xref: /linux/drivers/net/ethernet/cirrus/ep93xx_eth.c (revision 52c996d3f40b40f87ef9dc80596903309682acc3)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * EP93xx ethernet network device driver
4  * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
5  * Dedicated to Marija Kulikova.
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
9 
10 #include <linux/dma-mapping.h>
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/netdevice.h>
14 #include <linux/mii.h>
15 #include <linux/etherdevice.h>
16 #include <linux/ethtool.h>
17 #include <linux/interrupt.h>
18 #include <linux/moduleparam.h>
19 #include <linux/of.h>
20 #include <linux/platform_device.h>
21 #include <linux/delay.h>
22 #include <linux/io.h>
23 #include <linux/slab.h>
24 
25 #define DRV_MODULE_NAME		"ep93xx-eth"
26 
27 #define RX_QUEUE_ENTRIES	64
28 #define TX_QUEUE_ENTRIES	8
29 
30 #define MAX_PKT_SIZE		2044
31 #define PKT_BUF_SIZE		2048
32 
33 #define REG_RXCTL		0x0000
34 #define  REG_RXCTL_DEFAULT	0x00073800
35 #define REG_TXCTL		0x0004
36 #define  REG_TXCTL_ENABLE	0x00000001
37 #define REG_MIICMD		0x0010
38 #define  REG_MIICMD_READ	0x00008000
39 #define  REG_MIICMD_WRITE	0x00004000
40 #define REG_MIIDATA		0x0014
41 #define REG_MIISTS		0x0018
42 #define  REG_MIISTS_BUSY	0x00000001
43 #define REG_SELFCTL		0x0020
44 #define  REG_SELFCTL_RESET	0x00000001
45 #define REG_INTEN		0x0024
46 #define  REG_INTEN_TX		0x00000008
47 #define  REG_INTEN_RX		0x00000007
48 #define REG_INTSTSP		0x0028
49 #define  REG_INTSTS_TX		0x00000008
50 #define  REG_INTSTS_RX		0x00000004
51 #define REG_INTSTSC		0x002c
52 #define REG_AFP			0x004c
53 #define REG_INDAD0		0x0050
54 #define REG_INDAD1		0x0051
55 #define REG_INDAD2		0x0052
56 #define REG_INDAD3		0x0053
57 #define REG_INDAD4		0x0054
58 #define REG_INDAD5		0x0055
59 #define REG_GIINTMSK		0x0064
60 #define  REG_GIINTMSK_ENABLE	0x00008000
61 #define REG_BMCTL		0x0080
62 #define  REG_BMCTL_ENABLE_TX	0x00000100
63 #define  REG_BMCTL_ENABLE_RX	0x00000001
64 #define REG_BMSTS		0x0084
65 #define  REG_BMSTS_RX_ACTIVE	0x00000008
66 #define REG_RXDQBADD		0x0090
67 #define REG_RXDQBLEN		0x0094
68 #define REG_RXDCURADD		0x0098
69 #define REG_RXDENQ		0x009c
70 #define REG_RXSTSQBADD		0x00a0
71 #define REG_RXSTSQBLEN		0x00a4
72 #define REG_RXSTSQCURADD	0x00a8
73 #define REG_RXSTSENQ		0x00ac
74 #define REG_TXDQBADD		0x00b0
75 #define REG_TXDQBLEN		0x00b4
76 #define REG_TXDQCURADD		0x00b8
77 #define REG_TXDENQ		0x00bc
78 #define REG_TXSTSQBADD		0x00c0
79 #define REG_TXSTSQBLEN		0x00c4
80 #define REG_TXSTSQCURADD	0x00c8
81 #define REG_MAXFRMLEN		0x00e8
82 
83 struct ep93xx_rdesc
84 {
85 	u32	buf_addr;
86 	u32	rdesc1;
87 };
88 
89 #define RDESC1_NSOF		0x80000000
90 #define RDESC1_BUFFER_INDEX	0x7fff0000
91 #define RDESC1_BUFFER_LENGTH	0x0000ffff
92 
93 struct ep93xx_rstat
94 {
95 	u32	rstat0;
96 	u32	rstat1;
97 };
98 
99 #define RSTAT0_RFP		0x80000000
100 #define RSTAT0_RWE		0x40000000
101 #define RSTAT0_EOF		0x20000000
102 #define RSTAT0_EOB		0x10000000
103 #define RSTAT0_AM		0x00c00000
104 #define RSTAT0_RX_ERR		0x00200000
105 #define RSTAT0_OE		0x00100000
106 #define RSTAT0_FE		0x00080000
107 #define RSTAT0_RUNT		0x00040000
108 #define RSTAT0_EDATA		0x00020000
109 #define RSTAT0_CRCE		0x00010000
110 #define RSTAT0_CRCI		0x00008000
111 #define RSTAT0_HTI		0x00003f00
112 #define RSTAT1_RFP		0x80000000
113 #define RSTAT1_BUFFER_INDEX	0x7fff0000
114 #define RSTAT1_FRAME_LENGTH	0x0000ffff
115 
116 struct ep93xx_tdesc
117 {
118 	u32	buf_addr;
119 	u32	tdesc1;
120 };
121 
122 #define TDESC1_EOF		0x80000000
123 #define TDESC1_BUFFER_INDEX	0x7fff0000
124 #define TDESC1_BUFFER_ABORT	0x00008000
125 #define TDESC1_BUFFER_LENGTH	0x00000fff
126 
127 struct ep93xx_tstat
128 {
129 	u32	tstat0;
130 };
131 
132 #define TSTAT0_TXFP		0x80000000
133 #define TSTAT0_TXWE		0x40000000
134 #define TSTAT0_FA		0x20000000
135 #define TSTAT0_LCRS		0x10000000
136 #define TSTAT0_OW		0x04000000
137 #define TSTAT0_TXU		0x02000000
138 #define TSTAT0_ECOLL		0x01000000
139 #define TSTAT0_NCOLL		0x001f0000
140 #define TSTAT0_BUFFER_INDEX	0x00007fff
141 
142 struct ep93xx_descs
143 {
144 	struct ep93xx_rdesc	rdesc[RX_QUEUE_ENTRIES];
145 	struct ep93xx_tdesc	tdesc[TX_QUEUE_ENTRIES];
146 	struct ep93xx_rstat	rstat[RX_QUEUE_ENTRIES];
147 	struct ep93xx_tstat	tstat[TX_QUEUE_ENTRIES];
148 };
149 
150 struct ep93xx_priv
151 {
152 	struct resource		*res;
153 	void __iomem		*base_addr;
154 	int			irq;
155 
156 	struct ep93xx_descs	*descs;
157 	dma_addr_t		descs_dma_addr;
158 
159 	void			*rx_buf[RX_QUEUE_ENTRIES];
160 	void			*tx_buf[TX_QUEUE_ENTRIES];
161 
162 	spinlock_t		rx_lock;
163 	unsigned int		rx_pointer;
164 	unsigned int		tx_clean_pointer;
165 	unsigned int		tx_pointer;
166 	spinlock_t		tx_pending_lock;
167 	unsigned int		tx_pending;
168 
169 	struct net_device	*dev;
170 	struct napi_struct	napi;
171 
172 	struct mii_if_info	mii;
173 	u8			mdc_divisor;
174 };
175 
176 #define rdb(ep, off)		__raw_readb((ep)->base_addr + (off))
177 #define rdw(ep, off)		__raw_readw((ep)->base_addr + (off))
178 #define rdl(ep, off)		__raw_readl((ep)->base_addr + (off))
179 #define wrb(ep, off, val)	__raw_writeb((val), (ep)->base_addr + (off))
180 #define wrw(ep, off, val)	__raw_writew((val), (ep)->base_addr + (off))
181 #define wrl(ep, off, val)	__raw_writel((val), (ep)->base_addr + (off))
182 
183 static int ep93xx_mdio_read(struct net_device *dev, int phy_id, int reg)
184 {
185 	struct ep93xx_priv *ep = netdev_priv(dev);
186 	int data;
187 	int i;
188 
189 	wrl(ep, REG_MIICMD, REG_MIICMD_READ | (phy_id << 5) | reg);
190 
191 	for (i = 0; i < 10; i++) {
192 		if ((rdl(ep, REG_MIISTS) & REG_MIISTS_BUSY) == 0)
193 			break;
194 		msleep(1);
195 	}
196 
197 	if (i == 10) {
198 		pr_info("mdio read timed out\n");
199 		data = 0xffff;
200 	} else {
201 		data = rdl(ep, REG_MIIDATA);
202 	}
203 
204 	return data;
205 }
206 
207 static void ep93xx_mdio_write(struct net_device *dev, int phy_id, int reg, int data)
208 {
209 	struct ep93xx_priv *ep = netdev_priv(dev);
210 	int i;
211 
212 	wrl(ep, REG_MIIDATA, data);
213 	wrl(ep, REG_MIICMD, REG_MIICMD_WRITE | (phy_id << 5) | reg);
214 
215 	for (i = 0; i < 10; i++) {
216 		if ((rdl(ep, REG_MIISTS) & REG_MIISTS_BUSY) == 0)
217 			break;
218 		msleep(1);
219 	}
220 
221 	if (i == 10)
222 		pr_info("mdio write timed out\n");
223 }
224 
225 static int ep93xx_rx(struct net_device *dev, int budget)
226 {
227 	struct ep93xx_priv *ep = netdev_priv(dev);
228 	int processed = 0;
229 
230 	while (processed < budget) {
231 		int entry;
232 		struct ep93xx_rstat *rstat;
233 		u32 rstat0;
234 		u32 rstat1;
235 		int length;
236 		struct sk_buff *skb;
237 
238 		entry = ep->rx_pointer;
239 		rstat = ep->descs->rstat + entry;
240 
241 		rstat0 = rstat->rstat0;
242 		rstat1 = rstat->rstat1;
243 		if (!(rstat0 & RSTAT0_RFP) || !(rstat1 & RSTAT1_RFP))
244 			break;
245 
246 		rstat->rstat0 = 0;
247 		rstat->rstat1 = 0;
248 
249 		if (!(rstat0 & RSTAT0_EOF))
250 			pr_crit("not end-of-frame %.8x %.8x\n", rstat0, rstat1);
251 		if (!(rstat0 & RSTAT0_EOB))
252 			pr_crit("not end-of-buffer %.8x %.8x\n", rstat0, rstat1);
253 		if ((rstat1 & RSTAT1_BUFFER_INDEX) >> 16 != entry)
254 			pr_crit("entry mismatch %.8x %.8x\n", rstat0, rstat1);
255 
256 		if (!(rstat0 & RSTAT0_RWE)) {
257 			dev->stats.rx_errors++;
258 			if (rstat0 & RSTAT0_OE)
259 				dev->stats.rx_fifo_errors++;
260 			if (rstat0 & RSTAT0_FE)
261 				dev->stats.rx_frame_errors++;
262 			if (rstat0 & (RSTAT0_RUNT | RSTAT0_EDATA))
263 				dev->stats.rx_length_errors++;
264 			if (rstat0 & RSTAT0_CRCE)
265 				dev->stats.rx_crc_errors++;
266 			goto err;
267 		}
268 
269 		length = rstat1 & RSTAT1_FRAME_LENGTH;
270 		if (length > MAX_PKT_SIZE) {
271 			pr_notice("invalid length %.8x %.8x\n", rstat0, rstat1);
272 			goto err;
273 		}
274 
275 		/* Strip FCS.  */
276 		if (rstat0 & RSTAT0_CRCI)
277 			length -= 4;
278 
279 		skb = netdev_alloc_skb(dev, length + 2);
280 		if (likely(skb != NULL)) {
281 			struct ep93xx_rdesc *rxd = &ep->descs->rdesc[entry];
282 			skb_reserve(skb, 2);
283 			dma_sync_single_for_cpu(dev->dev.parent, rxd->buf_addr,
284 						length, DMA_FROM_DEVICE);
285 			skb_copy_to_linear_data(skb, ep->rx_buf[entry], length);
286 			dma_sync_single_for_device(dev->dev.parent,
287 						   rxd->buf_addr, length,
288 						   DMA_FROM_DEVICE);
289 			skb_put(skb, length);
290 			skb->protocol = eth_type_trans(skb, dev);
291 
292 			napi_gro_receive(&ep->napi, skb);
293 
294 			dev->stats.rx_packets++;
295 			dev->stats.rx_bytes += length;
296 		} else {
297 			dev->stats.rx_dropped++;
298 		}
299 
300 err:
301 		ep->rx_pointer = (entry + 1) & (RX_QUEUE_ENTRIES - 1);
302 		processed++;
303 	}
304 
305 	return processed;
306 }
307 
308 static int ep93xx_poll(struct napi_struct *napi, int budget)
309 {
310 	struct ep93xx_priv *ep = container_of(napi, struct ep93xx_priv, napi);
311 	struct net_device *dev = ep->dev;
312 	int rx;
313 
314 	rx = ep93xx_rx(dev, budget);
315 	if (rx < budget && napi_complete_done(napi, rx)) {
316 		spin_lock_irq(&ep->rx_lock);
317 		wrl(ep, REG_INTEN, REG_INTEN_TX | REG_INTEN_RX);
318 		spin_unlock_irq(&ep->rx_lock);
319 	}
320 
321 	if (rx) {
322 		wrw(ep, REG_RXDENQ, rx);
323 		wrw(ep, REG_RXSTSENQ, rx);
324 	}
325 
326 	return rx;
327 }
328 
329 static netdev_tx_t ep93xx_xmit(struct sk_buff *skb, struct net_device *dev)
330 {
331 	struct ep93xx_priv *ep = netdev_priv(dev);
332 	struct ep93xx_tdesc *txd;
333 	int entry;
334 
335 	if (unlikely(skb->len > MAX_PKT_SIZE)) {
336 		dev->stats.tx_dropped++;
337 		dev_kfree_skb(skb);
338 		return NETDEV_TX_OK;
339 	}
340 
341 	entry = ep->tx_pointer;
342 	ep->tx_pointer = (ep->tx_pointer + 1) & (TX_QUEUE_ENTRIES - 1);
343 
344 	txd = &ep->descs->tdesc[entry];
345 
346 	txd->tdesc1 = TDESC1_EOF | (entry << 16) | (skb->len & 0xfff);
347 	dma_sync_single_for_cpu(dev->dev.parent, txd->buf_addr, skb->len,
348 				DMA_TO_DEVICE);
349 	skb_copy_and_csum_dev(skb, ep->tx_buf[entry]);
350 	dma_sync_single_for_device(dev->dev.parent, txd->buf_addr, skb->len,
351 				   DMA_TO_DEVICE);
352 	dev_kfree_skb(skb);
353 
354 	spin_lock_irq(&ep->tx_pending_lock);
355 	ep->tx_pending++;
356 	if (ep->tx_pending == TX_QUEUE_ENTRIES)
357 		netif_stop_queue(dev);
358 	spin_unlock_irq(&ep->tx_pending_lock);
359 
360 	wrl(ep, REG_TXDENQ, 1);
361 
362 	return NETDEV_TX_OK;
363 }
364 
365 static void ep93xx_tx_complete(struct net_device *dev)
366 {
367 	struct ep93xx_priv *ep = netdev_priv(dev);
368 	int wake;
369 
370 	wake = 0;
371 
372 	spin_lock(&ep->tx_pending_lock);
373 	while (1) {
374 		int entry;
375 		struct ep93xx_tstat *tstat;
376 		u32 tstat0;
377 
378 		entry = ep->tx_clean_pointer;
379 		tstat = ep->descs->tstat + entry;
380 
381 		tstat0 = tstat->tstat0;
382 		if (!(tstat0 & TSTAT0_TXFP))
383 			break;
384 
385 		tstat->tstat0 = 0;
386 
387 		if (tstat0 & TSTAT0_FA)
388 			pr_crit("frame aborted %.8x\n", tstat0);
389 		if ((tstat0 & TSTAT0_BUFFER_INDEX) != entry)
390 			pr_crit("entry mismatch %.8x\n", tstat0);
391 
392 		if (tstat0 & TSTAT0_TXWE) {
393 			int length = ep->descs->tdesc[entry].tdesc1 & 0xfff;
394 
395 			dev->stats.tx_packets++;
396 			dev->stats.tx_bytes += length;
397 		} else {
398 			dev->stats.tx_errors++;
399 		}
400 
401 		if (tstat0 & TSTAT0_OW)
402 			dev->stats.tx_window_errors++;
403 		if (tstat0 & TSTAT0_TXU)
404 			dev->stats.tx_fifo_errors++;
405 		dev->stats.collisions += (tstat0 >> 16) & 0x1f;
406 
407 		ep->tx_clean_pointer = (entry + 1) & (TX_QUEUE_ENTRIES - 1);
408 		if (ep->tx_pending == TX_QUEUE_ENTRIES)
409 			wake = 1;
410 		ep->tx_pending--;
411 	}
412 	spin_unlock(&ep->tx_pending_lock);
413 
414 	if (wake)
415 		netif_wake_queue(dev);
416 }
417 
418 static irqreturn_t ep93xx_irq(int irq, void *dev_id)
419 {
420 	struct net_device *dev = dev_id;
421 	struct ep93xx_priv *ep = netdev_priv(dev);
422 	u32 status;
423 
424 	status = rdl(ep, REG_INTSTSC);
425 	if (status == 0)
426 		return IRQ_NONE;
427 
428 	if (status & REG_INTSTS_RX) {
429 		spin_lock(&ep->rx_lock);
430 		if (likely(napi_schedule_prep(&ep->napi))) {
431 			wrl(ep, REG_INTEN, REG_INTEN_TX);
432 			__napi_schedule(&ep->napi);
433 		}
434 		spin_unlock(&ep->rx_lock);
435 	}
436 
437 	if (status & REG_INTSTS_TX)
438 		ep93xx_tx_complete(dev);
439 
440 	return IRQ_HANDLED;
441 }
442 
443 static void ep93xx_free_buffers(struct ep93xx_priv *ep)
444 {
445 	struct device *dev = ep->dev->dev.parent;
446 	int i;
447 
448 	if (!ep->descs)
449 		return;
450 
451 	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
452 		dma_addr_t d;
453 
454 		d = ep->descs->rdesc[i].buf_addr;
455 		if (d)
456 			dma_unmap_single(dev, d, PKT_BUF_SIZE, DMA_FROM_DEVICE);
457 
458 		kfree(ep->rx_buf[i]);
459 	}
460 
461 	for (i = 0; i < TX_QUEUE_ENTRIES; i++) {
462 		dma_addr_t d;
463 
464 		d = ep->descs->tdesc[i].buf_addr;
465 		if (d)
466 			dma_unmap_single(dev, d, PKT_BUF_SIZE, DMA_TO_DEVICE);
467 
468 		kfree(ep->tx_buf[i]);
469 	}
470 
471 	dma_free_coherent(dev, sizeof(struct ep93xx_descs), ep->descs,
472 							ep->descs_dma_addr);
473 	ep->descs = NULL;
474 }
475 
476 static int ep93xx_alloc_buffers(struct ep93xx_priv *ep)
477 {
478 	struct device *dev = ep->dev->dev.parent;
479 	int i;
480 
481 	ep->descs = dma_alloc_coherent(dev, sizeof(struct ep93xx_descs),
482 				&ep->descs_dma_addr, GFP_KERNEL);
483 	if (ep->descs == NULL)
484 		return 1;
485 
486 	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
487 		void *buf;
488 		dma_addr_t d;
489 
490 		buf = kmalloc(PKT_BUF_SIZE, GFP_KERNEL);
491 		if (buf == NULL)
492 			goto err;
493 
494 		d = dma_map_single(dev, buf, PKT_BUF_SIZE, DMA_FROM_DEVICE);
495 		if (dma_mapping_error(dev, d)) {
496 			kfree(buf);
497 			goto err;
498 		}
499 
500 		ep->rx_buf[i] = buf;
501 		ep->descs->rdesc[i].buf_addr = d;
502 		ep->descs->rdesc[i].rdesc1 = (i << 16) | PKT_BUF_SIZE;
503 	}
504 
505 	for (i = 0; i < TX_QUEUE_ENTRIES; i++) {
506 		void *buf;
507 		dma_addr_t d;
508 
509 		buf = kmalloc(PKT_BUF_SIZE, GFP_KERNEL);
510 		if (buf == NULL)
511 			goto err;
512 
513 		d = dma_map_single(dev, buf, PKT_BUF_SIZE, DMA_TO_DEVICE);
514 		if (dma_mapping_error(dev, d)) {
515 			kfree(buf);
516 			goto err;
517 		}
518 
519 		ep->tx_buf[i] = buf;
520 		ep->descs->tdesc[i].buf_addr = d;
521 	}
522 
523 	return 0;
524 
525 err:
526 	ep93xx_free_buffers(ep);
527 	return 1;
528 }
529 
530 static int ep93xx_start_hw(struct net_device *dev)
531 {
532 	struct ep93xx_priv *ep = netdev_priv(dev);
533 	unsigned long addr;
534 	int i;
535 
536 	wrl(ep, REG_SELFCTL, REG_SELFCTL_RESET);
537 	for (i = 0; i < 10; i++) {
538 		if ((rdl(ep, REG_SELFCTL) & REG_SELFCTL_RESET) == 0)
539 			break;
540 		msleep(1);
541 	}
542 
543 	if (i == 10) {
544 		pr_crit("hw failed to reset\n");
545 		return 1;
546 	}
547 
548 	wrl(ep, REG_SELFCTL, ((ep->mdc_divisor - 1) << 9));
549 
550 	/* Does the PHY support preamble suppress?  */
551 	if ((ep93xx_mdio_read(dev, ep->mii.phy_id, MII_BMSR) & 0x0040) != 0)
552 		wrl(ep, REG_SELFCTL, ((ep->mdc_divisor - 1) << 9) | (1 << 8));
553 
554 	/* Receive descriptor ring.  */
555 	addr = ep->descs_dma_addr + offsetof(struct ep93xx_descs, rdesc);
556 	wrl(ep, REG_RXDQBADD, addr);
557 	wrl(ep, REG_RXDCURADD, addr);
558 	wrw(ep, REG_RXDQBLEN, RX_QUEUE_ENTRIES * sizeof(struct ep93xx_rdesc));
559 
560 	/* Receive status ring.  */
561 	addr = ep->descs_dma_addr + offsetof(struct ep93xx_descs, rstat);
562 	wrl(ep, REG_RXSTSQBADD, addr);
563 	wrl(ep, REG_RXSTSQCURADD, addr);
564 	wrw(ep, REG_RXSTSQBLEN, RX_QUEUE_ENTRIES * sizeof(struct ep93xx_rstat));
565 
566 	/* Transmit descriptor ring.  */
567 	addr = ep->descs_dma_addr + offsetof(struct ep93xx_descs, tdesc);
568 	wrl(ep, REG_TXDQBADD, addr);
569 	wrl(ep, REG_TXDQCURADD, addr);
570 	wrw(ep, REG_TXDQBLEN, TX_QUEUE_ENTRIES * sizeof(struct ep93xx_tdesc));
571 
572 	/* Transmit status ring.  */
573 	addr = ep->descs_dma_addr + offsetof(struct ep93xx_descs, tstat);
574 	wrl(ep, REG_TXSTSQBADD, addr);
575 	wrl(ep, REG_TXSTSQCURADD, addr);
576 	wrw(ep, REG_TXSTSQBLEN, TX_QUEUE_ENTRIES * sizeof(struct ep93xx_tstat));
577 
578 	wrl(ep, REG_BMCTL, REG_BMCTL_ENABLE_TX | REG_BMCTL_ENABLE_RX);
579 	wrl(ep, REG_INTEN, REG_INTEN_TX | REG_INTEN_RX);
580 	wrl(ep, REG_GIINTMSK, 0);
581 
582 	for (i = 0; i < 10; i++) {
583 		if ((rdl(ep, REG_BMSTS) & REG_BMSTS_RX_ACTIVE) != 0)
584 			break;
585 		msleep(1);
586 	}
587 
588 	if (i == 10) {
589 		pr_crit("hw failed to start\n");
590 		return 1;
591 	}
592 
593 	wrl(ep, REG_RXDENQ, RX_QUEUE_ENTRIES);
594 	wrl(ep, REG_RXSTSENQ, RX_QUEUE_ENTRIES);
595 
596 	wrb(ep, REG_INDAD0, dev->dev_addr[0]);
597 	wrb(ep, REG_INDAD1, dev->dev_addr[1]);
598 	wrb(ep, REG_INDAD2, dev->dev_addr[2]);
599 	wrb(ep, REG_INDAD3, dev->dev_addr[3]);
600 	wrb(ep, REG_INDAD4, dev->dev_addr[4]);
601 	wrb(ep, REG_INDAD5, dev->dev_addr[5]);
602 	wrl(ep, REG_AFP, 0);
603 
604 	wrl(ep, REG_MAXFRMLEN, (MAX_PKT_SIZE << 16) | MAX_PKT_SIZE);
605 
606 	wrl(ep, REG_RXCTL, REG_RXCTL_DEFAULT);
607 	wrl(ep, REG_TXCTL, REG_TXCTL_ENABLE);
608 
609 	return 0;
610 }
611 
612 static void ep93xx_stop_hw(struct net_device *dev)
613 {
614 	struct ep93xx_priv *ep = netdev_priv(dev);
615 	int i;
616 
617 	wrl(ep, REG_SELFCTL, REG_SELFCTL_RESET);
618 	for (i = 0; i < 10; i++) {
619 		if ((rdl(ep, REG_SELFCTL) & REG_SELFCTL_RESET) == 0)
620 			break;
621 		msleep(1);
622 	}
623 
624 	if (i == 10)
625 		pr_crit("hw failed to reset\n");
626 }
627 
628 static int ep93xx_open(struct net_device *dev)
629 {
630 	struct ep93xx_priv *ep = netdev_priv(dev);
631 	int err;
632 
633 	if (ep93xx_alloc_buffers(ep))
634 		return -ENOMEM;
635 
636 	napi_enable(&ep->napi);
637 
638 	if (ep93xx_start_hw(dev)) {
639 		napi_disable(&ep->napi);
640 		ep93xx_free_buffers(ep);
641 		return -EIO;
642 	}
643 
644 	spin_lock_init(&ep->rx_lock);
645 	ep->rx_pointer = 0;
646 	ep->tx_clean_pointer = 0;
647 	ep->tx_pointer = 0;
648 	spin_lock_init(&ep->tx_pending_lock);
649 	ep->tx_pending = 0;
650 
651 	err = request_irq(ep->irq, ep93xx_irq, IRQF_SHARED, dev->name, dev);
652 	if (err) {
653 		napi_disable(&ep->napi);
654 		ep93xx_stop_hw(dev);
655 		ep93xx_free_buffers(ep);
656 		return err;
657 	}
658 
659 	wrl(ep, REG_GIINTMSK, REG_GIINTMSK_ENABLE);
660 
661 	netif_start_queue(dev);
662 
663 	return 0;
664 }
665 
666 static int ep93xx_close(struct net_device *dev)
667 {
668 	struct ep93xx_priv *ep = netdev_priv(dev);
669 
670 	napi_disable(&ep->napi);
671 	netif_stop_queue(dev);
672 
673 	wrl(ep, REG_GIINTMSK, 0);
674 	free_irq(ep->irq, dev);
675 	ep93xx_stop_hw(dev);
676 	ep93xx_free_buffers(ep);
677 
678 	return 0;
679 }
680 
681 static int ep93xx_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
682 {
683 	struct ep93xx_priv *ep = netdev_priv(dev);
684 	struct mii_ioctl_data *data = if_mii(ifr);
685 
686 	return generic_mii_ioctl(&ep->mii, data, cmd, NULL);
687 }
688 
689 static void ep93xx_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
690 {
691 	strscpy(info->driver, DRV_MODULE_NAME, sizeof(info->driver));
692 }
693 
694 static int ep93xx_get_link_ksettings(struct net_device *dev,
695 				     struct ethtool_link_ksettings *cmd)
696 {
697 	struct ep93xx_priv *ep = netdev_priv(dev);
698 
699 	mii_ethtool_get_link_ksettings(&ep->mii, cmd);
700 
701 	return 0;
702 }
703 
704 static int ep93xx_set_link_ksettings(struct net_device *dev,
705 				     const struct ethtool_link_ksettings *cmd)
706 {
707 	struct ep93xx_priv *ep = netdev_priv(dev);
708 	return mii_ethtool_set_link_ksettings(&ep->mii, cmd);
709 }
710 
711 static int ep93xx_nway_reset(struct net_device *dev)
712 {
713 	struct ep93xx_priv *ep = netdev_priv(dev);
714 	return mii_nway_restart(&ep->mii);
715 }
716 
717 static u32 ep93xx_get_link(struct net_device *dev)
718 {
719 	struct ep93xx_priv *ep = netdev_priv(dev);
720 	return mii_link_ok(&ep->mii);
721 }
722 
723 static const struct ethtool_ops ep93xx_ethtool_ops = {
724 	.get_drvinfo		= ep93xx_get_drvinfo,
725 	.nway_reset		= ep93xx_nway_reset,
726 	.get_link		= ep93xx_get_link,
727 	.get_link_ksettings	= ep93xx_get_link_ksettings,
728 	.set_link_ksettings	= ep93xx_set_link_ksettings,
729 };
730 
731 static const struct net_device_ops ep93xx_netdev_ops = {
732 	.ndo_open		= ep93xx_open,
733 	.ndo_stop		= ep93xx_close,
734 	.ndo_start_xmit		= ep93xx_xmit,
735 	.ndo_eth_ioctl		= ep93xx_ioctl,
736 	.ndo_validate_addr	= eth_validate_addr,
737 	.ndo_set_mac_address	= eth_mac_addr,
738 };
739 
740 static void ep93xx_eth_remove(struct platform_device *pdev)
741 {
742 	struct net_device *dev;
743 	struct ep93xx_priv *ep;
744 	struct resource *mem;
745 
746 	dev = platform_get_drvdata(pdev);
747 	if (dev == NULL)
748 		return;
749 
750 	ep = netdev_priv(dev);
751 
752 	/* @@@ Force down.  */
753 	unregister_netdev(dev);
754 	ep93xx_free_buffers(ep);
755 
756 	if (ep->base_addr != NULL)
757 		iounmap(ep->base_addr);
758 
759 	if (ep->res != NULL) {
760 		mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
761 		release_mem_region(mem->start, resource_size(mem));
762 	}
763 
764 	free_netdev(dev);
765 }
766 
767 static int ep93xx_eth_probe(struct platform_device *pdev)
768 {
769 	struct net_device *dev;
770 	struct ep93xx_priv *ep;
771 	struct resource *mem;
772 	void __iomem *base_addr;
773 	struct device_node *np;
774 	u8 addr[ETH_ALEN];
775 	u32 phy_id;
776 	int irq;
777 	int err;
778 
779 	if (pdev == NULL)
780 		return -ENODEV;
781 
782 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
783 	irq = platform_get_irq(pdev, 0);
784 	if (!mem || irq < 0)
785 		return -ENXIO;
786 
787 	base_addr = ioremap(mem->start, resource_size(mem));
788 	if (!base_addr)
789 		return dev_err_probe(&pdev->dev, -EIO, "Failed to ioremap ethernet registers\n");
790 
791 	np = of_parse_phandle(pdev->dev.of_node, "phy-handle", 0);
792 	if (!np)
793 		return dev_err_probe(&pdev->dev, -ENODEV, "Please provide \"phy-handle\"\n");
794 
795 	err = of_property_read_u32(np, "reg", &phy_id);
796 	of_node_put(np);
797 	if (err)
798 		return dev_err_probe(&pdev->dev, -ENOENT, "Failed to locate \"phy_id\"\n");
799 
800 	dev = alloc_etherdev(sizeof(struct ep93xx_priv));
801 	if (dev == NULL) {
802 		err = -ENOMEM;
803 		goto err_out;
804 	}
805 
806 	memcpy_fromio(addr, base_addr + 0x50, ETH_ALEN);
807 	eth_hw_addr_set(dev, addr);
808 	dev->ethtool_ops = &ep93xx_ethtool_ops;
809 	dev->netdev_ops = &ep93xx_netdev_ops;
810 	dev->features |= NETIF_F_SG | NETIF_F_HW_CSUM;
811 
812 	ep = netdev_priv(dev);
813 	ep->dev = dev;
814 	SET_NETDEV_DEV(dev, &pdev->dev);
815 	netif_napi_add(dev, &ep->napi, ep93xx_poll);
816 
817 	platform_set_drvdata(pdev, dev);
818 
819 	ep->res = request_mem_region(mem->start, resource_size(mem),
820 				     dev_name(&pdev->dev));
821 	if (ep->res == NULL) {
822 		dev_err(&pdev->dev, "Could not reserve memory region\n");
823 		err = -ENOMEM;
824 		goto err_out;
825 	}
826 
827 	ep->base_addr = base_addr;
828 	ep->irq = irq;
829 
830 	ep->mii.phy_id = phy_id;
831 	ep->mii.phy_id_mask = 0x1f;
832 	ep->mii.reg_num_mask = 0x1f;
833 	ep->mii.dev = dev;
834 	ep->mii.mdio_read = ep93xx_mdio_read;
835 	ep->mii.mdio_write = ep93xx_mdio_write;
836 	ep->mdc_divisor = 40;	/* Max HCLK 100 MHz, min MDIO clk 2.5 MHz.  */
837 
838 	if (is_zero_ether_addr(dev->dev_addr))
839 		eth_hw_addr_random(dev);
840 
841 	err = register_netdev(dev);
842 	if (err) {
843 		dev_err(&pdev->dev, "Failed to register netdev\n");
844 		goto err_out;
845 	}
846 
847 	printk(KERN_INFO "%s: ep93xx on-chip ethernet, IRQ %d, %pM\n",
848 			dev->name, ep->irq, dev->dev_addr);
849 
850 	return 0;
851 
852 err_out:
853 	ep93xx_eth_remove(pdev);
854 	return err;
855 }
856 
857 static const struct of_device_id ep93xx_eth_of_ids[] = {
858 	{ .compatible = "cirrus,ep9301-eth" },
859 	{ /* sentinel */ }
860 };
861 MODULE_DEVICE_TABLE(of, ep93xx_eth_of_ids);
862 
863 static struct platform_driver ep93xx_eth_driver = {
864 	.probe		= ep93xx_eth_probe,
865 	.remove_new	= ep93xx_eth_remove,
866 	.driver		= {
867 		.name	= "ep93xx-eth",
868 		.of_match_table = ep93xx_eth_of_ids,
869 	},
870 };
871 
872 module_platform_driver(ep93xx_eth_driver);
873 
874 MODULE_DESCRIPTION("Cirrus EP93xx Ethernet driver");
875 MODULE_LICENSE("GPL");
876 MODULE_ALIAS("platform:ep93xx-eth");
877