_linear_data(skb,
290 						      skbn->data, pkt_len);
291 					/* swap */
292 					skbt = skb;
293 					skb = skbn;
294 					skbn = skbt;
295 				}
296 			} else {
297 				skbn = netdev_alloc_skb(dev, ENET_RX_FRSIZE);
298 
299 				if (skbn)
300 					skb_align(skbn, ENET_RX_ALIGN);
301 			}
302 
303 			if (skbn != NULL) {
304 				skb_put(skb, pkt_len);	/* Make room */
305 				skb->protocol = eth_type_trans(skb, dev);
306 				received++;
307 				netif_rx(skb);
308 			} else {
309 				fep->stats.rx_dropped++;
310 				skbn = skb;
311 			}
312 		}
313 
314 		fep->rx_skbuff[curidx] = skbn;
315 		CBDW_BUFADDR(bdp, dma_map_single(fep->dev, skbn->data,
316 			     L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
317 			     DMA_FROM_DEVICE));
318 		CBDW_DATLEN(bdp, 0);
319 		CBDW_SC(bdp, (sc & ~BD_ENET_RX_STATS) | BD_ENET_RX_EMPTY);
320 
321 		/*
322 		 * Update BD pointer to next entry.
323 		 */
324 		if ((sc & BD_ENET_RX_WRAP) == 0)
325 			bdp++;
326 		else
327 			bdp = fep->rx_bd_base;
328 
329 		(*fep->ops->rx_bd_done)(dev);
330 	}
331 
332 	fep->cur_rx = bdp;
333 
334 	return 0;
335 }
336 
337 static void fs_enet_tx(struct net_device *dev)
338 {
339 	struct fs_enet_private *fep = netdev_priv(dev);
340 	cbd_t __iomem *bdp;
341 	struct sk_buff *skb;
342 	int dirtyidx, do_wake, do_restart;
343 	u16 sc;
344 
345 	spin_lock(&fep->tx_lock);
346 	bdp = fep->dirty_tx;
347 
348 	do_wake = do_restart = 0;
349 	while (((sc = CBDR_SC(bdp)) & BD_ENET_TX_READY) == 0) {
350 		dirtyidx = bdp - fep->tx_bd_base;
351 
352 		if (fep->tx_free == fep->tx_ring)
353 			break;
354 
355 		skb = fep->tx_skbuff[dirtyidx];
356 
357 		/*
358 		 * Check for errors.
359 		 */
360 		if (sc & (BD_ENET_TX_HB | BD_ENET_TX_LC |
361 			  BD_ENET_TX_RL | BD_ENET_TX_UN | BD_ENET_TX_CSL)) {
362 
363 			if (sc & BD_ENET_TX_HB)	/* No heartbeat */
364 				fep->stats.tx_heartbeat_errors++;
365 			if (sc & BD_ENET_TX_LC)	/* Late collision */
366 				fep->stats.tx_window_errors++;
367 			if (sc & BD_ENET_TX_RL)	/* Retrans limit */
368 				fep->stats.tx_aborted_errors++;
369 			if (sc & BD_ENET_TX_UN)	/* Underrun */
370 				fep->stats.tx_fifo_errors++;
371 			if (sc & BD_ENET_TX_CSL)	/* Carrier lost */
372 				fep->stats.tx_carrier_errors++;
373 
374 			if (sc & (BD_ENET_TX_LC | BD_ENET_TX_RL | BD_ENET_TX_UN)) {
375 				fep->stats.tx_errors++;
376 				do_restart = 1;
377 			}
378 		} else
379 			fep->stats.tx_packets++;
380 
381 		if (sc & BD_ENET_TX_READY) {
382 			dev_warn(fep->dev,
383 				 "HEY! Enet xmit interrupt and TX_READY.\n");
384 		}
385 
386 		/*
387 		 * Deferred means some collisions occurred during transmit,
388 		 * but we eventually sent the packet OK.
389 		 */
390 		if (sc & BD_ENET_TX_DEF)
391 			fep->stats.collisions++;
392 
393 		/* unmap */
394 		dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp),
395 				skb->len, DMA_TO_DEVICE);
396 
397 		/*
398 		 * Free the sk buffer associated with this last transmit.
399 		 */
400 		dev_kfree_skb_irq(skb);
401 		fep->tx_skbuff[dirtyidx] = NULL;
402 
403 		/*
404 		 * Update pointer to next buffer descriptor to be transmitted.
405 		 */
406 		if ((sc & BD_ENET_TX_WRAP) == 0)
407 			bdp++;
408 		else
409 			bdp = fep->tx_bd_base;
410 
411 		/*
412 		 * Since we have freed up a buffer, the ring is no longer
413 		 * full.
414 		 */
415 		if (!fep->tx_free++)
416 			do_wake = 1;
417 	}
418 
419 	fep->dirty_tx = bdp;
420 
421 	if (do_restart)
422 		(*fep->ops->tx_restart)(dev);
423 
424 	spin_unlock(&fep->tx_lock);
425 
426 	if (do_wake)
427 		netif_wake_queue(dev);
428 }
429 
430 /*
431  * The interrupt handler.
432  * This is called from the MPC core interrupt.
433  */
434 static irqreturn_t
435 fs_enet_interrupt(int irq, void *dev_id)
436 {
437 	struct net_device *dev = dev_id;
438 	struct fs_enet_private *fep;
439 	const struct fs_platform_info *fpi;
440 	u32 int_events;
441 	u32 int_clr_events;
442 	int nr, napi_ok;
443 	int handled;
444 
445 	fep = netdev_priv(dev);
446 	fpi = fep->fpi;
447 
448 	nr = 0;
449 	while ((int_events = (*fep->ops->get_int_events)(dev)) != 0) {
450 		nr++;
451 
452 		int_clr_events = int_events;
453 		if (fpi->use_napi)
454 			int_clr_events &= ~fep->ev_napi_rx;
455 
456 		(*fep->ops->clear_int_events)(dev, int_clr_events);
457 
458 		if (int_events & fep->ev_err)
459 			(*fep->ops->ev_error)(dev, int_events);
460 
461 		if (int_events & fep->ev_rx) {
462 			if (!fpi->use_napi)
463 				fs_enet_rx_non_napi(dev);
464 			else {
465 				napi_ok = napi_schedule_prep(&fep->napi);
466 
467 				(*fep->ops->napi_disable_rx)(dev);
468 				(*fep->ops->clear_int_events)(dev, fep->ev_napi_rx);
469 
470 				/* NOTE: it is possible for FCCs in NAPI mode    */
471 				/* to submit a spurious interrupt while in poll  */
472 				if (napi_ok)
473 					__napi_schedule(&fep->napi);
474 			}
475 		}
476 
477 		if (int_events & fep->ev_tx)
478 			fs_enet_tx(dev);
479 	}
480 
481 	handled = nr > 0;
482 	return IRQ_RETVAL(handled);
483 }
484 
485 void fs_init_bds(struct net_device *dev)
486 {
487 	struct fs_enet_private *fep = netdev_priv(dev);
488 	cbd_t __iomem *bdp;
489 	struct sk_buff *skb;
490 	int i;
491 
492 	fs_cleanup_bds(dev);
493 
494 	fep->dirty_tx = fep->cur_tx = fep->tx_bd_base;
495 	fep->tx_free = fep->tx_ring;
496 	fep->cur_rx = fep->rx_bd_base;
497 
498 	/*
499 	 * Initialize the receive buffer descriptors.
500 	 */
501 	for (i = 0, bdp = fep->rx_bd_base; i < fep->rx_ring; i++, bdp++) {
502 		skb = netdev_alloc_skb(dev, ENET_RX_FRSIZE);
503 		if (skb == NULL)
504 			break;
505 
506 		skb_align(skb, ENET_RX_ALIGN);
507 		fep->rx_skbuff[i] = skb;
508 		CBDW_BUFADDR(bdp,
509 			dma_map_single(fep->dev, skb->data,
510 				L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
511 				DMA_FROM_DEVICE));
512 		CBDW_DATLEN(bdp, 0);	/* zero */
513 		CBDW_SC(bdp, BD_ENET_RX_EMPTY |
514 			((i < fep->rx_ring - 1) ? 0 : BD_SC_WRAP));
515 	}
516 	/*
517 	 * if we failed, fillup remainder
518 	 */
519 	for (; i < fep->rx_ring; i++, bdp++) {
520 		fep->rx_skbuff[i] = NULL;
521 		CBDW_SC(bdp, (i < fep->rx_ring - 1) ? 0 : BD_SC_WRAP);
522 	}
523 
524 	/*
525 	 * ...and the same for transmit.
526 	 */
527 	for (i = 0, bdp = fep->tx_bd_base; i < fep->tx_ring; i++, bdp++) {
528 		fep->tx_skbuff[i] = NULL;
529 		CBDW_BUFADDR(bdp, 0);
530 		CBDW_DATLEN(bdp, 0);
531 		CBDW_SC(bdp, (i < fep->tx_ring - 1) ? 0 : BD_SC_WRAP);
532 	}
533 }
534 
535 void fs_cleanup_bds(struct net_device *dev)
536 {
537 	struct fs_enet_private *fep = netdev_priv(dev);
538 	struct sk_buff *skb;
539 	cbd_t __iomem *bdp;
540 	int i;
541 
542 	/*
543 	 * Reset SKB transmit buffers.
544 	 */
545 	for (i = 0, bdp = fep->tx_bd_base; i < fep->tx_ring; i++, bdp++) {
546 		if ((skb = fep->tx_skbuff[i]) == NULL)
547 			continue;
548 
549 		/* unmap */
550 		dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp),
551 				skb->len, DMA_TO_DEVICE);
552 
553 		fep->tx_skbuff[i] = NULL;
554 		dev_kfree_skb(skb);
555 	}
556 
557 	/*
558 	 * Reset SKB receive buffers
559 	 */
560 	for (i = 0, bdp = fep->rx_bd_base; i < fep->rx_ring; i++, bdp++) {
561 		if ((skb = fep->rx_skbuff[i]) == NULL)
562 			continue;
563 
564 		/* unmap */
565 		dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp),
566 			L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
567 			DMA_FROM_DEVICE);
568 
569 		fep->rx_skbuff[i] = NULL;
570 
571 		dev_kfree_skb(skb);
572 	}
573 }
574 
575 /**********************************************************************************/
576 
577 #ifdef CONFIG_FS_ENET_MPC5121_FEC
578 /*
579  * MPC5121 FEC requeries 4-byte alignment for TX data buffer!
580  */
581 static struct sk_buff *tx_skb_align_workaround(struct net_device *dev,
582 					       struct sk_buff *skb)
583 {
584 	struct sk_buff *new_skb;
585 
586 	/* Alloc new skb */
587 	new_skb = netdev_alloc_skb(dev, skb->len + 4);
588 	if (!new_skb)
589 		return NULL;
590 
591 	/* Make sure new skb is properly aligned */
592 	skb_align(new_skb, 4);
593 
594 	/* Copy data to new skb ... */
595 	skb_copy_from_linear_data(skb, new_skb->data, skb->len);
596 	skb_put(new_skb, skb->len);
597 
598 	/* ... and free an old one */
599 	dev_kfree_skb_any(skb);
600 
601 	return new_skb;
602 }
603 #endif
604 
605 static int fs_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
606 {
607 	struct fs_enet_private *fep = netdev_priv(dev);
608 	cbd_t __iomem *bdp;
609 	int curidx;
610 	u16 sc;
611 	unsigned long flags;
612 
613 #ifdef CONFIG_FS_ENET_MPC5121_FEC
614 	if (((unsigned long)skb->data) & 0x3) {
615 		skb = tx_skb_align_workaround(dev, skb);
616 		if (!skb) {
617 			/*
618 			 * We have lost packet due to memory allocation error
619 			 * in tx_skb_align_workaround(). Hopefully original
620 			 * skb is still valid, so try transmit it later.
621 			 */
622 			return NETDEV_TX_BUSY;
623 		}
624 	}
625 #endif
626 	spin_lock_irqsave(&fep->tx_lock, flags);
627 
628 	/*
629 	 * Fill in a Tx ring entry
630 	 */
631 	bdp = fep->cur_tx;
632 
633 	if (!fep->tx_free || (CBDR_SC(bdp) & BD_ENET_TX_READY)) {
634 		netif_stop_queue(dev);
635 		spin_unlock_irqrestore(&fep->tx_lock, flags);
636 
637 		/*
638 		 * Ooops.  All transmit buffers are full.  Bail out.
639 		 * This should not happen, since the tx queue should be stopped.
640 		 */
641 		dev_warn(fep->dev, "tx queue full!.\n");
642 		return NETDEV_TX_BUSY;
643 	}
644 
645 	curidx = bdp - fep->tx_bd_base;
646 	/*
647 	 * Clear all of the status flags.
648 	 */
649 	CBDC_SC(bdp, BD_ENET_TX_STATS);
650 
651 	/*
652 	 * Save skb pointer.
653 	 */
654 	fep->tx_skbuff[curidx] = skb;
655 
656 	fep->stats.tx_bytes += skb->len;
657 
658 	/*
659 	 * Push the data cache so the CPM does not get stale memory data.
660 	 */
661 	CBDW_BUFADDR(bdp, dma_map_single(fep->dev,
662 				skb->data, skb->len, DMA_TO_DEVICE));
663 	CBDW_DATLEN(bdp, skb->len);
664 
665 	/*
666 	 * If this was the last BD in the ring, start at the beginning again.
667 	 */
668 	if ((CBDR_SC(bdp) & BD_ENET_TX_WRAP) == 0)
669 		fep->cur_tx++;
670 	else
671 		fep->cur_tx = fep->tx_bd_base;
672 
673 	if (!--fep->tx_free)
674 		netif_stop_queue(dev);
675 
676 	/* Trigger transmission start */
677 	sc = BD_ENET_TX_READY | BD_ENET_TX_INTR |
678 	     BD_ENET_TX_LAST | BD_ENET_TX_TC;
679 
680 	/* note that while FEC does not have this bit
681 	 * it marks it as available for software use
682 	 * yay for hw reuse :) */
683 	if (skb->len <= 60)
684 		sc |= BD_ENET_TX_PAD;
685 	CBDS_SC(bdp, sc);
686 
687 	skb_tx_timestamp(skb);
688 
689 	(*fep->ops->tx_kickstart)(dev);
690 
691 	spin_unlock_irqrestore(&fep->tx_lock, flags);
692 
693 	return NETDEV_TX_OK;
694 }
695 
696 static void fs_timeout(struct net_device *dev)
697 {
698 	struct fs_enet_private *fep = netdev_priv(dev);
699 	unsigned long flags;
700 	int wake = 0;
701 
702 	fep->stats.tx_errors++;
703 
704 	spin_lock_irqsave(&fep->lock, flags);
705 
706 	if (dev->flags & IFF_UP) {
707 		phy_stop(fep->phydev);
708 		(*fep->ops->stop)(dev);
709 		(*fep->ops->restart)(dev);
710 		phy_start(fep->phydev);
711 	}
712 
713 	phy_start(fep->phydev);
714 	wake = fep->tx_free && !(CBDR_SC(fep->cur_tx) & BD_ENET_TX_READY);
715 	spin_unlock_irqrestore(&fep->lock, flags);
716 
717 	if (wake)
718 		netif_wake_queue(dev);
719 }
720 
721 /*-----------------------------------------------------------------------------
722  *  generic link-change handler - should be sufficient for most cases
723  *-----------------------------------------------------------------------------*/
724 static void generic_adjust_link(struct  net_device *dev)
725 {
726 	struct fs_enet_private *fep = netdev_priv(dev);
727 	struct phy_device *phydev = fep->phydev;
728 	int new_state = 0;
729 
730 	if (phydev->link) {
731 		/* adjust to duplex mode */
732 		if (phydev->duplex != fep->oldduplex) {
733 			new_state = 1;
734 			fep->oldduplex = phydev->duplex;
735 		}
736 
737 		if (phydev->speed != fep->oldspeed) {
738 			new_state = 1;
739 			fep->oldspeed = phydev->speed;
740 		}
741 
742 		if (!fep->oldlink) {
743 			new_state = 1;
744 			fep->oldlink = 1;
745 		}
746 
747 		if (new_state)
748 			fep->ops->restart(dev);
749 	} else if (fep->oldlink) {
750 		new_state = 1;
751 		fep->oldlink = 0;
752 		fep->oldspeed = 0;
753 		fep->oldduplex = -1;
754 	}
755 
756 	if (new_state && netif_msg_link(fep))
757 		phy_print_status(phydev);
758 }
759 
760 
761 static void fs_adjust_link(struct net_device *dev)
762 {
763 	struct fs_enet_private *fep = netdev_priv(dev);
764 	unsigned long flags;
765 
766 	spin_lock_irqsave(&fep->lock, flags);
767 
768 	if(fep->ops->adjust_link)
769 		fep->ops->adjust_link(dev);
770 	else
771 		generic_adjust_link(dev);
772 
773 	spin_unlock_irqrestore(&fep->lock, flags);
774 }
775 
776 static int fs_init_phy(struct net_device *dev)
777 {
778 	struct fs_enet_private *fep = netdev_priv(dev);
779 	struct phy_device *phydev;
780 	phy_interface_t iface;
781 
782 	fep->oldlink = 0;
783 	fep->oldspeed = 0;
784 	fep->oldduplex = -1;
785 
786 	iface = fep->fpi->use_rmii ?
787 		PHY_INTERFACE_MODE_RMII : PHY_INTERFACE_MODE_MII;
788 
789 	phydev = of_phy_connect(dev, fep->fpi->phy_node, &fs_adjust_link, 0,
790 				iface);
791 	if (!phydev) {
792 		phydev = of_phy_connect_fixed_link(dev, &fs_adjust_link,
793 						   iface);
794 	}
795 	if (!phydev) {
796 		dev_err(&dev->dev, "Could not attach to PHY\n");
797 		return -ENODEV;
798 	}
799 
800 	fep->phydev = phydev;
801 
802 	return 0;
803 }
804 
805 static int fs_enet_open(struct net_device *dev)
806 {
807 	struct fs_enet_private *fep = netdev_priv(dev);
808 	int r;
809 	int err;
810 
811 	/* to initialize the fep->cur_rx,... */
812 	/* not doing this, will cause a crash in fs_enet_rx_napi */
813 	fs_init_bds(fep->ndev);
814 
815 	if (fep->fpi->use_napi)
816 		napi_enable(&fep->napi);
817 
818 	/* Install our interrupt handler. */
819 	r = request_irq(fep->interrupt, fs_enet_interrupt, IRQF_SHARED,
820 			"fs_enet-mac", dev);
821 	if (r != 0) {
822 		dev_err(fep->dev, "Could not allocate FS_ENET IRQ!");
823 		if (fep->fpi->use_napi)
824 			napi_disable(&fep->napi);
825 		return -EINVAL;
826 	}
827 
828 	err = fs_init_phy(dev);
829 	if (err) {
830 		free_irq(fep->interrupt, dev);
831 		if (fep->fpi->use_napi)
832 			napi_disable(&fep->napi);
833 		return err;
834 	}
835 	phy_start(fep->phydev);
836 
837 	netif_start_queue(dev);
838 
839 	return 0;
840 }
841 
842 static int fs_enet_close(struct net_device *dev)
843 {
844 	struct fs_enet_private *fep = netdev_priv(dev);
845 	unsigned long flags;
846 
847 	netif_stop_queue(dev);
848 	netif_carrier_off(dev);
849 	if (fep->fpi->use_napi)
850 		napi_disable(&fep->napi);
851 	phy_stop(fep->phydev);
852 
853 	spin_lock_irqsave(&fep->lock, flags);
854 	spin_lock(&fep->tx_lock);
855 	(*fep->ops->stop)(dev);
856 	spin_unlock(&fep->tx_lock);
857 	spin_unlock_irqrestore(&fep->lock, flags);
858 
859 	/* release any irqs */
860 	phy_disconnect(fep->phydev);
861 	fep->phydev = NULL;
862 	free_irq(fep->interrupt, dev);
863 
864 	return 0;
865 }
866 
867 static struct net_device_stats *fs_enet_get_stats(struct net_device *dev)
868 {
869 	struct fs_enet_private *fep = netdev_priv(dev);
870 	return &fep->stats;
871 }
872 
873 /*************************************************************************/
874 
875 static void fs_get_drvinfo(struct net_device *dev,
876 			    struct ethtool_drvinfo *info)
877 {
878 	strlcpy(info->driver, DRV_MODULE_NAME, sizeof(info->driver));
879 	strlcpy(info->version, DRV_MODULE_VERSION, sizeof(info->version));
880 }
881 
882 static int fs_get_regs_len(struct net_device *dev)
883 {
884 	struct fs_enet_private *fep = netdev_priv(dev);
885 
886 	return (*fep->ops->get_regs_len)(dev);
887 }
888 
889 static void fs_get_regs(struct net_device *dev, struct ethtool_regs *regs,
890 			 void *p)
891 {
892 	struct fs_enet_private *fep = netdev_priv(dev);
893 	unsigned long flags;
894 	int r, len;
895 
896 	len = regs->len;
897 
898 	spin_lock_irqsave(&fep->lock, flags);
899 	r = (*fep->ops->get_regs)(dev, p, &len);
900 	spin_unlock_irqrestore(&fep->lock, flags);
901 
902 	if (r == 0)
903 		regs->version = 0;
904 }
905 
906 static int fs_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
907 {
908 	struct fs_enet_private *fep = netdev_priv(dev);
909 
910 	if (!fep->phydev)
911 		return -ENODEV;
912 
913 	return phy_ethtool_gset(fep->phydev, cmd);
914 }
915 
916 static int fs_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
917 {
918 	struct fs_enet_private *fep = netdev_priv(dev);
919 
920 	if (!fep->phydev)
921 		return -ENODEV;
922 
923 	return phy_ethtool_sset(fep->phydev, cmd);
924 }
925 
926 static int fs_nway_reset(struct net_device *dev)
927 {
928 	return 0;
929 }
930 
931 static u32 fs_get_msglevel(struct net_device *dev)
932 {
933 	struct fs_enet_private *fep = netdev_priv(dev);
934 	return fep->msg_enable;
935 }
936 
937 static void fs_set_msglevel(struct net_device *dev, u32 value)
938 {
939 	struct fs_enet_private *fep = netdev_priv(dev);
940 	fep->msg_enable = value;
941 }
942 
943 static const struct ethtool_ops fs_ethtool_ops = {
944 	.get_drvinfo = fs_get_drvinfo,
945 	.get_regs_len = fs_get_regs_len,
946 	.get_settings = fs_get_settings,
947 	.set_settings = fs_set_settings,
948 	.nway_reset = fs_nway_reset,
949 	.get_link = ethtool_op_get_link,
950 	.get_msglevel = fs_get_msglevel,
951 	.set_msglevel = fs_set_msglevel,
952 	.get_regs = fs_get_regs,
953 	.get_ts_info = ethtool_op_get_ts_info,
954 };
955 
956 static int fs_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
957 {
958 	struct fs_enet_private *fep = netdev_priv(dev);
959 
960 	if (!netif_running(dev))
961 		return -EINVAL;
962 
963 	return phy_mii_ioctl(fep->phydev, rq, cmd);
964 }
965 
966 extern int fs_mii_connect(struct net_device *dev);
967 extern void fs_mii_disconnect(struct net_device *dev);
968 
969 /**************************************************************************************/
970 
971 #ifdef CONFIG_FS_ENET_HAS_FEC
972 #define IS_FEC(match) ((match)->data == &fs_fec_ops)
973 #else
974 #define IS_FEC(match) 0
975 #endif
976 
977 static const struct net_device_ops fs_enet_netdev_ops = {
978 	.ndo_open		= fs_enet_open,
979 	.ndo_stop		= fs_enet_close,
980 	.ndo_get_stats		= fs_enet_get_stats,
981 	.ndo_start_xmit		= fs_enet_start_xmit,
982 	.ndo_tx_timeout		= fs_timeout,
983 	.ndo_set_rx_mode	= fs_set_multicast_list,
984 	.ndo_do_ioctl		= fs_ioctl,
985 	.ndo_validate_addr	= eth_validate_addr,
986 	.ndo_set_mac_address	= eth_mac_addr,
987 	.ndo_change_mtu		= eth_change_mtu,
988 #ifdef CONFIG_NET_POLL_CONTROLLER
989 	.ndo_poll_controller	= fs_enet_netpoll,
990 #endif
991 };
992 
993 static struct of_device_id fs_enet_match[];
994 static int fs_enet_probe(struct platform_device *ofdev)
995 {
996 	const struct of_device_id *match;
997 	struct net_device *ndev;
998 	struct fs_enet_private *fep;
999 	struct fs_platform_info *fpi;
1000 	const u32 *data;
1001 	struct clk *clk;
1002 	int err;
1003 	const u8 *mac_addr;
1004 	const char *phy_connection_type;
1005 	int privsize, len, ret = -ENODEV;
1006 
1007 	match = of_match_device(fs_enet_match, &ofdev->dev);
1008 	if (!match)
1009 		return -EINVAL;
1010 
1011 	fpi = kzalloc(sizeof(*fpi), GFP_KERNEL);
1012 	if (!fpi)
1013 		return -ENOMEM;
1014 
1015 	if (!IS_FEC(match)) {
1016 		data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len);
1017 		if (!data || len != 4)
1018 			goto out_free_fpi;
1019 
1020 		fpi->cp_command = *data;
1021 	}
1022 
1023 	fpi->rx_ring = 32;
1024 	fpi->tx_ring = 32;
1025 	fpi->rx_copybreak = 240;
1026 	fpi->use_napi = 1;
1027 	fpi->napi_weight = 17;
1028 	fpi->phy_node = of_parse_phandle(ofdev->dev.of_node, "phy-handle", 0);
1029 	if ((!fpi->phy_node) && (!of_get_property(ofdev->dev.of_node, "fixed-link",
1030 						  NULL)))
1031 		goto out_free_fpi;
1032 
1033 	if (of_device_is_compatible(ofdev->dev.of_node, "fsl,mpc5125-fec")) {
1034 		phy_connection_type = of_get_property(ofdev->dev.of_node,
1035 						"phy-connection-type", NULL);
1036 		if (phy_connection_type && !strcmp("rmii", phy_connection_type))
1037 			fpi->use_rmii = 1;
1038 	}
1039 
1040 	/* make clock lookup non-fatal (the driver is shared among platforms),
1041 	 * but require enable to succeed when a clock was specified/found,
1042 	 * keep a reference to the clock upon successful acquisition
1043 	 */
1044 	clk = devm_clk_get(&ofdev->dev, "per");
1045 	if (!IS_ERR(clk)) {
1046 		err = clk_prepare_enable(clk);
1047 		if (err) {
1048 			ret = err;
1049 			goto out_free_fpi;
1050 		}
1051 		fpi->clk_per = clk;
1052 	}
1053 
1054 	privsize = sizeof(*fep) +
1055 	           sizeof(struct sk_buff **) *
1056 	           (fpi->rx_ring + fpi->tx_ring);
1057 
1058 	ndev = alloc_etherdev(privsize);
1059 	if (!ndev) {
1060 		ret = -ENOMEM;
1061 		goto out_put;
1062 	}
1063 
1064 	SET_NETDEV_DEV(ndev, &ofdev->dev);
1065 	platform_set_drvdata(ofdev, ndev);
1066 
1067 	fep = netdev_priv(ndev);
1068 	fep->dev = &ofdev->dev;
1069 	fep->ndev = ndev;
1070 	fep->fpi = fpi;
1071 	fep->ops = match->data;
1072 
1073 	ret = fep->ops->setup_data(ndev);
1074 	if (ret)
1075 		goto out_free_dev;
1076 
1077 	fep->rx_skbuff = (struct sk_buff **)&fep[1];
1078 	fep->tx_skbuff = fep->rx_skbuff + fpi->rx_ring;
1079 
1080 	spin_lock_init(&fep->lock);
1081 	spin_lock_init(&fep->tx_lock);
1082 
1083 	mac_addr = of_get_mac_address(ofdev->dev.of_node);
1084 	if (mac_addr)
1085 		memcpy(ndev->dev_addr, mac_addr, ETH_ALEN);
1086 
1087 	ret = fep->ops->allocate_bd(ndev);
1088 	if (ret)
1089 		goto out_cleanup_data;
1090 
1091 	fep->rx_bd_base = fep->ring_base;
1092 	fep->tx_bd_base = fep->rx_bd_base + fpi->rx_ring;
1093 
1094 	fep->tx_ring = fpi->tx_ring;
1095 	fep->rx_ring = fpi->rx_ring;
1096 
1097 	ndev->netdev_ops = &fs_enet_netdev_ops;
1098 	ndev->watchdog_timeo = 2 * HZ;
1099 	if (fpi->use_napi)
1100 		netif_napi_add(ndev, &fep->napi, fs_enet_rx_napi,
1101 		               fpi->napi_weight);
1102 
1103 	ndev->ethtool_ops = &fs_ethtool_ops;
1104 
1105 	init_timer(&fep->phy_timer_list);
1106 
1107 	netif_carrier_off(ndev);
1108 
1109 	ret = register_netdev(ndev);
1110 	if (ret)
1111 		goto out_free_bd;
1112 
1113 	pr_info("%s: fs_enet: %pM\n", ndev->name, ndev->dev_addr);
1114 
1115 	return 0;
1116 
1117 out_free_bd:
1118 	fep->ops->free_bd(ndev);
1119 out_cleanup_data:
1120 	fep->ops->cleanup_data(ndev);
1121 out_free_dev:
1122 	free_netdev(ndev);
1123 out_put:
1124 	of_node_put(fpi->phy_node);
1125 	if (fpi->clk_per)
1126 		clk_disable_unprepare(fpi->clk_per);
1127 out_free_fpi:
1128 	kfree(fpi);
1129 	return ret;
1130 }
1131 
1132 static int fs_enet_remove(struct platform_device *ofdev)
1133 {
1134 	struct net_device *ndev = platform_get_drvdata(ofdev);
1135 	struct fs_enet_private *fep = netdev_priv(ndev);
1136 
1137 	unregister_netdev(ndev);
1138 
1139 	fep->ops->free_bd(ndev);
1140 	fep->ops->cleanup_data(ndev);
1141 	dev_set_drvdata(fep->dev, NULL);
1142 	of_node_put(fep->fpi->phy_node);
1143 	if (fep->fpi->clk_per)
1144 		clk_disable_unprepare(fep->fpi->clk_per);
1145 	free_netdev(ndev);
1146 	return 0;
1147 }
1148 
1149 static struct of_device_id fs_enet_match[] = {
1150 #ifdef CONFIG_FS_ENET_HAS_SCC
1151 	{
1152 		.compatible = "fsl,cpm1-scc-enet",
1153 		.data = (void *)&fs_scc_ops,
1154 	},
1155 	{
1156 		.compatible = "fsl,cpm2-scc-enet",
1157 		.data = (void *)&fs_scc_ops,
1158 	},
1159 #endif
1160 #ifdef CONFIG_FS_ENET_HAS_FCC
1161 	{
1162 		.compatible = "fsl,cpm2-fcc-enet",
1163 		.data = (void *)&fs_fcc_ops,
1164 	},
1165 #endif
1166 #ifdef CONFIG_FS_ENET_HAS_FEC
1167 #ifdef CONFIG_FS_ENET_MPC5121_FEC
1168 	{
1169 		.compatible = "fsl,mpc5121-fec",
1170 		.data = (void *)&fs_fec_ops,
1171 	},
1172 	{
1173 		.compatible = "fsl,mpc5125-fec",
1174 		.data = (void *)&fs_fec_ops,
1175 	},
1176 #else
1177 	{
1178 		.compatible = "fsl,pq1-fec-enet",
1179 		.data = (void *)&fs_fec_ops,
1180 	},
1181 #endif
1182 #endif
1183 	{}
1184 };
1185 MODULE_DEVICE_TABLE(of, fs_enet_match);
1186 
1187 static struct platform_driver fs_enet_driver = {
1188 	.driver = {
1189 		.owner = THIS_MODULE,
1190 		.name = "fs_enet",
1191 		.of_match_table = fs_enet_match,
1192 	},
1193 	.probe = fs_enet_probe,
1194 	.remove = fs_enet_remove,
1195 };
1196 
1197 #ifdef CONFIG_NET_POLL_CONTROLLER
1198 static void fs_enet_netpoll(struct net_device *dev)
1199 {
1200        disable_irq(dev->irq);
1201        fs_enet_interrupt(dev->irq, dev);
1202        enable_irq(dev->irq);
1203 }
1204 #endif
1205 
1206 module_platform_driver(fs_enet_driver);
1207