1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Faraday FTGMAC100 Gigabit 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/clk.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/etherdevice.h>
14 #include <linux/ethtool.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/module.h>
18 #include <linux/netdevice.h>
19 #include <linux/of.h>
20 #include <linux/of_mdio.h>
21 #include <linux/phy.h>
22 #include <linux/platform_device.h>
23 #include <linux/property.h>
24 #include <linux/crc32.h>
25 #include <linux/if_vlan.h>
26 #include <linux/of_net.h>
27 #include <net/ip.h>
28 #include <net/ncsi.h>
29 
30 #include "ftgmac100.h"
31 
32 #define DRV_NAME	"ftgmac100"
33 
34 /* Arbitrary values, I am not sure the HW has limits */
35 #define MAX_RX_QUEUE_ENTRIES	1024
36 #define MAX_TX_QUEUE_ENTRIES	1024
37 #define MIN_RX_QUEUE_ENTRIES	32
38 #define MIN_TX_QUEUE_ENTRIES	32
39 
40 /* Defaults */
41 #define DEF_RX_QUEUE_ENTRIES	128
42 #define DEF_TX_QUEUE_ENTRIES	128
43 
44 #define MAX_PKT_SIZE		1536
45 #define RX_BUF_SIZE		MAX_PKT_SIZE	/* must be smaller than 0x3fff */
46 
47 /* Min number of tx ring entries before stopping queue */
48 #define TX_THRESHOLD		(MAX_SKB_FRAGS + 1)
49 
50 #define FTGMAC_100MHZ		100000000
51 #define FTGMAC_25MHZ		25000000
52 
53 struct ftgmac100 {
54 	/* Registers */
55 	struct resource *res;
56 	void __iomem *base;
57 
58 	/* Rx ring */
59 	unsigned int rx_q_entries;
60 	struct ftgmac100_rxdes *rxdes;
61 	dma_addr_t rxdes_dma;
62 	struct sk_buff **rx_skbs;
63 	unsigned int rx_pointer;
64 	u32 rxdes0_edorr_mask;
65 
66 	/* Tx ring */
67 	unsigned int tx_q_entries;
68 	struct ftgmac100_txdes *txdes;
69 	dma_addr_t txdes_dma;
70 	struct sk_buff **tx_skbs;
71 	unsigned int tx_clean_pointer;
72 	unsigned int tx_pointer;
73 	u32 txdes0_edotr_mask;
74 
75 	/* Used to signal the reset task of ring change request */
76 	unsigned int new_rx_q_entries;
77 	unsigned int new_tx_q_entries;
78 
79 	/* Scratch page to use when rx skb alloc fails */
80 	void *rx_scratch;
81 	dma_addr_t rx_scratch_dma;
82 
83 	/* Component structures */
84 	struct net_device *netdev;
85 	struct device *dev;
86 	struct ncsi_dev *ndev;
87 	struct napi_struct napi;
88 	struct work_struct reset_task;
89 	struct mii_bus *mii_bus;
90 	struct clk *clk;
91 
92 	/* AST2500/AST2600 RMII ref clock gate */
93 	struct clk *rclk;
94 
95 	/* Link management */
96 	int cur_speed;
97 	int cur_duplex;
98 	bool use_ncsi;
99 
100 	/* Multicast filter settings */
101 	u32 maht0;
102 	u32 maht1;
103 
104 	/* Flow control settings */
105 	bool tx_pause;
106 	bool rx_pause;
107 	bool aneg_pause;
108 
109 	/* Misc */
110 	bool need_mac_restart;
111 	bool is_aspeed;
112 };
113 
114 static int ftgmac100_reset_mac(struct ftgmac100 *priv, u32 maccr)
115 {
116 	struct net_device *netdev = priv->netdev;
117 	int i;
118 
119 	/* NOTE: reset clears all registers */
120 	iowrite32(maccr, priv->base + FTGMAC100_OFFSET_MACCR);
121 	iowrite32(maccr | FTGMAC100_MACCR_SW_RST,
122 		  priv->base + FTGMAC100_OFFSET_MACCR);
123 	for (i = 0; i < 200; i++) {
124 		unsigned int maccr;
125 
126 		maccr = ioread32(priv->base + FTGMAC100_OFFSET_MACCR);
127 		if (!(maccr & FTGMAC100_MACCR_SW_RST))
128 			return 0;
129 
130 		udelay(1);
131 	}
132 
133 	netdev_err(netdev, "Hardware reset failed\n");
134 	return -EIO;
135 }
136 
137 static int ftgmac100_reset_and_config_mac(struct ftgmac100 *priv)
138 {
139 	u32 maccr = 0;
140 
141 	switch (priv->cur_speed) {
142 	case SPEED_10:
143 	case 0: /* no link */
144 		break;
145 
146 	case SPEED_100:
147 		maccr |= FTGMAC100_MACCR_FAST_MODE;
148 		break;
149 
150 	case SPEED_1000:
151 		maccr |= FTGMAC100_MACCR_GIGA_MODE;
152 		break;
153 	default:
154 		netdev_err(priv->netdev, "Unknown speed %d !\n",
155 			   priv->cur_speed);
156 		break;
157 	}
158 
159 	/* (Re)initialize the queue pointers */
160 	priv->rx_pointer = 0;
161 	priv->tx_clean_pointer = 0;
162 	priv->tx_pointer = 0;
163 
164 	/* The doc says reset twice with 10us interval */
165 	if (ftgmac100_reset_mac(priv, maccr))
166 		return -EIO;
167 	usleep_range(10, 1000);
168 	return ftgmac100_reset_mac(priv, maccr);
169 }
170 
171 static void ftgmac100_write_mac_addr(struct ftgmac100 *priv, const u8 *mac)
172 {
173 	unsigned int maddr = mac[0] << 8 | mac[1];
174 	unsigned int laddr = mac[2] << 24 | mac[3] << 16 | mac[4] << 8 | mac[5];
175 
176 	iowrite32(maddr, priv->base + FTGMAC100_OFFSET_MAC_MADR);
177 	iowrite32(laddr, priv->base + FTGMAC100_OFFSET_MAC_LADR);
178 }
179 
180 static int ftgmac100_initial_mac(struct ftgmac100 *priv)
181 {
182 	u8 mac[ETH_ALEN];
183 	unsigned int m;
184 	unsigned int l;
185 	int err;
186 
187 	err = of_get_ethdev_address(priv->dev->of_node, priv->netdev);
188 	if (err == -EPROBE_DEFER)
189 		return err;
190 	if (!err) {
191 		dev_info(priv->dev, "Read MAC address %pM from device tree\n",
192 			 priv->netdev->dev_addr);
193 		return 0;
194 	}
195 
196 	m = ioread32(priv->base + FTGMAC100_OFFSET_MAC_MADR);
197 	l = ioread32(priv->base + FTGMAC100_OFFSET_MAC_LADR);
198 
199 	mac[0] = (m >> 8) & 0xff;
200 	mac[1] = m & 0xff;
201 	mac[2] = (l >> 24) & 0xff;
202 	mac[3] = (l >> 16) & 0xff;
203 	mac[4] = (l >> 8) & 0xff;
204 	mac[5] = l & 0xff;
205 
206 	if (is_valid_ether_addr(mac)) {
207 		eth_hw_addr_set(priv->netdev, mac);
208 		dev_info(priv->dev, "Read MAC address %pM from chip\n", mac);
209 	} else {
210 		eth_hw_addr_random(priv->netdev);
211 		dev_info(priv->dev, "Generated random MAC address %pM\n",
212 			 priv->netdev->dev_addr);
213 	}
214 
215 	return 0;
216 }
217 
218 static int ftgmac100_set_mac_addr(struct net_device *dev, void *p)
219 {
220 	int ret;
221 
222 	ret = eth_prepare_mac_addr_change(dev, p);
223 	if (ret < 0)
224 		return ret;
225 
226 	eth_commit_mac_addr_change(dev, p);
227 	ftgmac100_write_mac_addr(netdev_priv(dev), dev->dev_addr);
228 
229 	return 0;
230 }
231 
232 static void ftgmac100_config_pause(struct ftgmac100 *priv)
233 {
234 	u32 fcr = FTGMAC100_FCR_PAUSE_TIME(16);
235 
236 	/* Throttle tx queue when receiving pause frames */
237 	if (priv->rx_pause)
238 		fcr |= FTGMAC100_FCR_FC_EN;
239 
240 	/* Enables sending pause frames when the RX queue is past a
241 	 * certain threshold.
242 	 */
243 	if (priv->tx_pause)
244 		fcr |= FTGMAC100_FCR_FCTHR_EN;
245 
246 	iowrite32(fcr, priv->base + FTGMAC100_OFFSET_FCR);
247 }
248 
249 static void ftgmac100_init_hw(struct ftgmac100 *priv)
250 {
251 	u32 reg, rfifo_sz, tfifo_sz;
252 
253 	/* Clear stale interrupts */
254 	reg = ioread32(priv->base + FTGMAC100_OFFSET_ISR);
255 	iowrite32(reg, priv->base + FTGMAC100_OFFSET_ISR);
256 
257 	/* Setup RX ring buffer base */
258 	iowrite32(priv->rxdes_dma, priv->base + FTGMAC100_OFFSET_RXR_BADR);
259 
260 	/* Setup TX ring buffer base */
261 	iowrite32(priv->txdes_dma, priv->base + FTGMAC100_OFFSET_NPTXR_BADR);
262 
263 	/* Configure RX buffer size */
264 	iowrite32(FTGMAC100_RBSR_SIZE(RX_BUF_SIZE),
265 		  priv->base + FTGMAC100_OFFSET_RBSR);
266 
267 	/* Set RX descriptor autopoll */
268 	iowrite32(FTGMAC100_APTC_RXPOLL_CNT(1),
269 		  priv->base + FTGMAC100_OFFSET_APTC);
270 
271 	/* Write MAC address */
272 	ftgmac100_write_mac_addr(priv, priv->netdev->dev_addr);
273 
274 	/* Write multicast filter */
275 	iowrite32(priv->maht0, priv->base + FTGMAC100_OFFSET_MAHT0);
276 	iowrite32(priv->maht1, priv->base + FTGMAC100_OFFSET_MAHT1);
277 
278 	/* Configure descriptor sizes and increase burst sizes according
279 	 * to values in Aspeed SDK. The FIFO arbitration is enabled and
280 	 * the thresholds set based on the recommended values in the
281 	 * AST2400 specification.
282 	 */
283 	iowrite32(FTGMAC100_DBLAC_RXDES_SIZE(2) |   /* 2*8 bytes RX descs */
284 		  FTGMAC100_DBLAC_TXDES_SIZE(2) |   /* 2*8 bytes TX descs */
285 		  FTGMAC100_DBLAC_RXBURST_SIZE(3) | /* 512 bytes max RX bursts */
286 		  FTGMAC100_DBLAC_TXBURST_SIZE(3) | /* 512 bytes max TX bursts */
287 		  FTGMAC100_DBLAC_RX_THR_EN |       /* Enable fifo threshold arb */
288 		  FTGMAC100_DBLAC_RXFIFO_HTHR(6) |  /* 6/8 of FIFO high threshold */
289 		  FTGMAC100_DBLAC_RXFIFO_LTHR(2),   /* 2/8 of FIFO low threshold */
290 		  priv->base + FTGMAC100_OFFSET_DBLAC);
291 
292 	/* Interrupt mitigation configured for 1 interrupt/packet. HW interrupt
293 	 * mitigation doesn't seem to provide any benefit with NAPI so leave
294 	 * it at that.
295 	 */
296 	iowrite32(FTGMAC100_ITC_RXINT_THR(1) |
297 		  FTGMAC100_ITC_TXINT_THR(1),
298 		  priv->base + FTGMAC100_OFFSET_ITC);
299 
300 	/* Configure FIFO sizes in the TPAFCR register */
301 	reg = ioread32(priv->base + FTGMAC100_OFFSET_FEAR);
302 	rfifo_sz = reg & 0x00000007;
303 	tfifo_sz = (reg >> 3) & 0x00000007;
304 	reg = ioread32(priv->base + FTGMAC100_OFFSET_TPAFCR);
305 	reg &= ~0x3f000000;
306 	reg |= (tfifo_sz << 27);
307 	reg |= (rfifo_sz << 24);
308 	iowrite32(reg, priv->base + FTGMAC100_OFFSET_TPAFCR);
309 }
310 
311 static void ftgmac100_start_hw(struct ftgmac100 *priv)
312 {
313 	u32 maccr = ioread32(priv->base + FTGMAC100_OFFSET_MACCR);
314 
315 	/* Keep the original GMAC and FAST bits */
316 	maccr &= (FTGMAC100_MACCR_FAST_MODE | FTGMAC100_MACCR_GIGA_MODE);
317 
318 	/* Add all the main enable bits */
319 	maccr |= FTGMAC100_MACCR_TXDMA_EN	|
320 		 FTGMAC100_MACCR_RXDMA_EN	|
321 		 FTGMAC100_MACCR_TXMAC_EN	|
322 		 FTGMAC100_MACCR_RXMAC_EN	|
323 		 FTGMAC100_MACCR_CRC_APD	|
324 		 FTGMAC100_MACCR_PHY_LINK_LEVEL	|
325 		 FTGMAC100_MACCR_RX_RUNT	|
326 		 FTGMAC100_MACCR_RX_BROADPKT;
327 
328 	/* Add other bits as needed */
329 	if (priv->cur_duplex == DUPLEX_FULL)
330 		maccr |= FTGMAC100_MACCR_FULLDUP;
331 	if (priv->netdev->flags & IFF_PROMISC)
332 		maccr |= FTGMAC100_MACCR_RX_ALL;
333 	if (priv->netdev->flags & IFF_ALLMULTI)
334 		maccr |= FTGMAC100_MACCR_RX_MULTIPKT;
335 	else if (netdev_mc_count(priv->netdev))
336 		maccr |= FTGMAC100_MACCR_HT_MULTI_EN;
337 
338 	/* Vlan filtering enabled */
339 	if (priv->netdev->features & NETIF_F_HW_VLAN_CTAG_RX)
340 		maccr |= FTGMAC100_MACCR_RM_VLAN;
341 
342 	/* Hit the HW */
343 	iowrite32(maccr, priv->base + FTGMAC100_OFFSET_MACCR);
344 }
345 
346 static void ftgmac100_stop_hw(struct ftgmac100 *priv)
347 {
348 	iowrite32(0, priv->base + FTGMAC100_OFFSET_MACCR);
349 }
350 
351 static void ftgmac100_calc_mc_hash(struct ftgmac100 *priv)
352 {
353 	struct netdev_hw_addr *ha;
354 
355 	priv->maht1 = 0;
356 	priv->maht0 = 0;
357 	netdev_for_each_mc_addr(ha, priv->netdev) {
358 		u32 crc_val = ether_crc_le(ETH_ALEN, ha->addr);
359 
360 		crc_val = (~(crc_val >> 2)) & 0x3f;
361 		if (crc_val >= 32)
362 			priv->maht1 |= 1ul << (crc_val - 32);
363 		else
364 			priv->maht0 |= 1ul << (crc_val);
365 	}
366 }
367 
368 static void ftgmac100_set_rx_mode(struct net_device *netdev)
369 {
370 	struct ftgmac100 *priv = netdev_priv(netdev);
371 
372 	/* Setup the hash filter */
373 	ftgmac100_calc_mc_hash(priv);
374 
375 	/* Interface down ? that's all there is to do */
376 	if (!netif_running(netdev))
377 		return;
378 
379 	/* Update the HW */
380 	iowrite32(priv->maht0, priv->base + FTGMAC100_OFFSET_MAHT0);
381 	iowrite32(priv->maht1, priv->base + FTGMAC100_OFFSET_MAHT1);
382 
383 	/* Reconfigure MACCR */
384 	ftgmac100_start_hw(priv);
385 }
386 
387 static int ftgmac100_alloc_rx_buf(struct ftgmac100 *priv, unsigned int entry,
388 				  struct ftgmac100_rxdes *rxdes, gfp_t gfp)
389 {
390 	struct net_device *netdev = priv->netdev;
391 	struct sk_buff *skb;
392 	dma_addr_t map;
393 	int err = 0;
394 
395 	skb = netdev_alloc_skb_ip_align(netdev, RX_BUF_SIZE);
396 	if (unlikely(!skb)) {
397 		if (net_ratelimit())
398 			netdev_warn(netdev, "failed to allocate rx skb\n");
399 		err = -ENOMEM;
400 		map = priv->rx_scratch_dma;
401 	} else {
402 		map = dma_map_single(priv->dev, skb->data, RX_BUF_SIZE,
403 				     DMA_FROM_DEVICE);
404 		if (unlikely(dma_mapping_error(priv->dev, map))) {
405 			if (net_ratelimit())
406 				netdev_err(netdev, "failed to map rx page\n");
407 			dev_kfree_skb_any(skb);
408 			map = priv->rx_scratch_dma;
409 			skb = NULL;
410 			err = -ENOMEM;
411 		}
412 	}
413 
414 	/* Store skb */
415 	priv->rx_skbs[entry] = skb;
416 
417 	/* Store DMA address into RX desc */
418 	rxdes->rxdes3 = cpu_to_le32(map);
419 
420 	/* Ensure the above is ordered vs clearing the OWN bit */
421 	dma_wmb();
422 
423 	/* Clean status (which resets own bit) */
424 	if (entry == (priv->rx_q_entries - 1))
425 		rxdes->rxdes0 = cpu_to_le32(priv->rxdes0_edorr_mask);
426 	else
427 		rxdes->rxdes0 = 0;
428 
429 	return err;
430 }
431 
432 static unsigned int ftgmac100_next_rx_pointer(struct ftgmac100 *priv,
433 					      unsigned int pointer)
434 {
435 	return (pointer + 1) & (priv->rx_q_entries - 1);
436 }
437 
438 static void ftgmac100_rx_packet_error(struct ftgmac100 *priv, u32 status)
439 {
440 	struct net_device *netdev = priv->netdev;
441 
442 	if (status & FTGMAC100_RXDES0_RX_ERR)
443 		netdev->stats.rx_errors++;
444 
445 	if (status & FTGMAC100_RXDES0_CRC_ERR)
446 		netdev->stats.rx_crc_errors++;
447 
448 	if (status & (FTGMAC100_RXDES0_FTL |
449 		      FTGMAC100_RXDES0_RUNT |
450 		      FTGMAC100_RXDES0_RX_ODD_NB))
451 		netdev->stats.rx_length_errors++;
452 }
453 
454 static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)
455 {
456 	struct net_device *netdev = priv->netdev;
457 	struct ftgmac100_rxdes *rxdes;
458 	struct sk_buff *skb;
459 	unsigned int pointer, size;
460 	u32 status, csum_vlan;
461 	dma_addr_t map;
462 
463 	/* Grab next RX descriptor */
464 	pointer = priv->rx_pointer;
465 	rxdes = &priv->rxdes[pointer];
466 
467 	/* Grab descriptor status */
468 	status = le32_to_cpu(rxdes->rxdes0);
469 
470 	/* Do we have a packet ? */
471 	if (!(status & FTGMAC100_RXDES0_RXPKT_RDY))
472 		return false;
473 
474 	/* Order subsequent reads with the test for the ready bit */
475 	dma_rmb();
476 
477 	/* We don't cope with fragmented RX packets */
478 	if (unlikely(!(status & FTGMAC100_RXDES0_FRS) ||
479 		     !(status & FTGMAC100_RXDES0_LRS)))
480 		goto drop;
481 
482 	/* Grab received size and csum vlan field in the descriptor */
483 	size = status & FTGMAC100_RXDES0_VDBC;
484 	csum_vlan = le32_to_cpu(rxdes->rxdes1);
485 
486 	/* Any error (other than csum offload) flagged ? */
487 	if (unlikely(status & RXDES0_ANY_ERROR)) {
488 		/* Correct for incorrect flagging of runt packets
489 		 * with vlan tags... Just accept a runt packet that
490 		 * has been flagged as vlan and whose size is at
491 		 * least 60 bytes.
492 		 */
493 		if ((status & FTGMAC100_RXDES0_RUNT) &&
494 		    (csum_vlan & FTGMAC100_RXDES1_VLANTAG_AVAIL) &&
495 		    (size >= 60))
496 			status &= ~FTGMAC100_RXDES0_RUNT;
497 
498 		/* Any error still in there ? */
499 		if (status & RXDES0_ANY_ERROR) {
500 			ftgmac100_rx_packet_error(priv, status);
501 			goto drop;
502 		}
503 	}
504 
505 	/* If the packet had no skb (failed to allocate earlier)
506 	 * then try to allocate one and skip
507 	 */
508 	skb = priv->rx_skbs[pointer];
509 	if (!unlikely(skb)) {
510 		ftgmac100_alloc_rx_buf(priv, pointer, rxdes, GFP_ATOMIC);
511 		goto drop;
512 	}
513 
514 	if (unlikely(status & FTGMAC100_RXDES0_MULTICAST))
515 		netdev->stats.multicast++;
516 
517 	/* If the HW found checksum errors, bounce it to software.
518 	 *
519 	 * If we didn't, we need to see if the packet was recognized
520 	 * by HW as one of the supported checksummed protocols before
521 	 * we accept the HW test results.
522 	 */
523 	if (netdev->features & NETIF_F_RXCSUM) {
524 		u32 err_bits = FTGMAC100_RXDES1_TCP_CHKSUM_ERR |
525 			FTGMAC100_RXDES1_UDP_CHKSUM_ERR |
526 			FTGMAC100_RXDES1_IP_CHKSUM_ERR;
527 		if ((csum_vlan & err_bits) ||
528 		    !(csum_vlan & FTGMAC100_RXDES1_PROT_MASK))
529 			skb->ip_summed = CHECKSUM_NONE;
530 		else
531 			skb->ip_summed = CHECKSUM_UNNECESSARY;
532 	}
533 
534 	/* Transfer received size to skb */
535 	skb_put(skb, size);
536 
537 	/* Extract vlan tag */
538 	if ((netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
539 	    (csum_vlan & FTGMAC100_RXDES1_VLANTAG_AVAIL))
540 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
541 				       csum_vlan & 0xffff);
542 
543 	/* Tear down DMA mapping, do necessary cache management */
544 	map = le32_to_cpu(rxdes->rxdes3);
545 
546 #if defined(CONFIG_ARM) && !defined(CONFIG_ARM_DMA_USE_IOMMU)
547 	/* When we don't have an iommu, we can save cycles by not
548 	 * invalidating the cache for the part of the packet that
549 	 * wasn't received.
550 	 */
551 	dma_unmap_single(priv->dev, map, size, DMA_FROM_DEVICE);
552 #else
553 	dma_unmap_single(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
554 #endif
555 
556 
557 	/* Resplenish rx ring */
558 	ftgmac100_alloc_rx_buf(priv, pointer, rxdes, GFP_ATOMIC);
559 	priv->rx_pointer = ftgmac100_next_rx_pointer(priv, pointer);
560 
561 	skb->protocol = eth_type_trans(skb, netdev);
562 
563 	netdev->stats.rx_packets++;
564 	netdev->stats.rx_bytes += size;
565 
566 	/* push packet to protocol stack */
567 	if (skb->ip_summed == CHECKSUM_NONE)
568 		netif_receive_skb(skb);
569 	else
570 		napi_gro_receive(&priv->napi, skb);
571 
572 	(*processed)++;
573 	return true;
574 
575  drop:
576 	/* Clean rxdes0 (which resets own bit) */
577 	rxdes->rxdes0 = cpu_to_le32(status & priv->rxdes0_edorr_mask);
578 	priv->rx_pointer = ftgmac100_next_rx_pointer(priv, pointer);
579 	netdev->stats.rx_dropped++;
580 	return true;
581 }
582 
583 static u32 ftgmac100_base_tx_ctlstat(struct ftgmac100 *priv,
584 				     unsigned int index)
585 {
586 	if (index == (priv->tx_q_entries - 1))
587 		return priv->txdes0_edotr_mask;
588 	else
589 		return 0;
590 }
591 
592 static unsigned int ftgmac100_next_tx_pointer(struct ftgmac100 *priv,
593 					      unsigned int pointer)
594 {
595 	return (pointer + 1) & (priv->tx_q_entries - 1);
596 }
597 
598 static u32 ftgmac100_tx_buf_avail(struct ftgmac100 *priv)
599 {
600 	/* Returns the number of available slots in the TX queue
601 	 *
602 	 * This always leaves one free slot so we don't have to
603 	 * worry about empty vs. full, and this simplifies the
604 	 * test for ftgmac100_tx_buf_cleanable() below
605 	 */
606 	return (priv->tx_clean_pointer - priv->tx_pointer - 1) &
607 		(priv->tx_q_entries - 1);
608 }
609 
610 static bool ftgmac100_tx_buf_cleanable(struct ftgmac100 *priv)
611 {
612 	return priv->tx_pointer != priv->tx_clean_pointer;
613 }
614 
615 static void ftgmac100_free_tx_packet(struct ftgmac100 *priv,
616 				     unsigned int pointer,
617 				     struct sk_buff *skb,
618 				     struct ftgmac100_txdes *txdes,
619 				     u32 ctl_stat)
620 {
621 	dma_addr_t map = le32_to_cpu(txdes->txdes3);
622 	size_t len;
623 
624 	if (ctl_stat & FTGMAC100_TXDES0_FTS) {
625 		len = skb_headlen(skb);
626 		dma_unmap_single(priv->dev, map, len, DMA_TO_DEVICE);
627 	} else {
628 		len = FTGMAC100_TXDES0_TXBUF_SIZE(ctl_stat);
629 		dma_unmap_page(priv->dev, map, len, DMA_TO_DEVICE);
630 	}
631 
632 	/* Free SKB on last segment */
633 	if (ctl_stat & FTGMAC100_TXDES0_LTS)
634 		dev_kfree_skb(skb);
635 	priv->tx_skbs[pointer] = NULL;
636 }
637 
638 static bool ftgmac100_tx_complete_packet(struct ftgmac100 *priv)
639 {
640 	struct net_device *netdev = priv->netdev;
641 	struct ftgmac100_txdes *txdes;
642 	struct sk_buff *skb;
643 	unsigned int pointer;
644 	u32 ctl_stat;
645 
646 	pointer = priv->tx_clean_pointer;
647 	txdes = &priv->txdes[pointer];
648 
649 	ctl_stat = le32_to_cpu(txdes->txdes0);
650 	if (ctl_stat & FTGMAC100_TXDES0_TXDMA_OWN)
651 		return false;
652 
653 	skb = priv->tx_skbs[pointer];
654 	netdev->stats.tx_packets++;
655 	netdev->stats.tx_bytes += skb->len;
656 	ftgmac100_free_tx_packet(priv, pointer, skb, txdes, ctl_stat);
657 	txdes->txdes0 = cpu_to_le32(ctl_stat & priv->txdes0_edotr_mask);
658 
659 	priv->tx_clean_pointer = ftgmac100_next_tx_pointer(priv, pointer);
660 
661 	return true;
662 }
663 
664 static void ftgmac100_tx_complete(struct ftgmac100 *priv)
665 {
666 	struct net_device *netdev = priv->netdev;
667 
668 	/* Process all completed packets */
669 	while (ftgmac100_tx_buf_cleanable(priv) &&
670 	       ftgmac100_tx_complete_packet(priv))
671 		;
672 
673 	/* Restart queue if needed */
674 	smp_mb();
675 	if (unlikely(netif_queue_stopped(netdev) &&
676 		     ftgmac100_tx_buf_avail(priv) >= TX_THRESHOLD)) {
677 		struct netdev_queue *txq;
678 
679 		txq = netdev_get_tx_queue(netdev, 0);
680 		__netif_tx_lock(txq, smp_processor_id());
681 		if (netif_queue_stopped(netdev) &&
682 		    ftgmac100_tx_buf_avail(priv) >= TX_THRESHOLD)
683 			netif_wake_queue(netdev);
684 		__netif_tx_unlock(txq);
685 	}
686 }
687 
688 static bool ftgmac100_prep_tx_csum(struct sk_buff *skb, u32 *csum_vlan)
689 {
690 	if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
691 		u8 ip_proto = ip_hdr(skb)->protocol;
692 
693 		*csum_vlan |= FTGMAC100_TXDES1_IP_CHKSUM;
694 		switch(ip_proto) {
695 		case IPPROTO_TCP:
696 			*csum_vlan |= FTGMAC100_TXDES1_TCP_CHKSUM;
697 			return true;
698 		case IPPROTO_UDP:
699 			*csum_vlan |= FTGMAC100_TXDES1_UDP_CHKSUM;
700 			return true;
701 		case IPPROTO_IP:
702 			return true;
703 		}
704 	}
705 	return skb_checksum_help(skb) == 0;
706 }
707 
708 static netdev_tx_t ftgmac100_hard_start_xmit(struct sk_buff *skb,
709 					     struct net_device *netdev)
710 {
711 	struct ftgmac100 *priv = netdev_priv(netdev);
712 	struct ftgmac100_txdes *txdes, *first;
713 	unsigned int pointer, nfrags, len, i, j;
714 	u32 f_ctl_stat, ctl_stat, csum_vlan;
715 	dma_addr_t map;
716 
717 	/* The HW doesn't pad small frames */
718 	if (eth_skb_pad(skb)) {
719 		netdev->stats.tx_dropped++;
720 		return NETDEV_TX_OK;
721 	}
722 
723 	/* Reject oversize packets */
724 	if (unlikely(skb->len > MAX_PKT_SIZE)) {
725 		if (net_ratelimit())
726 			netdev_dbg(netdev, "tx packet too big\n");
727 		goto drop;
728 	}
729 
730 	/* Do we have a limit on #fragments ? I yet have to get a reply
731 	 * from Aspeed. If there's one I haven't hit it.
732 	 */
733 	nfrags = skb_shinfo(skb)->nr_frags;
734 
735 	/* Setup HW checksumming */
736 	csum_vlan = 0;
737 	if (skb->ip_summed == CHECKSUM_PARTIAL &&
738 	    !ftgmac100_prep_tx_csum(skb, &csum_vlan))
739 		goto drop;
740 
741 	/* Add VLAN tag */
742 	if (skb_vlan_tag_present(skb)) {
743 		csum_vlan |= FTGMAC100_TXDES1_INS_VLANTAG;
744 		csum_vlan |= skb_vlan_tag_get(skb) & 0xffff;
745 	}
746 
747 	/* Get header len */
748 	len = skb_headlen(skb);
749 
750 	/* Map the packet head */
751 	map = dma_map_single(priv->dev, skb->data, len, DMA_TO_DEVICE);
752 	if (dma_mapping_error(priv->dev, map)) {
753 		if (net_ratelimit())
754 			netdev_err(netdev, "map tx packet head failed\n");
755 		goto drop;
756 	}
757 
758 	/* Grab the next free tx descriptor */
759 	pointer = priv->tx_pointer;
760 	txdes = first = &priv->txdes[pointer];
761 
762 	/* Setup it up with the packet head. Don't write the head to the
763 	 * ring just yet
764 	 */
765 	priv->tx_skbs[pointer] = skb;
766 	f_ctl_stat = ftgmac100_base_tx_ctlstat(priv, pointer);
767 	f_ctl_stat |= FTGMAC100_TXDES0_TXDMA_OWN;
768 	f_ctl_stat |= FTGMAC100_TXDES0_TXBUF_SIZE(len);
769 	f_ctl_stat |= FTGMAC100_TXDES0_FTS;
770 	if (nfrags == 0)
771 		f_ctl_stat |= FTGMAC100_TXDES0_LTS;
772 	txdes->txdes3 = cpu_to_le32(map);
773 	txdes->txdes1 = cpu_to_le32(csum_vlan);
774 
775 	/* Next descriptor */
776 	pointer = ftgmac100_next_tx_pointer(priv, pointer);
777 
778 	/* Add the fragments */
779 	for (i = 0; i < nfrags; i++) {
780 		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
781 
782 		len = skb_frag_size(frag);
783 
784 		/* Map it */
785 		map = skb_frag_dma_map(priv->dev, frag, 0, len,
786 				       DMA_TO_DEVICE);
787 		if (dma_mapping_error(priv->dev, map))
788 			goto dma_err;
789 
790 		/* Setup descriptor */
791 		priv->tx_skbs[pointer] = skb;
792 		txdes = &priv->txdes[pointer];
793 		ctl_stat = ftgmac100_base_tx_ctlstat(priv, pointer);
794 		ctl_stat |= FTGMAC100_TXDES0_TXDMA_OWN;
795 		ctl_stat |= FTGMAC100_TXDES0_TXBUF_SIZE(len);
796 		if (i == (nfrags - 1))
797 			ctl_stat |= FTGMAC100_TXDES0_LTS;
798 		txdes->txdes0 = cpu_to_le32(ctl_stat);
799 		txdes->txdes1 = 0;
800 		txdes->txdes3 = cpu_to_le32(map);
801 
802 		/* Next one */
803 		pointer = ftgmac100_next_tx_pointer(priv, pointer);
804 	}
805 
806 	/* Order the previous packet and descriptor udpates
807 	 * before setting the OWN bit on the first descriptor.
808 	 */
809 	dma_wmb();
810 	first->txdes0 = cpu_to_le32(f_ctl_stat);
811 
812 	/* Update next TX pointer */
813 	priv->tx_pointer = pointer;
814 
815 	/* If there isn't enough room for all the fragments of a new packet
816 	 * in the TX ring, stop the queue. The sequence below is race free
817 	 * vs. a concurrent restart in ftgmac100_poll()
818 	 */
819 	if (unlikely(ftgmac100_tx_buf_avail(priv) < TX_THRESHOLD)) {
820 		netif_stop_queue(netdev);
821 		/* Order the queue stop with the test below */
822 		smp_mb();
823 		if (ftgmac100_tx_buf_avail(priv) >= TX_THRESHOLD)
824 			netif_wake_queue(netdev);
825 	}
826 
827 	/* Poke transmitter to read the updated TX descriptors */
828 	iowrite32(1, priv->base + FTGMAC100_OFFSET_NPTXPD);
829 
830 	return NETDEV_TX_OK;
831 
832  dma_err:
833 	if (net_ratelimit())
834 		netdev_err(netdev, "map tx fragment failed\n");
835 
836 	/* Free head */
837 	pointer = priv->tx_pointer;
838 	ftgmac100_free_tx_packet(priv, pointer, skb, first, f_ctl_stat);
839 	first->txdes0 = cpu_to_le32(f_ctl_stat & priv->txdes0_edotr_mask);
840 
841 	/* Then all fragments */
842 	for (j = 0; j < i; j++) {
843 		pointer = ftgmac100_next_tx_pointer(priv, pointer);
844 		txdes = &priv->txdes[pointer];
845 		ctl_stat = le32_to_cpu(txdes->txdes0);
846 		ftgmac100_free_tx_packet(priv, pointer, skb, txdes, ctl_stat);
847 		txdes->txdes0 = cpu_to_le32(ctl_stat & priv->txdes0_edotr_mask);
848 	}
849 
850 	/* This cannot be reached if we successfully mapped the
851 	 * last fragment, so we know ftgmac100_free_tx_packet()
852 	 * hasn't freed the skb yet.
853 	 */
854  drop:
855 	/* Drop the packet */
856 	dev_kfree_skb_any(skb);
857 	netdev->stats.tx_dropped++;
858 
859 	return NETDEV_TX_OK;
860 }
861 
862 static void ftgmac100_free_buffers(struct ftgmac100 *priv)
863 {
864 	int i;
865 
866 	/* Free all RX buffers */
867 	for (i = 0; i < priv->rx_q_entries; i++) {
868 		struct ftgmac100_rxdes *rxdes = &priv->rxdes[i];
869 		struct sk_buff *skb = priv->rx_skbs[i];
870 		dma_addr_t map = le32_to_cpu(rxdes->rxdes3);
871 
872 		if (!skb)
873 			continue;
874 
875 		priv->rx_skbs[i] = NULL;
876 		dma_unmap_single(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
877 		dev_kfree_skb_any(skb);
878 	}
879 
880 	/* Free all TX buffers */
881 	for (i = 0; i < priv->tx_q_entries; i++) {
882 		struct ftgmac100_txdes *txdes = &priv->txdes[i];
883 		struct sk_buff *skb = priv->tx_skbs[i];
884 
885 		if (!skb)
886 			continue;
887 		ftgmac100_free_tx_packet(priv, i, skb, txdes,
888 					 le32_to_cpu(txdes->txdes0));
889 	}
890 }
891 
892 static void ftgmac100_free_rings(struct ftgmac100 *priv)
893 {
894 	/* Free skb arrays */
895 	kfree(priv->rx_skbs);
896 	kfree(priv->tx_skbs);
897 
898 	/* Free descriptors */
899 	if (priv->rxdes)
900 		dma_free_coherent(priv->dev, MAX_RX_QUEUE_ENTRIES *
901 				  sizeof(struct ftgmac100_rxdes),
902 				  priv->rxdes, priv->rxdes_dma);
903 	priv->rxdes = NULL;
904 
905 	if (priv->txdes)
906 		dma_free_coherent(priv->dev, MAX_TX_QUEUE_ENTRIES *
907 				  sizeof(struct ftgmac100_txdes),
908 				  priv->txdes, priv->txdes_dma);
909 	priv->txdes = NULL;
910 
911 	/* Free scratch packet buffer */
912 	if (priv->rx_scratch)
913 		dma_free_coherent(priv->dev, RX_BUF_SIZE,
914 				  priv->rx_scratch, priv->rx_scratch_dma);
915 }
916 
917 static int ftgmac100_alloc_rings(struct ftgmac100 *priv)
918 {
919 	/* Allocate skb arrays */
920 	priv->rx_skbs = kcalloc(MAX_RX_QUEUE_ENTRIES, sizeof(void *),
921 				GFP_KERNEL);
922 	if (!priv->rx_skbs)
923 		return -ENOMEM;
924 	priv->tx_skbs = kcalloc(MAX_TX_QUEUE_ENTRIES, sizeof(void *),
925 				GFP_KERNEL);
926 	if (!priv->tx_skbs)
927 		return -ENOMEM;
928 
929 	/* Allocate descriptors */
930 	priv->rxdes = dma_alloc_coherent(priv->dev,
931 					 MAX_RX_QUEUE_ENTRIES * sizeof(struct ftgmac100_rxdes),
932 					 &priv->rxdes_dma, GFP_KERNEL);
933 	if (!priv->rxdes)
934 		return -ENOMEM;
935 	priv->txdes = dma_alloc_coherent(priv->dev,
936 					 MAX_TX_QUEUE_ENTRIES * sizeof(struct ftgmac100_txdes),
937 					 &priv->txdes_dma, GFP_KERNEL);
938 	if (!priv->txdes)
939 		return -ENOMEM;
940 
941 	/* Allocate scratch packet buffer */
942 	priv->rx_scratch = dma_alloc_coherent(priv->dev,
943 					      RX_BUF_SIZE,
944 					      &priv->rx_scratch_dma,
945 					      GFP_KERNEL);
946 	if (!priv->rx_scratch)
947 		return -ENOMEM;
948 
949 	return 0;
950 }
951 
952 static void ftgmac100_init_rings(struct ftgmac100 *priv)
953 {
954 	struct ftgmac100_rxdes *rxdes = NULL;
955 	struct ftgmac100_txdes *txdes = NULL;
956 	int i;
957 
958 	/* Update entries counts */
959 	priv->rx_q_entries = priv->new_rx_q_entries;
960 	priv->tx_q_entries = priv->new_tx_q_entries;
961 
962 	if (WARN_ON(priv->rx_q_entries < MIN_RX_QUEUE_ENTRIES))
963 		return;
964 
965 	/* Initialize RX ring */
966 	for (i = 0; i < priv->rx_q_entries; i++) {
967 		rxdes = &priv->rxdes[i];
968 		rxdes->rxdes0 = 0;
969 		rxdes->rxdes3 = cpu_to_le32(priv->rx_scratch_dma);
970 	}
971 	/* Mark the end of the ring */
972 	rxdes->rxdes0 |= cpu_to_le32(priv->rxdes0_edorr_mask);
973 
974 	if (WARN_ON(priv->tx_q_entries < MIN_RX_QUEUE_ENTRIES))
975 		return;
976 
977 	/* Initialize TX ring */
978 	for (i = 0; i < priv->tx_q_entries; i++) {
979 		txdes = &priv->txdes[i];
980 		txdes->txdes0 = 0;
981 	}
982 	txdes->txdes0 |= cpu_to_le32(priv->txdes0_edotr_mask);
983 }
984 
985 static int ftgmac100_alloc_rx_buffers(struct ftgmac100 *priv)
986 {
987 	int i;
988 
989 	for (i = 0; i < priv->rx_q_entries; i++) {
990 		struct ftgmac100_rxdes *rxdes = &priv->rxdes[i];
991 
992 		if (ftgmac100_alloc_rx_buf(priv, i, rxdes, GFP_KERNEL))
993 			return -ENOMEM;
994 	}
995 	return 0;
996 }
997 
998 static int ftgmac100_mdiobus_read(struct mii_bus *bus, int phy_addr, int regnum)
999 {
1000 	struct net_device *netdev = bus->priv;
1001 	struct ftgmac100 *priv = netdev_priv(netdev);
1002 	unsigned int phycr;
1003 	int i;
1004 
1005 	phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
1006 
1007 	/* preserve MDC cycle threshold */
1008 	phycr &= FTGMAC100_PHYCR_MDC_CYCTHR_MASK;
1009 
1010 	phycr |= FTGMAC100_PHYCR_PHYAD(phy_addr) |
1011 		 FTGMAC100_PHYCR_REGAD(regnum) |
1012 		 FTGMAC100_PHYCR_MIIRD;
1013 
1014 	iowrite32(phycr, priv->base + FTGMAC100_OFFSET_PHYCR);
1015 
1016 	for (i = 0; i < 10; i++) {
1017 		phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
1018 
1019 		if ((phycr & FTGMAC100_PHYCR_MIIRD) == 0) {
1020 			int data;
1021 
1022 			data = ioread32(priv->base + FTGMAC100_OFFSET_PHYDATA);
1023 			return FTGMAC100_PHYDATA_MIIRDATA(data);
1024 		}
1025 
1026 		udelay(100);
1027 	}
1028 
1029 	netdev_err(netdev, "mdio read timed out\n");
1030 	return -EIO;
1031 }
1032 
1033 static int ftgmac100_mdiobus_write(struct mii_bus *bus, int phy_addr,
1034 				   int regnum, u16 value)
1035 {
1036 	struct net_device *netdev = bus->priv;
1037 	struct ftgmac100 *priv = netdev_priv(netdev);
1038 	unsigned int phycr;
1039 	int data;
1040 	int i;
1041 
1042 	phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
1043 
1044 	/* preserve MDC cycle threshold */
1045 	phycr &= FTGMAC100_PHYCR_MDC_CYCTHR_MASK;
1046 
1047 	phycr |= FTGMAC100_PHYCR_PHYAD(phy_addr) |
1048 		 FTGMAC100_PHYCR_REGAD(regnum) |
1049 		 FTGMAC100_PHYCR_MIIWR;
1050 
1051 	data = FTGMAC100_PHYDATA_MIIWDATA(value);
1052 
1053 	iowrite32(data, priv->base + FTGMAC100_OFFSET_PHYDATA);
1054 	iowrite32(phycr, priv->base + FTGMAC100_OFFSET_PHYCR);
1055 
1056 	for (i = 0; i < 10; i++) {
1057 		phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
1058 
1059 		if ((phycr & FTGMAC100_PHYCR_MIIWR) == 0)
1060 			return 0;
1061 
1062 		udelay(100);
1063 	}
1064 
1065 	netdev_err(netdev, "mdio write timed out\n");
1066 	return -EIO;
1067 }
1068 
1069 static void ftgmac100_get_drvinfo(struct net_device *netdev,
1070 				  struct ethtool_drvinfo *info)
1071 {
1072 	strscpy(info->driver, DRV_NAME, sizeof(info->driver));
1073 	strscpy(info->bus_info, dev_name(&netdev->dev), sizeof(info->bus_info));
1074 }
1075 
1076 static void
1077 ftgmac100_get_ringparam(struct net_device *netdev,
1078 			struct ethtool_ringparam *ering,
1079 			struct kernel_ethtool_ringparam *kernel_ering,
1080 			struct netlink_ext_ack *extack)
1081 {
1082 	struct ftgmac100 *priv = netdev_priv(netdev);
1083 
1084 	memset(ering, 0, sizeof(*ering));
1085 	ering->rx_max_pending = MAX_RX_QUEUE_ENTRIES;
1086 	ering->tx_max_pending = MAX_TX_QUEUE_ENTRIES;
1087 	ering->rx_pending = priv->rx_q_entries;
1088 	ering->tx_pending = priv->tx_q_entries;
1089 }
1090 
1091 static int
1092 ftgmac100_set_ringparam(struct net_device *netdev,
1093 			struct ethtool_ringparam *ering,
1094 			struct kernel_ethtool_ringparam *kernel_ering,
1095 			struct netlink_ext_ack *extack)
1096 {
1097 	struct ftgmac100 *priv = netdev_priv(netdev);
1098 
1099 	if (ering->rx_pending > MAX_RX_QUEUE_ENTRIES ||
1100 	    ering->tx_pending > MAX_TX_QUEUE_ENTRIES ||
1101 	    ering->rx_pending < MIN_RX_QUEUE_ENTRIES ||
1102 	    ering->tx_pending < MIN_TX_QUEUE_ENTRIES ||
1103 	    !is_power_of_2(ering->rx_pending) ||
1104 	    !is_power_of_2(ering->tx_pending))
1105 		return -EINVAL;
1106 
1107 	priv->new_rx_q_entries = ering->rx_pending;
1108 	priv->new_tx_q_entries = ering->tx_pending;
1109 	if (netif_running(netdev))
1110 		schedule_work(&priv->reset_task);
1111 
1112 	return 0;
1113 }
1114 
1115 static void ftgmac100_get_pauseparam(struct net_device *netdev,
1116 				     struct ethtool_pauseparam *pause)
1117 {
1118 	struct ftgmac100 *priv = netdev_priv(netdev);
1119 
1120 	pause->autoneg = priv->aneg_pause;
1121 	pause->tx_pause = priv->tx_pause;
1122 	pause->rx_pause = priv->rx_pause;
1123 }
1124 
1125 static int ftgmac100_set_pauseparam(struct net_device *netdev,
1126 				    struct ethtool_pauseparam *pause)
1127 {
1128 	struct ftgmac100 *priv = netdev_priv(netdev);
1129 	struct phy_device *phydev = netdev->phydev;
1130 
1131 	priv->aneg_pause = pause->autoneg;
1132 	priv->tx_pause = pause->tx_pause;
1133 	priv->rx_pause = pause->rx_pause;
1134 
1135 	if (phydev)
1136 		phy_set_asym_pause(phydev, pause->rx_pause, pause->tx_pause);
1137 
1138 	if (netif_running(netdev)) {
1139 		if (!(phydev && priv->aneg_pause))
1140 			ftgmac100_config_pause(priv);
1141 	}
1142 
1143 	return 0;
1144 }
1145 
1146 static const struct ethtool_ops ftgmac100_ethtool_ops = {
1147 	.get_drvinfo		= ftgmac100_get_drvinfo,
1148 	.get_link		= ethtool_op_get_link,
1149 	.get_link_ksettings	= phy_ethtool_get_link_ksettings,
1150 	.set_link_ksettings	= phy_ethtool_set_link_ksettings,
1151 	.nway_reset		= phy_ethtool_nway_reset,
1152 	.get_ringparam		= ftgmac100_get_ringparam,
1153 	.set_ringparam		= ftgmac100_set_ringparam,
1154 	.get_pauseparam		= ftgmac100_get_pauseparam,
1155 	.set_pauseparam		= ftgmac100_set_pauseparam,
1156 };
1157 
1158 static irqreturn_t ftgmac100_interrupt(int irq, void *dev_id)
1159 {
1160 	struct net_device *netdev = dev_id;
1161 	struct ftgmac100 *priv = netdev_priv(netdev);
1162 	unsigned int status, new_mask = FTGMAC100_INT_BAD;
1163 
1164 	/* Fetch and clear interrupt bits, process abnormal ones */
1165 	status = ioread32(priv->base + FTGMAC100_OFFSET_ISR);
1166 	iowrite32(status, priv->base + FTGMAC100_OFFSET_ISR);
1167 	if (unlikely(status & FTGMAC100_INT_BAD)) {
1168 
1169 		/* RX buffer unavailable */
1170 		if (status & FTGMAC100_INT_NO_RXBUF)
1171 			netdev->stats.rx_over_errors++;
1172 
1173 		/* received packet lost due to RX FIFO full */
1174 		if (status & FTGMAC100_INT_RPKT_LOST)
1175 			netdev->stats.rx_fifo_errors++;
1176 
1177 		/* sent packet lost due to excessive TX collision */
1178 		if (status & FTGMAC100_INT_XPKT_LOST)
1179 			netdev->stats.tx_fifo_errors++;
1180 
1181 		/* AHB error -> Reset the chip */
1182 		if (status & FTGMAC100_INT_AHB_ERR) {
1183 			if (net_ratelimit())
1184 				netdev_warn(netdev,
1185 					   "AHB bus error ! Resetting chip.\n");
1186 			iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1187 			schedule_work(&priv->reset_task);
1188 			return IRQ_HANDLED;
1189 		}
1190 
1191 		/* We may need to restart the MAC after such errors, delay
1192 		 * this until after we have freed some Rx buffers though
1193 		 */
1194 		priv->need_mac_restart = true;
1195 
1196 		/* Disable those errors until we restart */
1197 		new_mask &= ~status;
1198 	}
1199 
1200 	/* Only enable "bad" interrupts while NAPI is on */
1201 	iowrite32(new_mask, priv->base + FTGMAC100_OFFSET_IER);
1202 
1203 	/* Schedule NAPI bh */
1204 	napi_schedule_irqoff(&priv->napi);
1205 
1206 	return IRQ_HANDLED;
1207 }
1208 
1209 static bool ftgmac100_check_rx(struct ftgmac100 *priv)
1210 {
1211 	struct ftgmac100_rxdes *rxdes = &priv->rxdes[priv->rx_pointer];
1212 
1213 	/* Do we have a packet ? */
1214 	return !!(rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_RXPKT_RDY));
1215 }
1216 
1217 static int ftgmac100_poll(struct napi_struct *napi, int budget)
1218 {
1219 	struct ftgmac100 *priv = container_of(napi, struct ftgmac100, napi);
1220 	int work_done = 0;
1221 	bool more;
1222 
1223 	/* Handle TX completions */
1224 	if (ftgmac100_tx_buf_cleanable(priv))
1225 		ftgmac100_tx_complete(priv);
1226 
1227 	/* Handle RX packets */
1228 	do {
1229 		more = ftgmac100_rx_packet(priv, &work_done);
1230 	} while (more && work_done < budget);
1231 
1232 
1233 	/* The interrupt is telling us to kick the MAC back to life
1234 	 * after an RX overflow
1235 	 */
1236 	if (unlikely(priv->need_mac_restart)) {
1237 		ftgmac100_start_hw(priv);
1238 		priv->need_mac_restart = false;
1239 
1240 		/* Re-enable "bad" interrupts */
1241 		iowrite32(FTGMAC100_INT_BAD,
1242 			  priv->base + FTGMAC100_OFFSET_IER);
1243 	}
1244 
1245 	/* As long as we are waiting for transmit packets to be
1246 	 * completed we keep NAPI going
1247 	 */
1248 	if (ftgmac100_tx_buf_cleanable(priv))
1249 		work_done = budget;
1250 
1251 	if (work_done < budget) {
1252 		/* We are about to re-enable all interrupts. However
1253 		 * the HW has been latching RX/TX packet interrupts while
1254 		 * they were masked. So we clear them first, then we need
1255 		 * to re-check if there's something to process
1256 		 */
1257 		iowrite32(FTGMAC100_INT_RXTX,
1258 			  priv->base + FTGMAC100_OFFSET_ISR);
1259 
1260 		/* Push the above (and provides a barrier vs. subsequent
1261 		 * reads of the descriptor).
1262 		 */
1263 		ioread32(priv->base + FTGMAC100_OFFSET_ISR);
1264 
1265 		/* Check RX and TX descriptors for more work to do */
1266 		if (ftgmac100_check_rx(priv) ||
1267 		    ftgmac100_tx_buf_cleanable(priv))
1268 			return budget;
1269 
1270 		/* deschedule NAPI */
1271 		napi_complete(napi);
1272 
1273 		/* enable all interrupts */
1274 		iowrite32(FTGMAC100_INT_ALL,
1275 			  priv->base + FTGMAC100_OFFSET_IER);
1276 	}
1277 
1278 	return work_done;
1279 }
1280 
1281 static int ftgmac100_init_all(struct ftgmac100 *priv, bool ignore_alloc_err)
1282 {
1283 	int err = 0;
1284 
1285 	/* Re-init descriptors (adjust queue sizes) */
1286 	ftgmac100_init_rings(priv);
1287 
1288 	/* Realloc rx descriptors */
1289 	err = ftgmac100_alloc_rx_buffers(priv);
1290 	if (err && !ignore_alloc_err)
1291 		return err;
1292 
1293 	/* Reinit and restart HW */
1294 	ftgmac100_init_hw(priv);
1295 	ftgmac100_config_pause(priv);
1296 	ftgmac100_start_hw(priv);
1297 
1298 	/* Re-enable the device */
1299 	napi_enable(&priv->napi);
1300 	netif_start_queue(priv->netdev);
1301 
1302 	/* Enable all interrupts */
1303 	iowrite32(FTGMAC100_INT_ALL, priv->base + FTGMAC100_OFFSET_IER);
1304 
1305 	return err;
1306 }
1307 
1308 static void ftgmac100_reset(struct ftgmac100 *priv)
1309 {
1310 	struct net_device *netdev = priv->netdev;
1311 	int err;
1312 
1313 	netdev_dbg(netdev, "Resetting NIC...\n");
1314 
1315 	/* Lock the world */
1316 	rtnl_lock();
1317 	if (netdev->phydev)
1318 		mutex_lock(&netdev->phydev->lock);
1319 	if (priv->mii_bus)
1320 		mutex_lock(&priv->mii_bus->mdio_lock);
1321 
1322 
1323 	/* Check if the interface is still up */
1324 	if (!netif_running(netdev))
1325 		goto bail;
1326 
1327 	/* Stop the network stack */
1328 	netif_trans_update(netdev);
1329 	napi_disable(&priv->napi);
1330 	netif_tx_disable(netdev);
1331 
1332 	/* Stop and reset the MAC */
1333 	ftgmac100_stop_hw(priv);
1334 	err = ftgmac100_reset_and_config_mac(priv);
1335 	if (err) {
1336 		/* Not much we can do ... it might come back... */
1337 		netdev_err(netdev, "attempting to continue...\n");
1338 	}
1339 
1340 	/* Free all rx and tx buffers */
1341 	ftgmac100_free_buffers(priv);
1342 
1343 	/* Setup everything again and restart chip */
1344 	ftgmac100_init_all(priv, true);
1345 
1346 	netdev_dbg(netdev, "Reset done !\n");
1347  bail:
1348 	if (priv->mii_bus)
1349 		mutex_unlock(&priv->mii_bus->mdio_lock);
1350 	if (netdev->phydev)
1351 		mutex_unlock(&netdev->phydev->lock);
1352 	rtnl_unlock();
1353 }
1354 
1355 static void ftgmac100_reset_task(struct work_struct *work)
1356 {
1357 	struct ftgmac100 *priv = container_of(work, struct ftgmac100,
1358 					      reset_task);
1359 
1360 	ftgmac100_reset(priv);
1361 }
1362 
1363 static void ftgmac100_adjust_link(struct net_device *netdev)
1364 {
1365 	struct ftgmac100 *priv = netdev_priv(netdev);
1366 	struct phy_device *phydev = netdev->phydev;
1367 	bool tx_pause, rx_pause;
1368 	int new_speed;
1369 
1370 	/* We store "no link" as speed 0 */
1371 	if (!phydev->link)
1372 		new_speed = 0;
1373 	else
1374 		new_speed = phydev->speed;
1375 
1376 	/* Grab pause settings from PHY if configured to do so */
1377 	if (priv->aneg_pause) {
1378 		rx_pause = tx_pause = phydev->pause;
1379 		if (phydev->asym_pause)
1380 			tx_pause = !rx_pause;
1381 	} else {
1382 		rx_pause = priv->rx_pause;
1383 		tx_pause = priv->tx_pause;
1384 	}
1385 
1386 	/* Link hasn't changed, do nothing */
1387 	if (phydev->speed == priv->cur_speed &&
1388 	    phydev->duplex == priv->cur_duplex &&
1389 	    rx_pause == priv->rx_pause &&
1390 	    tx_pause == priv->tx_pause)
1391 		return;
1392 
1393 	/* Print status if we have a link or we had one and just lost it,
1394 	 * don't print otherwise.
1395 	 */
1396 	if (new_speed || priv->cur_speed)
1397 		phy_print_status(phydev);
1398 
1399 	priv->cur_speed = new_speed;
1400 	priv->cur_duplex = phydev->duplex;
1401 	priv->rx_pause = rx_pause;
1402 	priv->tx_pause = tx_pause;
1403 
1404 	/* Link is down, do nothing else */
1405 	if (!new_speed)
1406 		return;
1407 
1408 	/* Disable all interrupts */
1409 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1410 
1411 	/* Release phy lock to allow ftgmac100_reset to aquire it, keeping lock
1412 	 * order consistent to prevent dead lock.
1413 	 */
1414 	if (netdev->phydev)
1415 		mutex_unlock(&netdev->phydev->lock);
1416 
1417 	ftgmac100_reset(priv);
1418 
1419 	if (netdev->phydev)
1420 		mutex_lock(&netdev->phydev->lock);
1421 
1422 }
1423 
1424 static int ftgmac100_mii_probe(struct net_device *netdev)
1425 {
1426 	struct ftgmac100 *priv = netdev_priv(netdev);
1427 	struct platform_device *pdev = to_platform_device(priv->dev);
1428 	struct device_node *np = pdev->dev.of_node;
1429 	struct phy_device *phydev;
1430 	phy_interface_t phy_intf;
1431 	int err;
1432 
1433 	/* Default to RGMII. It's a gigabit part after all */
1434 	err = of_get_phy_mode(np, &phy_intf);
1435 	if (err)
1436 		phy_intf = PHY_INTERFACE_MODE_RGMII;
1437 
1438 	/* Aspeed only supports these. I don't know about other IP
1439 	 * block vendors so I'm going to just let them through for
1440 	 * now. Note that this is only a warning if for some obscure
1441 	 * reason the DT really means to lie about it or it's a newer
1442 	 * part we don't know about.
1443 	 *
1444 	 * On the Aspeed SoC there are additionally straps and SCU
1445 	 * control bits that could tell us what the interface is
1446 	 * (or allow us to configure it while the IP block is held
1447 	 * in reset). For now I chose to keep this driver away from
1448 	 * those SoC specific bits and assume the device-tree is
1449 	 * right and the SCU has been configured properly by pinmux
1450 	 * or the firmware.
1451 	 */
1452 	if (priv->is_aspeed && !(phy_interface_mode_is_rgmii(phy_intf))) {
1453 		netdev_warn(netdev,
1454 			    "Unsupported PHY mode %s !\n",
1455 			    phy_modes(phy_intf));
1456 	}
1457 
1458 	phydev = phy_find_first(priv->mii_bus);
1459 	if (!phydev) {
1460 		netdev_info(netdev, "%s: no PHY found\n", netdev->name);
1461 		return -ENODEV;
1462 	}
1463 
1464 	phydev = phy_connect(netdev, phydev_name(phydev),
1465 			     &ftgmac100_adjust_link, phy_intf);
1466 
1467 	if (IS_ERR(phydev)) {
1468 		netdev_err(netdev, "%s: Could not attach to PHY\n", netdev->name);
1469 		return PTR_ERR(phydev);
1470 	}
1471 
1472 	/* Indicate that we support PAUSE frames (see comment in
1473 	 * Documentation/networking/phy.rst)
1474 	 */
1475 	phy_support_asym_pause(phydev);
1476 
1477 	/* Display what we found */
1478 	phy_attached_info(phydev);
1479 
1480 	return 0;
1481 }
1482 
1483 static int ftgmac100_open(struct net_device *netdev)
1484 {
1485 	struct ftgmac100 *priv = netdev_priv(netdev);
1486 	int err;
1487 
1488 	/* Allocate ring buffers  */
1489 	err = ftgmac100_alloc_rings(priv);
1490 	if (err) {
1491 		netdev_err(netdev, "Failed to allocate descriptors\n");
1492 		return err;
1493 	}
1494 
1495 	/* When using NC-SI we force the speed to 100Mbit/s full duplex,
1496 	 *
1497 	 * Otherwise we leave it set to 0 (no link), the link
1498 	 * message from the PHY layer will handle setting it up to
1499 	 * something else if needed.
1500 	 */
1501 	if (priv->use_ncsi) {
1502 		priv->cur_duplex = DUPLEX_FULL;
1503 		priv->cur_speed = SPEED_100;
1504 	} else {
1505 		priv->cur_duplex = 0;
1506 		priv->cur_speed = 0;
1507 	}
1508 
1509 	/* Reset the hardware */
1510 	err = ftgmac100_reset_and_config_mac(priv);
1511 	if (err)
1512 		goto err_hw;
1513 
1514 	/* Initialize NAPI */
1515 	netif_napi_add(netdev, &priv->napi, ftgmac100_poll);
1516 
1517 	/* Grab our interrupt */
1518 	err = request_irq(netdev->irq, ftgmac100_interrupt, 0, netdev->name, netdev);
1519 	if (err) {
1520 		netdev_err(netdev, "failed to request irq %d\n", netdev->irq);
1521 		goto err_irq;
1522 	}
1523 
1524 	/* Start things up */
1525 	err = ftgmac100_init_all(priv, false);
1526 	if (err) {
1527 		netdev_err(netdev, "Failed to allocate packet buffers\n");
1528 		goto err_alloc;
1529 	}
1530 
1531 	if (netdev->phydev) {
1532 		/* If we have a PHY, start polling */
1533 		phy_start(netdev->phydev);
1534 	} else if (priv->use_ncsi) {
1535 		/* If using NC-SI, set our carrier on and start the stack */
1536 		netif_carrier_on(netdev);
1537 
1538 		/* Start the NCSI device */
1539 		err = ncsi_start_dev(priv->ndev);
1540 		if (err)
1541 			goto err_ncsi;
1542 	}
1543 
1544 	return 0;
1545 
1546  err_ncsi:
1547 	napi_disable(&priv->napi);
1548 	netif_stop_queue(netdev);
1549  err_alloc:
1550 	ftgmac100_free_buffers(priv);
1551 	free_irq(netdev->irq, netdev);
1552  err_irq:
1553 	netif_napi_del(&priv->napi);
1554  err_hw:
1555 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1556 	ftgmac100_free_rings(priv);
1557 	return err;
1558 }
1559 
1560 static int ftgmac100_stop(struct net_device *netdev)
1561 {
1562 	struct ftgmac100 *priv = netdev_priv(netdev);
1563 
1564 	/* Note about the reset task: We are called with the rtnl lock
1565 	 * held, so we are synchronized against the core of the reset
1566 	 * task. We must not try to synchronously cancel it otherwise
1567 	 * we can deadlock. But since it will test for netif_running()
1568 	 * which has already been cleared by the net core, we don't
1569 	 * anything special to do.
1570 	 */
1571 
1572 	/* disable all interrupts */
1573 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1574 
1575 	netif_stop_queue(netdev);
1576 	napi_disable(&priv->napi);
1577 	netif_napi_del(&priv->napi);
1578 	if (netdev->phydev)
1579 		phy_stop(netdev->phydev);
1580 	else if (priv->use_ncsi)
1581 		ncsi_stop_dev(priv->ndev);
1582 
1583 	ftgmac100_stop_hw(priv);
1584 	free_irq(netdev->irq, netdev);
1585 	ftgmac100_free_buffers(priv);
1586 	ftgmac100_free_rings(priv);
1587 
1588 	return 0;
1589 }
1590 
1591 static void ftgmac100_tx_timeout(struct net_device *netdev, unsigned int txqueue)
1592 {
1593 	struct ftgmac100 *priv = netdev_priv(netdev);
1594 
1595 	/* Disable all interrupts */
1596 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1597 
1598 	/* Do the reset outside of interrupt context */
1599 	schedule_work(&priv->reset_task);
1600 }
1601 
1602 static int ftgmac100_set_features(struct net_device *netdev,
1603 				  netdev_features_t features)
1604 {
1605 	struct ftgmac100 *priv = netdev_priv(netdev);
1606 	netdev_features_t changed = netdev->features ^ features;
1607 
1608 	if (!netif_running(netdev))
1609 		return 0;
1610 
1611 	/* Update the vlan filtering bit */
1612 	if (changed & NETIF_F_HW_VLAN_CTAG_RX) {
1613 		u32 maccr;
1614 
1615 		maccr = ioread32(priv->base + FTGMAC100_OFFSET_MACCR);
1616 		if (priv->netdev->features & NETIF_F_HW_VLAN_CTAG_RX)
1617 			maccr |= FTGMAC100_MACCR_RM_VLAN;
1618 		else
1619 			maccr &= ~FTGMAC100_MACCR_RM_VLAN;
1620 		iowrite32(maccr, priv->base + FTGMAC100_OFFSET_MACCR);
1621 	}
1622 
1623 	return 0;
1624 }
1625 
1626 #ifdef CONFIG_NET_POLL_CONTROLLER
1627 static void ftgmac100_poll_controller(struct net_device *netdev)
1628 {
1629 	unsigned long flags;
1630 
1631 	local_irq_save(flags);
1632 	ftgmac100_interrupt(netdev->irq, netdev);
1633 	local_irq_restore(flags);
1634 }
1635 #endif
1636 
1637 static const struct net_device_ops ftgmac100_netdev_ops = {
1638 	.ndo_open		= ftgmac100_open,
1639 	.ndo_stop		= ftgmac100_stop,
1640 	.ndo_start_xmit		= ftgmac100_hard_start_xmit,
1641 	.ndo_set_mac_address	= ftgmac100_set_mac_addr,
1642 	.ndo_validate_addr	= eth_validate_addr,
1643 	.ndo_eth_ioctl		= phy_do_ioctl,
1644 	.ndo_tx_timeout		= ftgmac100_tx_timeout,
1645 	.ndo_set_rx_mode	= ftgmac100_set_rx_mode,
1646 	.ndo_set_features	= ftgmac100_set_features,
1647 #ifdef CONFIG_NET_POLL_CONTROLLER
1648 	.ndo_poll_controller	= ftgmac100_poll_controller,
1649 #endif
1650 	.ndo_vlan_rx_add_vid	= ncsi_vlan_rx_add_vid,
1651 	.ndo_vlan_rx_kill_vid	= ncsi_vlan_rx_kill_vid,
1652 };
1653 
1654 static int ftgmac100_setup_mdio(struct net_device *netdev)
1655 {
1656 	struct ftgmac100 *priv = netdev_priv(netdev);
1657 	struct platform_device *pdev = to_platform_device(priv->dev);
1658 	struct device_node *np = pdev->dev.of_node;
1659 	struct device_node *mdio_np;
1660 	int i, err = 0;
1661 	u32 reg;
1662 
1663 	/* initialize mdio bus */
1664 	priv->mii_bus = mdiobus_alloc();
1665 	if (!priv->mii_bus)
1666 		return -EIO;
1667 
1668 	if (of_device_is_compatible(np, "aspeed,ast2400-mac") ||
1669 	    of_device_is_compatible(np, "aspeed,ast2500-mac")) {
1670 		/* The AST2600 has a separate MDIO controller */
1671 
1672 		/* For the AST2400 and AST2500 this driver only supports the
1673 		 * old MDIO interface
1674 		 */
1675 		reg = ioread32(priv->base + FTGMAC100_OFFSET_REVR);
1676 		reg &= ~FTGMAC100_REVR_NEW_MDIO_INTERFACE;
1677 		iowrite32(reg, priv->base + FTGMAC100_OFFSET_REVR);
1678 	}
1679 
1680 	priv->mii_bus->name = "ftgmac100_mdio";
1681 	snprintf(priv->mii_bus->id, MII_BUS_ID_SIZE, "%s-%d",
1682 		 pdev->name, pdev->id);
1683 	priv->mii_bus->parent = priv->dev;
1684 	priv->mii_bus->priv = priv->netdev;
1685 	priv->mii_bus->read = ftgmac100_mdiobus_read;
1686 	priv->mii_bus->write = ftgmac100_mdiobus_write;
1687 
1688 	for (i = 0; i < PHY_MAX_ADDR; i++)
1689 		priv->mii_bus->irq[i] = PHY_POLL;
1690 
1691 	mdio_np = of_get_child_by_name(np, "mdio");
1692 
1693 	err = of_mdiobus_register(priv->mii_bus, mdio_np);
1694 	if (err) {
1695 		dev_err(priv->dev, "Cannot register MDIO bus!\n");
1696 		goto err_register_mdiobus;
1697 	}
1698 
1699 	of_node_put(mdio_np);
1700 
1701 	return 0;
1702 
1703 err_register_mdiobus:
1704 	mdiobus_free(priv->mii_bus);
1705 	return err;
1706 }
1707 
1708 static void ftgmac100_phy_disconnect(struct net_device *netdev)
1709 {
1710 	struct ftgmac100 *priv = netdev_priv(netdev);
1711 
1712 	if (!netdev->phydev)
1713 		return;
1714 
1715 	phy_disconnect(netdev->phydev);
1716 	if (of_phy_is_fixed_link(priv->dev->of_node))
1717 		of_phy_deregister_fixed_link(priv->dev->of_node);
1718 }
1719 
1720 static void ftgmac100_destroy_mdio(struct net_device *netdev)
1721 {
1722 	struct ftgmac100 *priv = netdev_priv(netdev);
1723 
1724 	if (!priv->mii_bus)
1725 		return;
1726 
1727 	mdiobus_unregister(priv->mii_bus);
1728 	mdiobus_free(priv->mii_bus);
1729 }
1730 
1731 static void ftgmac100_ncsi_handler(struct ncsi_dev *nd)
1732 {
1733 	if (unlikely(nd->state != ncsi_dev_state_functional))
1734 		return;
1735 
1736 	netdev_dbg(nd->dev, "NCSI interface %s\n",
1737 		   nd->link_up ? "up" : "down");
1738 }
1739 
1740 static int ftgmac100_setup_clk(struct ftgmac100 *priv)
1741 {
1742 	struct clk *clk;
1743 	int rc;
1744 
1745 	clk = devm_clk_get(priv->dev, NULL /* MACCLK */);
1746 	if (IS_ERR(clk))
1747 		return PTR_ERR(clk);
1748 	priv->clk = clk;
1749 	rc = clk_prepare_enable(priv->clk);
1750 	if (rc)
1751 		return rc;
1752 
1753 	/* Aspeed specifies a 100MHz clock is required for up to
1754 	 * 1000Mbit link speeds. As NCSI is limited to 100Mbit, 25MHz
1755 	 * is sufficient
1756 	 */
1757 	rc = clk_set_rate(priv->clk, priv->use_ncsi ? FTGMAC_25MHZ :
1758 			  FTGMAC_100MHZ);
1759 	if (rc)
1760 		goto cleanup_clk;
1761 
1762 	/* RCLK is for RMII, typically used for NCSI. Optional because it's not
1763 	 * necessary if it's the AST2400 MAC, or the MAC is configured for
1764 	 * RGMII, or the controller is not an ASPEED-based controller.
1765 	 */
1766 	priv->rclk = devm_clk_get_optional(priv->dev, "RCLK");
1767 	rc = clk_prepare_enable(priv->rclk);
1768 	if (!rc)
1769 		return 0;
1770 
1771 cleanup_clk:
1772 	clk_disable_unprepare(priv->clk);
1773 
1774 	return rc;
1775 }
1776 
1777 static bool ftgmac100_has_child_node(struct device_node *np, const char *name)
1778 {
1779 	struct device_node *child_np = of_get_child_by_name(np, name);
1780 	bool ret = false;
1781 
1782 	if (child_np) {
1783 		ret = true;
1784 		of_node_put(child_np);
1785 	}
1786 
1787 	return ret;
1788 }
1789 
1790 static int ftgmac100_probe(struct platform_device *pdev)
1791 {
1792 	struct resource *res;
1793 	int irq;
1794 	struct net_device *netdev;
1795 	struct ftgmac100 *priv;
1796 	struct device_node *np;
1797 	int err = 0;
1798 
1799 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1800 	if (!res)
1801 		return -ENXIO;
1802 
1803 	irq = platform_get_irq(pdev, 0);
1804 	if (irq < 0)
1805 		return irq;
1806 
1807 	/* setup net_device */
1808 	netdev = alloc_etherdev(sizeof(*priv));
1809 	if (!netdev) {
1810 		err = -ENOMEM;
1811 		goto err_alloc_etherdev;
1812 	}
1813 
1814 	SET_NETDEV_DEV(netdev, &pdev->dev);
1815 
1816 	netdev->ethtool_ops = &ftgmac100_ethtool_ops;
1817 	netdev->netdev_ops = &ftgmac100_netdev_ops;
1818 	netdev->watchdog_timeo = 5 * HZ;
1819 
1820 	platform_set_drvdata(pdev, netdev);
1821 
1822 	/* setup private data */
1823 	priv = netdev_priv(netdev);
1824 	priv->netdev = netdev;
1825 	priv->dev = &pdev->dev;
1826 	INIT_WORK(&priv->reset_task, ftgmac100_reset_task);
1827 
1828 	/* map io memory */
1829 	priv->res = request_mem_region(res->start, resource_size(res),
1830 				       dev_name(&pdev->dev));
1831 	if (!priv->res) {
1832 		dev_err(&pdev->dev, "Could not reserve memory region\n");
1833 		err = -ENOMEM;
1834 		goto err_req_mem;
1835 	}
1836 
1837 	priv->base = ioremap(res->start, resource_size(res));
1838 	if (!priv->base) {
1839 		dev_err(&pdev->dev, "Failed to ioremap ethernet registers\n");
1840 		err = -EIO;
1841 		goto err_ioremap;
1842 	}
1843 
1844 	netdev->irq = irq;
1845 
1846 	/* Enable pause */
1847 	priv->tx_pause = true;
1848 	priv->rx_pause = true;
1849 	priv->aneg_pause = true;
1850 
1851 	/* MAC address from chip or random one */
1852 	err = ftgmac100_initial_mac(priv);
1853 	if (err)
1854 		goto err_phy_connect;
1855 
1856 	np = pdev->dev.of_node;
1857 	if (np && (of_device_is_compatible(np, "aspeed,ast2400-mac") ||
1858 		   of_device_is_compatible(np, "aspeed,ast2500-mac") ||
1859 		   of_device_is_compatible(np, "aspeed,ast2600-mac"))) {
1860 		priv->rxdes0_edorr_mask = BIT(30);
1861 		priv->txdes0_edotr_mask = BIT(30);
1862 		priv->is_aspeed = true;
1863 	} else {
1864 		priv->rxdes0_edorr_mask = BIT(15);
1865 		priv->txdes0_edotr_mask = BIT(15);
1866 	}
1867 
1868 	if (np && of_get_property(np, "use-ncsi", NULL)) {
1869 		if (!IS_ENABLED(CONFIG_NET_NCSI)) {
1870 			dev_err(&pdev->dev, "NCSI stack not enabled\n");
1871 			err = -EINVAL;
1872 			goto err_phy_connect;
1873 		}
1874 
1875 		dev_info(&pdev->dev, "Using NCSI interface\n");
1876 		priv->use_ncsi = true;
1877 		priv->ndev = ncsi_register_dev(netdev, ftgmac100_ncsi_handler);
1878 		if (!priv->ndev) {
1879 			err = -EINVAL;
1880 			goto err_phy_connect;
1881 		}
1882 	} else if (np && of_phy_is_fixed_link(np)) {
1883 		struct phy_device *phy;
1884 
1885 		err = of_phy_register_fixed_link(np);
1886 		if (err) {
1887 			dev_err(&pdev->dev, "Failed to register fixed PHY\n");
1888 			goto err_phy_connect;
1889 		}
1890 
1891 		phy = of_phy_get_and_connect(priv->netdev, np,
1892 					     &ftgmac100_adjust_link);
1893 		if (!phy) {
1894 			dev_err(&pdev->dev, "Failed to connect to fixed PHY\n");
1895 			of_phy_deregister_fixed_link(np);
1896 			err = -EINVAL;
1897 			goto err_phy_connect;
1898 		}
1899 
1900 		/* Display what we found */
1901 		phy_attached_info(phy);
1902 	} else if (np && of_get_property(np, "phy-handle", NULL)) {
1903 		struct phy_device *phy;
1904 
1905 		/* Support "mdio"/"phy" child nodes for ast2400/2500 with
1906 		 * an embedded MDIO controller. Automatically scan the DTS for
1907 		 * available PHYs and register them.
1908 		 */
1909 		if (of_device_is_compatible(np, "aspeed,ast2400-mac") ||
1910 		    of_device_is_compatible(np, "aspeed,ast2500-mac")) {
1911 			err = ftgmac100_setup_mdio(netdev);
1912 			if (err)
1913 				goto err_setup_mdio;
1914 		}
1915 
1916 		phy = of_phy_get_and_connect(priv->netdev, np,
1917 					     &ftgmac100_adjust_link);
1918 		if (!phy) {
1919 			dev_err(&pdev->dev, "Failed to connect to phy\n");
1920 			err = -EINVAL;
1921 			goto err_phy_connect;
1922 		}
1923 
1924 		/* Indicate that we support PAUSE frames (see comment in
1925 		 * Documentation/networking/phy.rst)
1926 		 */
1927 		phy_support_asym_pause(phy);
1928 
1929 		/* Display what we found */
1930 		phy_attached_info(phy);
1931 	} else if (np && !ftgmac100_has_child_node(np, "mdio")) {
1932 		/* Support legacy ASPEED devicetree descriptions that decribe a
1933 		 * MAC with an embedded MDIO controller but have no "mdio"
1934 		 * child node. Automatically scan the MDIO bus for available
1935 		 * PHYs.
1936 		 */
1937 		priv->use_ncsi = false;
1938 		err = ftgmac100_setup_mdio(netdev);
1939 		if (err)
1940 			goto err_setup_mdio;
1941 
1942 		err = ftgmac100_mii_probe(netdev);
1943 		if (err) {
1944 			dev_err(priv->dev, "MII probe failed!\n");
1945 			goto err_ncsi_dev;
1946 		}
1947 
1948 	}
1949 
1950 	if (priv->is_aspeed) {
1951 		err = ftgmac100_setup_clk(priv);
1952 		if (err)
1953 			goto err_phy_connect;
1954 
1955 		/* Disable ast2600 problematic HW arbitration */
1956 		if (of_device_is_compatible(np, "aspeed,ast2600-mac"))
1957 			iowrite32(FTGMAC100_TM_DEFAULT,
1958 				  priv->base + FTGMAC100_OFFSET_TM);
1959 	}
1960 
1961 	/* Default ring sizes */
1962 	priv->rx_q_entries = priv->new_rx_q_entries = DEF_RX_QUEUE_ENTRIES;
1963 	priv->tx_q_entries = priv->new_tx_q_entries = DEF_TX_QUEUE_ENTRIES;
1964 
1965 	/* Base feature set */
1966 	netdev->hw_features = NETIF_F_RXCSUM | NETIF_F_HW_CSUM |
1967 		NETIF_F_GRO | NETIF_F_SG | NETIF_F_HW_VLAN_CTAG_RX |
1968 		NETIF_F_HW_VLAN_CTAG_TX;
1969 
1970 	if (priv->use_ncsi)
1971 		netdev->hw_features |= NETIF_F_HW_VLAN_CTAG_FILTER;
1972 
1973 	/* AST2400  doesn't have working HW checksum generation */
1974 	if (np && (of_device_is_compatible(np, "aspeed,ast2400-mac")))
1975 		netdev->hw_features &= ~NETIF_F_HW_CSUM;
1976 
1977 	/* AST2600 tx checksum with NCSI is broken */
1978 	if (priv->use_ncsi && of_device_is_compatible(np, "aspeed,ast2600-mac"))
1979 		netdev->hw_features &= ~NETIF_F_HW_CSUM;
1980 
1981 	if (np && of_get_property(np, "no-hw-checksum", NULL))
1982 		netdev->hw_features &= ~(NETIF_F_HW_CSUM | NETIF_F_RXCSUM);
1983 	netdev->features |= netdev->hw_features;
1984 
1985 	/* register network device */
1986 	err = register_netdev(netdev);
1987 	if (err) {
1988 		dev_err(&pdev->dev, "Failed to register netdev\n");
1989 		goto err_register_netdev;
1990 	}
1991 
1992 	netdev_info(netdev, "irq %d, mapped at %p\n", netdev->irq, priv->base);
1993 
1994 	return 0;
1995 
1996 err_register_netdev:
1997 	clk_disable_unprepare(priv->rclk);
1998 	clk_disable_unprepare(priv->clk);
1999 err_phy_connect:
2000 	ftgmac100_phy_disconnect(netdev);
2001 err_ncsi_dev:
2002 	if (priv->ndev)
2003 		ncsi_unregister_dev(priv->ndev);
2004 	ftgmac100_destroy_mdio(netdev);
2005 err_setup_mdio:
2006 	iounmap(priv->base);
2007 err_ioremap:
2008 	release_resource(priv->res);
2009 err_req_mem:
2010 	free_netdev(netdev);
2011 err_alloc_etherdev:
2012 	return err;
2013 }
2014 
2015 static int ftgmac100_remove(struct platform_device *pdev)
2016 {
2017 	struct net_device *netdev;
2018 	struct ftgmac100 *priv;
2019 
2020 	netdev = platform_get_drvdata(pdev);
2021 	priv = netdev_priv(netdev);
2022 
2023 	if (priv->ndev)
2024 		ncsi_unregister_dev(priv->ndev);
2025 	unregister_netdev(netdev);
2026 
2027 	clk_disable_unprepare(priv->rclk);
2028 	clk_disable_unprepare(priv->clk);
2029 
2030 	/* There's a small chance the reset task will have been re-queued,
2031 	 * during stop, make sure it's gone before we free the structure.
2032 	 */
2033 	cancel_work_sync(&priv->reset_task);
2034 
2035 	ftgmac100_phy_disconnect(netdev);
2036 	ftgmac100_destroy_mdio(netdev);
2037 
2038 	iounmap(priv->base);
2039 	release_resource(priv->res);
2040 
2041 	netif_napi_del(&priv->napi);
2042 	free_netdev(netdev);
2043 	return 0;
2044 }
2045 
2046 static const struct of_device_id ftgmac100_of_match[] = {
2047 	{ .compatible = "faraday,ftgmac100" },
2048 	{ }
2049 };
2050 MODULE_DEVICE_TABLE(of, ftgmac100_of_match);
2051 
2052 static struct platform_driver ftgmac100_driver = {
2053 	.probe	= ftgmac100_probe,
2054 	.remove	= ftgmac100_remove,
2055 	.driver	= {
2056 		.name		= DRV_NAME,
2057 		.of_match_table	= ftgmac100_of_match,
2058 	},
2059 };
2060 module_platform_driver(ftgmac100_driver);
2061 
2062 MODULE_AUTHOR("Po-Yu Chuang <ratbert@faraday-tech.com>");
2063 MODULE_DESCRIPTION("FTGMAC100 driver");
2064 MODULE_LICENSE("GPL");
2065