xref: /linux/drivers/net/ethernet/faraday/ftmac100.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
1 /*
2  * Faraday FTMAC100 10/100 Ethernet
3  *
4  * (C) Copyright 2009-2011 Faraday Technology
5  * Po-Yu Chuang <ratbert@faraday-tech.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20  */
21 
22 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
23 
24 #include <linux/dma-mapping.h>
25 #include <linux/etherdevice.h>
26 #include <linux/ethtool.h>
27 #include <linux/init.h>
28 #include <linux/io.h>
29 #include <linux/mii.h>
30 #include <linux/module.h>
31 #include <linux/netdevice.h>
32 #include <linux/platform_device.h>
33 
34 #include "ftmac100.h"
35 
36 #define DRV_NAME	"ftmac100"
37 #define DRV_VERSION	"0.2"
38 
39 #define RX_QUEUE_ENTRIES	128	/* must be power of 2 */
40 #define TX_QUEUE_ENTRIES	16	/* must be power of 2 */
41 
42 #define MAX_PKT_SIZE		1518
43 #define RX_BUF_SIZE		2044	/* must be smaller than 0x7ff */
44 
45 #if MAX_PKT_SIZE > 0x7ff
46 #error invalid MAX_PKT_SIZE
47 #endif
48 
49 #if RX_BUF_SIZE > 0x7ff || RX_BUF_SIZE > PAGE_SIZE
50 #error invalid RX_BUF_SIZE
51 #endif
52 
53 /******************************************************************************
54  * private data
55  *****************************************************************************/
56 struct ftmac100_descs {
57 	struct ftmac100_rxdes rxdes[RX_QUEUE_ENTRIES];
58 	struct ftmac100_txdes txdes[TX_QUEUE_ENTRIES];
59 };
60 
61 struct ftmac100 {
62 	struct resource *res;
63 	void __iomem *base;
64 	int irq;
65 
66 	struct ftmac100_descs *descs;
67 	dma_addr_t descs_dma_addr;
68 
69 	unsigned int rx_pointer;
70 	unsigned int tx_clean_pointer;
71 	unsigned int tx_pointer;
72 	unsigned int tx_pending;
73 
74 	spinlock_t tx_lock;
75 
76 	struct net_device *netdev;
77 	struct device *dev;
78 	struct napi_struct napi;
79 
80 	struct mii_if_info mii;
81 };
82 
83 static int ftmac100_alloc_rx_page(struct ftmac100 *priv,
84 				  struct ftmac100_rxdes *rxdes, gfp_t gfp);
85 
86 /******************************************************************************
87  * internal functions (hardware register access)
88  *****************************************************************************/
89 #define INT_MASK_ALL_ENABLED	(FTMAC100_INT_RPKT_FINISH	| \
90 				 FTMAC100_INT_NORXBUF		| \
91 				 FTMAC100_INT_XPKT_OK		| \
92 				 FTMAC100_INT_XPKT_LOST		| \
93 				 FTMAC100_INT_RPKT_LOST		| \
94 				 FTMAC100_INT_AHB_ERR		| \
95 				 FTMAC100_INT_PHYSTS_CHG)
96 
97 #define INT_MASK_ALL_DISABLED	0
98 
99 static void ftmac100_enable_all_int(struct ftmac100 *priv)
100 {
101 	iowrite32(INT_MASK_ALL_ENABLED, priv->base + FTMAC100_OFFSET_IMR);
102 }
103 
104 static void ftmac100_disable_all_int(struct ftmac100 *priv)
105 {
106 	iowrite32(INT_MASK_ALL_DISABLED, priv->base + FTMAC100_OFFSET_IMR);
107 }
108 
109 static void ftmac100_set_rx_ring_base(struct ftmac100 *priv, dma_addr_t addr)
110 {
111 	iowrite32(addr, priv->base + FTMAC100_OFFSET_RXR_BADR);
112 }
113 
114 static void ftmac100_set_tx_ring_base(struct ftmac100 *priv, dma_addr_t addr)
115 {
116 	iowrite32(addr, priv->base + FTMAC100_OFFSET_TXR_BADR);
117 }
118 
119 static void ftmac100_txdma_start_polling(struct ftmac100 *priv)
120 {
121 	iowrite32(1, priv->base + FTMAC100_OFFSET_TXPD);
122 }
123 
124 static int ftmac100_reset(struct ftmac100 *priv)
125 {
126 	struct net_device *netdev = priv->netdev;
127 	int i;
128 
129 	/* NOTE: reset clears all registers */
130 	iowrite32(FTMAC100_MACCR_SW_RST, priv->base + FTMAC100_OFFSET_MACCR);
131 
132 	for (i = 0; i < 5; i++) {
133 		unsigned int maccr;
134 
135 		maccr = ioread32(priv->base + FTMAC100_OFFSET_MACCR);
136 		if (!(maccr & FTMAC100_MACCR_SW_RST)) {
137 			/*
138 			 * FTMAC100_MACCR_SW_RST cleared does not indicate
139 			 * that hardware reset completed (what the f*ck).
140 			 * We still need to wait for a while.
141 			 */
142 			udelay(500);
143 			return 0;
144 		}
145 
146 		udelay(1000);
147 	}
148 
149 	netdev_err(netdev, "software reset failed\n");
150 	return -EIO;
151 }
152 
153 static void ftmac100_set_mac(struct ftmac100 *priv, const unsigned char *mac)
154 {
155 	unsigned int maddr = mac[0] << 8 | mac[1];
156 	unsigned int laddr = mac[2] << 24 | mac[3] << 16 | mac[4] << 8 | mac[5];
157 
158 	iowrite32(maddr, priv->base + FTMAC100_OFFSET_MAC_MADR);
159 	iowrite32(laddr, priv->base + FTMAC100_OFFSET_MAC_LADR);
160 }
161 
162 #define MACCR_ENABLE_ALL	(FTMAC100_MACCR_XMT_EN	| \
163 				 FTMAC100_MACCR_RCV_EN	| \
164 				 FTMAC100_MACCR_XDMA_EN	| \
165 				 FTMAC100_MACCR_RDMA_EN	| \
166 				 FTMAC100_MACCR_CRC_APD	| \
167 				 FTMAC100_MACCR_FULLDUP	| \
168 				 FTMAC100_MACCR_RX_RUNT	| \
169 				 FTMAC100_MACCR_RX_BROADPKT)
170 
171 static int ftmac100_start_hw(struct ftmac100 *priv)
172 {
173 	struct net_device *netdev = priv->netdev;
174 
175 	if (ftmac100_reset(priv))
176 		return -EIO;
177 
178 	/* setup ring buffer base registers */
179 	ftmac100_set_rx_ring_base(priv,
180 				  priv->descs_dma_addr +
181 				  offsetof(struct ftmac100_descs, rxdes));
182 	ftmac100_set_tx_ring_base(priv,
183 				  priv->descs_dma_addr +
184 				  offsetof(struct ftmac100_descs, txdes));
185 
186 	iowrite32(FTMAC100_APTC_RXPOLL_CNT(1), priv->base + FTMAC100_OFFSET_APTC);
187 
188 	ftmac100_set_mac(priv, netdev->dev_addr);
189 
190 	iowrite32(MACCR_ENABLE_ALL, priv->base + FTMAC100_OFFSET_MACCR);
191 	return 0;
192 }
193 
194 static void ftmac100_stop_hw(struct ftmac100 *priv)
195 {
196 	iowrite32(0, priv->base + FTMAC100_OFFSET_MACCR);
197 }
198 
199 /******************************************************************************
200  * internal functions (receive descriptor)
201  *****************************************************************************/
202 static bool ftmac100_rxdes_first_segment(struct ftmac100_rxdes *rxdes)
203 {
204 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_FRS);
205 }
206 
207 static bool ftmac100_rxdes_last_segment(struct ftmac100_rxdes *rxdes)
208 {
209 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_LRS);
210 }
211 
212 static bool ftmac100_rxdes_owned_by_dma(struct ftmac100_rxdes *rxdes)
213 {
214 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_RXDMA_OWN);
215 }
216 
217 static void ftmac100_rxdes_set_dma_own(struct ftmac100_rxdes *rxdes)
218 {
219 	/* clear status bits */
220 	rxdes->rxdes0 = cpu_to_le32(FTMAC100_RXDES0_RXDMA_OWN);
221 }
222 
223 static bool ftmac100_rxdes_rx_error(struct ftmac100_rxdes *rxdes)
224 {
225 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_RX_ERR);
226 }
227 
228 static bool ftmac100_rxdes_crc_error(struct ftmac100_rxdes *rxdes)
229 {
230 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_CRC_ERR);
231 }
232 
233 static bool ftmac100_rxdes_frame_too_long(struct ftmac100_rxdes *rxdes)
234 {
235 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_FTL);
236 }
237 
238 static bool ftmac100_rxdes_runt(struct ftmac100_rxdes *rxdes)
239 {
240 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_RUNT);
241 }
242 
243 static bool ftmac100_rxdes_odd_nibble(struct ftmac100_rxdes *rxdes)
244 {
245 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_RX_ODD_NB);
246 }
247 
248 static unsigned int ftmac100_rxdes_frame_length(struct ftmac100_rxdes *rxdes)
249 {
250 	return le32_to_cpu(rxdes->rxdes0) & FTMAC100_RXDES0_RFL;
251 }
252 
253 static bool ftmac100_rxdes_multicast(struct ftmac100_rxdes *rxdes)
254 {
255 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_MULTICAST);
256 }
257 
258 static void ftmac100_rxdes_set_buffer_size(struct ftmac100_rxdes *rxdes,
259 					   unsigned int size)
260 {
261 	rxdes->rxdes1 &= cpu_to_le32(FTMAC100_RXDES1_EDORR);
262 	rxdes->rxdes1 |= cpu_to_le32(FTMAC100_RXDES1_RXBUF_SIZE(size));
263 }
264 
265 static void ftmac100_rxdes_set_end_of_ring(struct ftmac100_rxdes *rxdes)
266 {
267 	rxdes->rxdes1 |= cpu_to_le32(FTMAC100_RXDES1_EDORR);
268 }
269 
270 static void ftmac100_rxdes_set_dma_addr(struct ftmac100_rxdes *rxdes,
271 					dma_addr_t addr)
272 {
273 	rxdes->rxdes2 = cpu_to_le32(addr);
274 }
275 
276 static dma_addr_t ftmac100_rxdes_get_dma_addr(struct ftmac100_rxdes *rxdes)
277 {
278 	return le32_to_cpu(rxdes->rxdes2);
279 }
280 
281 /*
282  * rxdes3 is not used by hardware. We use it to keep track of page.
283  * Since hardware does not touch it, we can skip cpu_to_le32()/le32_to_cpu().
284  */
285 static void ftmac100_rxdes_set_page(struct ftmac100_rxdes *rxdes, struct page *page)
286 {
287 	rxdes->rxdes3 = (unsigned int)page;
288 }
289 
290 static struct page *ftmac100_rxdes_get_page(struct ftmac100_rxdes *rxdes)
291 {
292 	return (struct page *)rxdes->rxdes3;
293 }
294 
295 /******************************************************************************
296  * internal functions (receive)
297  *****************************************************************************/
298 static int ftmac100_next_rx_pointer(int pointer)
299 {
300 	return (pointer + 1) & (RX_QUEUE_ENTRIES - 1);
301 }
302 
303 static void ftmac100_rx_pointer_advance(struct ftmac100 *priv)
304 {
305 	priv->rx_pointer = ftmac100_next_rx_pointer(priv->rx_pointer);
306 }
307 
308 static struct ftmac100_rxdes *ftmac100_current_rxdes(struct ftmac100 *priv)
309 {
310 	return &priv->descs->rxdes[priv->rx_pointer];
311 }
312 
313 static struct ftmac100_rxdes *
314 ftmac100_rx_locate_first_segment(struct ftmac100 *priv)
315 {
316 	struct ftmac100_rxdes *rxdes = ftmac100_current_rxdes(priv);
317 
318 	while (!ftmac100_rxdes_owned_by_dma(rxdes)) {
319 		if (ftmac100_rxdes_first_segment(rxdes))
320 			return rxdes;
321 
322 		ftmac100_rxdes_set_dma_own(rxdes);
323 		ftmac100_rx_pointer_advance(priv);
324 		rxdes = ftmac100_current_rxdes(priv);
325 	}
326 
327 	return NULL;
328 }
329 
330 static bool ftmac100_rx_packet_error(struct ftmac100 *priv,
331 				     struct ftmac100_rxdes *rxdes)
332 {
333 	struct net_device *netdev = priv->netdev;
334 	bool error = false;
335 
336 	if (unlikely(ftmac100_rxdes_rx_error(rxdes))) {
337 		if (net_ratelimit())
338 			netdev_info(netdev, "rx err\n");
339 
340 		netdev->stats.rx_errors++;
341 		error = true;
342 	}
343 
344 	if (unlikely(ftmac100_rxdes_crc_error(rxdes))) {
345 		if (net_ratelimit())
346 			netdev_info(netdev, "rx crc err\n");
347 
348 		netdev->stats.rx_crc_errors++;
349 		error = true;
350 	}
351 
352 	if (unlikely(ftmac100_rxdes_frame_too_long(rxdes))) {
353 		if (net_ratelimit())
354 			netdev_info(netdev, "rx frame too long\n");
355 
356 		netdev->stats.rx_length_errors++;
357 		error = true;
358 	} else if (unlikely(ftmac100_rxdes_runt(rxdes))) {
359 		if (net_ratelimit())
360 			netdev_info(netdev, "rx runt\n");
361 
362 		netdev->stats.rx_length_errors++;
363 		error = true;
364 	} else if (unlikely(ftmac100_rxdes_odd_nibble(rxdes))) {
365 		if (net_ratelimit())
366 			netdev_info(netdev, "rx odd nibble\n");
367 
368 		netdev->stats.rx_length_errors++;
369 		error = true;
370 	}
371 
372 	return error;
373 }
374 
375 static void ftmac100_rx_drop_packet(struct ftmac100 *priv)
376 {
377 	struct net_device *netdev = priv->netdev;
378 	struct ftmac100_rxdes *rxdes = ftmac100_current_rxdes(priv);
379 	bool done = false;
380 
381 	if (net_ratelimit())
382 		netdev_dbg(netdev, "drop packet %p\n", rxdes);
383 
384 	do {
385 		if (ftmac100_rxdes_last_segment(rxdes))
386 			done = true;
387 
388 		ftmac100_rxdes_set_dma_own(rxdes);
389 		ftmac100_rx_pointer_advance(priv);
390 		rxdes = ftmac100_current_rxdes(priv);
391 	} while (!done && !ftmac100_rxdes_owned_by_dma(rxdes));
392 
393 	netdev->stats.rx_dropped++;
394 }
395 
396 static bool ftmac100_rx_packet(struct ftmac100 *priv, int *processed)
397 {
398 	struct net_device *netdev = priv->netdev;
399 	struct ftmac100_rxdes *rxdes;
400 	struct sk_buff *skb;
401 	struct page *page;
402 	dma_addr_t map;
403 	int length;
404 
405 	rxdes = ftmac100_rx_locate_first_segment(priv);
406 	if (!rxdes)
407 		return false;
408 
409 	if (unlikely(ftmac100_rx_packet_error(priv, rxdes))) {
410 		ftmac100_rx_drop_packet(priv);
411 		return true;
412 	}
413 
414 	/*
415 	 * It is impossible to get multi-segment packets
416 	 * because we always provide big enough receive buffers.
417 	 */
418 	if (unlikely(!ftmac100_rxdes_last_segment(rxdes)))
419 		BUG();
420 
421 	/* start processing */
422 	skb = netdev_alloc_skb_ip_align(netdev, 128);
423 	if (unlikely(!skb)) {
424 		if (net_ratelimit())
425 			netdev_err(netdev, "rx skb alloc failed\n");
426 
427 		ftmac100_rx_drop_packet(priv);
428 		return true;
429 	}
430 
431 	if (unlikely(ftmac100_rxdes_multicast(rxdes)))
432 		netdev->stats.multicast++;
433 
434 	map = ftmac100_rxdes_get_dma_addr(rxdes);
435 	dma_unmap_page(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
436 
437 	length = ftmac100_rxdes_frame_length(rxdes);
438 	page = ftmac100_rxdes_get_page(rxdes);
439 	skb_fill_page_desc(skb, 0, page, 0, length);
440 	skb->len += length;
441 	skb->data_len += length;
442 
443 	/* page might be freed in __pskb_pull_tail() */
444 	if (length > 64)
445 		skb->truesize += PAGE_SIZE;
446 	__pskb_pull_tail(skb, min(length, 64));
447 
448 	ftmac100_alloc_rx_page(priv, rxdes, GFP_ATOMIC);
449 
450 	ftmac100_rx_pointer_advance(priv);
451 
452 	skb->protocol = eth_type_trans(skb, netdev);
453 
454 	netdev->stats.rx_packets++;
455 	netdev->stats.rx_bytes += skb->len;
456 
457 	/* push packet to protocol stack */
458 	netif_receive_skb(skb);
459 
460 	(*processed)++;
461 	return true;
462 }
463 
464 /******************************************************************************
465  * internal functions (transmit descriptor)
466  *****************************************************************************/
467 static void ftmac100_txdes_reset(struct ftmac100_txdes *txdes)
468 {
469 	/* clear all except end of ring bit */
470 	txdes->txdes0 = 0;
471 	txdes->txdes1 &= cpu_to_le32(FTMAC100_TXDES1_EDOTR);
472 	txdes->txdes2 = 0;
473 	txdes->txdes3 = 0;
474 }
475 
476 static bool ftmac100_txdes_owned_by_dma(struct ftmac100_txdes *txdes)
477 {
478 	return txdes->txdes0 & cpu_to_le32(FTMAC100_TXDES0_TXDMA_OWN);
479 }
480 
481 static void ftmac100_txdes_set_dma_own(struct ftmac100_txdes *txdes)
482 {
483 	/*
484 	 * Make sure dma own bit will not be set before any other
485 	 * descriptor fields.
486 	 */
487 	wmb();
488 	txdes->txdes0 |= cpu_to_le32(FTMAC100_TXDES0_TXDMA_OWN);
489 }
490 
491 static bool ftmac100_txdes_excessive_collision(struct ftmac100_txdes *txdes)
492 {
493 	return txdes->txdes0 & cpu_to_le32(FTMAC100_TXDES0_TXPKT_EXSCOL);
494 }
495 
496 static bool ftmac100_txdes_late_collision(struct ftmac100_txdes *txdes)
497 {
498 	return txdes->txdes0 & cpu_to_le32(FTMAC100_TXDES0_TXPKT_LATECOL);
499 }
500 
501 static void ftmac100_txdes_set_end_of_ring(struct ftmac100_txdes *txdes)
502 {
503 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_EDOTR);
504 }
505 
506 static void ftmac100_txdes_set_first_segment(struct ftmac100_txdes *txdes)
507 {
508 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_FTS);
509 }
510 
511 static void ftmac100_txdes_set_last_segment(struct ftmac100_txdes *txdes)
512 {
513 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_LTS);
514 }
515 
516 static void ftmac100_txdes_set_txint(struct ftmac100_txdes *txdes)
517 {
518 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_TXIC);
519 }
520 
521 static void ftmac100_txdes_set_buffer_size(struct ftmac100_txdes *txdes,
522 					   unsigned int len)
523 {
524 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_TXBUF_SIZE(len));
525 }
526 
527 static void ftmac100_txdes_set_dma_addr(struct ftmac100_txdes *txdes,
528 					dma_addr_t addr)
529 {
530 	txdes->txdes2 = cpu_to_le32(addr);
531 }
532 
533 static dma_addr_t ftmac100_txdes_get_dma_addr(struct ftmac100_txdes *txdes)
534 {
535 	return le32_to_cpu(txdes->txdes2);
536 }
537 
538 /*
539  * txdes3 is not used by hardware. We use it to keep track of socket buffer.
540  * Since hardware does not touch it, we can skip cpu_to_le32()/le32_to_cpu().
541  */
542 static void ftmac100_txdes_set_skb(struct ftmac100_txdes *txdes, struct sk_buff *skb)
543 {
544 	txdes->txdes3 = (unsigned int)skb;
545 }
546 
547 static struct sk_buff *ftmac100_txdes_get_skb(struct ftmac100_txdes *txdes)
548 {
549 	return (struct sk_buff *)txdes->txdes3;
550 }
551 
552 /******************************************************************************
553  * internal functions (transmit)
554  *****************************************************************************/
555 static int ftmac100_next_tx_pointer(int pointer)
556 {
557 	return (pointer + 1) & (TX_QUEUE_ENTRIES - 1);
558 }
559 
560 static void ftmac100_tx_pointer_advance(struct ftmac100 *priv)
561 {
562 	priv->tx_pointer = ftmac100_next_tx_pointer(priv->tx_pointer);
563 }
564 
565 static void ftmac100_tx_clean_pointer_advance(struct ftmac100 *priv)
566 {
567 	priv->tx_clean_pointer = ftmac100_next_tx_pointer(priv->tx_clean_pointer);
568 }
569 
570 static struct ftmac100_txdes *ftmac100_current_txdes(struct ftmac100 *priv)
571 {
572 	return &priv->descs->txdes[priv->tx_pointer];
573 }
574 
575 static struct ftmac100_txdes *ftmac100_current_clean_txdes(struct ftmac100 *priv)
576 {
577 	return &priv->descs->txdes[priv->tx_clean_pointer];
578 }
579 
580 static bool ftmac100_tx_complete_packet(struct ftmac100 *priv)
581 {
582 	struct net_device *netdev = priv->netdev;
583 	struct ftmac100_txdes *txdes;
584 	struct sk_buff *skb;
585 	dma_addr_t map;
586 
587 	if (priv->tx_pending == 0)
588 		return false;
589 
590 	txdes = ftmac100_current_clean_txdes(priv);
591 
592 	if (ftmac100_txdes_owned_by_dma(txdes))
593 		return false;
594 
595 	skb = ftmac100_txdes_get_skb(txdes);
596 	map = ftmac100_txdes_get_dma_addr(txdes);
597 
598 	if (unlikely(ftmac100_txdes_excessive_collision(txdes) ||
599 		     ftmac100_txdes_late_collision(txdes))) {
600 		/*
601 		 * packet transmitted to ethernet lost due to late collision
602 		 * or excessive collision
603 		 */
604 		netdev->stats.tx_aborted_errors++;
605 	} else {
606 		netdev->stats.tx_packets++;
607 		netdev->stats.tx_bytes += skb->len;
608 	}
609 
610 	dma_unmap_single(priv->dev, map, skb_headlen(skb), DMA_TO_DEVICE);
611 	dev_kfree_skb(skb);
612 
613 	ftmac100_txdes_reset(txdes);
614 
615 	ftmac100_tx_clean_pointer_advance(priv);
616 
617 	spin_lock(&priv->tx_lock);
618 	priv->tx_pending--;
619 	spin_unlock(&priv->tx_lock);
620 	netif_wake_queue(netdev);
621 
622 	return true;
623 }
624 
625 static void ftmac100_tx_complete(struct ftmac100 *priv)
626 {
627 	while (ftmac100_tx_complete_packet(priv))
628 		;
629 }
630 
631 static int ftmac100_xmit(struct ftmac100 *priv, struct sk_buff *skb,
632 			 dma_addr_t map)
633 {
634 	struct net_device *netdev = priv->netdev;
635 	struct ftmac100_txdes *txdes;
636 	unsigned int len = (skb->len < ETH_ZLEN) ? ETH_ZLEN : skb->len;
637 
638 	txdes = ftmac100_current_txdes(priv);
639 	ftmac100_tx_pointer_advance(priv);
640 
641 	/* setup TX descriptor */
642 	ftmac100_txdes_set_skb(txdes, skb);
643 	ftmac100_txdes_set_dma_addr(txdes, map);
644 
645 	ftmac100_txdes_set_first_segment(txdes);
646 	ftmac100_txdes_set_last_segment(txdes);
647 	ftmac100_txdes_set_txint(txdes);
648 	ftmac100_txdes_set_buffer_size(txdes, len);
649 
650 	spin_lock(&priv->tx_lock);
651 	priv->tx_pending++;
652 	if (priv->tx_pending == TX_QUEUE_ENTRIES)
653 		netif_stop_queue(netdev);
654 
655 	/* start transmit */
656 	ftmac100_txdes_set_dma_own(txdes);
657 	spin_unlock(&priv->tx_lock);
658 
659 	ftmac100_txdma_start_polling(priv);
660 	return NETDEV_TX_OK;
661 }
662 
663 /******************************************************************************
664  * internal functions (buffer)
665  *****************************************************************************/
666 static int ftmac100_alloc_rx_page(struct ftmac100 *priv,
667 				  struct ftmac100_rxdes *rxdes, gfp_t gfp)
668 {
669 	struct net_device *netdev = priv->netdev;
670 	struct page *page;
671 	dma_addr_t map;
672 
673 	page = alloc_page(gfp);
674 	if (!page) {
675 		if (net_ratelimit())
676 			netdev_err(netdev, "failed to allocate rx page\n");
677 		return -ENOMEM;
678 	}
679 
680 	map = dma_map_page(priv->dev, page, 0, RX_BUF_SIZE, DMA_FROM_DEVICE);
681 	if (unlikely(dma_mapping_error(priv->dev, map))) {
682 		if (net_ratelimit())
683 			netdev_err(netdev, "failed to map rx page\n");
684 		__free_page(page);
685 		return -ENOMEM;
686 	}
687 
688 	ftmac100_rxdes_set_page(rxdes, page);
689 	ftmac100_rxdes_set_dma_addr(rxdes, map);
690 	ftmac100_rxdes_set_buffer_size(rxdes, RX_BUF_SIZE);
691 	ftmac100_rxdes_set_dma_own(rxdes);
692 	return 0;
693 }
694 
695 static void ftmac100_free_buffers(struct ftmac100 *priv)
696 {
697 	int i;
698 
699 	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
700 		struct ftmac100_rxdes *rxdes = &priv->descs->rxdes[i];
701 		struct page *page = ftmac100_rxdes_get_page(rxdes);
702 		dma_addr_t map = ftmac100_rxdes_get_dma_addr(rxdes);
703 
704 		if (!page)
705 			continue;
706 
707 		dma_unmap_page(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
708 		__free_page(page);
709 	}
710 
711 	for (i = 0; i < TX_QUEUE_ENTRIES; i++) {
712 		struct ftmac100_txdes *txdes = &priv->descs->txdes[i];
713 		struct sk_buff *skb = ftmac100_txdes_get_skb(txdes);
714 		dma_addr_t map = ftmac100_txdes_get_dma_addr(txdes);
715 
716 		if (!skb)
717 			continue;
718 
719 		dma_unmap_single(priv->dev, map, skb_headlen(skb), DMA_TO_DEVICE);
720 		dev_kfree_skb(skb);
721 	}
722 
723 	dma_free_coherent(priv->dev, sizeof(struct ftmac100_descs),
724 			  priv->descs, priv->descs_dma_addr);
725 }
726 
727 static int ftmac100_alloc_buffers(struct ftmac100 *priv)
728 {
729 	int i;
730 
731 	priv->descs = dma_alloc_coherent(priv->dev, sizeof(struct ftmac100_descs),
732 					 &priv->descs_dma_addr, GFP_KERNEL);
733 	if (!priv->descs)
734 		return -ENOMEM;
735 
736 	memset(priv->descs, 0, sizeof(struct ftmac100_descs));
737 
738 	/* initialize RX ring */
739 	ftmac100_rxdes_set_end_of_ring(&priv->descs->rxdes[RX_QUEUE_ENTRIES - 1]);
740 
741 	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
742 		struct ftmac100_rxdes *rxdes = &priv->descs->rxdes[i];
743 
744 		if (ftmac100_alloc_rx_page(priv, rxdes, GFP_KERNEL))
745 			goto err;
746 	}
747 
748 	/* initialize TX ring */
749 	ftmac100_txdes_set_end_of_ring(&priv->descs->txdes[TX_QUEUE_ENTRIES - 1]);
750 	return 0;
751 
752 err:
753 	ftmac100_free_buffers(priv);
754 	return -ENOMEM;
755 }
756 
757 /******************************************************************************
758  * struct mii_if_info functions
759  *****************************************************************************/
760 static int ftmac100_mdio_read(struct net_device *netdev, int phy_id, int reg)
761 {
762 	struct ftmac100 *priv = netdev_priv(netdev);
763 	unsigned int phycr;
764 	int i;
765 
766 	phycr = FTMAC100_PHYCR_PHYAD(phy_id) |
767 		FTMAC100_PHYCR_REGAD(reg) |
768 		FTMAC100_PHYCR_MIIRD;
769 
770 	iowrite32(phycr, priv->base + FTMAC100_OFFSET_PHYCR);
771 
772 	for (i = 0; i < 10; i++) {
773 		phycr = ioread32(priv->base + FTMAC100_OFFSET_PHYCR);
774 
775 		if ((phycr & FTMAC100_PHYCR_MIIRD) == 0)
776 			return phycr & FTMAC100_PHYCR_MIIRDATA;
777 
778 		udelay(100);
779 	}
780 
781 	netdev_err(netdev, "mdio read timed out\n");
782 	return 0;
783 }
784 
785 static void ftmac100_mdio_write(struct net_device *netdev, int phy_id, int reg,
786 				int data)
787 {
788 	struct ftmac100 *priv = netdev_priv(netdev);
789 	unsigned int phycr;
790 	int i;
791 
792 	phycr = FTMAC100_PHYCR_PHYAD(phy_id) |
793 		FTMAC100_PHYCR_REGAD(reg) |
794 		FTMAC100_PHYCR_MIIWR;
795 
796 	data = FTMAC100_PHYWDATA_MIIWDATA(data);
797 
798 	iowrite32(data, priv->base + FTMAC100_OFFSET_PHYWDATA);
799 	iowrite32(phycr, priv->base + FTMAC100_OFFSET_PHYCR);
800 
801 	for (i = 0; i < 10; i++) {
802 		phycr = ioread32(priv->base + FTMAC100_OFFSET_PHYCR);
803 
804 		if ((phycr & FTMAC100_PHYCR_MIIWR) == 0)
805 			return;
806 
807 		udelay(100);
808 	}
809 
810 	netdev_err(netdev, "mdio write timed out\n");
811 }
812 
813 /******************************************************************************
814  * struct ethtool_ops functions
815  *****************************************************************************/
816 static void ftmac100_get_drvinfo(struct net_device *netdev,
817 				 struct ethtool_drvinfo *info)
818 {
819 	strcpy(info->driver, DRV_NAME);
820 	strcpy(info->version, DRV_VERSION);
821 	strcpy(info->bus_info, dev_name(&netdev->dev));
822 }
823 
824 static int ftmac100_get_settings(struct net_device *netdev, struct ethtool_cmd *cmd)
825 {
826 	struct ftmac100 *priv = netdev_priv(netdev);
827 	return mii_ethtool_gset(&priv->mii, cmd);
828 }
829 
830 static int ftmac100_set_settings(struct net_device *netdev, struct ethtool_cmd *cmd)
831 {
832 	struct ftmac100 *priv = netdev_priv(netdev);
833 	return mii_ethtool_sset(&priv->mii, cmd);
834 }
835 
836 static int ftmac100_nway_reset(struct net_device *netdev)
837 {
838 	struct ftmac100 *priv = netdev_priv(netdev);
839 	return mii_nway_restart(&priv->mii);
840 }
841 
842 static u32 ftmac100_get_link(struct net_device *netdev)
843 {
844 	struct ftmac100 *priv = netdev_priv(netdev);
845 	return mii_link_ok(&priv->mii);
846 }
847 
848 static const struct ethtool_ops ftmac100_ethtool_ops = {
849 	.set_settings		= ftmac100_set_settings,
850 	.get_settings		= ftmac100_get_settings,
851 	.get_drvinfo		= ftmac100_get_drvinfo,
852 	.nway_reset		= ftmac100_nway_reset,
853 	.get_link		= ftmac100_get_link,
854 };
855 
856 /******************************************************************************
857  * interrupt handler
858  *****************************************************************************/
859 static irqreturn_t ftmac100_interrupt(int irq, void *dev_id)
860 {
861 	struct net_device *netdev = dev_id;
862 	struct ftmac100 *priv = netdev_priv(netdev);
863 
864 	if (likely(netif_running(netdev))) {
865 		/* Disable interrupts for polling */
866 		ftmac100_disable_all_int(priv);
867 		napi_schedule(&priv->napi);
868 	}
869 
870 	return IRQ_HANDLED;
871 }
872 
873 /******************************************************************************
874  * struct napi_struct functions
875  *****************************************************************************/
876 static int ftmac100_poll(struct napi_struct *napi, int budget)
877 {
878 	struct ftmac100 *priv = container_of(napi, struct ftmac100, napi);
879 	struct net_device *netdev = priv->netdev;
880 	unsigned int status;
881 	bool completed = true;
882 	int rx = 0;
883 
884 	status = ioread32(priv->base + FTMAC100_OFFSET_ISR);
885 
886 	if (status & (FTMAC100_INT_RPKT_FINISH | FTMAC100_INT_NORXBUF)) {
887 		/*
888 		 * FTMAC100_INT_RPKT_FINISH:
889 		 *	RX DMA has received packets into RX buffer successfully
890 		 *
891 		 * FTMAC100_INT_NORXBUF:
892 		 *	RX buffer unavailable
893 		 */
894 		bool retry;
895 
896 		do {
897 			retry = ftmac100_rx_packet(priv, &rx);
898 		} while (retry && rx < budget);
899 
900 		if (retry && rx == budget)
901 			completed = false;
902 	}
903 
904 	if (status & (FTMAC100_INT_XPKT_OK | FTMAC100_INT_XPKT_LOST)) {
905 		/*
906 		 * FTMAC100_INT_XPKT_OK:
907 		 *	packet transmitted to ethernet successfully
908 		 *
909 		 * FTMAC100_INT_XPKT_LOST:
910 		 *	packet transmitted to ethernet lost due to late
911 		 *	collision or excessive collision
912 		 */
913 		ftmac100_tx_complete(priv);
914 	}
915 
916 	if (status & (FTMAC100_INT_NORXBUF | FTMAC100_INT_RPKT_LOST |
917 		      FTMAC100_INT_AHB_ERR | FTMAC100_INT_PHYSTS_CHG)) {
918 		if (net_ratelimit())
919 			netdev_info(netdev, "[ISR] = 0x%x: %s%s%s%s\n", status,
920 				    status & FTMAC100_INT_NORXBUF ? "NORXBUF " : "",
921 				    status & FTMAC100_INT_RPKT_LOST ? "RPKT_LOST " : "",
922 				    status & FTMAC100_INT_AHB_ERR ? "AHB_ERR " : "",
923 				    status & FTMAC100_INT_PHYSTS_CHG ? "PHYSTS_CHG" : "");
924 
925 		if (status & FTMAC100_INT_NORXBUF) {
926 			/* RX buffer unavailable */
927 			netdev->stats.rx_over_errors++;
928 		}
929 
930 		if (status & FTMAC100_INT_RPKT_LOST) {
931 			/* received packet lost due to RX FIFO full */
932 			netdev->stats.rx_fifo_errors++;
933 		}
934 
935 		if (status & FTMAC100_INT_PHYSTS_CHG) {
936 			/* PHY link status change */
937 			mii_check_link(&priv->mii);
938 		}
939 	}
940 
941 	if (completed) {
942 		/* stop polling */
943 		napi_complete(napi);
944 		ftmac100_enable_all_int(priv);
945 	}
946 
947 	return rx;
948 }
949 
950 /******************************************************************************
951  * struct net_device_ops functions
952  *****************************************************************************/
953 static int ftmac100_open(struct net_device *netdev)
954 {
955 	struct ftmac100 *priv = netdev_priv(netdev);
956 	int err;
957 
958 	err = ftmac100_alloc_buffers(priv);
959 	if (err) {
960 		netdev_err(netdev, "failed to allocate buffers\n");
961 		goto err_alloc;
962 	}
963 
964 	err = request_irq(priv->irq, ftmac100_interrupt, 0, netdev->name, netdev);
965 	if (err) {
966 		netdev_err(netdev, "failed to request irq %d\n", priv->irq);
967 		goto err_irq;
968 	}
969 
970 	priv->rx_pointer = 0;
971 	priv->tx_clean_pointer = 0;
972 	priv->tx_pointer = 0;
973 	priv->tx_pending = 0;
974 
975 	err = ftmac100_start_hw(priv);
976 	if (err)
977 		goto err_hw;
978 
979 	napi_enable(&priv->napi);
980 	netif_start_queue(netdev);
981 
982 	ftmac100_enable_all_int(priv);
983 
984 	return 0;
985 
986 err_hw:
987 	free_irq(priv->irq, netdev);
988 err_irq:
989 	ftmac100_free_buffers(priv);
990 err_alloc:
991 	return err;
992 }
993 
994 static int ftmac100_stop(struct net_device *netdev)
995 {
996 	struct ftmac100 *priv = netdev_priv(netdev);
997 
998 	ftmac100_disable_all_int(priv);
999 	netif_stop_queue(netdev);
1000 	napi_disable(&priv->napi);
1001 	ftmac100_stop_hw(priv);
1002 	free_irq(priv->irq, netdev);
1003 	ftmac100_free_buffers(priv);
1004 
1005 	return 0;
1006 }
1007 
1008 static int ftmac100_hard_start_xmit(struct sk_buff *skb, struct net_device *netdev)
1009 {
1010 	struct ftmac100 *priv = netdev_priv(netdev);
1011 	dma_addr_t map;
1012 
1013 	if (unlikely(skb->len > MAX_PKT_SIZE)) {
1014 		if (net_ratelimit())
1015 			netdev_dbg(netdev, "tx packet too big\n");
1016 
1017 		netdev->stats.tx_dropped++;
1018 		dev_kfree_skb(skb);
1019 		return NETDEV_TX_OK;
1020 	}
1021 
1022 	map = dma_map_single(priv->dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);
1023 	if (unlikely(dma_mapping_error(priv->dev, map))) {
1024 		/* drop packet */
1025 		if (net_ratelimit())
1026 			netdev_err(netdev, "map socket buffer failed\n");
1027 
1028 		netdev->stats.tx_dropped++;
1029 		dev_kfree_skb(skb);
1030 		return NETDEV_TX_OK;
1031 	}
1032 
1033 	return ftmac100_xmit(priv, skb, map);
1034 }
1035 
1036 /* optional */
1037 static int ftmac100_do_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
1038 {
1039 	struct ftmac100 *priv = netdev_priv(netdev);
1040 	struct mii_ioctl_data *data = if_mii(ifr);
1041 
1042 	return generic_mii_ioctl(&priv->mii, data, cmd, NULL);
1043 }
1044 
1045 static const struct net_device_ops ftmac100_netdev_ops = {
1046 	.ndo_open		= ftmac100_open,
1047 	.ndo_stop		= ftmac100_stop,
1048 	.ndo_start_xmit		= ftmac100_hard_start_xmit,
1049 	.ndo_set_mac_address	= eth_mac_addr,
1050 	.ndo_validate_addr	= eth_validate_addr,
1051 	.ndo_do_ioctl		= ftmac100_do_ioctl,
1052 };
1053 
1054 /******************************************************************************
1055  * struct platform_driver functions
1056  *****************************************************************************/
1057 static int ftmac100_probe(struct platform_device *pdev)
1058 {
1059 	struct resource *res;
1060 	int irq;
1061 	struct net_device *netdev;
1062 	struct ftmac100 *priv;
1063 	int err;
1064 
1065 	if (!pdev)
1066 		return -ENODEV;
1067 
1068 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1069 	if (!res)
1070 		return -ENXIO;
1071 
1072 	irq = platform_get_irq(pdev, 0);
1073 	if (irq < 0)
1074 		return irq;
1075 
1076 	/* setup net_device */
1077 	netdev = alloc_etherdev(sizeof(*priv));
1078 	if (!netdev) {
1079 		err = -ENOMEM;
1080 		goto err_alloc_etherdev;
1081 	}
1082 
1083 	SET_NETDEV_DEV(netdev, &pdev->dev);
1084 	SET_ETHTOOL_OPS(netdev, &ftmac100_ethtool_ops);
1085 	netdev->netdev_ops = &ftmac100_netdev_ops;
1086 
1087 	platform_set_drvdata(pdev, netdev);
1088 
1089 	/* setup private data */
1090 	priv = netdev_priv(netdev);
1091 	priv->netdev = netdev;
1092 	priv->dev = &pdev->dev;
1093 
1094 	spin_lock_init(&priv->tx_lock);
1095 
1096 	/* initialize NAPI */
1097 	netif_napi_add(netdev, &priv->napi, ftmac100_poll, 64);
1098 
1099 	/* map io memory */
1100 	priv->res = request_mem_region(res->start, resource_size(res),
1101 				       dev_name(&pdev->dev));
1102 	if (!priv->res) {
1103 		dev_err(&pdev->dev, "Could not reserve memory region\n");
1104 		err = -ENOMEM;
1105 		goto err_req_mem;
1106 	}
1107 
1108 	priv->base = ioremap(res->start, resource_size(res));
1109 	if (!priv->base) {
1110 		dev_err(&pdev->dev, "Failed to ioremap ethernet registers\n");
1111 		err = -EIO;
1112 		goto err_ioremap;
1113 	}
1114 
1115 	priv->irq = irq;
1116 
1117 	/* initialize struct mii_if_info */
1118 	priv->mii.phy_id	= 0;
1119 	priv->mii.phy_id_mask	= 0x1f;
1120 	priv->mii.reg_num_mask	= 0x1f;
1121 	priv->mii.dev		= netdev;
1122 	priv->mii.mdio_read	= ftmac100_mdio_read;
1123 	priv->mii.mdio_write	= ftmac100_mdio_write;
1124 
1125 	/* register network device */
1126 	err = register_netdev(netdev);
1127 	if (err) {
1128 		dev_err(&pdev->dev, "Failed to register netdev\n");
1129 		goto err_register_netdev;
1130 	}
1131 
1132 	netdev_info(netdev, "irq %d, mapped at %p\n", priv->irq, priv->base);
1133 
1134 	if (!is_valid_ether_addr(netdev->dev_addr)) {
1135 		random_ether_addr(netdev->dev_addr);
1136 		netdev_info(netdev, "generated random MAC address %pM\n",
1137 			    netdev->dev_addr);
1138 	}
1139 
1140 	return 0;
1141 
1142 err_register_netdev:
1143 	iounmap(priv->base);
1144 err_ioremap:
1145 	release_resource(priv->res);
1146 err_req_mem:
1147 	netif_napi_del(&priv->napi);
1148 	platform_set_drvdata(pdev, NULL);
1149 	free_netdev(netdev);
1150 err_alloc_etherdev:
1151 	return err;
1152 }
1153 
1154 static int __exit ftmac100_remove(struct platform_device *pdev)
1155 {
1156 	struct net_device *netdev;
1157 	struct ftmac100 *priv;
1158 
1159 	netdev = platform_get_drvdata(pdev);
1160 	priv = netdev_priv(netdev);
1161 
1162 	unregister_netdev(netdev);
1163 
1164 	iounmap(priv->base);
1165 	release_resource(priv->res);
1166 
1167 	netif_napi_del(&priv->napi);
1168 	platform_set_drvdata(pdev, NULL);
1169 	free_netdev(netdev);
1170 	return 0;
1171 }
1172 
1173 static struct platform_driver ftmac100_driver = {
1174 	.probe		= ftmac100_probe,
1175 	.remove		= __exit_p(ftmac100_remove),
1176 	.driver		= {
1177 		.name	= DRV_NAME,
1178 		.owner	= THIS_MODULE,
1179 	},
1180 };
1181 
1182 /******************************************************************************
1183  * initialization / finalization
1184  *****************************************************************************/
1185 static int __init ftmac100_init(void)
1186 {
1187 	pr_info("Loading version " DRV_VERSION " ...\n");
1188 	return platform_driver_register(&ftmac100_driver);
1189 }
1190 
1191 static void __exit ftmac100_exit(void)
1192 {
1193 	platform_driver_unregister(&ftmac100_driver);
1194 }
1195 
1196 module_init(ftmac100_init);
1197 module_exit(ftmac100_exit);
1198 
1199 MODULE_AUTHOR("Po-Yu Chuang <ratbert@faraday-tech.com>");
1200 MODULE_DESCRIPTION("FTMAC100 driver");
1201 MODULE_LICENSE("GPL");
1202