xref: /linux/drivers/net/ethernet/faraday/ftgmac100.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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 <linux/phy_fixed.h>
28 #include <net/ip.h>
29 #include <net/ncsi.h>
30 
31 #include "ftgmac100.h"
32 
33 #define DRV_NAME	"ftgmac100"
34 
35 /* Arbitrary values, I am not sure the HW has limits */
36 #define MAX_RX_QUEUE_ENTRIES	1024
37 #define MAX_TX_QUEUE_ENTRIES	1024
38 #define MIN_RX_QUEUE_ENTRIES	32
39 #define MIN_TX_QUEUE_ENTRIES	32
40 
41 /* Defaults */
42 #define DEF_RX_QUEUE_ENTRIES	128
43 #define DEF_TX_QUEUE_ENTRIES	128
44 
45 #define MAX_PKT_SIZE		1536
46 #define RX_BUF_SIZE		MAX_PKT_SIZE	/* must be smaller than 0x3fff */
47 
48 /* Min number of tx ring entries before stopping queue */
49 #define TX_THRESHOLD		(MAX_SKB_FRAGS + 1)
50 
51 #define FTGMAC_100MHZ		100000000
52 #define FTGMAC_25MHZ		25000000
53 
54 /* For NC-SI to register a fixed-link phy device */
55 static struct fixed_phy_status ncsi_phy_status = {
56 	.link = 1,
57 	.speed = SPEED_100,
58 	.duplex = DUPLEX_FULL,
59 	.pause = 0,
60 	.asym_pause = 0
61 };
62 
63 struct ftgmac100 {
64 	/* Registers */
65 	struct resource *res;
66 	void __iomem *base;
67 
68 	/* Rx ring */
69 	unsigned int rx_q_entries;
70 	struct ftgmac100_rxdes *rxdes;
71 	dma_addr_t rxdes_dma;
72 	struct sk_buff **rx_skbs;
73 	unsigned int rx_pointer;
74 	u32 rxdes0_edorr_mask;
75 
76 	/* Tx ring */
77 	unsigned int tx_q_entries;
78 	struct ftgmac100_txdes *txdes;
79 	dma_addr_t txdes_dma;
80 	struct sk_buff **tx_skbs;
81 	unsigned int tx_clean_pointer;
82 	unsigned int tx_pointer;
83 	u32 txdes0_edotr_mask;
84 
85 	/* Used to signal the reset task of ring change request */
86 	unsigned int new_rx_q_entries;
87 	unsigned int new_tx_q_entries;
88 
89 	/* Scratch page to use when rx skb alloc fails */
90 	void *rx_scratch;
91 	dma_addr_t rx_scratch_dma;
92 
93 	/* Component structures */
94 	struct net_device *netdev;
95 	struct device *dev;
96 	struct ncsi_dev *ndev;
97 	struct napi_struct napi;
98 	struct work_struct reset_task;
99 	struct mii_bus *mii_bus;
100 	struct clk *clk;
101 
102 	/* AST2500/AST2600 RMII ref clock gate */
103 	struct clk *rclk;
104 
105 	/* Link management */
106 	int cur_speed;
107 	int cur_duplex;
108 	bool use_ncsi;
109 
110 	/* Multicast filter settings */
111 	u32 maht0;
112 	u32 maht1;
113 
114 	/* Flow control settings */
115 	bool tx_pause;
116 	bool rx_pause;
117 	bool aneg_pause;
118 
119 	/* Misc */
120 	bool need_mac_restart;
121 	bool is_aspeed;
122 };
123 
124 static int ftgmac100_reset_mac(struct ftgmac100 *priv, u32 maccr)
125 {
126 	struct net_device *netdev = priv->netdev;
127 	int i;
128 
129 	/* NOTE: reset clears all registers */
130 	iowrite32(maccr, priv->base + FTGMAC100_OFFSET_MACCR);
131 	iowrite32(maccr | FTGMAC100_MACCR_SW_RST,
132 		  priv->base + FTGMAC100_OFFSET_MACCR);
133 	for (i = 0; i < 200; i++) {
134 		unsigned int maccr;
135 
136 		maccr = ioread32(priv->base + FTGMAC100_OFFSET_MACCR);
137 		if (!(maccr & FTGMAC100_MACCR_SW_RST))
138 			return 0;
139 
140 		udelay(1);
141 	}
142 
143 	netdev_err(netdev, "Hardware reset failed\n");
144 	return -EIO;
145 }
146 
147 static int ftgmac100_reset_and_config_mac(struct ftgmac100 *priv)
148 {
149 	u32 maccr = 0;
150 
151 	switch (priv->cur_speed) {
152 	case SPEED_10:
153 	case 0: /* no link */
154 		break;
155 
156 	case SPEED_100:
157 		maccr |= FTGMAC100_MACCR_FAST_MODE;
158 		break;
159 
160 	case SPEED_1000:
161 		maccr |= FTGMAC100_MACCR_GIGA_MODE;
162 		break;
163 	default:
164 		netdev_err(priv->netdev, "Unknown speed %d !\n",
165 			   priv->cur_speed);
166 		break;
167 	}
168 
169 	/* (Re)initialize the queue pointers */
170 	priv->rx_pointer = 0;
171 	priv->tx_clean_pointer = 0;
172 	priv->tx_pointer = 0;
173 
174 	/* The doc says reset twice with 10us interval */
175 	if (ftgmac100_reset_mac(priv, maccr))
176 		return -EIO;
177 	usleep_range(10, 1000);
178 	return ftgmac100_reset_mac(priv, maccr);
179 }
180 
181 static void ftgmac100_write_mac_addr(struct ftgmac100 *priv, const u8 *mac)
182 {
183 	unsigned int maddr = mac[0] << 8 | mac[1];
184 	unsigned int laddr = mac[2] << 24 | mac[3] << 16 | mac[4] << 8 | mac[5];
185 
186 	iowrite32(maddr, priv->base + FTGMAC100_OFFSET_MAC_MADR);
187 	iowrite32(laddr, priv->base + FTGMAC100_OFFSET_MAC_LADR);
188 }
189 
190 static int ftgmac100_initial_mac(struct ftgmac100 *priv)
191 {
192 	u8 mac[ETH_ALEN];
193 	unsigned int m;
194 	unsigned int l;
195 	int err;
196 
197 	err = of_get_ethdev_address(priv->dev->of_node, priv->netdev);
198 	if (err == -EPROBE_DEFER)
199 		return err;
200 	if (!err) {
201 		dev_info(priv->dev, "Read MAC address %pM from device tree\n",
202 			 priv->netdev->dev_addr);
203 		return 0;
204 	}
205 
206 	m = ioread32(priv->base + FTGMAC100_OFFSET_MAC_MADR);
207 	l = ioread32(priv->base + FTGMAC100_OFFSET_MAC_LADR);
208 
209 	mac[0] = (m >> 8) & 0xff;
210 	mac[1] = m & 0xff;
211 	mac[2] = (l >> 24) & 0xff;
212 	mac[3] = (l >> 16) & 0xff;
213 	mac[4] = (l >> 8) & 0xff;
214 	mac[5] = l & 0xff;
215 
216 	if (is_valid_ether_addr(mac)) {
217 		eth_hw_addr_set(priv->netdev, mac);
218 		dev_info(priv->dev, "Read MAC address %pM from chip\n", mac);
219 	} else {
220 		eth_hw_addr_random(priv->netdev);
221 		dev_info(priv->dev, "Generated random MAC address %pM\n",
222 			 priv->netdev->dev_addr);
223 	}
224 
225 	return 0;
226 }
227 
228 static int ftgmac100_set_mac_addr(struct net_device *dev, void *p)
229 {
230 	int ret;
231 
232 	ret = eth_prepare_mac_addr_change(dev, p);
233 	if (ret < 0)
234 		return ret;
235 
236 	eth_commit_mac_addr_change(dev, p);
237 	ftgmac100_write_mac_addr(netdev_priv(dev), dev->dev_addr);
238 
239 	return 0;
240 }
241 
242 static void ftgmac100_config_pause(struct ftgmac100 *priv)
243 {
244 	u32 fcr = FTGMAC100_FCR_PAUSE_TIME(16);
245 
246 	/* Throttle tx queue when receiving pause frames */
247 	if (priv->rx_pause)
248 		fcr |= FTGMAC100_FCR_FC_EN;
249 
250 	/* Enables sending pause frames when the RX queue is past a
251 	 * certain threshold.
252 	 */
253 	if (priv->tx_pause)
254 		fcr |= FTGMAC100_FCR_FCTHR_EN;
255 
256 	iowrite32(fcr, priv->base + FTGMAC100_OFFSET_FCR);
257 }
258 
259 static void ftgmac100_init_hw(struct ftgmac100 *priv)
260 {
261 	u32 reg, rfifo_sz, tfifo_sz;
262 
263 	/* Clear stale interrupts */
264 	reg = ioread32(priv->base + FTGMAC100_OFFSET_ISR);
265 	iowrite32(reg, priv->base + FTGMAC100_OFFSET_ISR);
266 
267 	/* Setup RX ring buffer base */
268 	iowrite32(priv->rxdes_dma, priv->base + FTGMAC100_OFFSET_RXR_BADR);
269 
270 	/* Setup TX ring buffer base */
271 	iowrite32(priv->txdes_dma, priv->base + FTGMAC100_OFFSET_NPTXR_BADR);
272 
273 	/* Configure RX buffer size */
274 	iowrite32(FTGMAC100_RBSR_SIZE(RX_BUF_SIZE),
275 		  priv->base + FTGMAC100_OFFSET_RBSR);
276 
277 	/* Set RX descriptor autopoll */
278 	iowrite32(FTGMAC100_APTC_RXPOLL_CNT(1),
279 		  priv->base + FTGMAC100_OFFSET_APTC);
280 
281 	/* Write MAC address */
282 	ftgmac100_write_mac_addr(priv, priv->netdev->dev_addr);
283 
284 	/* Write multicast filter */
285 	iowrite32(priv->maht0, priv->base + FTGMAC100_OFFSET_MAHT0);
286 	iowrite32(priv->maht1, priv->base + FTGMAC100_OFFSET_MAHT1);
287 
288 	/* Configure descriptor sizes and increase burst sizes according
289 	 * to values in Aspeed SDK. The FIFO arbitration is enabled and
290 	 * the thresholds set based on the recommended values in the
291 	 * AST2400 specification.
292 	 */
293 	iowrite32(FTGMAC100_DBLAC_RXDES_SIZE(2) |   /* 2*8 bytes RX descs */
294 		  FTGMAC100_DBLAC_TXDES_SIZE(2) |   /* 2*8 bytes TX descs */
295 		  FTGMAC100_DBLAC_RXBURST_SIZE(3) | /* 512 bytes max RX bursts */
296 		  FTGMAC100_DBLAC_TXBURST_SIZE(3) | /* 512 bytes max TX bursts */
297 		  FTGMAC100_DBLAC_RX_THR_EN |       /* Enable fifo threshold arb */
298 		  FTGMAC100_DBLAC_RXFIFO_HTHR(6) |  /* 6/8 of FIFO high threshold */
299 		  FTGMAC100_DBLAC_RXFIFO_LTHR(2),   /* 2/8 of FIFO low threshold */
300 		  priv->base + FTGMAC100_OFFSET_DBLAC);
301 
302 	/* Interrupt mitigation configured for 1 interrupt/packet. HW interrupt
303 	 * mitigation doesn't seem to provide any benefit with NAPI so leave
304 	 * it at that.
305 	 */
306 	iowrite32(FTGMAC100_ITC_RXINT_THR(1) |
307 		  FTGMAC100_ITC_TXINT_THR(1),
308 		  priv->base + FTGMAC100_OFFSET_ITC);
309 
310 	/* Configure FIFO sizes in the TPAFCR register */
311 	reg = ioread32(priv->base + FTGMAC100_OFFSET_FEAR);
312 	rfifo_sz = reg & 0x00000007;
313 	tfifo_sz = (reg >> 3) & 0x00000007;
314 	reg = ioread32(priv->base + FTGMAC100_OFFSET_TPAFCR);
315 	reg &= ~0x3f000000;
316 	reg |= (tfifo_sz << 27);
317 	reg |= (rfifo_sz << 24);
318 	iowrite32(reg, priv->base + FTGMAC100_OFFSET_TPAFCR);
319 }
320 
321 static void ftgmac100_start_hw(struct ftgmac100 *priv)
322 {
323 	u32 maccr = ioread32(priv->base + FTGMAC100_OFFSET_MACCR);
324 
325 	/* Keep the original GMAC and FAST bits */
326 	maccr &= (FTGMAC100_MACCR_FAST_MODE | FTGMAC100_MACCR_GIGA_MODE);
327 
328 	/* Add all the main enable bits */
329 	maccr |= FTGMAC100_MACCR_TXDMA_EN	|
330 		 FTGMAC100_MACCR_RXDMA_EN	|
331 		 FTGMAC100_MACCR_TXMAC_EN	|
332 		 FTGMAC100_MACCR_RXMAC_EN	|
333 		 FTGMAC100_MACCR_CRC_APD	|
334 		 FTGMAC100_MACCR_PHY_LINK_LEVEL	|
335 		 FTGMAC100_MACCR_RX_RUNT	|
336 		 FTGMAC100_MACCR_RX_BROADPKT;
337 
338 	/* Add other bits as needed */
339 	if (priv->cur_duplex == DUPLEX_FULL)
340 		maccr |= FTGMAC100_MACCR_FULLDUP;
341 	if (priv->netdev->flags & IFF_PROMISC)
342 		maccr |= FTGMAC100_MACCR_RX_ALL;
343 	if (priv->netdev->flags & IFF_ALLMULTI)
344 		maccr |= FTGMAC100_MACCR_RX_MULTIPKT;
345 	else if (netdev_mc_count(priv->netdev))
346 		maccr |= FTGMAC100_MACCR_HT_MULTI_EN;
347 
348 	/* Vlan filtering enabled */
349 	if (priv->netdev->features & NETIF_F_HW_VLAN_CTAG_RX)
350 		maccr |= FTGMAC100_MACCR_RM_VLAN;
351 
352 	/* Hit the HW */
353 	iowrite32(maccr, priv->base + FTGMAC100_OFFSET_MACCR);
354 }
355 
356 static void ftgmac100_stop_hw(struct ftgmac100 *priv)
357 {
358 	iowrite32(0, priv->base + FTGMAC100_OFFSET_MACCR);
359 }
360 
361 static void ftgmac100_calc_mc_hash(struct ftgmac100 *priv)
362 {
363 	struct netdev_hw_addr *ha;
364 
365 	priv->maht1 = 0;
366 	priv->maht0 = 0;
367 	netdev_for_each_mc_addr(ha, priv->netdev) {
368 		u32 crc_val = ether_crc_le(ETH_ALEN, ha->addr);
369 
370 		crc_val = (~(crc_val >> 2)) & 0x3f;
371 		if (crc_val >= 32)
372 			priv->maht1 |= 1ul << (crc_val - 32);
373 		else
374 			priv->maht0 |= 1ul << (crc_val);
375 	}
376 }
377 
378 static void ftgmac100_set_rx_mode(struct net_device *netdev)
379 {
380 	struct ftgmac100 *priv = netdev_priv(netdev);
381 
382 	/* Setup the hash filter */
383 	ftgmac100_calc_mc_hash(priv);
384 
385 	/* Interface down ? that's all there is to do */
386 	if (!netif_running(netdev))
387 		return;
388 
389 	/* Update the HW */
390 	iowrite32(priv->maht0, priv->base + FTGMAC100_OFFSET_MAHT0);
391 	iowrite32(priv->maht1, priv->base + FTGMAC100_OFFSET_MAHT1);
392 
393 	/* Reconfigure MACCR */
394 	ftgmac100_start_hw(priv);
395 }
396 
397 static int ftgmac100_alloc_rx_buf(struct ftgmac100 *priv, unsigned int entry,
398 				  struct ftgmac100_rxdes *rxdes, gfp_t gfp)
399 {
400 	struct net_device *netdev = priv->netdev;
401 	struct sk_buff *skb;
402 	dma_addr_t map;
403 	int err = 0;
404 
405 	skb = netdev_alloc_skb_ip_align(netdev, RX_BUF_SIZE);
406 	if (unlikely(!skb)) {
407 		if (net_ratelimit())
408 			netdev_warn(netdev, "failed to allocate rx skb\n");
409 		err = -ENOMEM;
410 		map = priv->rx_scratch_dma;
411 	} else {
412 		map = dma_map_single(priv->dev, skb->data, RX_BUF_SIZE,
413 				     DMA_FROM_DEVICE);
414 		if (unlikely(dma_mapping_error(priv->dev, map))) {
415 			if (net_ratelimit())
416 				netdev_err(netdev, "failed to map rx page\n");
417 			dev_kfree_skb_any(skb);
418 			map = priv->rx_scratch_dma;
419 			skb = NULL;
420 			err = -ENOMEM;
421 		}
422 	}
423 
424 	/* Store skb */
425 	priv->rx_skbs[entry] = skb;
426 
427 	/* Store DMA address into RX desc */
428 	rxdes->rxdes3 = cpu_to_le32(map);
429 
430 	/* Ensure the above is ordered vs clearing the OWN bit */
431 	dma_wmb();
432 
433 	/* Clean status (which resets own bit) */
434 	if (entry == (priv->rx_q_entries - 1))
435 		rxdes->rxdes0 = cpu_to_le32(priv->rxdes0_edorr_mask);
436 	else
437 		rxdes->rxdes0 = 0;
438 
439 	return err;
440 }
441 
442 static unsigned int ftgmac100_next_rx_pointer(struct ftgmac100 *priv,
443 					      unsigned int pointer)
444 {
445 	return (pointer + 1) & (priv->rx_q_entries - 1);
446 }
447 
448 static void ftgmac100_rx_packet_error(struct ftgmac100 *priv, u32 status)
449 {
450 	struct net_device *netdev = priv->netdev;
451 
452 	if (status & FTGMAC100_RXDES0_RX_ERR)
453 		netdev->stats.rx_errors++;
454 
455 	if (status & FTGMAC100_RXDES0_CRC_ERR)
456 		netdev->stats.rx_crc_errors++;
457 
458 	if (status & (FTGMAC100_RXDES0_FTL |
459 		      FTGMAC100_RXDES0_RUNT |
460 		      FTGMAC100_RXDES0_RX_ODD_NB))
461 		netdev->stats.rx_length_errors++;
462 }
463 
464 static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)
465 {
466 	struct net_device *netdev = priv->netdev;
467 	struct ftgmac100_rxdes *rxdes;
468 	struct sk_buff *skb;
469 	unsigned int pointer, size;
470 	u32 status, csum_vlan;
471 	dma_addr_t map;
472 
473 	/* Grab next RX descriptor */
474 	pointer = priv->rx_pointer;
475 	rxdes = &priv->rxdes[pointer];
476 
477 	/* Grab descriptor status */
478 	status = le32_to_cpu(rxdes->rxdes0);
479 
480 	/* Do we have a packet ? */
481 	if (!(status & FTGMAC100_RXDES0_RXPKT_RDY))
482 		return false;
483 
484 	/* Order subsequent reads with the test for the ready bit */
485 	dma_rmb();
486 
487 	/* We don't cope with fragmented RX packets */
488 	if (unlikely(!(status & FTGMAC100_RXDES0_FRS) ||
489 		     !(status & FTGMAC100_RXDES0_LRS)))
490 		goto drop;
491 
492 	/* Grab received size and csum vlan field in the descriptor */
493 	size = status & FTGMAC100_RXDES0_VDBC;
494 	csum_vlan = le32_to_cpu(rxdes->rxdes1);
495 
496 	/* Any error (other than csum offload) flagged ? */
497 	if (unlikely(status & RXDES0_ANY_ERROR)) {
498 		/* Correct for incorrect flagging of runt packets
499 		 * with vlan tags... Just accept a runt packet that
500 		 * has been flagged as vlan and whose size is at
501 		 * least 60 bytes.
502 		 */
503 		if ((status & FTGMAC100_RXDES0_RUNT) &&
504 		    (csum_vlan & FTGMAC100_RXDES1_VLANTAG_AVAIL) &&
505 		    (size >= 60))
506 			status &= ~FTGMAC100_RXDES0_RUNT;
507 
508 		/* Any error still in there ? */
509 		if (status & RXDES0_ANY_ERROR) {
510 			ftgmac100_rx_packet_error(priv, status);
511 			goto drop;
512 		}
513 	}
514 
515 	/* If the packet had no skb (failed to allocate earlier)
516 	 * then try to allocate one and skip
517 	 */
518 	skb = priv->rx_skbs[pointer];
519 	if (!unlikely(skb)) {
520 		ftgmac100_alloc_rx_buf(priv, pointer, rxdes, GFP_ATOMIC);
521 		goto drop;
522 	}
523 
524 	if (unlikely(status & FTGMAC100_RXDES0_MULTICAST))
525 		netdev->stats.multicast++;
526 
527 	/* If the HW found checksum errors, bounce it to software.
528 	 *
529 	 * If we didn't, we need to see if the packet was recognized
530 	 * by HW as one of the supported checksummed protocols before
531 	 * we accept the HW test results.
532 	 */
533 	if (netdev->features & NETIF_F_RXCSUM) {
534 		u32 err_bits = FTGMAC100_RXDES1_TCP_CHKSUM_ERR |
535 			FTGMAC100_RXDES1_UDP_CHKSUM_ERR |
536 			FTGMAC100_RXDES1_IP_CHKSUM_ERR;
537 		if ((csum_vlan & err_bits) ||
538 		    !(csum_vlan & FTGMAC100_RXDES1_PROT_MASK))
539 			skb->ip_summed = CHECKSUM_NONE;
540 		else
541 			skb->ip_summed = CHECKSUM_UNNECESSARY;
542 	}
543 
544 	/* Transfer received size to skb */
545 	skb_put(skb, size);
546 
547 	/* Extract vlan tag */
548 	if ((netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
549 	    (csum_vlan & FTGMAC100_RXDES1_VLANTAG_AVAIL))
550 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
551 				       csum_vlan & 0xffff);
552 
553 	/* Tear down DMA mapping, do necessary cache management */
554 	map = le32_to_cpu(rxdes->rxdes3);
555 
556 #if defined(CONFIG_ARM) && !defined(CONFIG_ARM_DMA_USE_IOMMU)
557 	/* When we don't have an iommu, we can save cycles by not
558 	 * invalidating the cache for the part of the packet that
559 	 * wasn't received.
560 	 */
561 	dma_unmap_single(priv->dev, map, size, DMA_FROM_DEVICE);
562 #else
563 	dma_unmap_single(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
564 #endif
565 
566 
567 	/* Resplenish rx ring */
568 	ftgmac100_alloc_rx_buf(priv, pointer, rxdes, GFP_ATOMIC);
569 	priv->rx_pointer = ftgmac100_next_rx_pointer(priv, pointer);
570 
571 	skb->protocol = eth_type_trans(skb, netdev);
572 
573 	netdev->stats.rx_packets++;
574 	netdev->stats.rx_bytes += size;
575 
576 	/* push packet to protocol stack */
577 	if (skb->ip_summed == CHECKSUM_NONE)
578 		netif_receive_skb(skb);
579 	else
580 		napi_gro_receive(&priv->napi, skb);
581 
582 	(*processed)++;
583 	return true;
584 
585 drop:
586 	/* Clean rxdes0 (which resets own bit) */
587 	rxdes->rxdes0 = cpu_to_le32(status & priv->rxdes0_edorr_mask);
588 	priv->rx_pointer = ftgmac100_next_rx_pointer(priv, pointer);
589 	netdev->stats.rx_dropped++;
590 	return true;
591 }
592 
593 static u32 ftgmac100_base_tx_ctlstat(struct ftgmac100 *priv,
594 				     unsigned int index)
595 {
596 	if (index == (priv->tx_q_entries - 1))
597 		return priv->txdes0_edotr_mask;
598 	else
599 		return 0;
600 }
601 
602 static unsigned int ftgmac100_next_tx_pointer(struct ftgmac100 *priv,
603 					      unsigned int pointer)
604 {
605 	return (pointer + 1) & (priv->tx_q_entries - 1);
606 }
607 
608 static u32 ftgmac100_tx_buf_avail(struct ftgmac100 *priv)
609 {
610 	/* Returns the number of available slots in the TX queue
611 	 *
612 	 * This always leaves one free slot so we don't have to
613 	 * worry about empty vs. full, and this simplifies the
614 	 * test for ftgmac100_tx_buf_cleanable() below
615 	 */
616 	return (priv->tx_clean_pointer - priv->tx_pointer - 1) &
617 		(priv->tx_q_entries - 1);
618 }
619 
620 static bool ftgmac100_tx_buf_cleanable(struct ftgmac100 *priv)
621 {
622 	return priv->tx_pointer != priv->tx_clean_pointer;
623 }
624 
625 static void ftgmac100_free_tx_packet(struct ftgmac100 *priv,
626 				     unsigned int pointer,
627 				     struct sk_buff *skb,
628 				     struct ftgmac100_txdes *txdes,
629 				     u32 ctl_stat)
630 {
631 	dma_addr_t map = le32_to_cpu(txdes->txdes3);
632 	size_t len;
633 
634 	if (ctl_stat & FTGMAC100_TXDES0_FTS) {
635 		len = skb_headlen(skb);
636 		dma_unmap_single(priv->dev, map, len, DMA_TO_DEVICE);
637 	} else {
638 		len = FTGMAC100_TXDES0_TXBUF_SIZE(ctl_stat);
639 		dma_unmap_page(priv->dev, map, len, DMA_TO_DEVICE);
640 	}
641 
642 	/* Free SKB on last segment */
643 	if (ctl_stat & FTGMAC100_TXDES0_LTS)
644 		dev_kfree_skb(skb);
645 	priv->tx_skbs[pointer] = NULL;
646 }
647 
648 static bool ftgmac100_tx_complete_packet(struct ftgmac100 *priv)
649 {
650 	struct net_device *netdev = priv->netdev;
651 	struct ftgmac100_txdes *txdes;
652 	struct sk_buff *skb;
653 	unsigned int pointer;
654 	u32 ctl_stat;
655 
656 	pointer = priv->tx_clean_pointer;
657 	txdes = &priv->txdes[pointer];
658 
659 	ctl_stat = le32_to_cpu(txdes->txdes0);
660 	if (ctl_stat & FTGMAC100_TXDES0_TXDMA_OWN)
661 		return false;
662 
663 	skb = priv->tx_skbs[pointer];
664 	netdev->stats.tx_packets++;
665 	netdev->stats.tx_bytes += skb->len;
666 	ftgmac100_free_tx_packet(priv, pointer, skb, txdes, ctl_stat);
667 	txdes->txdes0 = cpu_to_le32(ctl_stat & priv->txdes0_edotr_mask);
668 
669 	/* Ensure the descriptor config is visible before setting the tx
670 	 * pointer.
671 	 */
672 	smp_wmb();
673 
674 	priv->tx_clean_pointer = ftgmac100_next_tx_pointer(priv, pointer);
675 
676 	return true;
677 }
678 
679 static void ftgmac100_tx_complete(struct ftgmac100 *priv)
680 {
681 	struct net_device *netdev = priv->netdev;
682 
683 	/* Process all completed packets */
684 	while (ftgmac100_tx_buf_cleanable(priv) &&
685 	       ftgmac100_tx_complete_packet(priv))
686 		;
687 
688 	/* Restart queue if needed */
689 	smp_mb();
690 	if (unlikely(netif_queue_stopped(netdev) &&
691 		     ftgmac100_tx_buf_avail(priv) >= TX_THRESHOLD)) {
692 		struct netdev_queue *txq;
693 
694 		txq = netdev_get_tx_queue(netdev, 0);
695 		__netif_tx_lock(txq, smp_processor_id());
696 		if (netif_queue_stopped(netdev) &&
697 		    ftgmac100_tx_buf_avail(priv) >= TX_THRESHOLD)
698 			netif_wake_queue(netdev);
699 		__netif_tx_unlock(txq);
700 	}
701 }
702 
703 static bool ftgmac100_prep_tx_csum(struct sk_buff *skb, u32 *csum_vlan)
704 {
705 	if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
706 		u8 ip_proto = ip_hdr(skb)->protocol;
707 
708 		*csum_vlan |= FTGMAC100_TXDES1_IP_CHKSUM;
709 		switch(ip_proto) {
710 		case IPPROTO_TCP:
711 			*csum_vlan |= FTGMAC100_TXDES1_TCP_CHKSUM;
712 			return true;
713 		case IPPROTO_UDP:
714 			*csum_vlan |= FTGMAC100_TXDES1_UDP_CHKSUM;
715 			return true;
716 		case IPPROTO_IP:
717 			return true;
718 		}
719 	}
720 	return skb_checksum_help(skb) == 0;
721 }
722 
723 static netdev_tx_t ftgmac100_hard_start_xmit(struct sk_buff *skb,
724 					     struct net_device *netdev)
725 {
726 	struct ftgmac100 *priv = netdev_priv(netdev);
727 	struct ftgmac100_txdes *txdes, *first;
728 	unsigned int pointer, nfrags, len, i, j;
729 	u32 f_ctl_stat, ctl_stat, csum_vlan;
730 	dma_addr_t map;
731 
732 	/* The HW doesn't pad small frames */
733 	if (eth_skb_pad(skb)) {
734 		netdev->stats.tx_dropped++;
735 		return NETDEV_TX_OK;
736 	}
737 
738 	/* Reject oversize packets */
739 	if (unlikely(skb->len > MAX_PKT_SIZE)) {
740 		if (net_ratelimit())
741 			netdev_dbg(netdev, "tx packet too big\n");
742 		goto drop;
743 	}
744 
745 	/* Do we have a limit on #fragments ? I yet have to get a reply
746 	 * from Aspeed. If there's one I haven't hit it.
747 	 */
748 	nfrags = skb_shinfo(skb)->nr_frags;
749 
750 	/* Setup HW checksumming */
751 	csum_vlan = 0;
752 	if (skb->ip_summed == CHECKSUM_PARTIAL &&
753 	    !ftgmac100_prep_tx_csum(skb, &csum_vlan))
754 		goto drop;
755 
756 	/* Add VLAN tag */
757 	if (skb_vlan_tag_present(skb)) {
758 		csum_vlan |= FTGMAC100_TXDES1_INS_VLANTAG;
759 		csum_vlan |= skb_vlan_tag_get(skb) & 0xffff;
760 	}
761 
762 	/* Get header len */
763 	len = skb_headlen(skb);
764 
765 	/* Map the packet head */
766 	map = dma_map_single(priv->dev, skb->data, len, DMA_TO_DEVICE);
767 	if (dma_mapping_error(priv->dev, map)) {
768 		if (net_ratelimit())
769 			netdev_err(netdev, "map tx packet head failed\n");
770 		goto drop;
771 	}
772 
773 	/* Grab the next free tx descriptor */
774 	pointer = priv->tx_pointer;
775 	txdes = first = &priv->txdes[pointer];
776 
777 	/* Setup it up with the packet head. Don't write the head to the
778 	 * ring just yet
779 	 */
780 	priv->tx_skbs[pointer] = skb;
781 	f_ctl_stat = ftgmac100_base_tx_ctlstat(priv, pointer);
782 	f_ctl_stat |= FTGMAC100_TXDES0_TXDMA_OWN;
783 	f_ctl_stat |= FTGMAC100_TXDES0_TXBUF_SIZE(len);
784 	f_ctl_stat |= FTGMAC100_TXDES0_FTS;
785 	if (nfrags == 0)
786 		f_ctl_stat |= FTGMAC100_TXDES0_LTS;
787 	txdes->txdes3 = cpu_to_le32(map);
788 	txdes->txdes1 = cpu_to_le32(csum_vlan);
789 
790 	/* Next descriptor */
791 	pointer = ftgmac100_next_tx_pointer(priv, pointer);
792 
793 	/* Add the fragments */
794 	for (i = 0; i < nfrags; i++) {
795 		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
796 
797 		len = skb_frag_size(frag);
798 
799 		/* Map it */
800 		map = skb_frag_dma_map(priv->dev, frag, 0, len,
801 				       DMA_TO_DEVICE);
802 		if (dma_mapping_error(priv->dev, map))
803 			goto dma_err;
804 
805 		/* Setup descriptor */
806 		priv->tx_skbs[pointer] = skb;
807 		txdes = &priv->txdes[pointer];
808 		ctl_stat = ftgmac100_base_tx_ctlstat(priv, pointer);
809 		ctl_stat |= FTGMAC100_TXDES0_TXDMA_OWN;
810 		ctl_stat |= FTGMAC100_TXDES0_TXBUF_SIZE(len);
811 		if (i == (nfrags - 1))
812 			ctl_stat |= FTGMAC100_TXDES0_LTS;
813 		txdes->txdes0 = cpu_to_le32(ctl_stat);
814 		txdes->txdes1 = 0;
815 		txdes->txdes3 = cpu_to_le32(map);
816 
817 		/* Next one */
818 		pointer = ftgmac100_next_tx_pointer(priv, pointer);
819 	}
820 
821 	/* Order the previous packet and descriptor udpates
822 	 * before setting the OWN bit on the first descriptor.
823 	 */
824 	dma_wmb();
825 	first->txdes0 = cpu_to_le32(f_ctl_stat);
826 
827 	/* Ensure the descriptor config is visible before setting the tx
828 	 * pointer.
829 	 */
830 	smp_wmb();
831 
832 	/* Update next TX pointer */
833 	priv->tx_pointer = pointer;
834 
835 	/* If there isn't enough room for all the fragments of a new packet
836 	 * in the TX ring, stop the queue. The sequence below is race free
837 	 * vs. a concurrent restart in ftgmac100_poll()
838 	 */
839 	if (unlikely(ftgmac100_tx_buf_avail(priv) < TX_THRESHOLD)) {
840 		netif_stop_queue(netdev);
841 		/* Order the queue stop with the test below */
842 		smp_mb();
843 		if (ftgmac100_tx_buf_avail(priv) >= TX_THRESHOLD)
844 			netif_wake_queue(netdev);
845 	}
846 
847 	/* Poke transmitter to read the updated TX descriptors */
848 	iowrite32(1, priv->base + FTGMAC100_OFFSET_NPTXPD);
849 
850 	return NETDEV_TX_OK;
851 
852 dma_err:
853 	if (net_ratelimit())
854 		netdev_err(netdev, "map tx fragment failed\n");
855 
856 	/* Free head */
857 	pointer = priv->tx_pointer;
858 	ftgmac100_free_tx_packet(priv, pointer, skb, first, f_ctl_stat);
859 	first->txdes0 = cpu_to_le32(f_ctl_stat & priv->txdes0_edotr_mask);
860 
861 	/* Then all fragments */
862 	for (j = 0; j < i; j++) {
863 		pointer = ftgmac100_next_tx_pointer(priv, pointer);
864 		txdes = &priv->txdes[pointer];
865 		ctl_stat = le32_to_cpu(txdes->txdes0);
866 		ftgmac100_free_tx_packet(priv, pointer, skb, txdes, ctl_stat);
867 		txdes->txdes0 = cpu_to_le32(ctl_stat & priv->txdes0_edotr_mask);
868 	}
869 
870 	/* This cannot be reached if we successfully mapped the
871 	 * last fragment, so we know ftgmac100_free_tx_packet()
872 	 * hasn't freed the skb yet.
873 	 */
874 drop:
875 	/* Drop the packet */
876 	dev_kfree_skb_any(skb);
877 	netdev->stats.tx_dropped++;
878 
879 	return NETDEV_TX_OK;
880 }
881 
882 static void ftgmac100_free_buffers(struct ftgmac100 *priv)
883 {
884 	int i;
885 
886 	/* Free all RX buffers */
887 	for (i = 0; i < priv->rx_q_entries; i++) {
888 		struct ftgmac100_rxdes *rxdes = &priv->rxdes[i];
889 		struct sk_buff *skb = priv->rx_skbs[i];
890 		dma_addr_t map = le32_to_cpu(rxdes->rxdes3);
891 
892 		if (!skb)
893 			continue;
894 
895 		priv->rx_skbs[i] = NULL;
896 		dma_unmap_single(priv->dev, map, RX_BUF_SIZE, DMA_FROM_DEVICE);
897 		dev_kfree_skb_any(skb);
898 	}
899 
900 	/* Free all TX buffers */
901 	for (i = 0; i < priv->tx_q_entries; i++) {
902 		struct ftgmac100_txdes *txdes = &priv->txdes[i];
903 		struct sk_buff *skb = priv->tx_skbs[i];
904 
905 		if (!skb)
906 			continue;
907 		ftgmac100_free_tx_packet(priv, i, skb, txdes,
908 					 le32_to_cpu(txdes->txdes0));
909 	}
910 }
911 
912 static void ftgmac100_free_rings(struct ftgmac100 *priv)
913 {
914 	/* Free skb arrays */
915 	kfree(priv->rx_skbs);
916 	kfree(priv->tx_skbs);
917 
918 	/* Free descriptors */
919 	if (priv->rxdes)
920 		dma_free_coherent(priv->dev, MAX_RX_QUEUE_ENTRIES *
921 				  sizeof(struct ftgmac100_rxdes),
922 				  priv->rxdes, priv->rxdes_dma);
923 	priv->rxdes = NULL;
924 
925 	if (priv->txdes)
926 		dma_free_coherent(priv->dev, MAX_TX_QUEUE_ENTRIES *
927 				  sizeof(struct ftgmac100_txdes),
928 				  priv->txdes, priv->txdes_dma);
929 	priv->txdes = NULL;
930 
931 	/* Free scratch packet buffer */
932 	if (priv->rx_scratch)
933 		dma_free_coherent(priv->dev, RX_BUF_SIZE,
934 				  priv->rx_scratch, priv->rx_scratch_dma);
935 }
936 
937 static int ftgmac100_alloc_rings(struct ftgmac100 *priv)
938 {
939 	/* Allocate skb arrays */
940 	priv->rx_skbs = kcalloc(MAX_RX_QUEUE_ENTRIES, sizeof(void *),
941 				GFP_KERNEL);
942 	if (!priv->rx_skbs)
943 		return -ENOMEM;
944 	priv->tx_skbs = kcalloc(MAX_TX_QUEUE_ENTRIES, sizeof(void *),
945 				GFP_KERNEL);
946 	if (!priv->tx_skbs)
947 		return -ENOMEM;
948 
949 	/* Allocate descriptors */
950 	priv->rxdes = dma_alloc_coherent(priv->dev,
951 					 MAX_RX_QUEUE_ENTRIES * sizeof(struct ftgmac100_rxdes),
952 					 &priv->rxdes_dma, GFP_KERNEL);
953 	if (!priv->rxdes)
954 		return -ENOMEM;
955 	priv->txdes = dma_alloc_coherent(priv->dev,
956 					 MAX_TX_QUEUE_ENTRIES * sizeof(struct ftgmac100_txdes),
957 					 &priv->txdes_dma, GFP_KERNEL);
958 	if (!priv->txdes)
959 		return -ENOMEM;
960 
961 	/* Allocate scratch packet buffer */
962 	priv->rx_scratch = dma_alloc_coherent(priv->dev,
963 					      RX_BUF_SIZE,
964 					      &priv->rx_scratch_dma,
965 					      GFP_KERNEL);
966 	if (!priv->rx_scratch)
967 		return -ENOMEM;
968 
969 	return 0;
970 }
971 
972 static void ftgmac100_init_rings(struct ftgmac100 *priv)
973 {
974 	struct ftgmac100_rxdes *rxdes = NULL;
975 	struct ftgmac100_txdes *txdes = NULL;
976 	int i;
977 
978 	/* Update entries counts */
979 	priv->rx_q_entries = priv->new_rx_q_entries;
980 	priv->tx_q_entries = priv->new_tx_q_entries;
981 
982 	if (WARN_ON(priv->rx_q_entries < MIN_RX_QUEUE_ENTRIES))
983 		return;
984 
985 	/* Initialize RX ring */
986 	for (i = 0; i < priv->rx_q_entries; i++) {
987 		rxdes = &priv->rxdes[i];
988 		rxdes->rxdes0 = 0;
989 		rxdes->rxdes3 = cpu_to_le32(priv->rx_scratch_dma);
990 	}
991 	/* Mark the end of the ring */
992 	rxdes->rxdes0 |= cpu_to_le32(priv->rxdes0_edorr_mask);
993 
994 	if (WARN_ON(priv->tx_q_entries < MIN_RX_QUEUE_ENTRIES))
995 		return;
996 
997 	/* Initialize TX ring */
998 	for (i = 0; i < priv->tx_q_entries; i++) {
999 		txdes = &priv->txdes[i];
1000 		txdes->txdes0 = 0;
1001 	}
1002 	txdes->txdes0 |= cpu_to_le32(priv->txdes0_edotr_mask);
1003 }
1004 
1005 static int ftgmac100_alloc_rx_buffers(struct ftgmac100 *priv)
1006 {
1007 	int i;
1008 
1009 	for (i = 0; i < priv->rx_q_entries; i++) {
1010 		struct ftgmac100_rxdes *rxdes = &priv->rxdes[i];
1011 
1012 		if (ftgmac100_alloc_rx_buf(priv, i, rxdes, GFP_KERNEL))
1013 			return -ENOMEM;
1014 	}
1015 	return 0;
1016 }
1017 
1018 static int ftgmac100_mdiobus_read(struct mii_bus *bus, int phy_addr, int regnum)
1019 {
1020 	struct net_device *netdev = bus->priv;
1021 	struct ftgmac100 *priv = netdev_priv(netdev);
1022 	unsigned int phycr;
1023 	int i;
1024 
1025 	phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
1026 
1027 	/* preserve MDC cycle threshold */
1028 	phycr &= FTGMAC100_PHYCR_MDC_CYCTHR_MASK;
1029 
1030 	phycr |= FTGMAC100_PHYCR_PHYAD(phy_addr) |
1031 		 FTGMAC100_PHYCR_REGAD(regnum) |
1032 		 FTGMAC100_PHYCR_MIIRD;
1033 
1034 	iowrite32(phycr, priv->base + FTGMAC100_OFFSET_PHYCR);
1035 
1036 	for (i = 0; i < 10; i++) {
1037 		phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
1038 
1039 		if ((phycr & FTGMAC100_PHYCR_MIIRD) == 0) {
1040 			int data;
1041 
1042 			data = ioread32(priv->base + FTGMAC100_OFFSET_PHYDATA);
1043 			return FTGMAC100_PHYDATA_MIIRDATA(data);
1044 		}
1045 
1046 		udelay(100);
1047 	}
1048 
1049 	netdev_err(netdev, "mdio read timed out\n");
1050 	return -EIO;
1051 }
1052 
1053 static int ftgmac100_mdiobus_write(struct mii_bus *bus, int phy_addr,
1054 				   int regnum, u16 value)
1055 {
1056 	struct net_device *netdev = bus->priv;
1057 	struct ftgmac100 *priv = netdev_priv(netdev);
1058 	unsigned int phycr;
1059 	int data;
1060 	int i;
1061 
1062 	phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
1063 
1064 	/* preserve MDC cycle threshold */
1065 	phycr &= FTGMAC100_PHYCR_MDC_CYCTHR_MASK;
1066 
1067 	phycr |= FTGMAC100_PHYCR_PHYAD(phy_addr) |
1068 		 FTGMAC100_PHYCR_REGAD(regnum) |
1069 		 FTGMAC100_PHYCR_MIIWR;
1070 
1071 	data = FTGMAC100_PHYDATA_MIIWDATA(value);
1072 
1073 	iowrite32(data, priv->base + FTGMAC100_OFFSET_PHYDATA);
1074 	iowrite32(phycr, priv->base + FTGMAC100_OFFSET_PHYCR);
1075 
1076 	for (i = 0; i < 10; i++) {
1077 		phycr = ioread32(priv->base + FTGMAC100_OFFSET_PHYCR);
1078 
1079 		if ((phycr & FTGMAC100_PHYCR_MIIWR) == 0)
1080 			return 0;
1081 
1082 		udelay(100);
1083 	}
1084 
1085 	netdev_err(netdev, "mdio write timed out\n");
1086 	return -EIO;
1087 }
1088 
1089 static void ftgmac100_get_drvinfo(struct net_device *netdev,
1090 				  struct ethtool_drvinfo *info)
1091 {
1092 	strscpy(info->driver, DRV_NAME, sizeof(info->driver));
1093 	strscpy(info->bus_info, dev_name(&netdev->dev), sizeof(info->bus_info));
1094 }
1095 
1096 static void
1097 ftgmac100_get_ringparam(struct net_device *netdev,
1098 			struct ethtool_ringparam *ering,
1099 			struct kernel_ethtool_ringparam *kernel_ering,
1100 			struct netlink_ext_ack *extack)
1101 {
1102 	struct ftgmac100 *priv = netdev_priv(netdev);
1103 
1104 	memset(ering, 0, sizeof(*ering));
1105 	ering->rx_max_pending = MAX_RX_QUEUE_ENTRIES;
1106 	ering->tx_max_pending = MAX_TX_QUEUE_ENTRIES;
1107 	ering->rx_pending = priv->rx_q_entries;
1108 	ering->tx_pending = priv->tx_q_entries;
1109 }
1110 
1111 static int
1112 ftgmac100_set_ringparam(struct net_device *netdev,
1113 			struct ethtool_ringparam *ering,
1114 			struct kernel_ethtool_ringparam *kernel_ering,
1115 			struct netlink_ext_ack *extack)
1116 {
1117 	struct ftgmac100 *priv = netdev_priv(netdev);
1118 
1119 	if (ering->rx_pending > MAX_RX_QUEUE_ENTRIES ||
1120 	    ering->tx_pending > MAX_TX_QUEUE_ENTRIES ||
1121 	    ering->rx_pending < MIN_RX_QUEUE_ENTRIES ||
1122 	    ering->tx_pending < MIN_TX_QUEUE_ENTRIES ||
1123 	    !is_power_of_2(ering->rx_pending) ||
1124 	    !is_power_of_2(ering->tx_pending))
1125 		return -EINVAL;
1126 
1127 	priv->new_rx_q_entries = ering->rx_pending;
1128 	priv->new_tx_q_entries = ering->tx_pending;
1129 	if (netif_running(netdev))
1130 		schedule_work(&priv->reset_task);
1131 
1132 	return 0;
1133 }
1134 
1135 static void ftgmac100_get_pauseparam(struct net_device *netdev,
1136 				     struct ethtool_pauseparam *pause)
1137 {
1138 	struct ftgmac100 *priv = netdev_priv(netdev);
1139 
1140 	pause->autoneg = priv->aneg_pause;
1141 	pause->tx_pause = priv->tx_pause;
1142 	pause->rx_pause = priv->rx_pause;
1143 }
1144 
1145 static int ftgmac100_set_pauseparam(struct net_device *netdev,
1146 				    struct ethtool_pauseparam *pause)
1147 {
1148 	struct ftgmac100 *priv = netdev_priv(netdev);
1149 	struct phy_device *phydev = netdev->phydev;
1150 
1151 	priv->aneg_pause = pause->autoneg;
1152 	priv->tx_pause = pause->tx_pause;
1153 	priv->rx_pause = pause->rx_pause;
1154 
1155 	if (phydev)
1156 		phy_set_asym_pause(phydev, pause->rx_pause, pause->tx_pause);
1157 
1158 	if (netif_running(netdev)) {
1159 		if (!(phydev && priv->aneg_pause))
1160 			ftgmac100_config_pause(priv);
1161 	}
1162 
1163 	return 0;
1164 }
1165 
1166 static const struct ethtool_ops ftgmac100_ethtool_ops = {
1167 	.get_drvinfo		= ftgmac100_get_drvinfo,
1168 	.get_link		= ethtool_op_get_link,
1169 	.get_link_ksettings	= phy_ethtool_get_link_ksettings,
1170 	.set_link_ksettings	= phy_ethtool_set_link_ksettings,
1171 	.nway_reset		= phy_ethtool_nway_reset,
1172 	.get_ringparam		= ftgmac100_get_ringparam,
1173 	.set_ringparam		= ftgmac100_set_ringparam,
1174 	.get_pauseparam		= ftgmac100_get_pauseparam,
1175 	.set_pauseparam		= ftgmac100_set_pauseparam,
1176 };
1177 
1178 static irqreturn_t ftgmac100_interrupt(int irq, void *dev_id)
1179 {
1180 	struct net_device *netdev = dev_id;
1181 	struct ftgmac100 *priv = netdev_priv(netdev);
1182 	unsigned int status, new_mask = FTGMAC100_INT_BAD;
1183 
1184 	/* Fetch and clear interrupt bits, process abnormal ones */
1185 	status = ioread32(priv->base + FTGMAC100_OFFSET_ISR);
1186 	iowrite32(status, priv->base + FTGMAC100_OFFSET_ISR);
1187 	if (unlikely(status & FTGMAC100_INT_BAD)) {
1188 
1189 		/* RX buffer unavailable */
1190 		if (status & FTGMAC100_INT_NO_RXBUF)
1191 			netdev->stats.rx_over_errors++;
1192 
1193 		/* received packet lost due to RX FIFO full */
1194 		if (status & FTGMAC100_INT_RPKT_LOST)
1195 			netdev->stats.rx_fifo_errors++;
1196 
1197 		/* sent packet lost due to excessive TX collision */
1198 		if (status & FTGMAC100_INT_XPKT_LOST)
1199 			netdev->stats.tx_fifo_errors++;
1200 
1201 		/* AHB error -> Reset the chip */
1202 		if (status & FTGMAC100_INT_AHB_ERR) {
1203 			if (net_ratelimit())
1204 				netdev_warn(netdev,
1205 					   "AHB bus error ! Resetting chip.\n");
1206 			iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1207 			schedule_work(&priv->reset_task);
1208 			return IRQ_HANDLED;
1209 		}
1210 
1211 		/* We may need to restart the MAC after such errors, delay
1212 		 * this until after we have freed some Rx buffers though
1213 		 */
1214 		priv->need_mac_restart = true;
1215 
1216 		/* Disable those errors until we restart */
1217 		new_mask &= ~status;
1218 	}
1219 
1220 	/* Only enable "bad" interrupts while NAPI is on */
1221 	iowrite32(new_mask, priv->base + FTGMAC100_OFFSET_IER);
1222 
1223 	/* Schedule NAPI bh */
1224 	napi_schedule_irqoff(&priv->napi);
1225 
1226 	return IRQ_HANDLED;
1227 }
1228 
1229 static bool ftgmac100_check_rx(struct ftgmac100 *priv)
1230 {
1231 	struct ftgmac100_rxdes *rxdes = &priv->rxdes[priv->rx_pointer];
1232 
1233 	/* Do we have a packet ? */
1234 	return !!(rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_RXPKT_RDY));
1235 }
1236 
1237 static int ftgmac100_poll(struct napi_struct *napi, int budget)
1238 {
1239 	struct ftgmac100 *priv = container_of(napi, struct ftgmac100, napi);
1240 	int work_done = 0;
1241 	bool more;
1242 
1243 	/* Handle TX completions */
1244 	if (ftgmac100_tx_buf_cleanable(priv))
1245 		ftgmac100_tx_complete(priv);
1246 
1247 	/* Handle RX packets */
1248 	do {
1249 		more = ftgmac100_rx_packet(priv, &work_done);
1250 	} while (more && work_done < budget);
1251 
1252 
1253 	/* The interrupt is telling us to kick the MAC back to life
1254 	 * after an RX overflow
1255 	 */
1256 	if (unlikely(priv->need_mac_restart)) {
1257 		ftgmac100_start_hw(priv);
1258 		priv->need_mac_restart = false;
1259 
1260 		/* Re-enable "bad" interrupts */
1261 		iowrite32(FTGMAC100_INT_BAD,
1262 			  priv->base + FTGMAC100_OFFSET_IER);
1263 	}
1264 
1265 	/* As long as we are waiting for transmit packets to be
1266 	 * completed we keep NAPI going
1267 	 */
1268 	if (ftgmac100_tx_buf_cleanable(priv))
1269 		work_done = budget;
1270 
1271 	if (work_done < budget) {
1272 		/* We are about to re-enable all interrupts. However
1273 		 * the HW has been latching RX/TX packet interrupts while
1274 		 * they were masked. So we clear them first, then we need
1275 		 * to re-check if there's something to process
1276 		 */
1277 		iowrite32(FTGMAC100_INT_RXTX,
1278 			  priv->base + FTGMAC100_OFFSET_ISR);
1279 
1280 		/* Push the above (and provides a barrier vs. subsequent
1281 		 * reads of the descriptor).
1282 		 */
1283 		ioread32(priv->base + FTGMAC100_OFFSET_ISR);
1284 
1285 		/* Check RX and TX descriptors for more work to do */
1286 		if (ftgmac100_check_rx(priv) ||
1287 		    ftgmac100_tx_buf_cleanable(priv))
1288 			return budget;
1289 
1290 		/* deschedule NAPI */
1291 		napi_complete(napi);
1292 
1293 		/* enable all interrupts */
1294 		iowrite32(FTGMAC100_INT_ALL,
1295 			  priv->base + FTGMAC100_OFFSET_IER);
1296 	}
1297 
1298 	return work_done;
1299 }
1300 
1301 static int ftgmac100_init_all(struct ftgmac100 *priv, bool ignore_alloc_err)
1302 {
1303 	int err = 0;
1304 
1305 	/* Re-init descriptors (adjust queue sizes) */
1306 	ftgmac100_init_rings(priv);
1307 
1308 	/* Realloc rx descriptors */
1309 	err = ftgmac100_alloc_rx_buffers(priv);
1310 	if (err && !ignore_alloc_err)
1311 		return err;
1312 
1313 	/* Reinit and restart HW */
1314 	ftgmac100_init_hw(priv);
1315 	ftgmac100_config_pause(priv);
1316 	ftgmac100_start_hw(priv);
1317 
1318 	/* Re-enable the device */
1319 	napi_enable(&priv->napi);
1320 	netif_start_queue(priv->netdev);
1321 
1322 	/* Enable all interrupts */
1323 	iowrite32(FTGMAC100_INT_ALL, priv->base + FTGMAC100_OFFSET_IER);
1324 
1325 	return err;
1326 }
1327 
1328 static void ftgmac100_reset(struct ftgmac100 *priv)
1329 {
1330 	struct net_device *netdev = priv->netdev;
1331 	int err;
1332 
1333 	netdev_dbg(netdev, "Resetting NIC...\n");
1334 
1335 	/* Lock the world */
1336 	rtnl_lock();
1337 	if (netdev->phydev)
1338 		mutex_lock(&netdev->phydev->lock);
1339 	if (priv->mii_bus)
1340 		mutex_lock(&priv->mii_bus->mdio_lock);
1341 
1342 
1343 	/* Check if the interface is still up */
1344 	if (!netif_running(netdev))
1345 		goto bail;
1346 
1347 	/* Stop the network stack */
1348 	netif_trans_update(netdev);
1349 	napi_disable(&priv->napi);
1350 	netif_tx_disable(netdev);
1351 
1352 	/* Stop and reset the MAC */
1353 	ftgmac100_stop_hw(priv);
1354 	err = ftgmac100_reset_and_config_mac(priv);
1355 	if (err) {
1356 		/* Not much we can do ... it might come back... */
1357 		netdev_err(netdev, "attempting to continue...\n");
1358 	}
1359 
1360 	/* Free all rx and tx buffers */
1361 	ftgmac100_free_buffers(priv);
1362 
1363 	/* Setup everything again and restart chip */
1364 	ftgmac100_init_all(priv, true);
1365 
1366 	netdev_dbg(netdev, "Reset done !\n");
1367 bail:
1368 	if (priv->mii_bus)
1369 		mutex_unlock(&priv->mii_bus->mdio_lock);
1370 	if (netdev->phydev)
1371 		mutex_unlock(&netdev->phydev->lock);
1372 	rtnl_unlock();
1373 }
1374 
1375 static void ftgmac100_reset_task(struct work_struct *work)
1376 {
1377 	struct ftgmac100 *priv = container_of(work, struct ftgmac100,
1378 					      reset_task);
1379 
1380 	ftgmac100_reset(priv);
1381 }
1382 
1383 static void ftgmac100_adjust_link(struct net_device *netdev)
1384 {
1385 	struct ftgmac100 *priv = netdev_priv(netdev);
1386 	struct phy_device *phydev = netdev->phydev;
1387 	bool tx_pause, rx_pause;
1388 	int new_speed;
1389 
1390 	/* We store "no link" as speed 0 */
1391 	if (!phydev->link)
1392 		new_speed = 0;
1393 	else
1394 		new_speed = phydev->speed;
1395 
1396 	/* Grab pause settings from PHY if configured to do so */
1397 	if (priv->aneg_pause) {
1398 		rx_pause = tx_pause = phydev->pause;
1399 		if (phydev->asym_pause)
1400 			tx_pause = !rx_pause;
1401 	} else {
1402 		rx_pause = priv->rx_pause;
1403 		tx_pause = priv->tx_pause;
1404 	}
1405 
1406 	/* Link hasn't changed, do nothing */
1407 	if (phydev->speed == priv->cur_speed &&
1408 	    phydev->duplex == priv->cur_duplex &&
1409 	    rx_pause == priv->rx_pause &&
1410 	    tx_pause == priv->tx_pause)
1411 		return;
1412 
1413 	/* Print status if we have a link or we had one and just lost it,
1414 	 * don't print otherwise.
1415 	 */
1416 	if (new_speed || priv->cur_speed)
1417 		phy_print_status(phydev);
1418 
1419 	priv->cur_speed = new_speed;
1420 	priv->cur_duplex = phydev->duplex;
1421 	priv->rx_pause = rx_pause;
1422 	priv->tx_pause = tx_pause;
1423 
1424 	/* Link is down, do nothing else */
1425 	if (!new_speed)
1426 		return;
1427 
1428 	/* Disable all interrupts */
1429 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1430 
1431 	/* Release phy lock to allow ftgmac100_reset to aquire it, keeping lock
1432 	 * order consistent to prevent dead lock.
1433 	 */
1434 	if (netdev->phydev)
1435 		mutex_unlock(&netdev->phydev->lock);
1436 
1437 	ftgmac100_reset(priv);
1438 
1439 	if (netdev->phydev)
1440 		mutex_lock(&netdev->phydev->lock);
1441 
1442 }
1443 
1444 static int ftgmac100_mii_probe(struct net_device *netdev)
1445 {
1446 	struct ftgmac100 *priv = netdev_priv(netdev);
1447 	struct platform_device *pdev = to_platform_device(priv->dev);
1448 	struct device_node *np = pdev->dev.of_node;
1449 	struct phy_device *phydev;
1450 	phy_interface_t phy_intf;
1451 	int err;
1452 
1453 	/* Default to RGMII. It's a gigabit part after all */
1454 	err = of_get_phy_mode(np, &phy_intf);
1455 	if (err)
1456 		phy_intf = PHY_INTERFACE_MODE_RGMII;
1457 
1458 	/* Aspeed only supports these. I don't know about other IP
1459 	 * block vendors so I'm going to just let them through for
1460 	 * now. Note that this is only a warning if for some obscure
1461 	 * reason the DT really means to lie about it or it's a newer
1462 	 * part we don't know about.
1463 	 *
1464 	 * On the Aspeed SoC there are additionally straps and SCU
1465 	 * control bits that could tell us what the interface is
1466 	 * (or allow us to configure it while the IP block is held
1467 	 * in reset). For now I chose to keep this driver away from
1468 	 * those SoC specific bits and assume the device-tree is
1469 	 * right and the SCU has been configured properly by pinmux
1470 	 * or the firmware.
1471 	 */
1472 	if (priv->is_aspeed && !(phy_interface_mode_is_rgmii(phy_intf))) {
1473 		netdev_warn(netdev,
1474 			    "Unsupported PHY mode %s !\n",
1475 			    phy_modes(phy_intf));
1476 	}
1477 
1478 	phydev = phy_find_first(priv->mii_bus);
1479 	if (!phydev) {
1480 		netdev_info(netdev, "%s: no PHY found\n", netdev->name);
1481 		return -ENODEV;
1482 	}
1483 
1484 	phydev = phy_connect(netdev, phydev_name(phydev),
1485 			     &ftgmac100_adjust_link, phy_intf);
1486 
1487 	if (IS_ERR(phydev)) {
1488 		netdev_err(netdev, "%s: Could not attach to PHY\n", netdev->name);
1489 		return PTR_ERR(phydev);
1490 	}
1491 
1492 	/* Indicate that we support PAUSE frames (see comment in
1493 	 * Documentation/networking/phy.rst)
1494 	 */
1495 	phy_support_asym_pause(phydev);
1496 
1497 	/* Display what we found */
1498 	phy_attached_info(phydev);
1499 
1500 	return 0;
1501 }
1502 
1503 static int ftgmac100_open(struct net_device *netdev)
1504 {
1505 	struct ftgmac100 *priv = netdev_priv(netdev);
1506 	int err;
1507 
1508 	/* Allocate ring buffers  */
1509 	err = ftgmac100_alloc_rings(priv);
1510 	if (err) {
1511 		netdev_err(netdev, "Failed to allocate descriptors\n");
1512 		return err;
1513 	}
1514 
1515 	/* When using NC-SI we force the speed to 100Mbit/s full duplex,
1516 	 *
1517 	 * Otherwise we leave it set to 0 (no link), the link
1518 	 * message from the PHY layer will handle setting it up to
1519 	 * something else if needed.
1520 	 */
1521 	if (priv->use_ncsi) {
1522 		priv->cur_duplex = DUPLEX_FULL;
1523 		priv->cur_speed = SPEED_100;
1524 	} else {
1525 		priv->cur_duplex = 0;
1526 		priv->cur_speed = 0;
1527 	}
1528 
1529 	/* Reset the hardware */
1530 	err = ftgmac100_reset_and_config_mac(priv);
1531 	if (err)
1532 		goto err_hw;
1533 
1534 	/* Initialize NAPI */
1535 	netif_napi_add(netdev, &priv->napi, ftgmac100_poll);
1536 
1537 	/* Grab our interrupt */
1538 	err = request_irq(netdev->irq, ftgmac100_interrupt, 0, netdev->name, netdev);
1539 	if (err) {
1540 		netdev_err(netdev, "failed to request irq %d\n", netdev->irq);
1541 		goto err_irq;
1542 	}
1543 
1544 	/* Start things up */
1545 	err = ftgmac100_init_all(priv, false);
1546 	if (err) {
1547 		netdev_err(netdev, "Failed to allocate packet buffers\n");
1548 		goto err_alloc;
1549 	}
1550 
1551 	if (netdev->phydev) {
1552 		/* If we have a PHY, start polling */
1553 		phy_start(netdev->phydev);
1554 	}
1555 	if (priv->use_ncsi) {
1556 		/* If using NC-SI, set our carrier on and start the stack */
1557 		netif_carrier_on(netdev);
1558 
1559 		/* Start the NCSI device */
1560 		err = ncsi_start_dev(priv->ndev);
1561 		if (err)
1562 			goto err_ncsi;
1563 	}
1564 
1565 	return 0;
1566 
1567 err_ncsi:
1568 	phy_stop(netdev->phydev);
1569 	napi_disable(&priv->napi);
1570 	netif_stop_queue(netdev);
1571 err_alloc:
1572 	ftgmac100_free_buffers(priv);
1573 	free_irq(netdev->irq, netdev);
1574 err_irq:
1575 	netif_napi_del(&priv->napi);
1576 err_hw:
1577 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1578 	ftgmac100_free_rings(priv);
1579 	return err;
1580 }
1581 
1582 static int ftgmac100_stop(struct net_device *netdev)
1583 {
1584 	struct ftgmac100 *priv = netdev_priv(netdev);
1585 
1586 	/* Note about the reset task: We are called with the rtnl lock
1587 	 * held, so we are synchronized against the core of the reset
1588 	 * task. We must not try to synchronously cancel it otherwise
1589 	 * we can deadlock. But since it will test for netif_running()
1590 	 * which has already been cleared by the net core, we don't
1591 	 * anything special to do.
1592 	 */
1593 
1594 	/* disable all interrupts */
1595 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1596 
1597 	netif_stop_queue(netdev);
1598 	napi_disable(&priv->napi);
1599 	netif_napi_del(&priv->napi);
1600 	if (netdev->phydev)
1601 		phy_stop(netdev->phydev);
1602 	if (priv->use_ncsi)
1603 		ncsi_stop_dev(priv->ndev);
1604 
1605 	ftgmac100_stop_hw(priv);
1606 	free_irq(netdev->irq, netdev);
1607 	ftgmac100_free_buffers(priv);
1608 	ftgmac100_free_rings(priv);
1609 
1610 	return 0;
1611 }
1612 
1613 static void ftgmac100_tx_timeout(struct net_device *netdev, unsigned int txqueue)
1614 {
1615 	struct ftgmac100 *priv = netdev_priv(netdev);
1616 
1617 	/* Disable all interrupts */
1618 	iowrite32(0, priv->base + FTGMAC100_OFFSET_IER);
1619 
1620 	/* Do the reset outside of interrupt context */
1621 	schedule_work(&priv->reset_task);
1622 }
1623 
1624 static int ftgmac100_set_features(struct net_device *netdev,
1625 				  netdev_features_t features)
1626 {
1627 	struct ftgmac100 *priv = netdev_priv(netdev);
1628 	netdev_features_t changed = netdev->features ^ features;
1629 
1630 	if (!netif_running(netdev))
1631 		return 0;
1632 
1633 	/* Update the vlan filtering bit */
1634 	if (changed & NETIF_F_HW_VLAN_CTAG_RX) {
1635 		u32 maccr;
1636 
1637 		maccr = ioread32(priv->base + FTGMAC100_OFFSET_MACCR);
1638 		if (priv->netdev->features & NETIF_F_HW_VLAN_CTAG_RX)
1639 			maccr |= FTGMAC100_MACCR_RM_VLAN;
1640 		else
1641 			maccr &= ~FTGMAC100_MACCR_RM_VLAN;
1642 		iowrite32(maccr, priv->base + FTGMAC100_OFFSET_MACCR);
1643 	}
1644 
1645 	return 0;
1646 }
1647 
1648 #ifdef CONFIG_NET_POLL_CONTROLLER
1649 static void ftgmac100_poll_controller(struct net_device *netdev)
1650 {
1651 	unsigned long flags;
1652 
1653 	local_irq_save(flags);
1654 	ftgmac100_interrupt(netdev->irq, netdev);
1655 	local_irq_restore(flags);
1656 }
1657 #endif
1658 
1659 static const struct net_device_ops ftgmac100_netdev_ops = {
1660 	.ndo_open		= ftgmac100_open,
1661 	.ndo_stop		= ftgmac100_stop,
1662 	.ndo_start_xmit		= ftgmac100_hard_start_xmit,
1663 	.ndo_set_mac_address	= ftgmac100_set_mac_addr,
1664 	.ndo_validate_addr	= eth_validate_addr,
1665 	.ndo_eth_ioctl		= phy_do_ioctl,
1666 	.ndo_tx_timeout		= ftgmac100_tx_timeout,
1667 	.ndo_set_rx_mode	= ftgmac100_set_rx_mode,
1668 	.ndo_set_features	= ftgmac100_set_features,
1669 #ifdef CONFIG_NET_POLL_CONTROLLER
1670 	.ndo_poll_controller	= ftgmac100_poll_controller,
1671 #endif
1672 	.ndo_vlan_rx_add_vid	= ncsi_vlan_rx_add_vid,
1673 	.ndo_vlan_rx_kill_vid	= ncsi_vlan_rx_kill_vid,
1674 };
1675 
1676 static int ftgmac100_setup_mdio(struct net_device *netdev)
1677 {
1678 	struct ftgmac100 *priv = netdev_priv(netdev);
1679 	struct platform_device *pdev = to_platform_device(priv->dev);
1680 	struct device_node *np = pdev->dev.of_node;
1681 	struct device_node *mdio_np;
1682 	int i, err = 0;
1683 	u32 reg;
1684 
1685 	/* initialize mdio bus */
1686 	priv->mii_bus = mdiobus_alloc();
1687 	if (!priv->mii_bus)
1688 		return -EIO;
1689 
1690 	if (of_device_is_compatible(np, "aspeed,ast2400-mac") ||
1691 	    of_device_is_compatible(np, "aspeed,ast2500-mac")) {
1692 		/* The AST2600 has a separate MDIO controller */
1693 
1694 		/* For the AST2400 and AST2500 this driver only supports the
1695 		 * old MDIO interface
1696 		 */
1697 		reg = ioread32(priv->base + FTGMAC100_OFFSET_REVR);
1698 		reg &= ~FTGMAC100_REVR_NEW_MDIO_INTERFACE;
1699 		iowrite32(reg, priv->base + FTGMAC100_OFFSET_REVR);
1700 	}
1701 
1702 	priv->mii_bus->name = "ftgmac100_mdio";
1703 	snprintf(priv->mii_bus->id, MII_BUS_ID_SIZE, "%s-%d",
1704 		 pdev->name, pdev->id);
1705 	priv->mii_bus->parent = priv->dev;
1706 	priv->mii_bus->priv = priv->netdev;
1707 	priv->mii_bus->read = ftgmac100_mdiobus_read;
1708 	priv->mii_bus->write = ftgmac100_mdiobus_write;
1709 
1710 	for (i = 0; i < PHY_MAX_ADDR; i++)
1711 		priv->mii_bus->irq[i] = PHY_POLL;
1712 
1713 	mdio_np = of_get_child_by_name(np, "mdio");
1714 
1715 	err = of_mdiobus_register(priv->mii_bus, mdio_np);
1716 	if (err) {
1717 		dev_err(priv->dev, "Cannot register MDIO bus!\n");
1718 		goto err_register_mdiobus;
1719 	}
1720 
1721 	of_node_put(mdio_np);
1722 
1723 	return 0;
1724 
1725 err_register_mdiobus:
1726 	mdiobus_free(priv->mii_bus);
1727 	return err;
1728 }
1729 
1730 static void ftgmac100_phy_disconnect(struct net_device *netdev)
1731 {
1732 	struct ftgmac100 *priv = netdev_priv(netdev);
1733 
1734 	if (!netdev->phydev)
1735 		return;
1736 
1737 	phy_disconnect(netdev->phydev);
1738 	if (of_phy_is_fixed_link(priv->dev->of_node))
1739 		of_phy_deregister_fixed_link(priv->dev->of_node);
1740 
1741 	if (priv->use_ncsi)
1742 		fixed_phy_unregister(netdev->phydev);
1743 }
1744 
1745 static void ftgmac100_destroy_mdio(struct net_device *netdev)
1746 {
1747 	struct ftgmac100 *priv = netdev_priv(netdev);
1748 
1749 	if (!priv->mii_bus)
1750 		return;
1751 
1752 	mdiobus_unregister(priv->mii_bus);
1753 	mdiobus_free(priv->mii_bus);
1754 }
1755 
1756 static void ftgmac100_ncsi_handler(struct ncsi_dev *nd)
1757 {
1758 	if (unlikely(nd->state != ncsi_dev_state_functional))
1759 		return;
1760 
1761 	netdev_dbg(nd->dev, "NCSI interface %s\n",
1762 		   nd->link_up ? "up" : "down");
1763 }
1764 
1765 static int ftgmac100_setup_clk(struct ftgmac100 *priv)
1766 {
1767 	struct clk *clk;
1768 	int rc;
1769 
1770 	clk = devm_clk_get(priv->dev, NULL /* MACCLK */);
1771 	if (IS_ERR(clk))
1772 		return PTR_ERR(clk);
1773 	priv->clk = clk;
1774 	rc = clk_prepare_enable(priv->clk);
1775 	if (rc)
1776 		return rc;
1777 
1778 	/* Aspeed specifies a 100MHz clock is required for up to
1779 	 * 1000Mbit link speeds. As NCSI is limited to 100Mbit, 25MHz
1780 	 * is sufficient
1781 	 */
1782 	rc = clk_set_rate(priv->clk, priv->use_ncsi ? FTGMAC_25MHZ :
1783 			  FTGMAC_100MHZ);
1784 	if (rc)
1785 		goto cleanup_clk;
1786 
1787 	/* RCLK is for RMII, typically used for NCSI. Optional because it's not
1788 	 * necessary if it's the AST2400 MAC, or the MAC is configured for
1789 	 * RGMII, or the controller is not an ASPEED-based controller.
1790 	 */
1791 	priv->rclk = devm_clk_get_optional(priv->dev, "RCLK");
1792 	rc = clk_prepare_enable(priv->rclk);
1793 	if (!rc)
1794 		return 0;
1795 
1796 cleanup_clk:
1797 	clk_disable_unprepare(priv->clk);
1798 
1799 	return rc;
1800 }
1801 
1802 static bool ftgmac100_has_child_node(struct device_node *np, const char *name)
1803 {
1804 	struct device_node *child_np = of_get_child_by_name(np, name);
1805 	bool ret = false;
1806 
1807 	if (child_np) {
1808 		ret = true;
1809 		of_node_put(child_np);
1810 	}
1811 
1812 	return ret;
1813 }
1814 
1815 static int ftgmac100_probe(struct platform_device *pdev)
1816 {
1817 	struct resource *res;
1818 	int irq;
1819 	struct net_device *netdev;
1820 	struct phy_device *phydev;
1821 	struct ftgmac100 *priv;
1822 	struct device_node *np;
1823 	int err = 0;
1824 
1825 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1826 	if (!res)
1827 		return -ENXIO;
1828 
1829 	irq = platform_get_irq(pdev, 0);
1830 	if (irq < 0)
1831 		return irq;
1832 
1833 	/* setup net_device */
1834 	netdev = alloc_etherdev(sizeof(*priv));
1835 	if (!netdev) {
1836 		err = -ENOMEM;
1837 		goto err_alloc_etherdev;
1838 	}
1839 
1840 	SET_NETDEV_DEV(netdev, &pdev->dev);
1841 
1842 	netdev->ethtool_ops = &ftgmac100_ethtool_ops;
1843 	netdev->netdev_ops = &ftgmac100_netdev_ops;
1844 	netdev->watchdog_timeo = 5 * HZ;
1845 
1846 	platform_set_drvdata(pdev, netdev);
1847 
1848 	/* setup private data */
1849 	priv = netdev_priv(netdev);
1850 	priv->netdev = netdev;
1851 	priv->dev = &pdev->dev;
1852 	INIT_WORK(&priv->reset_task, ftgmac100_reset_task);
1853 
1854 	/* map io memory */
1855 	priv->res = request_mem_region(res->start, resource_size(res),
1856 				       dev_name(&pdev->dev));
1857 	if (!priv->res) {
1858 		dev_err(&pdev->dev, "Could not reserve memory region\n");
1859 		err = -ENOMEM;
1860 		goto err_req_mem;
1861 	}
1862 
1863 	priv->base = ioremap(res->start, resource_size(res));
1864 	if (!priv->base) {
1865 		dev_err(&pdev->dev, "Failed to ioremap ethernet registers\n");
1866 		err = -EIO;
1867 		goto err_ioremap;
1868 	}
1869 
1870 	netdev->irq = irq;
1871 
1872 	/* Enable pause */
1873 	priv->tx_pause = true;
1874 	priv->rx_pause = true;
1875 	priv->aneg_pause = true;
1876 
1877 	/* MAC address from chip or random one */
1878 	err = ftgmac100_initial_mac(priv);
1879 	if (err)
1880 		goto err_phy_connect;
1881 
1882 	np = pdev->dev.of_node;
1883 	if (np && (of_device_is_compatible(np, "aspeed,ast2400-mac") ||
1884 		   of_device_is_compatible(np, "aspeed,ast2500-mac") ||
1885 		   of_device_is_compatible(np, "aspeed,ast2600-mac"))) {
1886 		priv->rxdes0_edorr_mask = BIT(30);
1887 		priv->txdes0_edotr_mask = BIT(30);
1888 		priv->is_aspeed = true;
1889 	} else {
1890 		priv->rxdes0_edorr_mask = BIT(15);
1891 		priv->txdes0_edotr_mask = BIT(15);
1892 	}
1893 
1894 	if (np && of_get_property(np, "use-ncsi", NULL)) {
1895 		if (!IS_ENABLED(CONFIG_NET_NCSI)) {
1896 			dev_err(&pdev->dev, "NCSI stack not enabled\n");
1897 			err = -EINVAL;
1898 			goto err_phy_connect;
1899 		}
1900 
1901 		dev_info(&pdev->dev, "Using NCSI interface\n");
1902 		priv->use_ncsi = true;
1903 		priv->ndev = ncsi_register_dev(netdev, ftgmac100_ncsi_handler);
1904 		if (!priv->ndev) {
1905 			err = -EINVAL;
1906 			goto err_phy_connect;
1907 		}
1908 
1909 		phydev = fixed_phy_register(PHY_POLL, &ncsi_phy_status, np);
1910 		if (IS_ERR(phydev)) {
1911 			dev_err(&pdev->dev, "failed to register fixed PHY device\n");
1912 			err = PTR_ERR(phydev);
1913 			goto err_phy_connect;
1914 		}
1915 		err = phy_connect_direct(netdev, phydev, ftgmac100_adjust_link,
1916 					 PHY_INTERFACE_MODE_MII);
1917 		if (err) {
1918 			dev_err(&pdev->dev, "Connecting PHY failed\n");
1919 			goto err_phy_connect;
1920 		}
1921 	} else if (np && of_phy_is_fixed_link(np)) {
1922 		struct phy_device *phy;
1923 
1924 		err = of_phy_register_fixed_link(np);
1925 		if (err) {
1926 			dev_err(&pdev->dev, "Failed to register fixed PHY\n");
1927 			goto err_phy_connect;
1928 		}
1929 
1930 		phy = of_phy_get_and_connect(priv->netdev, np,
1931 					     &ftgmac100_adjust_link);
1932 		if (!phy) {
1933 			dev_err(&pdev->dev, "Failed to connect to fixed PHY\n");
1934 			of_phy_deregister_fixed_link(np);
1935 			err = -EINVAL;
1936 			goto err_phy_connect;
1937 		}
1938 
1939 		/* Display what we found */
1940 		phy_attached_info(phy);
1941 	} else if (np && of_get_property(np, "phy-handle", NULL)) {
1942 		struct phy_device *phy;
1943 
1944 		/* Support "mdio"/"phy" child nodes for ast2400/2500 with
1945 		 * an embedded MDIO controller. Automatically scan the DTS for
1946 		 * available PHYs and register them.
1947 		 */
1948 		if (of_device_is_compatible(np, "aspeed,ast2400-mac") ||
1949 		    of_device_is_compatible(np, "aspeed,ast2500-mac")) {
1950 			err = ftgmac100_setup_mdio(netdev);
1951 			if (err)
1952 				goto err_setup_mdio;
1953 		}
1954 
1955 		phy = of_phy_get_and_connect(priv->netdev, np,
1956 					     &ftgmac100_adjust_link);
1957 		if (!phy) {
1958 			dev_err(&pdev->dev, "Failed to connect to phy\n");
1959 			err = -EINVAL;
1960 			goto err_phy_connect;
1961 		}
1962 
1963 		/* Indicate that we support PAUSE frames (see comment in
1964 		 * Documentation/networking/phy.rst)
1965 		 */
1966 		phy_support_asym_pause(phy);
1967 
1968 		/* Display what we found */
1969 		phy_attached_info(phy);
1970 	} else if (np && !ftgmac100_has_child_node(np, "mdio")) {
1971 		/* Support legacy ASPEED devicetree descriptions that decribe a
1972 		 * MAC with an embedded MDIO controller but have no "mdio"
1973 		 * child node. Automatically scan the MDIO bus for available
1974 		 * PHYs.
1975 		 */
1976 		priv->use_ncsi = false;
1977 		err = ftgmac100_setup_mdio(netdev);
1978 		if (err)
1979 			goto err_setup_mdio;
1980 
1981 		err = ftgmac100_mii_probe(netdev);
1982 		if (err) {
1983 			dev_err(priv->dev, "MII probe failed!\n");
1984 			goto err_ncsi_dev;
1985 		}
1986 
1987 	}
1988 
1989 	if (priv->is_aspeed) {
1990 		err = ftgmac100_setup_clk(priv);
1991 		if (err)
1992 			goto err_phy_connect;
1993 
1994 		/* Disable ast2600 problematic HW arbitration */
1995 		if (of_device_is_compatible(np, "aspeed,ast2600-mac"))
1996 			iowrite32(FTGMAC100_TM_DEFAULT,
1997 				  priv->base + FTGMAC100_OFFSET_TM);
1998 	}
1999 
2000 	/* Default ring sizes */
2001 	priv->rx_q_entries = priv->new_rx_q_entries = DEF_RX_QUEUE_ENTRIES;
2002 	priv->tx_q_entries = priv->new_tx_q_entries = DEF_TX_QUEUE_ENTRIES;
2003 
2004 	/* Base feature set */
2005 	netdev->hw_features = NETIF_F_RXCSUM | NETIF_F_HW_CSUM |
2006 		NETIF_F_GRO | NETIF_F_SG | NETIF_F_HW_VLAN_CTAG_RX |
2007 		NETIF_F_HW_VLAN_CTAG_TX;
2008 
2009 	if (priv->use_ncsi)
2010 		netdev->hw_features |= NETIF_F_HW_VLAN_CTAG_FILTER;
2011 
2012 	/* AST2400  doesn't have working HW checksum generation */
2013 	if (np && (of_device_is_compatible(np, "aspeed,ast2400-mac")))
2014 		netdev->hw_features &= ~NETIF_F_HW_CSUM;
2015 
2016 	/* AST2600 tx checksum with NCSI is broken */
2017 	if (priv->use_ncsi && of_device_is_compatible(np, "aspeed,ast2600-mac"))
2018 		netdev->hw_features &= ~NETIF_F_HW_CSUM;
2019 
2020 	if (np && of_get_property(np, "no-hw-checksum", NULL))
2021 		netdev->hw_features &= ~(NETIF_F_HW_CSUM | NETIF_F_RXCSUM);
2022 	netdev->features |= netdev->hw_features;
2023 
2024 	/* register network device */
2025 	err = register_netdev(netdev);
2026 	if (err) {
2027 		dev_err(&pdev->dev, "Failed to register netdev\n");
2028 		goto err_register_netdev;
2029 	}
2030 
2031 	netdev_info(netdev, "irq %d, mapped at %p\n", netdev->irq, priv->base);
2032 
2033 	return 0;
2034 
2035 err_register_netdev:
2036 	clk_disable_unprepare(priv->rclk);
2037 	clk_disable_unprepare(priv->clk);
2038 err_phy_connect:
2039 	ftgmac100_phy_disconnect(netdev);
2040 err_ncsi_dev:
2041 	if (priv->ndev)
2042 		ncsi_unregister_dev(priv->ndev);
2043 	ftgmac100_destroy_mdio(netdev);
2044 err_setup_mdio:
2045 	iounmap(priv->base);
2046 err_ioremap:
2047 	release_resource(priv->res);
2048 err_req_mem:
2049 	free_netdev(netdev);
2050 err_alloc_etherdev:
2051 	return err;
2052 }
2053 
2054 static void ftgmac100_remove(struct platform_device *pdev)
2055 {
2056 	struct net_device *netdev;
2057 	struct ftgmac100 *priv;
2058 
2059 	netdev = platform_get_drvdata(pdev);
2060 	priv = netdev_priv(netdev);
2061 
2062 	if (priv->ndev)
2063 		ncsi_unregister_dev(priv->ndev);
2064 	unregister_netdev(netdev);
2065 
2066 	clk_disable_unprepare(priv->rclk);
2067 	clk_disable_unprepare(priv->clk);
2068 
2069 	/* There's a small chance the reset task will have been re-queued,
2070 	 * during stop, make sure it's gone before we free the structure.
2071 	 */
2072 	cancel_work_sync(&priv->reset_task);
2073 
2074 	ftgmac100_phy_disconnect(netdev);
2075 	ftgmac100_destroy_mdio(netdev);
2076 
2077 	iounmap(priv->base);
2078 	release_resource(priv->res);
2079 
2080 	netif_napi_del(&priv->napi);
2081 	free_netdev(netdev);
2082 }
2083 
2084 static const struct of_device_id ftgmac100_of_match[] = {
2085 	{ .compatible = "faraday,ftgmac100" },
2086 	{ }
2087 };
2088 MODULE_DEVICE_TABLE(of, ftgmac100_of_match);
2089 
2090 static struct platform_driver ftgmac100_driver = {
2091 	.probe	= ftgmac100_probe,
2092 	.remove_new = ftgmac100_remove,
2093 	.driver	= {
2094 		.name		= DRV_NAME,
2095 		.of_match_table	= ftgmac100_of_match,
2096 	},
2097 };
2098 module_platform_driver(ftgmac100_driver);
2099 
2100 MODULE_AUTHOR("Po-Yu Chuang <ratbert@faraday-tech.com>");
2101 MODULE_DESCRIPTION("FTGMAC100 driver");
2102 MODULE_LICENSE("GPL");
2103