1 /*
2  * Faraday FTGMAC100 Gigabit 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/interrupt.h>
28 #include <linux/io.h>
29 #include <linux/module.h>
30 #include <linux/netdevice.h>
31 #include <linux/of.h>
32 #include <linux/phy.h>
33 #include <linux/platform_device.h>
34 #include <linux/property.h>
35 #include <net/ip.h>
36 #include <net/ncsi.h>
37 
38 #include "ftgmac100.h"
39 
40 #define DRV_NAME	"ftgmac100"
41 #define DRV_VERSION	"0.7"
42 
43 #define RX_QUEUE_ENTRIES	256	/* must be power of 2 */
44 #define TX_QUEUE_ENTRIES	512	/* must be power of 2 */
45 
46 #define MAX_PKT_SIZE		1536
47 #define RX_BUF_SIZE		MAX_PKT_SIZE	/* must be smaller than 0x3fff */
48 
49 /* Min number of tx ring entries before stopping queue */
50 #define TX_THRESHOLD		(MAX_SKB_FRAGS + 1)
51 
52 struct ftgmac100_descs {
53 	struct ftgmac100_rxdes rxdes[RX_QUEUE_ENTRIES];
54 	struct ftgmac100_txdes txdes[TX_QUEUE_ENTRIES];
55 };
56 
57 struct ftgmac100 {
58 	/* Registers */
59 	struct resource *res;
60 	void __iomem *base;
61 
62 	struct ftgmac100_descs *descs;
63 	dma_addr_t descs_dma_addr;
64 
65 	/* Rx ring */
66 	struct sk_buff *rx_skbs[RX_QUEUE_ENTRIES];
67 	unsigned int rx_pointer;
68 	u32 rxdes0_edorr_mask;
69 
70 	/* Tx ring */
71 	struct sk_buff *tx_skbs[TX_QUEUE_ENTRIES];
72 	unsigned int tx_clean_pointer;
73 	unsigned int tx_pointer;
74 	u32 txdes0_edotr_mask;
75 
76 	/* Scratch page to use when rx skb alloc fails */
77 	void *rx_scratch;
78 	dma_addr_t rx_scratch_dma;
79 
80 	/* Component structures */
81 	struct net_device *netdev;
82 	struct device *dev;
83 	struct ncsi_dev *ndev;
84 	struct napi_struct napi;
85 	struct work_struct reset_task;
86 	struct mii_bus *mii_bus;
87 
88 	/* Link management */
89 	int cur_speed;
90 	int cur_duplex;
91 	bool use_ncsi;
92 
93 	/* Misc */
94 	bool need_mac_restart;
95 	bool is_aspeed;
96 };
97 
98 static void ftgmac100_set_rx_ring_base(struct ftgmac100 *priv, dma_addr_t addr)
99 {
100 	iowrite32(addr, priv->base + FTGMAC100_OFFSET_RXR_BADR);
101 }
102 
103 static void ftgmac100_set_rx_buffer_size(struct ftgmac100 *priv,
104 		unsigned int size)
105 {
106 	size = FTGMAC100_RBSR_SIZE(size);
107 	iowrite32(size, priv->base + FTGMAC100_OFFSET_RBSR);
108 }
109 
110 static void ftgmac100_set_normal_prio_tx_ring_base(struct ftgmac100 *priv,
111 						   dma_addr_t addr)
112 {
113 	iowrite32(addr, priv->base + FTGMAC100_OFFSET_NPTXR_BADR);
114 }
115 
116 static void ftgmac100_txdma_normal_prio_start_polling(struct ftgmac100 *priv)
117 {
118 	iowrite32(1, priv->base + FTGMAC100_OFFSET_NPTXPD);
119 }
120 
121 static int ftgmac100_reset_mac(struct ftgmac100 *priv, u32 maccr)
122 {
123 	struct net_device *netdev = priv->netdev;
124 	int i;
125 
126 	/* NOTE: reset clears all registers */
127 	iowrite32(maccr, priv->base + FTGMAC100_OFFSET_MACCR);
128 	iowrite32(maccr | FTGMAC100_MACCR_SW_RST,
129 		  priv->base + FTGMAC100_OFFSET_MACCR);
130 	for (i = 0; i < 50; i++) {
131 		unsigned int maccr;
132 
133 		maccr = ioread32(priv->base + FTGMAC100_OFFSET_MACCR);
134 		if (!(maccr & FTGMAC100_MACCR_SW_RST))
135 			return 0;
136 
137 		udelay(1);
138 	}
139 
140 	netdev_err(netdev, "Hardware reset failed\n");
141 	return -EIO;
142 }
143 
144 static int ftgmac100_reset_and_config_mac(struct ftgmac100 *priv)
145 {
146 	u32 maccr = 0;
147 
148 	switch (priv->cur_speed) {
149 	case SPEED_10:
150 	case 0: /* no link */
151 		break;
152 
153 	case SPEED_100:
154 		maccr |= FTGMAC100_MACCR_FAST_MODE;
155 		break;
156 
157 	case SPEED_1000:
158 		maccr |= FTGMAC100_MACCR_GIGA_MODE;
159 		break;
160 	default:
161 		netdev_err(priv->netdev, "Unknown speed %d !\n",
162 			   priv->cur_speed);
163 		break;
164 	}
165 
166 	/* (Re)initialize the queue pointers */
167 	priv->rx_pointer = 0;
168 	priv->tx_clean_pointer = 0;
169 	priv->tx_pointer = 0;
170 
171 	/* The doc says reset twice with 10us interval */
172 	if (ftgmac100_reset_mac(priv, maccr))
173 		return -EIO;
174 	usleep_range(10, 1000);
175 	return ftgmac100_reset_mac(priv, maccr);
176 }
177 
178 static void ftgmac100_write_mac_addr(struct ftgmac100 *priv, const u8 *mac)
179 {
180 	unsigned int maddr = mac[0] << 8 | mac[1];
181 	unsigned int laddr = mac[2] << 24 | mac[3] << 16 | mac[4] << 8 | mac[5];
182 
183 	iowrite32(maddr, priv->base + FTGMAC100_OFFSET_MAC_MADR);
184 	iowrite32(laddr, priv->base + FTGMAC100_OFFSET_MAC_LADR);
185 }
186 
187 static void ftgmac100_initial_mac(struct ftgmac100 *priv)
188 {
189 	u8 mac[ETH_ALEN];
190 	unsigned int m;
191 	unsigned int l;
192 	void *addr;
193 
194 	addr = device_get_mac_address(priv->dev, mac, ETH_ALEN);
195 	if (addr) {
196 		ether_addr_copy(priv->netdev->dev_addr, mac);
197 		dev_info(priv->dev, "Read MAC address %pM from device tree\n",
198 			 mac);
199 		return;
200 	}
201 
202 	m = ioread32(priv->base + FTGMAC100_OFFSET_MAC_MADR);
203 	l = ioread32(priv->base + FTGMAC100_OFFSET_MAC_LADR);
204 
205 	mac[0] = (m >> 8) & 0xff;
206 	mac[1] = m & 0xff;
207 	mac[2] = (l >> 24) & 0xff;
208 	mac[3] = (l >> 16) & 0xff;
209 	mac[4] = (l >> 8) & 0xff;
210 	mac[5] = l & 0xff;
211 
212 	if (is_valid_ether_addr(mac)) {
213 		ether_addr_copy(priv->netdev->dev_addr, mac);
214 		dev_info(priv->dev, "Read MAC address %pM from chip\n", mac);
215 	} else {
216 		eth_hw_addr_random(priv->netdev);
217 		dev_info(priv->dev, "Generated random MAC address %pM\n",
218 			 priv->netdev->dev_addr);
219 	}
220 }
221 
222 static int ftgmac100_set_mac_addr(struct net_device *dev, void *p)
223 {
224 	int ret;
225 
226 	ret = eth_prepare_mac_addr_change(dev, p);
227 	if (ret < 0)
228 		return ret;
229 
230 	eth_commit_mac_addr_change(dev, p);
231 	ftgmac100_write_mac_addr(netdev_priv(dev), dev->dev_addr);
232 
233 	return 0;
234 }
235 
236 static void ftgmac100_init_hw(struct ftgmac100 *priv)
237 {
238 	/* setup ring buffer base registers */
239 	ftgmac100_set_rx_ring_base(priv,
240 				   priv->descs_dma_addr +
241 				   offsetof(struct ftgmac100_descs, rxdes));
242 	ftgmac100_set_normal_prio_tx_ring_base(priv,
243 					       priv->descs_dma_addr +
244 					       offsetof(struct ftgmac100_descs, txdes));
245 
246 	ftgmac100_set_rx_buffer_size(priv, RX_BUF_SIZE);
247 
248 	iowrite32(FTGMAC100_APTC_RXPOLL_CNT(1), priv->base + FTGMAC100_OFFSET_APTC);
249 
250 	ftgmac100_write_mac_addr(priv, priv->netdev->dev_addr);
251 }
252 
253 static void ftgmac100_start_hw(struct ftgmac100 *priv)
254 {
255 	u32 maccr = ioread32(priv->base + FTGMAC100_OFFSET_MACCR);
256 
257 	/* Keep the original GMAC and FAST bits */
258 	maccr &= (FTGMAC100_MACCR_FAST_MODE | FTGMAC100_MACCR_GIGA_MODE);
259 
260 	/* Add all the main enable bits */
261 	maccr |= FTGMAC100_MACCR_TXDMA_EN	|
262 		 FTGMAC100_MACCR_RXDMA_EN	|
263 		 FTGMAC100_MACCR_TXMAC_EN	|
264 		 FTGMAC100_MACCR_RXMAC_EN	|
265 		 FTGMAC100_MACCR_CRC_APD	|
266 		 FTGMAC100_MACCR_PHY_LINK_LEVEL	|
267 		 FTGMAC100_MACCR_RX_RUNT	|
268 		 FTGMAC100_MACCR_RX_BROADPKT;
269 
270 	/* Add other bits as needed */
271 	if (priv->cur_duplex == DUPLEX_FULL)
272 		maccr |= FTGMAC100_MACCR_FULLDUP;
273 
274 	/* Hit the HW */
275 	iowrite32(maccr, priv->base + FTGMAC100_OFFSET_MACCR);
276 }
277 
278 static void ftgmac100_stop_hw(struct ftgmac100 *priv)
279 {
280 	iowrite32(0, priv->base + FTGMAC100_OFFSET_MACCR);
281 }
282 
283 static int ftgmac100_alloc_rx_buf(struct ftgmac100 *priv, unsigned int entry,
284 				  struct ftgmac100_rxdes *rxdes, gfp_t gfp)
285 {
286 	struct net_device *netdev = priv->netdev;
287 	struct sk_buff *skb;
288 	dma_addr_t map;
289 	int err;
290 
291 	skb = netdev_alloc_skb_ip_align(netdev, RX_BUF_SIZE);
292 	if (unlikely(!skb)) {
293 		if (net_ratelimit())
294 			netdev_warn(netdev, "failed to allocate rx skb\n");
295 		err = -ENOMEM;
296 		map = priv->rx_scratch_dma;
297 	} else {
298 		map = dma_map_single(priv->dev, skb->data, RX_BUF_SIZE,
299 				     DMA_FROM_DEVICE);
300 		if (unlikely(dma_mapping_error(priv->dev, map))) {
301 			if (net_ratelimit())
302 				netdev_err(netdev, "failed to map rx page\n");
303 			dev_kfree_skb_any(skb);
304 			map = priv->rx_scratch_dma;
305 			skb = NULL;
306 			err = -ENOMEM;
307 		}
308 	}
309 
310 	/* Store skb */
311 	priv->rx_skbs[entry] = skb;
312 
313 	/* Store DMA address into RX desc */
314 	rxdes->rxdes3 = cpu_to_le32(map);
315 
316 	/* Ensure the above is ordered vs clearing the OWN bit */
317 	dma_wmb();
318 
319 	/* Clean status (which resets own bit) */
320 	if (entry == (RX_QUEUE_ENTRIES - 1))
321 		rxdes->rxdes0 = cpu_to_le32(priv->rxdes0_edorr_mask);
322 	else
323 		rxdes->rxdes0 = 0;
324 
325 	return 0;
326 }
327 
328 static int ftgmac100_next_rx_pointer(int pointer)
329 {
330 	return (pointer + 1) & (RX_QUEUE_ENTRIES - 1);
331 }
332 
333 static void ftgmac100_rx_packet_error(struct ftgmac100 *priv, u32 status)
334 {
335 	struct net_device *netdev = priv->netdev;
336 
337 	if (status & FTGMAC100_RXDES0_RX_ERR)
338 		netdev->stats.rx_errors++;
339 
340 	if (status & FTGMAC100_RXDES0_CRC_ERR)
341 		netdev->stats.rx_crc_errors++;
342 
343 	if (status & (FTGMAC100_RXDES0_FTL |
344 		      FTGMAC100_RXDES0_RUNT |
345 		      FTGMAC100_RXDES0_RX_ODD_NB))
346 		netdev->stats.rx_length_errors++;
347 }
348 
349 static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)
350 {
351 	struct net_device *netdev = priv->netdev;
352 	struct ftgmac100_rxdes *rxdes;
353 	struct sk_buff *skb;
354 	unsigned int pointer, size;
355 	u32 status, csum_vlan;
356 	dma_addr_t map;
357 
358 	/* Grab next RX descriptor */
359 	pointer = priv->rx_pointer;
360 	rxdes = &priv->descs->rxdes[pointer];
361 
362 	/* Grab descriptor status */
363 	status = le32_to_cpu(rxdes->rxdes0);
364 
365 	/* Do we have a packet ? */
366 	if (!(status & FTGMAC100_RXDES0_RXPKT_RDY))
367 		return false;
368 
369 	/* Order subsequent reads with the test for the ready bit */
370 	dma_rmb();
371 
372 	/* We don't cope with fragmented RX packets */
373 	if (unlikely(!(status & FTGMAC100_RXDES0_FRS) ||
374 		     !(status & FTGMAC100_RXDES0_LRS)))
375 		goto drop;
376 
377 	/* Grab received size and csum vlan field in the descriptor */
378 	size = status & FTGMAC100_RXDES0_VDBC;
379 	csum_vlan = le32_to_cpu(rxdes->rxdes1);
380 
381 	/* Any error (other than csum offload) flagged ? */
382 	if (unlikely(status & RXDES0_ANY_ERROR)) {
383 		/* Correct for incorrect flagging of runt packets
384 		 * with vlan tags... Just accept a runt packet that
385 		 * has been flagged as vlan and whose size is at
386 		 * least 60 bytes.
387 		 */
388 		if ((status & FTGMAC100_RXDES0_RUNT) &&
389 		    (csum_vlan & FTGMAC100_RXDES1_VLANTAG_AVAIL) &&
390 		    (size >= 60))
391 			status &= ~FTGMAC100_RXDES0_RUNT;
392 
393 		/* Any error still in there ? */
394 		if (status & RXDES0_ANY_ERROR) {
395 			ftgmac100_rx_packet_error(priv, status);
396 			goto drop;
397 		}
398 	}
399 
400 	/* If the packet had no skb (failed to allocate earlier)
401 	 * then try to allocate one and skip
402 	 */
403 	skb = priv->rx_skbs[pointer];
404 	if (!unlikely(skb)) {
405 		ftgmac100_alloc_rx_buf(priv, pointer, rxdes, GFP_ATOMIC);
406 		goto drop;
407 	}
408 
409 	if (unlikely(status & FTGMAC100_RXDES0_MULTICAST))
410 		netdev->stats.multicast++;
411 
412 	/* If the HW found checksum errors, bounce it to software.
413 	 *
414 	 * If we didn't, we need to see if the packet was recognized
415 	 * by HW as one of the supported checksummed protocols before
416 	 * we accept the HW test results.
417 	 */
418 	if (netdev->features & NETIF_F_RXCSUM) {
419 		u32 err_bits = FTGMAC100_RXDES1_TCP_CHKSUM_ERR |
420 			FTGMAC100_RXDES1_UDP_CHKSUM_ERR |
421 			FTGMAC100_RXDES1_IP_CHKSUM_ERR;
422 		if ((csum_vlan & err_bits) ||
423 		    !(csum_vlan & FTGMAC100_RXDES1_PROT_MASK))
424 			skb->ip_summed = CHECKSUM_NONE;
425 		else
426 			skb->ip_summed = CHECKSUM_UNNECESSARY;
427 	}
428 
429 	/* Transfer received size to skb */
430 	skb_put(skb, size);
431 
432 	/* Tear down DMA mapping, do necessary cache management */
433 	map = le32_to_cpu(rxdes->rxdes3);
434 
435 #if defined(CONFIG_ARM) && !defined(CONFIG_ARM_DMA_USE_IOMMU)
436 	/* When we don't have an iommu, we can save cycles by not
437 	 * invalidating the cache for the part of the packet that
438 	 * wasn't received.
439 	 */
440 	dma_unmap_single(priv->dev, map, size, DMA_FROM_DEVICE);
441 #else
442 	dma_unmap_single(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
443 #endif
444 
445 
446 	/* Resplenish rx ring */
447 	ftgmac100_alloc_rx_buf(priv, pointer, rxdes, GFP_ATOMIC);
448 	priv->rx_pointer = ftgmac100_next_rx_pointer(pointer);
449 
450 	skb->protocol = eth_type_trans(skb, netdev);
451 
452 	netdev->stats.rx_packets++;
453 	netdev->stats.rx_bytes += size;
454 
455 	/* push packet to protocol stack */
456 	if (skb->ip_summed == CHECKSUM_NONE)
457 		netif_receive_skb(skb);
458 	else
459 		napi_gro_receive(&priv->napi, skb);
460 
461 	(*processed)++;
462 	return true;
463 
464  drop:
465 	/* Clean rxdes0 (which resets own bit) */
466 	rxdes->rxdes0 = cpu_to_le32(status & priv->rxdes0_edorr_mask);
467 	priv->rx_pointer = ftgmac100_next_rx_pointer(pointer);
468 	netdev->stats.rx_dropped++;
469 	return true;
470 }
471 
472 static u32 ftgmac100_base_tx_ctlstat(struct ftgmac100 *priv,
473 				     unsigned int index)
474 {
475 	if (index == (TX_QUEUE_ENTRIES - 1))
476 		return priv->txdes0_edotr_mask;
477 	else
478 		return 0;
479 }
480 
481 static int ftgmac100_next_tx_pointer(int pointer)
482 {
483 	return (pointer + 1) & (TX_QUEUE_ENTRIES - 1);
484 }
485 
486 static u32 ftgmac100_tx_buf_avail(struct ftgmac100 *priv)
487 {
488 	/* Returns the number of available slots in the TX queue
489 	 *
490 	 * This always leaves one free slot so we don't have to
491 	 * worry about empty vs. full, and this simplifies the
492 	 * test for ftgmac100_tx_buf_cleanable() below
493 	 */
494 	return (priv->tx_clean_pointer - priv->tx_pointer - 1) &
495 		(TX_QUEUE_ENTRIES - 1);
496 }
497 
498 static bool ftgmac100_tx_buf_cleanable(struct ftgmac100 *priv)
499 {
500 	return priv->tx_pointer != priv->tx_clean_pointer;
501 }
502 
503 static void ftgmac100_free_tx_packet(struct ftgmac100 *priv,
504 				     unsigned int pointer,
505 				     struct sk_buff *skb,
506 				     struct ftgmac100_txdes *txdes,
507 				     u32 ctl_stat)
508 {
509 	dma_addr_t map = le32_to_cpu(txdes->txdes3);
510 	size_t len;
511 
512 	if (ctl_stat & FTGMAC100_TXDES0_FTS) {
513 		len = skb_headlen(skb);
514 		dma_unmap_single(priv->dev, map, len, DMA_TO_DEVICE);
515 	} else {
516 		len = FTGMAC100_TXDES0_TXBUF_SIZE(ctl_stat);
517 		dma_unmap_page(priv->dev, map, len, DMA_TO_DEVICE);
518 	}
519 
520 	/* Free SKB on last segment */
521 	if (ctl_stat & FTGMAC100_TXDES0_LTS)
522 		dev_kfree_skb(skb);
523 	priv->tx_skbs[pointer] = NULL;
524 }
525 
526 static bool ftgmac100_tx_complete_packet(struct ftgmac100 *priv)
527 {
528 	struct net_device *netdev = priv->netdev;
529 	struct ftgmac100_txdes *txdes;
530 	struct sk_buff *skb;
531 	unsigned int pointer;
532 	u32 ctl_stat;
533 
534 	pointer = priv->tx_clean_pointer;
535 	txdes = &priv->descs->txdes[pointer];
536 
537 	ctl_stat = le32_to_cpu(txdes->txdes0);
538 	if (ctl_stat & FTGMAC100_TXDES0_TXDMA_OWN)
539 		return false;
540 
541 	skb = priv->tx_skbs[pointer];
542 	netdev->stats.tx_packets++;
543 	netdev->stats.tx_bytes += skb->len;
544 	ftgmac100_free_tx_packet(priv, pointer, skb, txdes, ctl_stat);
545 	txdes->txdes0 = cpu_to_le32(ctl_stat & priv->txdes0_edotr_mask);
546 
547 	priv->tx_clean_pointer = ftgmac100_next_tx_pointer(pointer);
548 
549 	return true;
550 }
551 
552 static void ftgmac100_tx_complete(struct ftgmac100 *priv)
553 {
554 	struct net_device *netdev = priv->netdev;
555 
556 	/* Process all completed packets */
557 	while (ftgmac100_tx_buf_cleanable(priv) &&
558 	       ftgmac100_tx_complete_packet(priv))
559 		;
560 
561 	/* Restart queue if needed */
562 	smp_mb();
563 	if (unlikely(netif_queue_stopped(netdev) &&
564 		     ftgmac100_tx_buf_avail(priv) >= TX_THRESHOLD)) {
565 		struct netdev_queue *txq;
566 
567 		txq = netdev_get_tx_queue(netdev, 0);
568 		__netif_tx_lock(txq, smp_processor_id());
569 		if (netif_queue_stopped(netdev) &&
570 		    ftgmac100_tx_buf_avail(priv) >= TX_THRESHOLD)
571 			netif_wake_queue(netdev);
572 		__netif_tx_unlock(txq);
573 	}
574 }
575 
576 static bool ftgmac100_prep_tx_csum(struct sk_buff *skb, u32 *csum_vlan)
577 {
578 	if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
579 		u8 ip_proto = ip_hdr(skb)->protocol;
580 
581 		*csum_vlan |= FTGMAC100_TXDES1_IP_CHKSUM;
582 		switch(ip_proto) {
583 		case IPPROTO_TCP:
584 			*csum_vlan |= FTGMAC100_TXDES1_TCP_CHKSUM;
585 			return true;
586 		case IPPROTO_UDP:
587 			*csum_vlan |= FTGMAC100_TXDES1_UDP_CHKSUM;
588 			return true;
589 		case IPPROTO_IP:
590 			return true;
591 		}
592 	}
593 	return skb_checksum_help(skb) == 0;
594 }
595 
596 static int ftgmac100_hard_start_xmit(struct sk_buff *skb,
597 				     struct net_device *netdev)
598 {
599 	struct ftgmac100 *priv = netdev_priv(netdev);
600 	struct ftgmac100_txdes *txdes, *first;
601 	unsigned int pointer, nfrags, len, i, j;
602 	u32 f_ctl_stat, ctl_stat, csum_vlan;
603 	dma_addr_t map;
604 
605 	/* The HW doesn't pad small frames */
606 	if (eth_skb_pad(skb)) {
607 		netdev->stats.tx_dropped++;
608 		return NETDEV_TX_OK;
609 	}
610 
611 	/* Reject oversize packets */
612 	if (unlikely(skb->len > MAX_PKT_SIZE)) {
613 		if (net_ratelimit())
614 			netdev_dbg(netdev, "tx packet too big\n");
615 		goto drop;
616 	}
617 
618 	/* Do we have a limit on #fragments ? I yet have to get a reply
619 	 * from Aspeed. If there's one I haven't hit it.
620 	 */
621 	nfrags = skb_shinfo(skb)->nr_frags;
622 
623 	/* Get header len */
624 	len = skb_headlen(skb);
625 
626 	/* Map the packet head */
627 	map = dma_map_single(priv->dev, skb->data, len, DMA_TO_DEVICE);
628 	if (dma_mapping_error(priv->dev, map)) {
629 		if (net_ratelimit())
630 			netdev_err(netdev, "map tx packet head failed\n");
631 		goto drop;
632 	}
633 
634 	/* Grab the next free tx descriptor */
635 	pointer = priv->tx_pointer;
636 	txdes = first = &priv->descs->txdes[pointer];
637 
638 	/* Setup it up with the packet head. Don't write the head to the
639 	 * ring just yet
640 	 */
641 	priv->tx_skbs[pointer] = skb;
642 	f_ctl_stat = ftgmac100_base_tx_ctlstat(priv, pointer);
643 	f_ctl_stat |= FTGMAC100_TXDES0_TXDMA_OWN;
644 	f_ctl_stat |= FTGMAC100_TXDES0_TXBUF_SIZE(len);
645 	f_ctl_stat |= FTGMAC100_TXDES0_FTS;
646 	if (nfrags == 0)
647 		f_ctl_stat |= FTGMAC100_TXDES0_LTS;
648 	txdes->txdes3 = cpu_to_le32(map);
649 
650 	/* Setup HW checksumming */
651 	csum_vlan = 0;
652 	if (skb->ip_summed == CHECKSUM_PARTIAL &&
653 	    !ftgmac100_prep_tx_csum(skb, &csum_vlan))
654 		goto drop;
655 	txdes->txdes1 = cpu_to_le32(csum_vlan);
656 
657 	/* Next descriptor */
658 	pointer = ftgmac100_next_tx_pointer(pointer);
659 
660 	/* Add the fragments */
661 	for (i = 0; i < nfrags; i++) {
662 		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
663 
664 		len = frag->size;
665 
666 		/* Map it */
667 		map = skb_frag_dma_map(priv->dev, frag, 0, len,
668 				       DMA_TO_DEVICE);
669 		if (dma_mapping_error(priv->dev, map))
670 			goto dma_err;
671 
672 		/* Setup descriptor */
673 		priv->tx_skbs[pointer] = skb;
674 		txdes = &priv->descs->txdes[pointer];
675 		ctl_stat = ftgmac100_base_tx_ctlstat(priv, pointer);
676 		ctl_stat |= FTGMAC100_TXDES0_TXDMA_OWN;
677 		ctl_stat |= FTGMAC100_TXDES0_TXBUF_SIZE(len);
678 		if (i == (nfrags - 1))
679 			ctl_stat |= FTGMAC100_TXDES0_LTS;
680 		txdes->txdes0 = cpu_to_le32(ctl_stat);
681 		txdes->txdes1 = 0;
682 		txdes->txdes3 = cpu_to_le32(map);
683 
684 		/* Next one */
685 		pointer = ftgmac100_next_tx_pointer(pointer);
686 	}
687 
688 	/* Order the previous packet and descriptor udpates
689 	 * before setting the OWN bit on the first descriptor.
690 	 */
691 	dma_wmb();
692 	first->txdes0 = cpu_to_le32(f_ctl_stat);
693 
694 	/* Update next TX pointer */
695 	priv->tx_pointer = pointer;
696 
697 	/* If there isn't enough room for all the fragments of a new packet
698 	 * in the TX ring, stop the queue. The sequence below is race free
699 	 * vs. a concurrent restart in ftgmac100_poll()
700 	 */
701 	if (unlikely(ftgmac100_tx_buf_avail(priv) < TX_THRESHOLD)) {
702 		netif_stop_queue(netdev);
703 		/* Order the queue stop with the test below */
704 		smp_mb();
705 		if (ftgmac100_tx_buf_avail(priv) >= TX_THRESHOLD)
706 			netif_wake_queue(netdev);
707 	}
708 
709 	ftgmac100_txdma_normal_prio_start_polling(priv);
710 
711 	return NETDEV_TX_OK;
712 
713  dma_err:
714 	if (net_ratelimit())
715 		netdev_err(netdev, "map tx fragment failed\n");
716 
717 	/* Free head */
718 	pointer = priv->tx_pointer;
719 	ftgmac100_free_tx_packet(priv, pointer, skb, first, f_ctl_stat);
720 	first->txdes0 = cpu_to_le32(f_ctl_stat & priv->txdes0_edotr_mask);
721 
722 	/* Then all fragments */
723 	for (j = 0; j < i; j++) {
724 		pointer = ftgmac100_next_tx_pointer(pointer);
725 		txdes = &priv->descs->txdes[pointer];
726 		ctl_stat = le32_to_cpu(txdes->txdes0);
727 		ftgmac100_free_tx_packet(priv, pointer, skb, txdes, ctl_stat);
728 		txdes->txdes0 = cpu_to_le32(ctl_stat & priv->txdes0_edotr_mask);
729 	}
730 
731 	/* This cannot be reached if we successfully mapped the
732 	 * last fragment, so we know ftgmac100_free_tx_packet()
733 	 * hasn't freed the skb yet.
734 	 */
735  drop:
736 	/* Drop the packet */
737 	dev_kfree_skb_any(skb);
738 	netdev->stats.tx_dropped++;
739 
740 	return NETDEV_TX_OK;
741 }
742 
743 static void ftgmac100_free_buffers(struct ftgmac100 *priv)
744 {
745 	int i;
746 
747 	/* Free all RX buffers */
748 	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
749 		struct ftgmac100_rxdes *rxdes = &priv->descs->rxdes[i];
750 		struct sk_buff *skb = priv->rx_skbs[i];
751 		dma_addr_t map = le32_to_cpu(rxdes->rxdes3);
752 
753 		if (!skb)
754 			continue;
755 
756 		priv->rx_skbs[i] = NULL;
757 		dma_unmap_single(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
758 		dev_kfree_skb_any(skb);
759 	}
760 
761 	/* Free all TX buffers */
762 	for (i = 0; i < TX_QUEUE_ENTRIES; i++) {
763 		struct ftgmac100_txdes *txdes = &priv->descs->txdes[i];
764 		struct sk_buff *skb = priv->tx_skbs[i];
765 
766 		if (!skb)
767 			continue;
768 		ftgmac100_free_tx_packet(priv, i, skb, txdes,
769 					 le32_to_cpu(txdes->txdes0));
770 	}
771 }
772 
773 static void ftgmac100_free_rings(struct ftgmac100 *priv)
774 {
775 	/* Free descriptors */
776 	if (priv->descs)
777 		dma_free_coherent(priv->dev, sizeof(struct ftgmac100_descs),
778 				  priv->descs, priv->descs_dma_addr);
779 
780 	/* Free scratch packet buffer */
781 	if (priv->rx_scratch)
782 		dma_free_coherent(priv->dev, RX_BUF_SIZE,
783 				  priv->rx_scratch, priv->rx_scratch_dma);
784 }
785 
786 static int ftgmac100_alloc_rings(struct ftgmac100 *priv)
787 {
788 	/* Allocate descriptors */
789 	priv->descs = dma_zalloc_coherent(priv->dev,
790 					  sizeof(struct ftgmac100_descs),
791 					  &priv->descs_dma_addr, GFP_KERNEL);
792 	if (!priv->descs)
793 		return -ENOMEM;
794 
795 	/* Allocate scratch packet buffer */
796 	priv->rx_scratch = dma_alloc_coherent(priv->dev,
797 					      RX_BUF_SIZE,
798 					      &priv->rx_scratch_dma,
799 					      GFP_KERNEL);
800 	if (!priv->rx_scratch)
801 		return -ENOMEM;
802 
803 	return 0;
804 }
805 
806 static void ftgmac100_init_rings(struct ftgmac100 *priv)
807 {
808 	struct ftgmac100_rxdes *rxdes;
809 	struct ftgmac100_txdes *txdes;
810 	int i;
811 
812 	/* Initialize RX ring */
813 	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
814 		rxdes = &priv->descs->rxdes[i];
815 		rxdes->rxdes0 = 0;
816 		rxdes->rxdes3 = cpu_to_le32(priv->rx_scratch_dma);
817 	}
818 	/* Mark the end of the ring */
819 	rxdes->rxdes0 |= cpu_to_le32(priv->rxdes0_edorr_mask);
820 
821 	/* Initialize TX ring */
822 	for (i = 0; i < TX_QUEUE_ENTRIES; i++) {
823 		txdes = &priv->descs->txdes[i];
824 		txdes->txdes0 = 0;
825 	}
826 	txdes->txdes0 |= cpu_to_le32(priv->txdes0_edotr_mask);
827 }
828 
829 static int ftgmac100_alloc_rx_buffers(struct ftgmac100 *priv)
830 {
831 	int i;
832 
833 	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
834 		struct ftgmac100_rxdes *rxdes = &priv->descs->rxdes[i];
835 
836 		if (ftgmac100_alloc_rx_buf(priv, i, rxdes, GFP_KERNEL))
837 			return -ENOMEM;
838 	}
839 	return 0;
840 }
841 
842 static void ftgmac100_adjust_link(struct net_device *netdev)
843 {
844 	struct ftgmac100 *priv = netdev_priv(netdev);
845 	struct phy_device *phydev = netdev->phydev;
846 	int new_speed;
847 
848 	/* We store "no link" as speed 0 */
849 	if (!phydev->link)
850 		new_speed = 0;
851 	else
852 		new_speed = phydev->speed;
853 
854 	if (phydev->speed == priv->cur_speed &&
855 	    phydev->duplex == priv->cur_duplex)
856 		return;
857 
858 	/* Print status if we have a link or we had one and just lost it,
859 	 * don't print otherwise.
860 	 */
861 	if (new_speed || priv->cur_speed)
862 		phy_print_status(phydev);
863 
864 	priv->cur_speed = new_speed;
865 	priv->cur_duplex = phydev->duplex;
866 
867 	/* Link is down, do nothing else */
868 	if (!new_speed)
869 		return;
870 
871 	/* Disable all interrupts */
872 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
873 
874 	/* Reset the adapter asynchronously */
875 	schedule_work(&priv->reset_task);
876 }
877 
878 static int ftgmac100_mii_probe(struct ftgmac100 *priv)
879 {
880 	struct net_device *netdev = priv->netdev;
881 	struct phy_device *phydev;
882 
883 	phydev = phy_find_first(priv->mii_bus);
884 	if (!phydev) {
885 		netdev_info(netdev, "%s: no PHY found\n", netdev->name);
886 		return -ENODEV;
887 	}
888 
889 	phydev = phy_connect(netdev, phydev_name(phydev),
890 			     &ftgmac100_adjust_link, PHY_INTERFACE_MODE_GMII);
891 
892 	if (IS_ERR(phydev)) {
893 		netdev_err(netdev, "%s: Could not attach to PHY\n", netdev->name);
894 		return PTR_ERR(phydev);
895 	}
896 
897 	return 0;
898 }
899 
900 static int ftgmac100_mdiobus_read(struct mii_bus *bus, int phy_addr, int regnum)
901 {
902 	struct net_device *netdev = bus->priv;
903 	struct ftgmac100 *priv = netdev_priv(netdev);
904 	unsigned int phycr;
905 	int i;
906 
907 	phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
908 
909 	/* preserve MDC cycle threshold */
910 	phycr &= FTGMAC100_PHYCR_MDC_CYCTHR_MASK;
911 
912 	phycr |= FTGMAC100_PHYCR_PHYAD(phy_addr) |
913 		 FTGMAC100_PHYCR_REGAD(regnum) |
914 		 FTGMAC100_PHYCR_MIIRD;
915 
916 	iowrite32(phycr, priv->base + FTGMAC100_OFFSET_PHYCR);
917 
918 	for (i = 0; i < 10; i++) {
919 		phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
920 
921 		if ((phycr & FTGMAC100_PHYCR_MIIRD) == 0) {
922 			int data;
923 
924 			data = ioread32(priv->base + FTGMAC100_OFFSET_PHYDATA);
925 			return FTGMAC100_PHYDATA_MIIRDATA(data);
926 		}
927 
928 		udelay(100);
929 	}
930 
931 	netdev_err(netdev, "mdio read timed out\n");
932 	return -EIO;
933 }
934 
935 static int ftgmac100_mdiobus_write(struct mii_bus *bus, int phy_addr,
936 				   int regnum, u16 value)
937 {
938 	struct net_device *netdev = bus->priv;
939 	struct ftgmac100 *priv = netdev_priv(netdev);
940 	unsigned int phycr;
941 	int data;
942 	int i;
943 
944 	phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
945 
946 	/* preserve MDC cycle threshold */
947 	phycr &= FTGMAC100_PHYCR_MDC_CYCTHR_MASK;
948 
949 	phycr |= FTGMAC100_PHYCR_PHYAD(phy_addr) |
950 		 FTGMAC100_PHYCR_REGAD(regnum) |
951 		 FTGMAC100_PHYCR_MIIWR;
952 
953 	data = FTGMAC100_PHYDATA_MIIWDATA(value);
954 
955 	iowrite32(data, priv->base + FTGMAC100_OFFSET_PHYDATA);
956 	iowrite32(phycr, priv->base + FTGMAC100_OFFSET_PHYCR);
957 
958 	for (i = 0; i < 10; i++) {
959 		phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
960 
961 		if ((phycr & FTGMAC100_PHYCR_MIIWR) == 0)
962 			return 0;
963 
964 		udelay(100);
965 	}
966 
967 	netdev_err(netdev, "mdio write timed out\n");
968 	return -EIO;
969 }
970 
971 static void ftgmac100_get_drvinfo(struct net_device *netdev,
972 				  struct ethtool_drvinfo *info)
973 {
974 	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
975 	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
976 	strlcpy(info->bus_info, dev_name(&netdev->dev), sizeof(info->bus_info));
977 }
978 
979 static const struct ethtool_ops ftgmac100_ethtool_ops = {
980 	.get_drvinfo		= ftgmac100_get_drvinfo,
981 	.get_link		= ethtool_op_get_link,
982 	.get_link_ksettings	= phy_ethtool_get_link_ksettings,
983 	.set_link_ksettings	= phy_ethtool_set_link_ksettings,
984 };
985 
986 static irqreturn_t ftgmac100_interrupt(int irq, void *dev_id)
987 {
988 	struct net_device *netdev = dev_id;
989 	struct ftgmac100 *priv = netdev_priv(netdev);
990 	unsigned int status, new_mask = FTGMAC100_INT_BAD;
991 
992 	/* Fetch and clear interrupt bits, process abnormal ones */
993 	status = ioread32(priv->base + FTGMAC100_OFFSET_ISR);
994 	iowrite32(status, priv->base + FTGMAC100_OFFSET_ISR);
995 	if (unlikely(status & FTGMAC100_INT_BAD)) {
996 
997 		/* RX buffer unavailable */
998 		if (status & FTGMAC100_INT_NO_RXBUF)
999 			netdev->stats.rx_over_errors++;
1000 
1001 		/* received packet lost due to RX FIFO full */
1002 		if (status & FTGMAC100_INT_RPKT_LOST)
1003 			netdev->stats.rx_fifo_errors++;
1004 
1005 		/* sent packet lost due to excessive TX collision */
1006 		if (status & FTGMAC100_INT_XPKT_LOST)
1007 			netdev->stats.tx_fifo_errors++;
1008 
1009 		/* AHB error -> Reset the chip */
1010 		if (status & FTGMAC100_INT_AHB_ERR) {
1011 			if (net_ratelimit())
1012 				netdev_warn(netdev,
1013 					   "AHB bus error ! Resetting chip.\n");
1014 			iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1015 			schedule_work(&priv->reset_task);
1016 			return IRQ_HANDLED;
1017 		}
1018 
1019 		/* We may need to restart the MAC after such errors, delay
1020 		 * this until after we have freed some Rx buffers though
1021 		 */
1022 		priv->need_mac_restart = true;
1023 
1024 		/* Disable those errors until we restart */
1025 		new_mask &= ~status;
1026 	}
1027 
1028 	/* Only enable "bad" interrupts while NAPI is on */
1029 	iowrite32(new_mask, priv->base + FTGMAC100_OFFSET_IER);
1030 
1031 	/* Schedule NAPI bh */
1032 	napi_schedule_irqoff(&priv->napi);
1033 
1034 	return IRQ_HANDLED;
1035 }
1036 
1037 static bool ftgmac100_check_rx(struct ftgmac100 *priv)
1038 {
1039 	struct ftgmac100_rxdes *rxdes = &priv->descs->rxdes[priv->rx_pointer];
1040 
1041 	/* Do we have a packet ? */
1042 	return !!(rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_RXPKT_RDY));
1043 }
1044 
1045 static int ftgmac100_poll(struct napi_struct *napi, int budget)
1046 {
1047 	struct ftgmac100 *priv = container_of(napi, struct ftgmac100, napi);
1048 	int work_done = 0;
1049 	bool more;
1050 
1051 	/* Handle TX completions */
1052 	if (ftgmac100_tx_buf_cleanable(priv))
1053 		ftgmac100_tx_complete(priv);
1054 
1055 	/* Handle RX packets */
1056 	do {
1057 		more = ftgmac100_rx_packet(priv, &work_done);
1058 	} while (more && work_done < budget);
1059 
1060 
1061 	/* The interrupt is telling us to kick the MAC back to life
1062 	 * after an RX overflow
1063 	 */
1064 	if (unlikely(priv->need_mac_restart)) {
1065 		ftgmac100_start_hw(priv);
1066 
1067 		/* Re-enable "bad" interrupts */
1068 		iowrite32(FTGMAC100_INT_BAD,
1069 			  priv->base + FTGMAC100_OFFSET_IER);
1070 	}
1071 
1072 	/* As long as we are waiting for transmit packets to be
1073 	 * completed we keep NAPI going
1074 	 */
1075 	if (ftgmac100_tx_buf_cleanable(priv))
1076 		work_done = budget;
1077 
1078 	if (work_done < budget) {
1079 		/* We are about to re-enable all interrupts. However
1080 		 * the HW has been latching RX/TX packet interrupts while
1081 		 * they were masked. So we clear them first, then we need
1082 		 * to re-check if there's something to process
1083 		 */
1084 		iowrite32(FTGMAC100_INT_RXTX,
1085 			  priv->base + FTGMAC100_OFFSET_ISR);
1086 		if (ftgmac100_check_rx(priv) ||
1087 		    ftgmac100_tx_buf_cleanable(priv))
1088 			return budget;
1089 
1090 		/* deschedule NAPI */
1091 		napi_complete(napi);
1092 
1093 		/* enable all interrupts */
1094 		iowrite32(FTGMAC100_INT_ALL,
1095 			  priv->base + FTGMAC100_OFFSET_IER);
1096 	}
1097 
1098 	return work_done;
1099 }
1100 
1101 static int ftgmac100_init_all(struct ftgmac100 *priv, bool ignore_alloc_err)
1102 {
1103 	int err = 0;
1104 
1105 	/* Re-init descriptors (adjust queue sizes) */
1106 	ftgmac100_init_rings(priv);
1107 
1108 	/* Realloc rx descriptors */
1109 	err = ftgmac100_alloc_rx_buffers(priv);
1110 	if (err && !ignore_alloc_err)
1111 		return err;
1112 
1113 	/* Reinit and restart HW */
1114 	ftgmac100_init_hw(priv);
1115 	ftgmac100_start_hw(priv);
1116 
1117 	/* Re-enable the device */
1118 	napi_enable(&priv->napi);
1119 	netif_start_queue(priv->netdev);
1120 
1121 	/* Enable all interrupts */
1122 	iowrite32(FTGMAC100_INT_ALL, priv->base + FTGMAC100_OFFSET_IER);
1123 
1124 	return err;
1125 }
1126 
1127 static void ftgmac100_reset_task(struct work_struct *work)
1128 {
1129 	struct ftgmac100 *priv = container_of(work, struct ftgmac100,
1130 					      reset_task);
1131 	struct net_device *netdev = priv->netdev;
1132 	int err;
1133 
1134 	netdev_dbg(netdev, "Resetting NIC...\n");
1135 
1136 	/* Lock the world */
1137 	rtnl_lock();
1138 	if (netdev->phydev)
1139 		mutex_lock(&netdev->phydev->lock);
1140 	if (priv->mii_bus)
1141 		mutex_lock(&priv->mii_bus->mdio_lock);
1142 
1143 
1144 	/* Check if the interface is still up */
1145 	if (!netif_running(netdev))
1146 		goto bail;
1147 
1148 	/* Stop the network stack */
1149 	netif_trans_update(netdev);
1150 	napi_disable(&priv->napi);
1151 	netif_tx_disable(netdev);
1152 
1153 	/* Stop and reset the MAC */
1154 	ftgmac100_stop_hw(priv);
1155 	err = ftgmac100_reset_and_config_mac(priv);
1156 	if (err) {
1157 		/* Not much we can do ... it might come back... */
1158 		netdev_err(netdev, "attempting to continue...\n");
1159 	}
1160 
1161 	/* Free all rx and tx buffers */
1162 	ftgmac100_free_buffers(priv);
1163 
1164 	/* Setup everything again and restart chip */
1165 	ftgmac100_init_all(priv, true);
1166 
1167 	netdev_dbg(netdev, "Reset done !\n");
1168  bail:
1169 	if (priv->mii_bus)
1170 		mutex_unlock(&priv->mii_bus->mdio_lock);
1171 	if (netdev->phydev)
1172 		mutex_unlock(&netdev->phydev->lock);
1173 	rtnl_unlock();
1174 }
1175 
1176 static int ftgmac100_open(struct net_device *netdev)
1177 {
1178 	struct ftgmac100 *priv = netdev_priv(netdev);
1179 	int err;
1180 
1181 	/* Allocate ring buffers  */
1182 	err = ftgmac100_alloc_rings(priv);
1183 	if (err) {
1184 		netdev_err(netdev, "Failed to allocate descriptors\n");
1185 		return err;
1186 	}
1187 
1188 	/* When using NC-SI we force the speed to 100Mbit/s full duplex,
1189 	 *
1190 	 * Otherwise we leave it set to 0 (no link), the link
1191 	 * message from the PHY layer will handle setting it up to
1192 	 * something else if needed.
1193 	 */
1194 	if (priv->use_ncsi) {
1195 		priv->cur_duplex = DUPLEX_FULL;
1196 		priv->cur_speed = SPEED_100;
1197 	} else {
1198 		priv->cur_duplex = 0;
1199 		priv->cur_speed = 0;
1200 	}
1201 
1202 	/* Reset the hardware */
1203 	err = ftgmac100_reset_and_config_mac(priv);
1204 	if (err)
1205 		goto err_hw;
1206 
1207 	/* Initialize NAPI */
1208 	netif_napi_add(netdev, &priv->napi, ftgmac100_poll, 64);
1209 
1210 	/* Grab our interrupt */
1211 	err = request_irq(netdev->irq, ftgmac100_interrupt, 0, netdev->name, netdev);
1212 	if (err) {
1213 		netdev_err(netdev, "failed to request irq %d\n", netdev->irq);
1214 		goto err_irq;
1215 	}
1216 
1217 	/* Start things up */
1218 	err = ftgmac100_init_all(priv, false);
1219 	if (err) {
1220 		netdev_err(netdev, "Failed to allocate packet buffers\n");
1221 		goto err_alloc;
1222 	}
1223 
1224 	if (netdev->phydev) {
1225 		/* If we have a PHY, start polling */
1226 		phy_start(netdev->phydev);
1227 	} else if (priv->use_ncsi) {
1228 		/* If using NC-SI, set our carrier on and start the stack */
1229 		netif_carrier_on(netdev);
1230 
1231 		/* Start the NCSI device */
1232 		err = ncsi_start_dev(priv->ndev);
1233 		if (err)
1234 			goto err_ncsi;
1235 	}
1236 
1237 	return 0;
1238 
1239  err_ncsi:
1240 	napi_disable(&priv->napi);
1241 	netif_stop_queue(netdev);
1242  err_alloc:
1243 	ftgmac100_free_buffers(priv);
1244 	free_irq(netdev->irq, netdev);
1245  err_irq:
1246 	netif_napi_del(&priv->napi);
1247  err_hw:
1248 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1249 	ftgmac100_free_rings(priv);
1250 	return err;
1251 }
1252 
1253 static int ftgmac100_stop(struct net_device *netdev)
1254 {
1255 	struct ftgmac100 *priv = netdev_priv(netdev);
1256 
1257 	/* Note about the reset task: We are called with the rtnl lock
1258 	 * held, so we are synchronized against the core of the reset
1259 	 * task. We must not try to synchronously cancel it otherwise
1260 	 * we can deadlock. But since it will test for netif_running()
1261 	 * which has already been cleared by the net core, we don't
1262 	 * anything special to do.
1263 	 */
1264 
1265 	/* disable all interrupts */
1266 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1267 
1268 	netif_stop_queue(netdev);
1269 	napi_disable(&priv->napi);
1270 	netif_napi_del(&priv->napi);
1271 	if (netdev->phydev)
1272 		phy_stop(netdev->phydev);
1273 	else if (priv->use_ncsi)
1274 		ncsi_stop_dev(priv->ndev);
1275 
1276 	ftgmac100_stop_hw(priv);
1277 	free_irq(netdev->irq, netdev);
1278 	ftgmac100_free_buffers(priv);
1279 	ftgmac100_free_rings(priv);
1280 
1281 	return 0;
1282 }
1283 
1284 /* optional */
1285 static int ftgmac100_do_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
1286 {
1287 	if (!netdev->phydev)
1288 		return -ENXIO;
1289 
1290 	return phy_mii_ioctl(netdev->phydev, ifr, cmd);
1291 }
1292 
1293 static void ftgmac100_tx_timeout(struct net_device *netdev)
1294 {
1295 	struct ftgmac100 *priv = netdev_priv(netdev);
1296 
1297 	/* Disable all interrupts */
1298 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1299 
1300 	/* Do the reset outside of interrupt context */
1301 	schedule_work(&priv->reset_task);
1302 }
1303 
1304 static const struct net_device_ops ftgmac100_netdev_ops = {
1305 	.ndo_open		= ftgmac100_open,
1306 	.ndo_stop		= ftgmac100_stop,
1307 	.ndo_start_xmit		= ftgmac100_hard_start_xmit,
1308 	.ndo_set_mac_address	= ftgmac100_set_mac_addr,
1309 	.ndo_validate_addr	= eth_validate_addr,
1310 	.ndo_do_ioctl		= ftgmac100_do_ioctl,
1311 	.ndo_tx_timeout		= ftgmac100_tx_timeout,
1312 };
1313 
1314 static int ftgmac100_setup_mdio(struct net_device *netdev)
1315 {
1316 	struct ftgmac100 *priv = netdev_priv(netdev);
1317 	struct platform_device *pdev = to_platform_device(priv->dev);
1318 	int i, err = 0;
1319 	u32 reg;
1320 
1321 	/* initialize mdio bus */
1322 	priv->mii_bus = mdiobus_alloc();
1323 	if (!priv->mii_bus)
1324 		return -EIO;
1325 
1326 	if (priv->is_aspeed) {
1327 		/* This driver supports the old MDIO interface */
1328 		reg = ioread32(priv->base + FTGMAC100_OFFSET_REVR);
1329 		reg &= ~FTGMAC100_REVR_NEW_MDIO_INTERFACE;
1330 		iowrite32(reg, priv->base + FTGMAC100_OFFSET_REVR);
1331 	};
1332 
1333 	priv->mii_bus->name = "ftgmac100_mdio";
1334 	snprintf(priv->mii_bus->id, MII_BUS_ID_SIZE, "%s-%d",
1335 		 pdev->name, pdev->id);
1336 	priv->mii_bus->priv = priv->netdev;
1337 	priv->mii_bus->read = ftgmac100_mdiobus_read;
1338 	priv->mii_bus->write = ftgmac100_mdiobus_write;
1339 
1340 	for (i = 0; i < PHY_MAX_ADDR; i++)
1341 		priv->mii_bus->irq[i] = PHY_POLL;
1342 
1343 	err = mdiobus_register(priv->mii_bus);
1344 	if (err) {
1345 		dev_err(priv->dev, "Cannot register MDIO bus!\n");
1346 		goto err_register_mdiobus;
1347 	}
1348 
1349 	err = ftgmac100_mii_probe(priv);
1350 	if (err) {
1351 		dev_err(priv->dev, "MII Probe failed!\n");
1352 		goto err_mii_probe;
1353 	}
1354 
1355 	return 0;
1356 
1357 err_mii_probe:
1358 	mdiobus_unregister(priv->mii_bus);
1359 err_register_mdiobus:
1360 	mdiobus_free(priv->mii_bus);
1361 	return err;
1362 }
1363 
1364 static void ftgmac100_destroy_mdio(struct net_device *netdev)
1365 {
1366 	struct ftgmac100 *priv = netdev_priv(netdev);
1367 
1368 	if (!netdev->phydev)
1369 		return;
1370 
1371 	phy_disconnect(netdev->phydev);
1372 	mdiobus_unregister(priv->mii_bus);
1373 	mdiobus_free(priv->mii_bus);
1374 }
1375 
1376 static void ftgmac100_ncsi_handler(struct ncsi_dev *nd)
1377 {
1378 	if (unlikely(nd->state != ncsi_dev_state_functional))
1379 		return;
1380 
1381 	netdev_info(nd->dev, "NCSI interface %s\n",
1382 		    nd->link_up ? "up" : "down");
1383 }
1384 
1385 static int ftgmac100_probe(struct platform_device *pdev)
1386 {
1387 	struct resource *res;
1388 	int irq;
1389 	struct net_device *netdev;
1390 	struct ftgmac100 *priv;
1391 	struct device_node *np;
1392 	int err = 0;
1393 
1394 	if (!pdev)
1395 		return -ENODEV;
1396 
1397 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1398 	if (!res)
1399 		return -ENXIO;
1400 
1401 	irq = platform_get_irq(pdev, 0);
1402 	if (irq < 0)
1403 		return irq;
1404 
1405 	/* setup net_device */
1406 	netdev = alloc_etherdev(sizeof(*priv));
1407 	if (!netdev) {
1408 		err = -ENOMEM;
1409 		goto err_alloc_etherdev;
1410 	}
1411 
1412 	SET_NETDEV_DEV(netdev, &pdev->dev);
1413 
1414 	netdev->ethtool_ops = &ftgmac100_ethtool_ops;
1415 	netdev->netdev_ops = &ftgmac100_netdev_ops;
1416 	netdev->watchdog_timeo = 5 * HZ;
1417 
1418 	platform_set_drvdata(pdev, netdev);
1419 
1420 	/* setup private data */
1421 	priv = netdev_priv(netdev);
1422 	priv->netdev = netdev;
1423 	priv->dev = &pdev->dev;
1424 	INIT_WORK(&priv->reset_task, ftgmac100_reset_task);
1425 
1426 	/* map io memory */
1427 	priv->res = request_mem_region(res->start, resource_size(res),
1428 				       dev_name(&pdev->dev));
1429 	if (!priv->res) {
1430 		dev_err(&pdev->dev, "Could not reserve memory region\n");
1431 		err = -ENOMEM;
1432 		goto err_req_mem;
1433 	}
1434 
1435 	priv->base = ioremap(res->start, resource_size(res));
1436 	if (!priv->base) {
1437 		dev_err(&pdev->dev, "Failed to ioremap ethernet registers\n");
1438 		err = -EIO;
1439 		goto err_ioremap;
1440 	}
1441 
1442 	netdev->irq = irq;
1443 
1444 	/* MAC address from chip or random one */
1445 	ftgmac100_initial_mac(priv);
1446 
1447 	np = pdev->dev.of_node;
1448 	if (np && (of_device_is_compatible(np, "aspeed,ast2400-mac") ||
1449 		   of_device_is_compatible(np, "aspeed,ast2500-mac"))) {
1450 		priv->rxdes0_edorr_mask = BIT(30);
1451 		priv->txdes0_edotr_mask = BIT(30);
1452 		priv->is_aspeed = true;
1453 	} else {
1454 		priv->rxdes0_edorr_mask = BIT(15);
1455 		priv->txdes0_edotr_mask = BIT(15);
1456 	}
1457 
1458 	if (np && of_get_property(np, "use-ncsi", NULL)) {
1459 		if (!IS_ENABLED(CONFIG_NET_NCSI)) {
1460 			dev_err(&pdev->dev, "NCSI stack not enabled\n");
1461 			goto err_ncsi_dev;
1462 		}
1463 
1464 		dev_info(&pdev->dev, "Using NCSI interface\n");
1465 		priv->use_ncsi = true;
1466 		priv->ndev = ncsi_register_dev(netdev, ftgmac100_ncsi_handler);
1467 		if (!priv->ndev)
1468 			goto err_ncsi_dev;
1469 	} else {
1470 		priv->use_ncsi = false;
1471 		err = ftgmac100_setup_mdio(netdev);
1472 		if (err)
1473 			goto err_setup_mdio;
1474 	}
1475 
1476 	/* Base feature set */
1477 	netdev->hw_features = NETIF_F_RXCSUM | NETIF_F_HW_CSUM |
1478 		NETIF_F_GRO | NETIF_F_SG;
1479 
1480 	/* AST2400  doesn't have working HW checksum generation */
1481 	if (np && (of_device_is_compatible(np, "aspeed,ast2400-mac")))
1482 		netdev->hw_features &= ~NETIF_F_HW_CSUM;
1483 	if (np && of_get_property(np, "no-hw-checksum", NULL))
1484 		netdev->hw_features &= ~(NETIF_F_HW_CSUM | NETIF_F_RXCSUM);
1485 	netdev->features |= netdev->hw_features;
1486 
1487 	/* register network device */
1488 	err = register_netdev(netdev);
1489 	if (err) {
1490 		dev_err(&pdev->dev, "Failed to register netdev\n");
1491 		goto err_register_netdev;
1492 	}
1493 
1494 	netdev_info(netdev, "irq %d, mapped at %p\n", netdev->irq, priv->base);
1495 
1496 	return 0;
1497 
1498 err_ncsi_dev:
1499 err_register_netdev:
1500 	ftgmac100_destroy_mdio(netdev);
1501 err_setup_mdio:
1502 	iounmap(priv->base);
1503 err_ioremap:
1504 	release_resource(priv->res);
1505 err_req_mem:
1506 	netif_napi_del(&priv->napi);
1507 	free_netdev(netdev);
1508 err_alloc_etherdev:
1509 	return err;
1510 }
1511 
1512 static int ftgmac100_remove(struct platform_device *pdev)
1513 {
1514 	struct net_device *netdev;
1515 	struct ftgmac100 *priv;
1516 
1517 	netdev = platform_get_drvdata(pdev);
1518 	priv = netdev_priv(netdev);
1519 
1520 	unregister_netdev(netdev);
1521 
1522 	/* There's a small chance the reset task will have been re-queued,
1523 	 * during stop, make sure it's gone before we free the structure.
1524 	 */
1525 	cancel_work_sync(&priv->reset_task);
1526 
1527 	ftgmac100_destroy_mdio(netdev);
1528 
1529 	iounmap(priv->base);
1530 	release_resource(priv->res);
1531 
1532 	netif_napi_del(&priv->napi);
1533 	free_netdev(netdev);
1534 	return 0;
1535 }
1536 
1537 static const struct of_device_id ftgmac100_of_match[] = {
1538 	{ .compatible = "faraday,ftgmac100" },
1539 	{ }
1540 };
1541 MODULE_DEVICE_TABLE(of, ftgmac100_of_match);
1542 
1543 static struct platform_driver ftgmac100_driver = {
1544 	.probe	= ftgmac100_probe,
1545 	.remove	= ftgmac100_remove,
1546 	.driver	= {
1547 		.name		= DRV_NAME,
1548 		.of_match_table	= ftgmac100_of_match,
1549 	},
1550 };
1551 module_platform_driver(ftgmac100_driver);
1552 
1553 MODULE_AUTHOR("Po-Yu Chuang <ratbert@faraday-tech.com>");
1554 MODULE_DESCRIPTION("FTGMAC100 driver");
1555 MODULE_LICENSE("GPL");
1556