xref: /linux/drivers/net/ethernet/faraday/ftmac100.c (revision 1a931707ad4a46e79d4ecfee56d8f6e8cc8d4f28)
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/if_ether.h>
15 #include <linux/if_vlan.h>
16 #include <linux/init.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/mii.h>
20 #include <linux/module.h>
21 #include <linux/mod_devicetable.h>
22 #include <linux/netdevice.h>
23 #include <linux/platform_device.h>
24 
25 #include "ftmac100.h"
26 
27 #define DRV_NAME	"ftmac100"
28 
29 #define RX_QUEUE_ENTRIES	128	/* must be power of 2 */
30 #define TX_QUEUE_ENTRIES	16	/* must be power of 2 */
31 
32 #define RX_BUF_SIZE		2044	/* must be smaller than 0x7ff */
33 #define MAX_PKT_SIZE		RX_BUF_SIZE /* multi-segment not supported */
34 
35 #if MAX_PKT_SIZE > 0x7ff
36 #error invalid MAX_PKT_SIZE
37 #endif
38 
39 #if RX_BUF_SIZE > 0x7ff || RX_BUF_SIZE > PAGE_SIZE
40 #error invalid RX_BUF_SIZE
41 #endif
42 
43 /******************************************************************************
44  * private data
45  *****************************************************************************/
46 struct ftmac100_descs {
47 	struct ftmac100_rxdes rxdes[RX_QUEUE_ENTRIES];
48 	struct ftmac100_txdes txdes[TX_QUEUE_ENTRIES];
49 };
50 
51 struct ftmac100 {
52 	struct resource *res;
53 	void __iomem *base;
54 	int irq;
55 
56 	struct ftmac100_descs *descs;
57 	dma_addr_t descs_dma_addr;
58 
59 	unsigned int rx_pointer;
60 	unsigned int tx_clean_pointer;
61 	unsigned int tx_pointer;
62 	unsigned int tx_pending;
63 
64 	spinlock_t tx_lock;
65 
66 	struct net_device *netdev;
67 	struct device *dev;
68 	struct napi_struct napi;
69 
70 	struct mii_if_info mii;
71 };
72 
73 static int ftmac100_alloc_rx_page(struct ftmac100 *priv,
74 				  struct ftmac100_rxdes *rxdes, gfp_t gfp);
75 
76 /******************************************************************************
77  * internal functions (hardware register access)
78  *****************************************************************************/
79 #define INT_MASK_ALL_ENABLED	(FTMAC100_INT_RPKT_FINISH	| \
80 				 FTMAC100_INT_NORXBUF		| \
81 				 FTMAC100_INT_XPKT_OK		| \
82 				 FTMAC100_INT_XPKT_LOST		| \
83 				 FTMAC100_INT_RPKT_LOST		| \
84 				 FTMAC100_INT_AHB_ERR		| \
85 				 FTMAC100_INT_PHYSTS_CHG)
86 
87 #define INT_MASK_ALL_DISABLED	0
88 
89 static void ftmac100_enable_all_int(struct ftmac100 *priv)
90 {
91 	iowrite32(INT_MASK_ALL_ENABLED, priv->base + FTMAC100_OFFSET_IMR);
92 }
93 
94 static void ftmac100_disable_all_int(struct ftmac100 *priv)
95 {
96 	iowrite32(INT_MASK_ALL_DISABLED, priv->base + FTMAC100_OFFSET_IMR);
97 }
98 
99 static void ftmac100_set_rx_ring_base(struct ftmac100 *priv, dma_addr_t addr)
100 {
101 	iowrite32(addr, priv->base + FTMAC100_OFFSET_RXR_BADR);
102 }
103 
104 static void ftmac100_set_tx_ring_base(struct ftmac100 *priv, dma_addr_t addr)
105 {
106 	iowrite32(addr, priv->base + FTMAC100_OFFSET_TXR_BADR);
107 }
108 
109 static void ftmac100_txdma_start_polling(struct ftmac100 *priv)
110 {
111 	iowrite32(1, priv->base + FTMAC100_OFFSET_TXPD);
112 }
113 
114 static int ftmac100_reset(struct ftmac100 *priv)
115 {
116 	struct net_device *netdev = priv->netdev;
117 	int i;
118 
119 	/* NOTE: reset clears all registers */
120 	iowrite32(FTMAC100_MACCR_SW_RST, priv->base + FTMAC100_OFFSET_MACCR);
121 
122 	for (i = 0; i < 5; i++) {
123 		unsigned int maccr;
124 
125 		maccr = ioread32(priv->base + FTMAC100_OFFSET_MACCR);
126 		if (!(maccr & FTMAC100_MACCR_SW_RST)) {
127 			/*
128 			 * FTMAC100_MACCR_SW_RST cleared does not indicate
129 			 * that hardware reset completed (what the f*ck).
130 			 * We still need to wait for a while.
131 			 */
132 			udelay(500);
133 			return 0;
134 		}
135 
136 		udelay(1000);
137 	}
138 
139 	netdev_err(netdev, "software reset failed\n");
140 	return -EIO;
141 }
142 
143 static void ftmac100_set_mac(struct ftmac100 *priv, const unsigned char *mac)
144 {
145 	unsigned int maddr = mac[0] << 8 | mac[1];
146 	unsigned int laddr = mac[2] << 24 | mac[3] << 16 | mac[4] << 8 | mac[5];
147 
148 	iowrite32(maddr, priv->base + FTMAC100_OFFSET_MAC_MADR);
149 	iowrite32(laddr, priv->base + FTMAC100_OFFSET_MAC_LADR);
150 }
151 
152 #define MACCR_ENABLE_ALL	(FTMAC100_MACCR_XMT_EN	| \
153 				 FTMAC100_MACCR_RCV_EN	| \
154 				 FTMAC100_MACCR_XDMA_EN	| \
155 				 FTMAC100_MACCR_RDMA_EN	| \
156 				 FTMAC100_MACCR_CRC_APD	| \
157 				 FTMAC100_MACCR_FULLDUP	| \
158 				 FTMAC100_MACCR_RX_RUNT	| \
159 				 FTMAC100_MACCR_RX_BROADPKT)
160 
161 static int ftmac100_start_hw(struct ftmac100 *priv)
162 {
163 	struct net_device *netdev = priv->netdev;
164 	unsigned int maccr = MACCR_ENABLE_ALL;
165 
166 	if (ftmac100_reset(priv))
167 		return -EIO;
168 
169 	/* setup ring buffer base registers */
170 	ftmac100_set_rx_ring_base(priv,
171 				  priv->descs_dma_addr +
172 				  offsetof(struct ftmac100_descs, rxdes));
173 	ftmac100_set_tx_ring_base(priv,
174 				  priv->descs_dma_addr +
175 				  offsetof(struct ftmac100_descs, txdes));
176 
177 	iowrite32(FTMAC100_APTC_RXPOLL_CNT(1), priv->base + FTMAC100_OFFSET_APTC);
178 
179 	ftmac100_set_mac(priv, netdev->dev_addr);
180 
181 	 /* See ftmac100_change_mtu() */
182 	if (netdev->mtu > ETH_DATA_LEN)
183 		maccr |= FTMAC100_MACCR_RX_FTL;
184 
185 	iowrite32(maccr, priv->base + FTMAC100_OFFSET_MACCR);
186 	return 0;
187 }
188 
189 static void ftmac100_stop_hw(struct ftmac100 *priv)
190 {
191 	iowrite32(0, priv->base + FTMAC100_OFFSET_MACCR);
192 }
193 
194 /******************************************************************************
195  * internal functions (receive descriptor)
196  *****************************************************************************/
197 static bool ftmac100_rxdes_first_segment(struct ftmac100_rxdes *rxdes)
198 {
199 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_FRS);
200 }
201 
202 static bool ftmac100_rxdes_last_segment(struct ftmac100_rxdes *rxdes)
203 {
204 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_LRS);
205 }
206 
207 static bool ftmac100_rxdes_owned_by_dma(struct ftmac100_rxdes *rxdes)
208 {
209 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_RXDMA_OWN);
210 }
211 
212 static void ftmac100_rxdes_set_dma_own(struct ftmac100_rxdes *rxdes)
213 {
214 	/* clear status bits */
215 	rxdes->rxdes0 = cpu_to_le32(FTMAC100_RXDES0_RXDMA_OWN);
216 }
217 
218 static bool ftmac100_rxdes_rx_error(struct ftmac100_rxdes *rxdes)
219 {
220 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_RX_ERR);
221 }
222 
223 static bool ftmac100_rxdes_crc_error(struct ftmac100_rxdes *rxdes)
224 {
225 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_CRC_ERR);
226 }
227 
228 static bool ftmac100_rxdes_runt(struct ftmac100_rxdes *rxdes)
229 {
230 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_RUNT);
231 }
232 
233 static bool ftmac100_rxdes_odd_nibble(struct ftmac100_rxdes *rxdes)
234 {
235 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_RX_ODD_NB);
236 }
237 
238 static unsigned int ftmac100_rxdes_frame_length(struct ftmac100_rxdes *rxdes)
239 {
240 	return le32_to_cpu(rxdes->rxdes0) & FTMAC100_RXDES0_RFL;
241 }
242 
243 static bool ftmac100_rxdes_multicast(struct ftmac100_rxdes *rxdes)
244 {
245 	return rxdes->rxdes0 & cpu_to_le32(FTMAC100_RXDES0_MULTICAST);
246 }
247 
248 static void ftmac100_rxdes_set_buffer_size(struct ftmac100_rxdes *rxdes,
249 					   unsigned int size)
250 {
251 	rxdes->rxdes1 &= cpu_to_le32(FTMAC100_RXDES1_EDORR);
252 	rxdes->rxdes1 |= cpu_to_le32(FTMAC100_RXDES1_RXBUF_SIZE(size));
253 }
254 
255 static void ftmac100_rxdes_set_end_of_ring(struct ftmac100_rxdes *rxdes)
256 {
257 	rxdes->rxdes1 |= cpu_to_le32(FTMAC100_RXDES1_EDORR);
258 }
259 
260 static void ftmac100_rxdes_set_dma_addr(struct ftmac100_rxdes *rxdes,
261 					dma_addr_t addr)
262 {
263 	rxdes->rxdes2 = cpu_to_le32(addr);
264 }
265 
266 static dma_addr_t ftmac100_rxdes_get_dma_addr(struct ftmac100_rxdes *rxdes)
267 {
268 	return le32_to_cpu(rxdes->rxdes2);
269 }
270 
271 /*
272  * rxdes3 is not used by hardware. We use it to keep track of page.
273  * Since hardware does not touch it, we can skip cpu_to_le32()/le32_to_cpu().
274  */
275 static void ftmac100_rxdes_set_page(struct ftmac100_rxdes *rxdes, struct page *page)
276 {
277 	rxdes->rxdes3 = (unsigned int)page;
278 }
279 
280 static struct page *ftmac100_rxdes_get_page(struct ftmac100_rxdes *rxdes)
281 {
282 	return (struct page *)rxdes->rxdes3;
283 }
284 
285 /******************************************************************************
286  * internal functions (receive)
287  *****************************************************************************/
288 static int ftmac100_next_rx_pointer(int pointer)
289 {
290 	return (pointer + 1) & (RX_QUEUE_ENTRIES - 1);
291 }
292 
293 static void ftmac100_rx_pointer_advance(struct ftmac100 *priv)
294 {
295 	priv->rx_pointer = ftmac100_next_rx_pointer(priv->rx_pointer);
296 }
297 
298 static struct ftmac100_rxdes *ftmac100_current_rxdes(struct ftmac100 *priv)
299 {
300 	return &priv->descs->rxdes[priv->rx_pointer];
301 }
302 
303 static struct ftmac100_rxdes *
304 ftmac100_rx_locate_first_segment(struct ftmac100 *priv)
305 {
306 	struct ftmac100_rxdes *rxdes = ftmac100_current_rxdes(priv);
307 
308 	while (!ftmac100_rxdes_owned_by_dma(rxdes)) {
309 		if (ftmac100_rxdes_first_segment(rxdes))
310 			return rxdes;
311 
312 		ftmac100_rxdes_set_dma_own(rxdes);
313 		ftmac100_rx_pointer_advance(priv);
314 		rxdes = ftmac100_current_rxdes(priv);
315 	}
316 
317 	return NULL;
318 }
319 
320 static bool ftmac100_rx_packet_error(struct ftmac100 *priv,
321 				     struct ftmac100_rxdes *rxdes)
322 {
323 	struct net_device *netdev = priv->netdev;
324 	bool error = false;
325 
326 	if (unlikely(ftmac100_rxdes_rx_error(rxdes))) {
327 		if (net_ratelimit())
328 			netdev_info(netdev, "rx err\n");
329 
330 		netdev->stats.rx_errors++;
331 		error = true;
332 	}
333 
334 	if (unlikely(ftmac100_rxdes_crc_error(rxdes))) {
335 		if (net_ratelimit())
336 			netdev_info(netdev, "rx crc err\n");
337 
338 		netdev->stats.rx_crc_errors++;
339 		error = true;
340 	}
341 
342 	if (unlikely(ftmac100_rxdes_runt(rxdes))) {
343 		if (net_ratelimit())
344 			netdev_info(netdev, "rx runt\n");
345 
346 		netdev->stats.rx_length_errors++;
347 		error = true;
348 	} else if (unlikely(ftmac100_rxdes_odd_nibble(rxdes))) {
349 		if (net_ratelimit())
350 			netdev_info(netdev, "rx odd nibble\n");
351 
352 		netdev->stats.rx_length_errors++;
353 		error = true;
354 	}
355 	/*
356 	 * FTMAC100_RXDES0_FTL is not an error, it just indicates that the
357 	 * frame is longer than 1518 octets. Receiving these is possible when
358 	 * we told the hardware not to drop them, via FTMAC100_MACCR_RX_FTL.
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 	/* We don't support multi-segment packets for now, so drop them. */
405 	ret = ftmac100_rxdes_last_segment(rxdes);
406 	if (unlikely(!ret)) {
407 		netdev->stats.rx_length_errors++;
408 		ftmac100_rx_drop_packet(priv);
409 		return true;
410 	}
411 
412 	/* start processing */
413 	skb = netdev_alloc_skb_ip_align(netdev, 128);
414 	if (unlikely(!skb)) {
415 		if (net_ratelimit())
416 			netdev_err(netdev, "rx skb alloc failed\n");
417 
418 		ftmac100_rx_drop_packet(priv);
419 		return true;
420 	}
421 
422 	if (unlikely(ftmac100_rxdes_multicast(rxdes)))
423 		netdev->stats.multicast++;
424 
425 	map = ftmac100_rxdes_get_dma_addr(rxdes);
426 	dma_unmap_page(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
427 
428 	length = ftmac100_rxdes_frame_length(rxdes);
429 	page = ftmac100_rxdes_get_page(rxdes);
430 	skb_fill_page_desc(skb, 0, page, 0, length);
431 	skb->len += length;
432 	skb->data_len += length;
433 
434 	if (length > 128) {
435 		skb->truesize += PAGE_SIZE;
436 		/* We pull the minimum amount into linear part */
437 		__pskb_pull_tail(skb, ETH_HLEN);
438 	} else {
439 		/* Small frames are copied into linear part to free one page */
440 		__pskb_pull_tail(skb, length);
441 	}
442 	ftmac100_alloc_rx_page(priv, rxdes, GFP_ATOMIC);
443 
444 	ftmac100_rx_pointer_advance(priv);
445 
446 	skb->protocol = eth_type_trans(skb, netdev);
447 
448 	netdev->stats.rx_packets++;
449 	netdev->stats.rx_bytes += skb->len;
450 
451 	/* push packet to protocol stack */
452 	netif_receive_skb(skb);
453 
454 	(*processed)++;
455 	return true;
456 }
457 
458 /******************************************************************************
459  * internal functions (transmit descriptor)
460  *****************************************************************************/
461 static void ftmac100_txdes_reset(struct ftmac100_txdes *txdes)
462 {
463 	/* clear all except end of ring bit */
464 	txdes->txdes0 = 0;
465 	txdes->txdes1 &= cpu_to_le32(FTMAC100_TXDES1_EDOTR);
466 	txdes->txdes2 = 0;
467 	txdes->txdes3 = 0;
468 }
469 
470 static bool ftmac100_txdes_owned_by_dma(struct ftmac100_txdes *txdes)
471 {
472 	return txdes->txdes0 & cpu_to_le32(FTMAC100_TXDES0_TXDMA_OWN);
473 }
474 
475 static void ftmac100_txdes_set_dma_own(struct ftmac100_txdes *txdes)
476 {
477 	/*
478 	 * Make sure dma own bit will not be set before any other
479 	 * descriptor fields.
480 	 */
481 	wmb();
482 	txdes->txdes0 |= cpu_to_le32(FTMAC100_TXDES0_TXDMA_OWN);
483 }
484 
485 static bool ftmac100_txdes_excessive_collision(struct ftmac100_txdes *txdes)
486 {
487 	return txdes->txdes0 & cpu_to_le32(FTMAC100_TXDES0_TXPKT_EXSCOL);
488 }
489 
490 static bool ftmac100_txdes_late_collision(struct ftmac100_txdes *txdes)
491 {
492 	return txdes->txdes0 & cpu_to_le32(FTMAC100_TXDES0_TXPKT_LATECOL);
493 }
494 
495 static void ftmac100_txdes_set_end_of_ring(struct ftmac100_txdes *txdes)
496 {
497 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_EDOTR);
498 }
499 
500 static void ftmac100_txdes_set_first_segment(struct ftmac100_txdes *txdes)
501 {
502 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_FTS);
503 }
504 
505 static void ftmac100_txdes_set_last_segment(struct ftmac100_txdes *txdes)
506 {
507 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_LTS);
508 }
509 
510 static void ftmac100_txdes_set_txint(struct ftmac100_txdes *txdes)
511 {
512 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_TXIC);
513 }
514 
515 static void ftmac100_txdes_set_buffer_size(struct ftmac100_txdes *txdes,
516 					   unsigned int len)
517 {
518 	txdes->txdes1 |= cpu_to_le32(FTMAC100_TXDES1_TXBUF_SIZE(len));
519 }
520 
521 static void ftmac100_txdes_set_dma_addr(struct ftmac100_txdes *txdes,
522 					dma_addr_t addr)
523 {
524 	txdes->txdes2 = cpu_to_le32(addr);
525 }
526 
527 static dma_addr_t ftmac100_txdes_get_dma_addr(struct ftmac100_txdes *txdes)
528 {
529 	return le32_to_cpu(txdes->txdes2);
530 }
531 
532 /*
533  * txdes3 is not used by hardware. We use it to keep track of socket buffer.
534  * Since hardware does not touch it, we can skip cpu_to_le32()/le32_to_cpu().
535  */
536 static void ftmac100_txdes_set_skb(struct ftmac100_txdes *txdes, struct sk_buff *skb)
537 {
538 	txdes->txdes3 = (unsigned int)skb;
539 }
540 
541 static struct sk_buff *ftmac100_txdes_get_skb(struct ftmac100_txdes *txdes)
542 {
543 	return (struct sk_buff *)txdes->txdes3;
544 }
545 
546 /******************************************************************************
547  * internal functions (transmit)
548  *****************************************************************************/
549 static int ftmac100_next_tx_pointer(int pointer)
550 {
551 	return (pointer + 1) & (TX_QUEUE_ENTRIES - 1);
552 }
553 
554 static void ftmac100_tx_pointer_advance(struct ftmac100 *priv)
555 {
556 	priv->tx_pointer = ftmac100_next_tx_pointer(priv->tx_pointer);
557 }
558 
559 static void ftmac100_tx_clean_pointer_advance(struct ftmac100 *priv)
560 {
561 	priv->tx_clean_pointer = ftmac100_next_tx_pointer(priv->tx_clean_pointer);
562 }
563 
564 static struct ftmac100_txdes *ftmac100_current_txdes(struct ftmac100 *priv)
565 {
566 	return &priv->descs->txdes[priv->tx_pointer];
567 }
568 
569 static struct ftmac100_txdes *ftmac100_current_clean_txdes(struct ftmac100 *priv)
570 {
571 	return &priv->descs->txdes[priv->tx_clean_pointer];
572 }
573 
574 static bool ftmac100_tx_complete_packet(struct ftmac100 *priv)
575 {
576 	struct net_device *netdev = priv->netdev;
577 	struct ftmac100_txdes *txdes;
578 	struct sk_buff *skb;
579 	dma_addr_t map;
580 
581 	if (priv->tx_pending == 0)
582 		return false;
583 
584 	txdes = ftmac100_current_clean_txdes(priv);
585 
586 	if (ftmac100_txdes_owned_by_dma(txdes))
587 		return false;
588 
589 	skb = ftmac100_txdes_get_skb(txdes);
590 	map = ftmac100_txdes_get_dma_addr(txdes);
591 
592 	if (unlikely(ftmac100_txdes_excessive_collision(txdes) ||
593 		     ftmac100_txdes_late_collision(txdes))) {
594 		/*
595 		 * packet transmitted to ethernet lost due to late collision
596 		 * or excessive collision
597 		 */
598 		netdev->stats.tx_aborted_errors++;
599 	} else {
600 		netdev->stats.tx_packets++;
601 		netdev->stats.tx_bytes += skb->len;
602 	}
603 
604 	dma_unmap_single(priv->dev, map, skb_headlen(skb), DMA_TO_DEVICE);
605 	dev_kfree_skb(skb);
606 
607 	ftmac100_txdes_reset(txdes);
608 
609 	ftmac100_tx_clean_pointer_advance(priv);
610 
611 	spin_lock(&priv->tx_lock);
612 	priv->tx_pending--;
613 	spin_unlock(&priv->tx_lock);
614 	netif_wake_queue(netdev);
615 
616 	return true;
617 }
618 
619 static void ftmac100_tx_complete(struct ftmac100 *priv)
620 {
621 	while (ftmac100_tx_complete_packet(priv))
622 		;
623 }
624 
625 static netdev_tx_t ftmac100_xmit(struct ftmac100 *priv, struct sk_buff *skb,
626 				 dma_addr_t map)
627 {
628 	struct net_device *netdev = priv->netdev;
629 	struct ftmac100_txdes *txdes;
630 	unsigned int len = (skb->len < ETH_ZLEN) ? ETH_ZLEN : skb->len;
631 
632 	txdes = ftmac100_current_txdes(priv);
633 	ftmac100_tx_pointer_advance(priv);
634 
635 	/* setup TX descriptor */
636 	ftmac100_txdes_set_skb(txdes, skb);
637 	ftmac100_txdes_set_dma_addr(txdes, map);
638 
639 	ftmac100_txdes_set_first_segment(txdes);
640 	ftmac100_txdes_set_last_segment(txdes);
641 	ftmac100_txdes_set_txint(txdes);
642 	ftmac100_txdes_set_buffer_size(txdes, len);
643 
644 	spin_lock(&priv->tx_lock);
645 	priv->tx_pending++;
646 	if (priv->tx_pending == TX_QUEUE_ENTRIES)
647 		netif_stop_queue(netdev);
648 
649 	/* start transmit */
650 	ftmac100_txdes_set_dma_own(txdes);
651 	spin_unlock(&priv->tx_lock);
652 
653 	ftmac100_txdma_start_polling(priv);
654 	return NETDEV_TX_OK;
655 }
656 
657 /******************************************************************************
658  * internal functions (buffer)
659  *****************************************************************************/
660 static int ftmac100_alloc_rx_page(struct ftmac100 *priv,
661 				  struct ftmac100_rxdes *rxdes, gfp_t gfp)
662 {
663 	struct net_device *netdev = priv->netdev;
664 	struct page *page;
665 	dma_addr_t map;
666 
667 	page = alloc_page(gfp);
668 	if (!page) {
669 		if (net_ratelimit())
670 			netdev_err(netdev, "failed to allocate rx page\n");
671 		return -ENOMEM;
672 	}
673 
674 	map = dma_map_page(priv->dev, page, 0, RX_BUF_SIZE, DMA_FROM_DEVICE);
675 	if (unlikely(dma_mapping_error(priv->dev, map))) {
676 		if (net_ratelimit())
677 			netdev_err(netdev, "failed to map rx page\n");
678 		__free_page(page);
679 		return -ENOMEM;
680 	}
681 
682 	ftmac100_rxdes_set_page(rxdes, page);
683 	ftmac100_rxdes_set_dma_addr(rxdes, map);
684 	ftmac100_rxdes_set_buffer_size(rxdes, RX_BUF_SIZE);
685 	ftmac100_rxdes_set_dma_own(rxdes);
686 	return 0;
687 }
688 
689 static void ftmac100_free_buffers(struct ftmac100 *priv)
690 {
691 	int i;
692 
693 	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
694 		struct ftmac100_rxdes *rxdes = &priv->descs->rxdes[i];
695 		struct page *page = ftmac100_rxdes_get_page(rxdes);
696 		dma_addr_t map = ftmac100_rxdes_get_dma_addr(rxdes);
697 
698 		if (!page)
699 			continue;
700 
701 		dma_unmap_page(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
702 		__free_page(page);
703 	}
704 
705 	for (i = 0; i < TX_QUEUE_ENTRIES; i++) {
706 		struct ftmac100_txdes *txdes = &priv->descs->txdes[i];
707 		struct sk_buff *skb = ftmac100_txdes_get_skb(txdes);
708 		dma_addr_t map = ftmac100_txdes_get_dma_addr(txdes);
709 
710 		if (!skb)
711 			continue;
712 
713 		dma_unmap_single(priv->dev, map, skb_headlen(skb), DMA_TO_DEVICE);
714 		dev_kfree_skb(skb);
715 	}
716 
717 	dma_free_coherent(priv->dev, sizeof(struct ftmac100_descs),
718 			  priv->descs, priv->descs_dma_addr);
719 }
720 
721 static int ftmac100_alloc_buffers(struct ftmac100 *priv)
722 {
723 	int i;
724 
725 	priv->descs = dma_alloc_coherent(priv->dev,
726 					 sizeof(struct ftmac100_descs),
727 					 &priv->descs_dma_addr, GFP_KERNEL);
728 	if (!priv->descs)
729 		return -ENOMEM;
730 
731 	/* initialize RX ring */
732 	ftmac100_rxdes_set_end_of_ring(&priv->descs->rxdes[RX_QUEUE_ENTRIES - 1]);
733 
734 	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
735 		struct ftmac100_rxdes *rxdes = &priv->descs->rxdes[i];
736 
737 		if (ftmac100_alloc_rx_page(priv, rxdes, GFP_KERNEL))
738 			goto err;
739 	}
740 
741 	/* initialize TX ring */
742 	ftmac100_txdes_set_end_of_ring(&priv->descs->txdes[TX_QUEUE_ENTRIES - 1]);
743 	return 0;
744 
745 err:
746 	ftmac100_free_buffers(priv);
747 	return -ENOMEM;
748 }
749 
750 /******************************************************************************
751  * struct mii_if_info functions
752  *****************************************************************************/
753 static int ftmac100_mdio_read(struct net_device *netdev, int phy_id, int reg)
754 {
755 	struct ftmac100 *priv = netdev_priv(netdev);
756 	unsigned int phycr;
757 	int i;
758 
759 	phycr = FTMAC100_PHYCR_PHYAD(phy_id) |
760 		FTMAC100_PHYCR_REGAD(reg) |
761 		FTMAC100_PHYCR_MIIRD;
762 
763 	iowrite32(phycr, priv->base + FTMAC100_OFFSET_PHYCR);
764 
765 	for (i = 0; i < 10; i++) {
766 		phycr = ioread32(priv->base + FTMAC100_OFFSET_PHYCR);
767 
768 		if ((phycr & FTMAC100_PHYCR_MIIRD) == 0)
769 			return phycr & FTMAC100_PHYCR_MIIRDATA;
770 
771 		udelay(100);
772 	}
773 
774 	netdev_err(netdev, "mdio read timed out\n");
775 	return 0;
776 }
777 
778 static void ftmac100_mdio_write(struct net_device *netdev, int phy_id, int reg,
779 				int data)
780 {
781 	struct ftmac100 *priv = netdev_priv(netdev);
782 	unsigned int phycr;
783 	int i;
784 
785 	phycr = FTMAC100_PHYCR_PHYAD(phy_id) |
786 		FTMAC100_PHYCR_REGAD(reg) |
787 		FTMAC100_PHYCR_MIIWR;
788 
789 	data = FTMAC100_PHYWDATA_MIIWDATA(data);
790 
791 	iowrite32(data, priv->base + FTMAC100_OFFSET_PHYWDATA);
792 	iowrite32(phycr, priv->base + FTMAC100_OFFSET_PHYCR);
793 
794 	for (i = 0; i < 10; i++) {
795 		phycr = ioread32(priv->base + FTMAC100_OFFSET_PHYCR);
796 
797 		if ((phycr & FTMAC100_PHYCR_MIIWR) == 0)
798 			return;
799 
800 		udelay(100);
801 	}
802 
803 	netdev_err(netdev, "mdio write timed out\n");
804 }
805 
806 /******************************************************************************
807  * struct ethtool_ops functions
808  *****************************************************************************/
809 static void ftmac100_get_drvinfo(struct net_device *netdev,
810 				 struct ethtool_drvinfo *info)
811 {
812 	strscpy(info->driver, DRV_NAME, sizeof(info->driver));
813 	strscpy(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 int ftmac100_change_mtu(struct net_device *netdev, int mtu)
1043 {
1044 	struct ftmac100 *priv = netdev_priv(netdev);
1045 	unsigned int maccr;
1046 
1047 	maccr = ioread32(priv->base + FTMAC100_OFFSET_MACCR);
1048 	if (mtu > ETH_DATA_LEN) {
1049 		/* process long packets in the driver */
1050 		maccr |= FTMAC100_MACCR_RX_FTL;
1051 	} else {
1052 		/* Let the controller drop incoming packets greater
1053 		 * than 1518 (that is 1500 + 14 Ethernet + 4 FCS).
1054 		 */
1055 		maccr &= ~FTMAC100_MACCR_RX_FTL;
1056 	}
1057 	iowrite32(maccr, priv->base + FTMAC100_OFFSET_MACCR);
1058 
1059 	netdev->mtu = mtu;
1060 
1061 	return 0;
1062 }
1063 
1064 static const struct net_device_ops ftmac100_netdev_ops = {
1065 	.ndo_open		= ftmac100_open,
1066 	.ndo_stop		= ftmac100_stop,
1067 	.ndo_start_xmit		= ftmac100_hard_start_xmit,
1068 	.ndo_set_mac_address	= eth_mac_addr,
1069 	.ndo_validate_addr	= eth_validate_addr,
1070 	.ndo_eth_ioctl		= ftmac100_do_ioctl,
1071 	.ndo_change_mtu		= ftmac100_change_mtu,
1072 };
1073 
1074 /******************************************************************************
1075  * struct platform_driver functions
1076  *****************************************************************************/
1077 static int ftmac100_probe(struct platform_device *pdev)
1078 {
1079 	struct resource *res;
1080 	int irq;
1081 	struct net_device *netdev;
1082 	struct ftmac100 *priv;
1083 	int err;
1084 
1085 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1086 	if (!res)
1087 		return -ENXIO;
1088 
1089 	irq = platform_get_irq(pdev, 0);
1090 	if (irq < 0)
1091 		return irq;
1092 
1093 	/* setup net_device */
1094 	netdev = alloc_etherdev(sizeof(*priv));
1095 	if (!netdev) {
1096 		err = -ENOMEM;
1097 		goto err_alloc_etherdev;
1098 	}
1099 
1100 	SET_NETDEV_DEV(netdev, &pdev->dev);
1101 	netdev->ethtool_ops = &ftmac100_ethtool_ops;
1102 	netdev->netdev_ops = &ftmac100_netdev_ops;
1103 	netdev->max_mtu = MAX_PKT_SIZE - VLAN_ETH_HLEN;
1104 
1105 	err = platform_get_ethdev_address(&pdev->dev, netdev);
1106 	if (err == -EPROBE_DEFER)
1107 		goto defer_get_mac;
1108 
1109 	platform_set_drvdata(pdev, netdev);
1110 
1111 	/* setup private data */
1112 	priv = netdev_priv(netdev);
1113 	priv->netdev = netdev;
1114 	priv->dev = &pdev->dev;
1115 
1116 	spin_lock_init(&priv->tx_lock);
1117 
1118 	/* initialize NAPI */
1119 	netif_napi_add(netdev, &priv->napi, ftmac100_poll);
1120 
1121 	/* map io memory */
1122 	priv->res = request_mem_region(res->start, resource_size(res),
1123 				       dev_name(&pdev->dev));
1124 	if (!priv->res) {
1125 		dev_err(&pdev->dev, "Could not reserve memory region\n");
1126 		err = -ENOMEM;
1127 		goto err_req_mem;
1128 	}
1129 
1130 	priv->base = ioremap(res->start, resource_size(res));
1131 	if (!priv->base) {
1132 		dev_err(&pdev->dev, "Failed to ioremap ethernet registers\n");
1133 		err = -EIO;
1134 		goto err_ioremap;
1135 	}
1136 
1137 	priv->irq = irq;
1138 
1139 	/* initialize struct mii_if_info */
1140 	priv->mii.phy_id	= 0;
1141 	priv->mii.phy_id_mask	= 0x1f;
1142 	priv->mii.reg_num_mask	= 0x1f;
1143 	priv->mii.dev		= netdev;
1144 	priv->mii.mdio_read	= ftmac100_mdio_read;
1145 	priv->mii.mdio_write	= ftmac100_mdio_write;
1146 
1147 	/* register network device */
1148 	err = register_netdev(netdev);
1149 	if (err) {
1150 		dev_err(&pdev->dev, "Failed to register netdev\n");
1151 		goto err_register_netdev;
1152 	}
1153 
1154 	netdev_info(netdev, "irq %d, mapped at %p\n", priv->irq, priv->base);
1155 
1156 	if (!is_valid_ether_addr(netdev->dev_addr)) {
1157 		eth_hw_addr_random(netdev);
1158 		netdev_info(netdev, "generated random MAC address %pM\n",
1159 			    netdev->dev_addr);
1160 	}
1161 
1162 	return 0;
1163 
1164 err_register_netdev:
1165 	iounmap(priv->base);
1166 err_ioremap:
1167 	release_resource(priv->res);
1168 err_req_mem:
1169 	netif_napi_del(&priv->napi);
1170 defer_get_mac:
1171 	free_netdev(netdev);
1172 err_alloc_etherdev:
1173 	return err;
1174 }
1175 
1176 static int ftmac100_remove(struct platform_device *pdev)
1177 {
1178 	struct net_device *netdev;
1179 	struct ftmac100 *priv;
1180 
1181 	netdev = platform_get_drvdata(pdev);
1182 	priv = netdev_priv(netdev);
1183 
1184 	unregister_netdev(netdev);
1185 
1186 	iounmap(priv->base);
1187 	release_resource(priv->res);
1188 
1189 	netif_napi_del(&priv->napi);
1190 	free_netdev(netdev);
1191 	return 0;
1192 }
1193 
1194 static const struct of_device_id ftmac100_of_ids[] = {
1195 	{ .compatible = "andestech,atmac100" },
1196 	{ }
1197 };
1198 
1199 static struct platform_driver ftmac100_driver = {
1200 	.probe		= ftmac100_probe,
1201 	.remove		= ftmac100_remove,
1202 	.driver		= {
1203 		.name	= DRV_NAME,
1204 		.of_match_table = ftmac100_of_ids
1205 	},
1206 };
1207 
1208 /******************************************************************************
1209  * initialization / finalization
1210  *****************************************************************************/
1211 module_platform_driver(ftmac100_driver);
1212 
1213 MODULE_AUTHOR("Po-Yu Chuang <ratbert@faraday-tech.com>");
1214 MODULE_DESCRIPTION("FTMAC100 driver");
1215 MODULE_LICENSE("GPL");
1216 MODULE_DEVICE_TABLE(of, ftmac100_of_ids);
1217