xref: /linux/drivers/net/ethernet/faraday/ftmac100.c (revision 22d55f02b8922a097cd4be1e2f131dfa7ef65901)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Faraday FTMAC100 10/100 Ethernet
4  *
5  * (C) Copyright 2009-2011 Faraday Technology
6  * Po-Yu Chuang <ratbert@faraday-tech.com>
7  */
8 
9 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
10 
11 #include <linux/dma-mapping.h>
12 #include <linux/etherdevice.h>
13 #include <linux/ethtool.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/mii.h>
18 #include <linux/module.h>
19 #include <linux/mod_devicetable.h>
20 #include <linux/netdevice.h>
21 #include <linux/platform_device.h>
22 
23 #include "ftmac100.h"
24 
25 #define DRV_NAME	"ftmac100"
26 #define DRV_VERSION	"0.2"
27 
28 #define RX_QUEUE_ENTRIES	128	/* must be power of 2 */
29 #define TX_QUEUE_ENTRIES	16	/* must be power of 2 */
30 
31 #define MAX_PKT_SIZE		1518
32 #define RX_BUF_SIZE		2044	/* must be smaller than 0x7ff */
33 
34 #if MAX_PKT_SIZE > 0x7ff
35 #error invalid MAX_PKT_SIZE
36 #endif
37 
38 #if RX_BUF_SIZE > 0x7ff || RX_BUF_SIZE > PAGE_SIZE
39 #error invalid RX_BUF_SIZE
40 #endif
41 
42 /******************************************************************************
43  * private data
44  *****************************************************************************/
45 struct ftmac100_descs {
46 	struct ftmac100_rxdes rxdes[RX_QUEUE_ENTRIES];
47 	struct ftmac100_txdes txdes[TX_QUEUE_ENTRIES];
48 };
49 
50 struct ftmac100 {
51 	struct resource *res;
52 	void __iomem *base;
53 	int irq;
54 
55 	struct ftmac100_descs *descs;
56 	dma_addr_t descs_dma_addr;
57 
58 	unsigned int rx_pointer;
59 	unsigned int tx_clean_pointer;
60 	unsigned int tx_pointer;
61 	unsigned int tx_pending;
62 
63 	spinlock_t tx_lock;
64 
65 	struct net_device *netdev;
66 	struct device *dev;
67 	struct napi_struct napi;
68 
69 	struct mii_if_info mii;
70 };
71 
72 static int ftmac100_alloc_rx_page(struct ftmac100 *priv,
73 				  struct ftmac100_rxdes *rxdes, gfp_t gfp);
74 
75 /******************************************************************************
76  * internal functions (hardware register access)
77  *****************************************************************************/
78 #define INT_MASK_ALL_ENABLED	(FTMAC100_INT_RPKT_FINISH	| \
79 				 FTMAC100_INT_NORXBUF		| \
80 				 FTMAC100_INT_XPKT_OK		| \
81 				 FTMAC100_INT_XPKT_LOST		| \
82 				 FTMAC100_INT_RPKT_LOST		| \
83 				 FTMAC100_INT_AHB_ERR		| \
84 				 FTMAC100_INT_PHYSTS_CHG)
85 
86 #define INT_MASK_ALL_DISABLED	0
87 
88 static void ftmac100_enable_all_int(struct ftmac100 *priv)
89 {
90 	iowrite32(INT_MASK_ALL_ENABLED, priv->base + FTMAC100_OFFSET_IMR);
91 }
92 
93 static void ftmac100_disable_all_int(struct ftmac100 *priv)
94 {
95 	iowrite32(INT_MASK_ALL_DISABLED, priv->base + FTMAC100_OFFSET_IMR);
96 }
97 
98 static void ftmac100_set_rx_ring_base(struct ftmac100 *priv, dma_addr_t addr)
99 {
100 	iowrite32(addr, priv->base + FTMAC100_OFFSET_RXR_BADR);
101 }
102 
103 static void ftmac100_set_tx_ring_base(struct ftmac100 *priv, dma_addr_t addr)
104 {
105 	iowrite32(addr, priv->base + FTMAC100_OFFSET_TXR_BADR);
106 }
107 
108 static void ftmac100_txdma_start_polling(struct ftmac100 *priv)
109 {
110 	iowrite32(1, priv->base + FTMAC100_OFFSET_TXPD);
111 }
112 
113 static int ftmac100_reset(struct ftmac100 *priv)
114 {
115 	struct net_device *netdev = priv->netdev;
116 	int i;
117 
118 	/* NOTE: reset clears all registers */
119 	iowrite32(FTMAC100_MACCR_SW_RST, priv->base + FTMAC100_OFFSET_MACCR);
120 
121 	for (i = 0; i < 5; i++) {
122 		unsigned int maccr;
123 
124 		maccr = ioread32(priv->base + FTMAC100_OFFSET_MACCR);
125 		if (!(maccr & FTMAC100_MACCR_SW_RST)) {
126 			/*
127 			 * FTMAC100_MACCR_SW_RST cleared does not indicate
128 			 * that hardware reset completed (what the f*ck).
129 			 * We still need to wait for a while.
130 			 */
131 			udelay(500);
132 			return 0;
133 		}
134 
135 		udelay(1000);
136 	}
137 
138 	netdev_err(netdev, "software reset failed\n");
139 	return -EIO;
140 }
141 
142 static void ftmac100_set_mac(struct ftmac100 *priv, const unsigned char *mac)
143 {
144 	unsigned int maddr = mac[0] << 8 | mac[1];
145 	unsigned int laddr = mac[2] << 24 | mac[3] << 16 | mac[4] << 8 | mac[5];
146 
147 	iowrite32(maddr, priv->base + FTMAC100_OFFSET_MAC_MADR);
148 	iowrite32(laddr, priv->base + FTMAC100_OFFSET_MAC_LADR);
149 }
150 
151 #define MACCR_ENABLE_ALL	(FTMAC100_MACCR_XMT_EN	| \
152 				 FTMAC100_MACCR_RCV_EN	| \
153 				 FTMAC100_MACCR_XDMA_EN	| \
154 				 FTMAC100_MACCR_RDMA_EN	| \
155 				 FTMAC100_MACCR_CRC_APD	| \
156 				 FTMAC100_MACCR_FULLDUP	| \
157 				 FTMAC100_MACCR_RX_RUNT	| \
158 				 FTMAC100_MACCR_RX_BROADPKT)
159 
160 static int ftmac100_start_hw(struct ftmac100 *priv)
161 {
162 	struct net_device *netdev = priv->netdev;
163 
164 	if (ftmac100_reset(priv))
165 		return -EIO;
166 
167 	/* setup ring buffer base registers */
168 	ftmac100_set_rx_ring_base(priv,
169 				  priv->descs_dma_addr +
170 				  offsetof(struct ftmac100_descs, rxdes));
171 	ftmac100_set_tx_ring_base(priv,
172 				  priv->descs_dma_addr +
173 				  offsetof(struct ftmac100_descs, txdes));
174 
175 	iowrite32(FTMAC100_APTC_RXPOLL_CNT(1), priv->base + FTMAC100_OFFSET_APTC);
176 
177 	ftmac100_set_mac(priv, netdev->dev_addr);
178 
179 	iowrite32(MACCR_ENABLE_ALL, priv->base + FTMAC100_OFFSET_MACCR);
180 	return 0;
181 }
182 
183 static void ftmac100_stop_hw(struct ftmac100 *priv)
184 {
185 	iowrite32(0, priv->base + FTMAC100_OFFSET_MACCR);
186 }
187 
188 /******************************************************************************
189  * internal functions (receive descriptor)
190  *****************************************************************************/
191 static bool ftmac100_rxdes_first_segment(struct ftmac100_rxdes *rxdes)
192 {
193 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_FRS);
194 }
195 
196 static bool ftmac100_rxdes_last_segment(struct ftmac100_rxdes *rxdes)
197 {
198 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_LRS);
199 }
200 
201 static bool ftmac100_rxdes_owned_by_dma(struct ftmac100_rxdes *rxdes)
202 {
203 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_RXDMA_OWN);
204 }
205 
206 static void ftmac100_rxdes_set_dma_own(struct ftmac100_rxdes *rxdes)
207 {
208 	/* clear status bits */
209 	rxdes->rxdes0 = cpu_to_le32(FTMAC100_RXDES0_RXDMA_OWN);
210 }
211 
212 static bool ftmac100_rxdes_rx_error(struct ftmac100_rxdes *rxdes)
213 {
214 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_RX_ERR);
215 }
216 
217 static bool ftmac100_rxdes_crc_error(struct ftmac100_rxdes *rxdes)
218 {
219 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_CRC_ERR);
220 }
221 
222 static bool ftmac100_rxdes_frame_too_long(struct ftmac100_rxdes *rxdes)
223 {
224 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_FTL);
225 }
226 
227 static bool ftmac100_rxdes_runt(struct ftmac100_rxdes *rxdes)
228 {
229 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_RUNT);
230 }
231 
232 static bool ftmac100_rxdes_odd_nibble(struct ftmac100_rxdes *rxdes)
233 {
234 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_RX_ODD_NB);
235 }
236 
237 static unsigned int ftmac100_rxdes_frame_length(struct ftmac100_rxdes *rxdes)
238 {
239 	return le32_to_cpu(rxdes->rxdes0) & FTMAC100_RXDES0_RFL;
240 }
241 
242 static bool ftmac100_rxdes_multicast(struct ftmac100_rxdes *rxdes)
243 {
244 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_MULTICAST);
245 }
246 
247 static void ftmac100_rxdes_set_buffer_size(struct ftmac100_rxdes *rxdes,
248 					   unsigned int size)
249 {
250 	rxdes->rxdes1 &= cpu_to_le32(FTMAC100_RXDES1_EDORR);
251 	rxdes->rxdes1 |= cpu_to_le32(FTMAC100_RXDES1_RXBUF_SIZE(size));
252 }
253 
254 static void ftmac100_rxdes_set_end_of_ring(struct ftmac100_rxdes *rxdes)
255 {
256 	rxdes->rxdes1 |= cpu_to_le32(FTMAC100_RXDES1_EDORR);
257 }
258 
259 static void ftmac100_rxdes_set_dma_addr(struct ftmac100_rxdes *rxdes,
260 					dma_addr_t addr)
261 {
262 	rxdes->rxdes2 = cpu_to_le32(addr);
263 }
264 
265 static dma_addr_t ftmac100_rxdes_get_dma_addr(struct ftmac100_rxdes *rxdes)
266 {
267 	return le32_to_cpu(rxdes->rxdes2);
268 }
269 
270 /*
271  * rxdes3 is not used by hardware. We use it to keep track of page.
272  * Since hardware does not touch it, we can skip cpu_to_le32()/le32_to_cpu().
273  */
274 static void ftmac100_rxdes_set_page(struct ftmac100_rxdes *rxdes, struct page *page)
275 {
276 	rxdes->rxdes3 = (unsigned int)page;
277 }
278 
279 static struct page *ftmac100_rxdes_get_page(struct ftmac100_rxdes *rxdes)
280 {
281 	return (struct page *)rxdes->rxdes3;
282 }
283 
284 /******************************************************************************
285  * internal functions (receive)
286  *****************************************************************************/
287 static int ftmac100_next_rx_pointer(int pointer)
288 {
289 	return (pointer + 1) & (RX_QUEUE_ENTRIES - 1);
290 }
291 
292 static void ftmac100_rx_pointer_advance(struct ftmac100 *priv)
293 {
294 	priv->rx_pointer = ftmac100_next_rx_pointer(priv->rx_pointer);
295 }
296 
297 static struct ftmac100_rxdes *ftmac100_current_rxdes(struct ftmac100 *priv)
298 {
299 	return &priv->descs->rxdes[priv->rx_pointer];
300 }
301 
302 static struct ftmac100_rxdes *
303 ftmac100_rx_locate_first_segment(struct ftmac100 *priv)
304 {
305 	struct ftmac100_rxdes *rxdes = ftmac100_current_rxdes(priv);
306 
307 	while (!ftmac100_rxdes_owned_by_dma(rxdes)) {
308 		if (ftmac100_rxdes_first_segment(rxdes))
309 			return rxdes;
310 
311 		ftmac100_rxdes_set_dma_own(rxdes);
312 		ftmac100_rx_pointer_advance(priv);
313 		rxdes = ftmac100_current_rxdes(priv);
314 	}
315 
316 	return NULL;
317 }
318 
319 static bool ftmac100_rx_packet_error(struct ftmac100 *priv,
320 				     struct ftmac100_rxdes *rxdes)
321 {
322 	struct net_device *netdev = priv->netdev;
323 	bool error = false;
324 
325 	if (unlikely(ftmac100_rxdes_rx_error(rxdes))) {
326 		if (net_ratelimit())
327 			netdev_info(netdev, "rx err\n");
328 
329 		netdev->stats.rx_errors++;
330 		error = true;
331 	}
332 
333 	if (unlikely(ftmac100_rxdes_crc_error(rxdes))) {
334 		if (net_ratelimit())
335 			netdev_info(netdev, "rx crc err\n");
336 
337 		netdev->stats.rx_crc_errors++;
338 		error = true;
339 	}
340 
341 	if (unlikely(ftmac100_rxdes_frame_too_long(rxdes))) {
342 		if (net_ratelimit())
343 			netdev_info(netdev, "rx frame too long\n");
344 
345 		netdev->stats.rx_length_errors++;
346 		error = true;
347 	} else if (unlikely(ftmac100_rxdes_runt(rxdes))) {
348 		if (net_ratelimit())
349 			netdev_info(netdev, "rx runt\n");
350 
351 		netdev->stats.rx_length_errors++;
352 		error = true;
353 	} else if (unlikely(ftmac100_rxdes_odd_nibble(rxdes))) {
354 		if (net_ratelimit())
355 			netdev_info(netdev, "rx odd nibble\n");
356 
357 		netdev->stats.rx_length_errors++;
358 		error = true;
359 	}
360 
361 	return error;
362 }
363 
364 static void ftmac100_rx_drop_packet(struct ftmac100 *priv)
365 {
366 	struct net_device *netdev = priv->netdev;
367 	struct ftmac100_rxdes *rxdes = ftmac100_current_rxdes(priv);
368 	bool done = false;
369 
370 	if (net_ratelimit())
371 		netdev_dbg(netdev, "drop packet %p\n", rxdes);
372 
373 	do {
374 		if (ftmac100_rxdes_last_segment(rxdes))
375 			done = true;
376 
377 		ftmac100_rxdes_set_dma_own(rxdes);
378 		ftmac100_rx_pointer_advance(priv);
379 		rxdes = ftmac100_current_rxdes(priv);
380 	} while (!done && !ftmac100_rxdes_owned_by_dma(rxdes));
381 
382 	netdev->stats.rx_dropped++;
383 }
384 
385 static bool ftmac100_rx_packet(struct ftmac100 *priv, int *processed)
386 {
387 	struct net_device *netdev = priv->netdev;
388 	struct ftmac100_rxdes *rxdes;
389 	struct sk_buff *skb;
390 	struct page *page;
391 	dma_addr_t map;
392 	int length;
393 	bool ret;
394 
395 	rxdes = ftmac100_rx_locate_first_segment(priv);
396 	if (!rxdes)
397 		return false;
398 
399 	if (unlikely(ftmac100_rx_packet_error(priv, rxdes))) {
400 		ftmac100_rx_drop_packet(priv);
401 		return true;
402 	}
403 
404 	/*
405 	 * It is impossible to get multi-segment packets
406 	 * because we always provide big enough receive buffers.
407 	 */
408 	ret = ftmac100_rxdes_last_segment(rxdes);
409 	BUG_ON(!ret);
410 
411 	/* start processing */
412 	skb = netdev_alloc_skb_ip_align(netdev, 128);
413 	if (unlikely(!skb)) {
414 		if (net_ratelimit())
415 			netdev_err(netdev, "rx skb alloc failed\n");
416 
417 		ftmac100_rx_drop_packet(priv);
418 		return true;
419 	}
420 
421 	if (unlikely(ftmac100_rxdes_multicast(rxdes)))
422 		netdev->stats.multicast++;
423 
424 	map = ftmac100_rxdes_get_dma_addr(rxdes);
425 	dma_unmap_page(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
426 
427 	length = ftmac100_rxdes_frame_length(rxdes);
428 	page = ftmac100_rxdes_get_page(rxdes);
429 	skb_fill_page_desc(skb, 0, page, 0, length);
430 	skb->len += length;
431 	skb->data_len += length;
432 
433 	if (length > 128) {
434 		skb->truesize += PAGE_SIZE;
435 		/* We pull the minimum amount into linear part */
436 		__pskb_pull_tail(skb, ETH_HLEN);
437 	} else {
438 		/* Small frames are copied into linear part to free one page */
439 		__pskb_pull_tail(skb, length);
440 	}
441 	ftmac100_alloc_rx_page(priv, rxdes, GFP_ATOMIC);
442 
443 	ftmac100_rx_pointer_advance(priv);
444 
445 	skb->protocol = eth_type_trans(skb, netdev);
446 
447 	netdev->stats.rx_packets++;
448 	netdev->stats.rx_bytes += skb->len;
449 
450 	/* push packet to protocol stack */
451 	netif_receive_skb(skb);
452 
453 	(*processed)++;
454 	return true;
455 }
456 
457 /******************************************************************************
458  * internal functions (transmit descriptor)
459  *****************************************************************************/
460 static void ftmac100_txdes_reset(struct ftmac100_txdes *txdes)
461 {
462 	/* clear all except end of ring bit */
463 	txdes->txdes0 = 0;
464 	txdes->txdes1 &= cpu_to_le32(FTMAC100_TXDES1_EDOTR);
465 	txdes->txdes2 = 0;
466 	txdes->txdes3 = 0;
467 }
468 
469 static bool ftmac100_txdes_owned_by_dma(struct ftmac100_txdes *txdes)
470 {
471 	return txdes->txdes0 & cpu_to_le32(FTMAC100_TXDES0_TXDMA_OWN);
472 }
473 
474 static void ftmac100_txdes_set_dma_own(struct ftmac100_txdes *txdes)
475 {
476 	/*
477 	 * Make sure dma own bit will not be set before any other
478 	 * descriptor fields.
479 	 */
480 	wmb();
481 	txdes->txdes0 |= cpu_to_le32(FTMAC100_TXDES0_TXDMA_OWN);
482 }
483 
484 static bool ftmac100_txdes_excessive_collision(struct ftmac100_txdes *txdes)
485 {
486 	return txdes->txdes0 & cpu_to_le32(FTMAC100_TXDES0_TXPKT_EXSCOL);
487 }
488 
489 static bool ftmac100_txdes_late_collision(struct ftmac100_txdes *txdes)
490 {
491 	return txdes->txdes0 & cpu_to_le32(FTMAC100_TXDES0_TXPKT_LATECOL);
492 }
493 
494 static void ftmac100_txdes_set_end_of_ring(struct ftmac100_txdes *txdes)
495 {
496 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_EDOTR);
497 }
498 
499 static void ftmac100_txdes_set_first_segment(struct ftmac100_txdes *txdes)
500 {
501 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_FTS);
502 }
503 
504 static void ftmac100_txdes_set_last_segment(struct ftmac100_txdes *txdes)
505 {
506 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_LTS);
507 }
508 
509 static void ftmac100_txdes_set_txint(struct ftmac100_txdes *txdes)
510 {
511 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_TXIC);
512 }
513 
514 static void ftmac100_txdes_set_buffer_size(struct ftmac100_txdes *txdes,
515 					   unsigned int len)
516 {
517 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_TXBUF_SIZE(len));
518 }
519 
520 static void ftmac100_txdes_set_dma_addr(struct ftmac100_txdes *txdes,
521 					dma_addr_t addr)
522 {
523 	txdes->txdes2 = cpu_to_le32(addr);
524 }
525 
526 static dma_addr_t ftmac100_txdes_get_dma_addr(struct ftmac100_txdes *txdes)
527 {
528 	return le32_to_cpu(txdes->txdes2);
529 }
530 
531 /*
532  * txdes3 is not used by hardware. We use it to keep track of socket buffer.
533  * Since hardware does not touch it, we can skip cpu_to_le32()/le32_to_cpu().
534  */
535 static void ftmac100_txdes_set_skb(struct ftmac100_txdes *txdes, struct sk_buff *skb)
536 {
537 	txdes->txdes3 = (unsigned int)skb;
538 }
539 
540 static struct sk_buff *ftmac100_txdes_get_skb(struct ftmac100_txdes *txdes)
541 {
542 	return (struct sk_buff *)txdes->txdes3;
543 }
544 
545 /******************************************************************************
546  * internal functions (transmit)
547  *****************************************************************************/
548 static int ftmac100_next_tx_pointer(int pointer)
549 {
550 	return (pointer + 1) & (TX_QUEUE_ENTRIES - 1);
551 }
552 
553 static void ftmac100_tx_pointer_advance(struct ftmac100 *priv)
554 {
555 	priv->tx_pointer = ftmac100_next_tx_pointer(priv->tx_pointer);
556 }
557 
558 static void ftmac100_tx_clean_pointer_advance(struct ftmac100 *priv)
559 {
560 	priv->tx_clean_pointer = ftmac100_next_tx_pointer(priv->tx_clean_pointer);
561 }
562 
563 static struct ftmac100_txdes *ftmac100_current_txdes(struct ftmac100 *priv)
564 {
565 	return &priv->descs->txdes[priv->tx_pointer];
566 }
567 
568 static struct ftmac100_txdes *ftmac100_current_clean_txdes(struct ftmac100 *priv)
569 {
570 	return &priv->descs->txdes[priv->tx_clean_pointer];
571 }
572 
573 static bool ftmac100_tx_complete_packet(struct ftmac100 *priv)
574 {
575 	struct net_device *netdev = priv->netdev;
576 	struct ftmac100_txdes *txdes;
577 	struct sk_buff *skb;
578 	dma_addr_t map;
579 
580 	if (priv->tx_pending == 0)
581 		return false;
582 
583 	txdes = ftmac100_current_clean_txdes(priv);
584 
585 	if (ftmac100_txdes_owned_by_dma(txdes))
586 		return false;
587 
588 	skb = ftmac100_txdes_get_skb(txdes);
589 	map = ftmac100_txdes_get_dma_addr(txdes);
590 
591 	if (unlikely(ftmac100_txdes_excessive_collision(txdes) ||
592 		     ftmac100_txdes_late_collision(txdes))) {
593 		/*
594 		 * packet transmitted to ethernet lost due to late collision
595 		 * or excessive collision
596 		 */
597 		netdev->stats.tx_aborted_errors++;
598 	} else {
599 		netdev->stats.tx_packets++;
600 		netdev->stats.tx_bytes += skb->len;
601 	}
602 
603 	dma_unmap_single(priv->dev, map, skb_headlen(skb), DMA_TO_DEVICE);
604 	dev_kfree_skb(skb);
605 
606 	ftmac100_txdes_reset(txdes);
607 
608 	ftmac100_tx_clean_pointer_advance(priv);
609 
610 	spin_lock(&priv->tx_lock);
611 	priv->tx_pending--;
612 	spin_unlock(&priv->tx_lock);
613 	netif_wake_queue(netdev);
614 
615 	return true;
616 }
617 
618 static void ftmac100_tx_complete(struct ftmac100 *priv)
619 {
620 	while (ftmac100_tx_complete_packet(priv))
621 		;
622 }
623 
624 static netdev_tx_t ftmac100_xmit(struct ftmac100 *priv, struct sk_buff *skb,
625 				 dma_addr_t map)
626 {
627 	struct net_device *netdev = priv->netdev;
628 	struct ftmac100_txdes *txdes;
629 	unsigned int len = (skb->len < ETH_ZLEN) ? ETH_ZLEN : skb->len;
630 
631 	txdes = ftmac100_current_txdes(priv);
632 	ftmac100_tx_pointer_advance(priv);
633 
634 	/* setup TX descriptor */
635 	ftmac100_txdes_set_skb(txdes, skb);
636 	ftmac100_txdes_set_dma_addr(txdes, map);
637 
638 	ftmac100_txdes_set_first_segment(txdes);
639 	ftmac100_txdes_set_last_segment(txdes);
640 	ftmac100_txdes_set_txint(txdes);
641 	ftmac100_txdes_set_buffer_size(txdes, len);
642 
643 	spin_lock(&priv->tx_lock);
644 	priv->tx_pending++;
645 	if (priv->tx_pending == TX_QUEUE_ENTRIES)
646 		netif_stop_queue(netdev);
647 
648 	/* start transmit */
649 	ftmac100_txdes_set_dma_own(txdes);
650 	spin_unlock(&priv->tx_lock);
651 
652 	ftmac100_txdma_start_polling(priv);
653 	return NETDEV_TX_OK;
654 }
655 
656 /******************************************************************************
657  * internal functions (buffer)
658  *****************************************************************************/
659 static int ftmac100_alloc_rx_page(struct ftmac100 *priv,
660 				  struct ftmac100_rxdes *rxdes, gfp_t gfp)
661 {
662 	struct net_device *netdev = priv->netdev;
663 	struct page *page;
664 	dma_addr_t map;
665 
666 	page = alloc_page(gfp);
667 	if (!page) {
668 		if (net_ratelimit())
669 			netdev_err(netdev, "failed to allocate rx page\n");
670 		return -ENOMEM;
671 	}
672 
673 	map = dma_map_page(priv->dev, page, 0, RX_BUF_SIZE, DMA_FROM_DEVICE);
674 	if (unlikely(dma_mapping_error(priv->dev, map))) {
675 		if (net_ratelimit())
676 			netdev_err(netdev, "failed to map rx page\n");
677 		__free_page(page);
678 		return -ENOMEM;
679 	}
680 
681 	ftmac100_rxdes_set_page(rxdes, page);
682 	ftmac100_rxdes_set_dma_addr(rxdes, map);
683 	ftmac100_rxdes_set_buffer_size(rxdes, RX_BUF_SIZE);
684 	ftmac100_rxdes_set_dma_own(rxdes);
685 	return 0;
686 }
687 
688 static void ftmac100_free_buffers(struct ftmac100 *priv)
689 {
690 	int i;
691 
692 	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
693 		struct ftmac100_rxdes *rxdes = &priv->descs->rxdes[i];
694 		struct page *page = ftmac100_rxdes_get_page(rxdes);
695 		dma_addr_t map = ftmac100_rxdes_get_dma_addr(rxdes);
696 
697 		if (!page)
698 			continue;
699 
700 		dma_unmap_page(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
701 		__free_page(page);
702 	}
703 
704 	for (i = 0; i < TX_QUEUE_ENTRIES; i++) {
705 		struct ftmac100_txdes *txdes = &priv->descs->txdes[i];
706 		struct sk_buff *skb = ftmac100_txdes_get_skb(txdes);
707 		dma_addr_t map = ftmac100_txdes_get_dma_addr(txdes);
708 
709 		if (!skb)
710 			continue;
711 
712 		dma_unmap_single(priv->dev, map, skb_headlen(skb), DMA_TO_DEVICE);
713 		dev_kfree_skb(skb);
714 	}
715 
716 	dma_free_coherent(priv->dev, sizeof(struct ftmac100_descs),
717 			  priv->descs, priv->descs_dma_addr);
718 }
719 
720 static int ftmac100_alloc_buffers(struct ftmac100 *priv)
721 {
722 	int i;
723 
724 	priv->descs = dma_alloc_coherent(priv->dev,
725 					 sizeof(struct ftmac100_descs),
726 					 &priv->descs_dma_addr, GFP_KERNEL);
727 	if (!priv->descs)
728 		return -ENOMEM;
729 
730 	/* initialize RX ring */
731 	ftmac100_rxdes_set_end_of_ring(&priv->descs->rxdes[RX_QUEUE_ENTRIES - 1]);
732 
733 	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
734 		struct ftmac100_rxdes *rxdes = &priv->descs->rxdes[i];
735 
736 		if (ftmac100_alloc_rx_page(priv, rxdes, GFP_KERNEL))
737 			goto err;
738 	}
739 
740 	/* initialize TX ring */
741 	ftmac100_txdes_set_end_of_ring(&priv->descs->txdes[TX_QUEUE_ENTRIES - 1]);
742 	return 0;
743 
744 err:
745 	ftmac100_free_buffers(priv);
746 	return -ENOMEM;
747 }
748 
749 /******************************************************************************
750  * struct mii_if_info functions
751  *****************************************************************************/
752 static int ftmac100_mdio_read(struct net_device *netdev, int phy_id, int reg)
753 {
754 	struct ftmac100 *priv = netdev_priv(netdev);
755 	unsigned int phycr;
756 	int i;
757 
758 	phycr = FTMAC100_PHYCR_PHYAD(phy_id) |
759 		FTMAC100_PHYCR_REGAD(reg) |
760 		FTMAC100_PHYCR_MIIRD;
761 
762 	iowrite32(phycr, priv->base + FTMAC100_OFFSET_PHYCR);
763 
764 	for (i = 0; i < 10; i++) {
765 		phycr = ioread32(priv->base + FTMAC100_OFFSET_PHYCR);
766 
767 		if ((phycr & FTMAC100_PHYCR_MIIRD) == 0)
768 			return phycr & FTMAC100_PHYCR_MIIRDATA;
769 
770 		udelay(100);
771 	}
772 
773 	netdev_err(netdev, "mdio read timed out\n");
774 	return 0;
775 }
776 
777 static void ftmac100_mdio_write(struct net_device *netdev, int phy_id, int reg,
778 				int data)
779 {
780 	struct ftmac100 *priv = netdev_priv(netdev);
781 	unsigned int phycr;
782 	int i;
783 
784 	phycr = FTMAC100_PHYCR_PHYAD(phy_id) |
785 		FTMAC100_PHYCR_REGAD(reg) |
786 		FTMAC100_PHYCR_MIIWR;
787 
788 	data = FTMAC100_PHYWDATA_MIIWDATA(data);
789 
790 	iowrite32(data, priv->base + FTMAC100_OFFSET_PHYWDATA);
791 	iowrite32(phycr, priv->base + FTMAC100_OFFSET_PHYCR);
792 
793 	for (i = 0; i < 10; i++) {
794 		phycr = ioread32(priv->base + FTMAC100_OFFSET_PHYCR);
795 
796 		if ((phycr & FTMAC100_PHYCR_MIIWR) == 0)
797 			return;
798 
799 		udelay(100);
800 	}
801 
802 	netdev_err(netdev, "mdio write timed out\n");
803 }
804 
805 /******************************************************************************
806  * struct ethtool_ops functions
807  *****************************************************************************/
808 static void ftmac100_get_drvinfo(struct net_device *netdev,
809 				 struct ethtool_drvinfo *info)
810 {
811 	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
812 	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
813 	strlcpy(info->bus_info, dev_name(&netdev->dev), sizeof(info->bus_info));
814 }
815 
816 static int ftmac100_get_link_ksettings(struct net_device *netdev,
817 				       struct ethtool_link_ksettings *cmd)
818 {
819 	struct ftmac100 *priv = netdev_priv(netdev);
820 
821 	mii_ethtool_get_link_ksettings(&priv->mii, cmd);
822 
823 	return 0;
824 }
825 
826 static int ftmac100_set_link_ksettings(struct net_device *netdev,
827 				       const struct ethtool_link_ksettings *cmd)
828 {
829 	struct ftmac100 *priv = netdev_priv(netdev);
830 	return mii_ethtool_set_link_ksettings(&priv->mii, cmd);
831 }
832 
833 static int ftmac100_nway_reset(struct net_device *netdev)
834 {
835 	struct ftmac100 *priv = netdev_priv(netdev);
836 	return mii_nway_restart(&priv->mii);
837 }
838 
839 static u32 ftmac100_get_link(struct net_device *netdev)
840 {
841 	struct ftmac100 *priv = netdev_priv(netdev);
842 	return mii_link_ok(&priv->mii);
843 }
844 
845 static const struct ethtool_ops ftmac100_ethtool_ops = {
846 	.get_drvinfo		= ftmac100_get_drvinfo,
847 	.nway_reset		= ftmac100_nway_reset,
848 	.get_link		= ftmac100_get_link,
849 	.get_link_ksettings	= ftmac100_get_link_ksettings,
850 	.set_link_ksettings	= ftmac100_set_link_ksettings,
851 };
852 
853 /******************************************************************************
854  * interrupt handler
855  *****************************************************************************/
856 static irqreturn_t ftmac100_interrupt(int irq, void *dev_id)
857 {
858 	struct net_device *netdev = dev_id;
859 	struct ftmac100 *priv = netdev_priv(netdev);
860 
861 	/* Disable interrupts for polling */
862 	ftmac100_disable_all_int(priv);
863 	if (likely(netif_running(netdev)))
864 		napi_schedule(&priv->napi);
865 
866 	return IRQ_HANDLED;
867 }
868 
869 /******************************************************************************
870  * struct napi_struct functions
871  *****************************************************************************/
872 static int ftmac100_poll(struct napi_struct *napi, int budget)
873 {
874 	struct ftmac100 *priv = container_of(napi, struct ftmac100, napi);
875 	struct net_device *netdev = priv->netdev;
876 	unsigned int status;
877 	bool completed = true;
878 	int rx = 0;
879 
880 	status = ioread32(priv->base + FTMAC100_OFFSET_ISR);
881 
882 	if (status & (FTMAC100_INT_RPKT_FINISH | FTMAC100_INT_NORXBUF)) {
883 		/*
884 		 * FTMAC100_INT_RPKT_FINISH:
885 		 *	RX DMA has received packets into RX buffer successfully
886 		 *
887 		 * FTMAC100_INT_NORXBUF:
888 		 *	RX buffer unavailable
889 		 */
890 		bool retry;
891 
892 		do {
893 			retry = ftmac100_rx_packet(priv, &rx);
894 		} while (retry && rx < budget);
895 
896 		if (retry && rx == budget)
897 			completed = false;
898 	}
899 
900 	if (status & (FTMAC100_INT_XPKT_OK | FTMAC100_INT_XPKT_LOST)) {
901 		/*
902 		 * FTMAC100_INT_XPKT_OK:
903 		 *	packet transmitted to ethernet successfully
904 		 *
905 		 * FTMAC100_INT_XPKT_LOST:
906 		 *	packet transmitted to ethernet lost due to late
907 		 *	collision or excessive collision
908 		 */
909 		ftmac100_tx_complete(priv);
910 	}
911 
912 	if (status & (FTMAC100_INT_NORXBUF | FTMAC100_INT_RPKT_LOST |
913 		      FTMAC100_INT_AHB_ERR | FTMAC100_INT_PHYSTS_CHG)) {
914 		if (net_ratelimit())
915 			netdev_info(netdev, "[ISR] = 0x%x: %s%s%s%s\n", status,
916 				    status & FTMAC100_INT_NORXBUF ? "NORXBUF " : "",
917 				    status & FTMAC100_INT_RPKT_LOST ? "RPKT_LOST " : "",
918 				    status & FTMAC100_INT_AHB_ERR ? "AHB_ERR " : "",
919 				    status & FTMAC100_INT_PHYSTS_CHG ? "PHYSTS_CHG" : "");
920 
921 		if (status & FTMAC100_INT_NORXBUF) {
922 			/* RX buffer unavailable */
923 			netdev->stats.rx_over_errors++;
924 		}
925 
926 		if (status & FTMAC100_INT_RPKT_LOST) {
927 			/* received packet lost due to RX FIFO full */
928 			netdev->stats.rx_fifo_errors++;
929 		}
930 
931 		if (status & FTMAC100_INT_PHYSTS_CHG) {
932 			/* PHY link status change */
933 			mii_check_link(&priv->mii);
934 		}
935 	}
936 
937 	if (completed) {
938 		/* stop polling */
939 		napi_complete(napi);
940 		ftmac100_enable_all_int(priv);
941 	}
942 
943 	return rx;
944 }
945 
946 /******************************************************************************
947  * struct net_device_ops functions
948  *****************************************************************************/
949 static int ftmac100_open(struct net_device *netdev)
950 {
951 	struct ftmac100 *priv = netdev_priv(netdev);
952 	int err;
953 
954 	err = ftmac100_alloc_buffers(priv);
955 	if (err) {
956 		netdev_err(netdev, "failed to allocate buffers\n");
957 		goto err_alloc;
958 	}
959 
960 	err = request_irq(priv->irq, ftmac100_interrupt, 0, netdev->name, netdev);
961 	if (err) {
962 		netdev_err(netdev, "failed to request irq %d\n", priv->irq);
963 		goto err_irq;
964 	}
965 
966 	priv->rx_pointer = 0;
967 	priv->tx_clean_pointer = 0;
968 	priv->tx_pointer = 0;
969 	priv->tx_pending = 0;
970 
971 	err = ftmac100_start_hw(priv);
972 	if (err)
973 		goto err_hw;
974 
975 	napi_enable(&priv->napi);
976 	netif_start_queue(netdev);
977 
978 	ftmac100_enable_all_int(priv);
979 
980 	return 0;
981 
982 err_hw:
983 	free_irq(priv->irq, netdev);
984 err_irq:
985 	ftmac100_free_buffers(priv);
986 err_alloc:
987 	return err;
988 }
989 
990 static int ftmac100_stop(struct net_device *netdev)
991 {
992 	struct ftmac100 *priv = netdev_priv(netdev);
993 
994 	ftmac100_disable_all_int(priv);
995 	netif_stop_queue(netdev);
996 	napi_disable(&priv->napi);
997 	ftmac100_stop_hw(priv);
998 	free_irq(priv->irq, netdev);
999 	ftmac100_free_buffers(priv);
1000 
1001 	return 0;
1002 }
1003 
1004 static netdev_tx_t
1005 ftmac100_hard_start_xmit(struct sk_buff *skb, struct net_device *netdev)
1006 {
1007 	struct ftmac100 *priv = netdev_priv(netdev);
1008 	dma_addr_t map;
1009 
1010 	if (unlikely(skb->len > MAX_PKT_SIZE)) {
1011 		if (net_ratelimit())
1012 			netdev_dbg(netdev, "tx packet too big\n");
1013 
1014 		netdev->stats.tx_dropped++;
1015 		dev_kfree_skb(skb);
1016 		return NETDEV_TX_OK;
1017 	}
1018 
1019 	map = dma_map_single(priv->dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);
1020 	if (unlikely(dma_mapping_error(priv->dev, map))) {
1021 		/* drop packet */
1022 		if (net_ratelimit())
1023 			netdev_err(netdev, "map socket buffer failed\n");
1024 
1025 		netdev->stats.tx_dropped++;
1026 		dev_kfree_skb(skb);
1027 		return NETDEV_TX_OK;
1028 	}
1029 
1030 	return ftmac100_xmit(priv, skb, map);
1031 }
1032 
1033 /* optional */
1034 static int ftmac100_do_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
1035 {
1036 	struct ftmac100 *priv = netdev_priv(netdev);
1037 	struct mii_ioctl_data *data = if_mii(ifr);
1038 
1039 	return generic_mii_ioctl(&priv->mii, data, cmd, NULL);
1040 }
1041 
1042 static const struct net_device_ops ftmac100_netdev_ops = {
1043 	.ndo_open		= ftmac100_open,
1044 	.ndo_stop		= ftmac100_stop,
1045 	.ndo_start_xmit		= ftmac100_hard_start_xmit,
1046 	.ndo_set_mac_address	= eth_mac_addr,
1047 	.ndo_validate_addr	= eth_validate_addr,
1048 	.ndo_do_ioctl		= ftmac100_do_ioctl,
1049 };
1050 
1051 /******************************************************************************
1052  * struct platform_driver functions
1053  *****************************************************************************/
1054 static int ftmac100_probe(struct platform_device *pdev)
1055 {
1056 	struct resource *res;
1057 	int irq;
1058 	struct net_device *netdev;
1059 	struct ftmac100 *priv;
1060 	int err;
1061 
1062 	if (!pdev)
1063 		return -ENODEV;
1064 
1065 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1066 	if (!res)
1067 		return -ENXIO;
1068 
1069 	irq = platform_get_irq(pdev, 0);
1070 	if (irq < 0)
1071 		return irq;
1072 
1073 	/* setup net_device */
1074 	netdev = alloc_etherdev(sizeof(*priv));
1075 	if (!netdev) {
1076 		err = -ENOMEM;
1077 		goto err_alloc_etherdev;
1078 	}
1079 
1080 	SET_NETDEV_DEV(netdev, &pdev->dev);
1081 	netdev->ethtool_ops = &ftmac100_ethtool_ops;
1082 	netdev->netdev_ops = &ftmac100_netdev_ops;
1083 
1084 	platform_set_drvdata(pdev, netdev);
1085 
1086 	/* setup private data */
1087 	priv = netdev_priv(netdev);
1088 	priv->netdev = netdev;
1089 	priv->dev = &pdev->dev;
1090 
1091 	spin_lock_init(&priv->tx_lock);
1092 
1093 	/* initialize NAPI */
1094 	netif_napi_add(netdev, &priv->napi, ftmac100_poll, 64);
1095 
1096 	/* map io memory */
1097 	priv->res = request_mem_region(res->start, resource_size(res),
1098 				       dev_name(&pdev->dev));
1099 	if (!priv->res) {
1100 		dev_err(&pdev->dev, "Could not reserve memory region\n");
1101 		err = -ENOMEM;
1102 		goto err_req_mem;
1103 	}
1104 
1105 	priv->base = ioremap(res->start, resource_size(res));
1106 	if (!priv->base) {
1107 		dev_err(&pdev->dev, "Failed to ioremap ethernet registers\n");
1108 		err = -EIO;
1109 		goto err_ioremap;
1110 	}
1111 
1112 	priv->irq = irq;
1113 
1114 	/* initialize struct mii_if_info */
1115 	priv->mii.phy_id	= 0;
1116 	priv->mii.phy_id_mask	= 0x1f;
1117 	priv->mii.reg_num_mask	= 0x1f;
1118 	priv->mii.dev		= netdev;
1119 	priv->mii.mdio_read	= ftmac100_mdio_read;
1120 	priv->mii.mdio_write	= ftmac100_mdio_write;
1121 
1122 	/* register network device */
1123 	err = register_netdev(netdev);
1124 	if (err) {
1125 		dev_err(&pdev->dev, "Failed to register netdev\n");
1126 		goto err_register_netdev;
1127 	}
1128 
1129 	netdev_info(netdev, "irq %d, mapped at %p\n", priv->irq, priv->base);
1130 
1131 	if (!is_valid_ether_addr(netdev->dev_addr)) {
1132 		eth_hw_addr_random(netdev);
1133 		netdev_info(netdev, "generated random MAC address %pM\n",
1134 			    netdev->dev_addr);
1135 	}
1136 
1137 	return 0;
1138 
1139 err_register_netdev:
1140 	iounmap(priv->base);
1141 err_ioremap:
1142 	release_resource(priv->res);
1143 err_req_mem:
1144 	netif_napi_del(&priv->napi);
1145 	free_netdev(netdev);
1146 err_alloc_etherdev:
1147 	return err;
1148 }
1149 
1150 static int ftmac100_remove(struct platform_device *pdev)
1151 {
1152 	struct net_device *netdev;
1153 	struct ftmac100 *priv;
1154 
1155 	netdev = platform_get_drvdata(pdev);
1156 	priv = netdev_priv(netdev);
1157 
1158 	unregister_netdev(netdev);
1159 
1160 	iounmap(priv->base);
1161 	release_resource(priv->res);
1162 
1163 	netif_napi_del(&priv->napi);
1164 	free_netdev(netdev);
1165 	return 0;
1166 }
1167 
1168 static const struct of_device_id ftmac100_of_ids[] = {
1169 	{ .compatible = "andestech,atmac100" },
1170 	{ }
1171 };
1172 
1173 static struct platform_driver ftmac100_driver = {
1174 	.probe		= ftmac100_probe,
1175 	.remove		= ftmac100_remove,
1176 	.driver		= {
1177 		.name	= DRV_NAME,
1178 		.of_match_table = ftmac100_of_ids
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 MODULE_DEVICE_TABLE(of, ftmac100_of_ids);
1203