xref: /linux/drivers/net/ethernet/ethoc.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  * linux/drivers/net/ethernet/ethoc.c
3  *
4  * Copyright (C) 2007-2008 Avionic Design Development GmbH
5  * Copyright (C) 2008-2009 Avionic Design GmbH
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * Written by Thierry Reding <thierry.reding@avionic-design.de>
12  */
13 
14 #include <linux/dma-mapping.h>
15 #include <linux/etherdevice.h>
16 #include <linux/crc32.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/mii.h>
20 #include <linux/phy.h>
21 #include <linux/platform_device.h>
22 #include <linux/sched.h>
23 #include <linux/slab.h>
24 #include <linux/of.h>
25 #include <linux/module.h>
26 #include <net/ethoc.h>
27 
28 static int buffer_size = 0x8000; /* 32 KBytes */
29 module_param(buffer_size, int, 0);
30 MODULE_PARM_DESC(buffer_size, "DMA buffer allocation size");
31 
32 /* register offsets */
33 #define	MODER		0x00
34 #define	INT_SOURCE	0x04
35 #define	INT_MASK	0x08
36 #define	IPGT		0x0c
37 #define	IPGR1		0x10
38 #define	IPGR2		0x14
39 #define	PACKETLEN	0x18
40 #define	COLLCONF	0x1c
41 #define	TX_BD_NUM	0x20
42 #define	CTRLMODER	0x24
43 #define	MIIMODER	0x28
44 #define	MIICOMMAND	0x2c
45 #define	MIIADDRESS	0x30
46 #define	MIITX_DATA	0x34
47 #define	MIIRX_DATA	0x38
48 #define	MIISTATUS	0x3c
49 #define	MAC_ADDR0	0x40
50 #define	MAC_ADDR1	0x44
51 #define	ETH_HASH0	0x48
52 #define	ETH_HASH1	0x4c
53 #define	ETH_TXCTRL	0x50
54 
55 /* mode register */
56 #define	MODER_RXEN	(1 <<  0) /* receive enable */
57 #define	MODER_TXEN	(1 <<  1) /* transmit enable */
58 #define	MODER_NOPRE	(1 <<  2) /* no preamble */
59 #define	MODER_BRO	(1 <<  3) /* broadcast address */
60 #define	MODER_IAM	(1 <<  4) /* individual address mode */
61 #define	MODER_PRO	(1 <<  5) /* promiscuous mode */
62 #define	MODER_IFG	(1 <<  6) /* interframe gap for incoming frames */
63 #define	MODER_LOOP	(1 <<  7) /* loopback */
64 #define	MODER_NBO	(1 <<  8) /* no back-off */
65 #define	MODER_EDE	(1 <<  9) /* excess defer enable */
66 #define	MODER_FULLD	(1 << 10) /* full duplex */
67 #define	MODER_RESET	(1 << 11) /* FIXME: reset (undocumented) */
68 #define	MODER_DCRC	(1 << 12) /* delayed CRC enable */
69 #define	MODER_CRC	(1 << 13) /* CRC enable */
70 #define	MODER_HUGE	(1 << 14) /* huge packets enable */
71 #define	MODER_PAD	(1 << 15) /* padding enabled */
72 #define	MODER_RSM	(1 << 16) /* receive small packets */
73 
74 /* interrupt source and mask registers */
75 #define	INT_MASK_TXF	(1 << 0) /* transmit frame */
76 #define	INT_MASK_TXE	(1 << 1) /* transmit error */
77 #define	INT_MASK_RXF	(1 << 2) /* receive frame */
78 #define	INT_MASK_RXE	(1 << 3) /* receive error */
79 #define	INT_MASK_BUSY	(1 << 4)
80 #define	INT_MASK_TXC	(1 << 5) /* transmit control frame */
81 #define	INT_MASK_RXC	(1 << 6) /* receive control frame */
82 
83 #define	INT_MASK_TX	(INT_MASK_TXF | INT_MASK_TXE)
84 #define	INT_MASK_RX	(INT_MASK_RXF | INT_MASK_RXE)
85 
86 #define	INT_MASK_ALL ( \
87 		INT_MASK_TXF | INT_MASK_TXE | \
88 		INT_MASK_RXF | INT_MASK_RXE | \
89 		INT_MASK_TXC | INT_MASK_RXC | \
90 		INT_MASK_BUSY \
91 	)
92 
93 /* packet length register */
94 #define	PACKETLEN_MIN(min)		(((min) & 0xffff) << 16)
95 #define	PACKETLEN_MAX(max)		(((max) & 0xffff) <<  0)
96 #define	PACKETLEN_MIN_MAX(min, max)	(PACKETLEN_MIN(min) | \
97 					PACKETLEN_MAX(max))
98 
99 /* transmit buffer number register */
100 #define	TX_BD_NUM_VAL(x)	(((x) <= 0x80) ? (x) : 0x80)
101 
102 /* control module mode register */
103 #define	CTRLMODER_PASSALL	(1 << 0) /* pass all receive frames */
104 #define	CTRLMODER_RXFLOW	(1 << 1) /* receive control flow */
105 #define	CTRLMODER_TXFLOW	(1 << 2) /* transmit control flow */
106 
107 /* MII mode register */
108 #define	MIIMODER_CLKDIV(x)	((x) & 0xfe) /* needs to be an even number */
109 #define	MIIMODER_NOPRE		(1 << 8) /* no preamble */
110 
111 /* MII command register */
112 #define	MIICOMMAND_SCAN		(1 << 0) /* scan status */
113 #define	MIICOMMAND_READ		(1 << 1) /* read status */
114 #define	MIICOMMAND_WRITE	(1 << 2) /* write control data */
115 
116 /* MII address register */
117 #define	MIIADDRESS_FIAD(x)		(((x) & 0x1f) << 0)
118 #define	MIIADDRESS_RGAD(x)		(((x) & 0x1f) << 8)
119 #define	MIIADDRESS_ADDR(phy, reg)	(MIIADDRESS_FIAD(phy) | \
120 					MIIADDRESS_RGAD(reg))
121 
122 /* MII transmit data register */
123 #define	MIITX_DATA_VAL(x)	((x) & 0xffff)
124 
125 /* MII receive data register */
126 #define	MIIRX_DATA_VAL(x)	((x) & 0xffff)
127 
128 /* MII status register */
129 #define	MIISTATUS_LINKFAIL	(1 << 0)
130 #define	MIISTATUS_BUSY		(1 << 1)
131 #define	MIISTATUS_INVALID	(1 << 2)
132 
133 /* TX buffer descriptor */
134 #define	TX_BD_CS		(1 <<  0) /* carrier sense lost */
135 #define	TX_BD_DF		(1 <<  1) /* defer indication */
136 #define	TX_BD_LC		(1 <<  2) /* late collision */
137 #define	TX_BD_RL		(1 <<  3) /* retransmission limit */
138 #define	TX_BD_RETRY_MASK	(0x00f0)
139 #define	TX_BD_RETRY(x)		(((x) & 0x00f0) >>  4)
140 #define	TX_BD_UR		(1 <<  8) /* transmitter underrun */
141 #define	TX_BD_CRC		(1 << 11) /* TX CRC enable */
142 #define	TX_BD_PAD		(1 << 12) /* pad enable for short packets */
143 #define	TX_BD_WRAP		(1 << 13)
144 #define	TX_BD_IRQ		(1 << 14) /* interrupt request enable */
145 #define	TX_BD_READY		(1 << 15) /* TX buffer ready */
146 #define	TX_BD_LEN(x)		(((x) & 0xffff) << 16)
147 #define	TX_BD_LEN_MASK		(0xffff << 16)
148 
149 #define	TX_BD_STATS		(TX_BD_CS | TX_BD_DF | TX_BD_LC | \
150 				TX_BD_RL | TX_BD_RETRY_MASK | TX_BD_UR)
151 
152 /* RX buffer descriptor */
153 #define	RX_BD_LC	(1 <<  0) /* late collision */
154 #define	RX_BD_CRC	(1 <<  1) /* RX CRC error */
155 #define	RX_BD_SF	(1 <<  2) /* short frame */
156 #define	RX_BD_TL	(1 <<  3) /* too long */
157 #define	RX_BD_DN	(1 <<  4) /* dribble nibble */
158 #define	RX_BD_IS	(1 <<  5) /* invalid symbol */
159 #define	RX_BD_OR	(1 <<  6) /* receiver overrun */
160 #define	RX_BD_MISS	(1 <<  7)
161 #define	RX_BD_CF	(1 <<  8) /* control frame */
162 #define	RX_BD_WRAP	(1 << 13)
163 #define	RX_BD_IRQ	(1 << 14) /* interrupt request enable */
164 #define	RX_BD_EMPTY	(1 << 15)
165 #define	RX_BD_LEN(x)	(((x) & 0xffff) << 16)
166 
167 #define	RX_BD_STATS	(RX_BD_LC | RX_BD_CRC | RX_BD_SF | RX_BD_TL | \
168 			RX_BD_DN | RX_BD_IS | RX_BD_OR | RX_BD_MISS)
169 
170 #define	ETHOC_BUFSIZ		1536
171 #define	ETHOC_ZLEN		64
172 #define	ETHOC_BD_BASE		0x400
173 #define	ETHOC_TIMEOUT		(HZ / 2)
174 #define	ETHOC_MII_TIMEOUT	(1 + (HZ / 5))
175 
176 /**
177  * struct ethoc - driver-private device structure
178  * @iobase:	pointer to I/O memory region
179  * @membase:	pointer to buffer memory region
180  * @dma_alloc:	dma allocated buffer size
181  * @io_region_size:	I/O memory region size
182  * @num_tx:	number of send buffers
183  * @cur_tx:	last send buffer written
184  * @dty_tx:	last buffer actually sent
185  * @num_rx:	number of receive buffers
186  * @cur_rx:	current receive buffer
187  * @vma:        pointer to array of virtual memory addresses for buffers
188  * @netdev:	pointer to network device structure
189  * @napi:	NAPI structure
190  * @msg_enable:	device state flags
191  * @lock:	device lock
192  * @phy:	attached PHY
193  * @mdio:	MDIO bus for PHY access
194  * @phy_id:	address of attached PHY
195  */
196 struct ethoc {
197 	void __iomem *iobase;
198 	void __iomem *membase;
199 	int dma_alloc;
200 	resource_size_t io_region_size;
201 
202 	unsigned int num_tx;
203 	unsigned int cur_tx;
204 	unsigned int dty_tx;
205 
206 	unsigned int num_rx;
207 	unsigned int cur_rx;
208 
209 	void **vma;
210 
211 	struct net_device *netdev;
212 	struct napi_struct napi;
213 	u32 msg_enable;
214 
215 	spinlock_t lock;
216 
217 	struct phy_device *phy;
218 	struct mii_bus *mdio;
219 	s8 phy_id;
220 };
221 
222 /**
223  * struct ethoc_bd - buffer descriptor
224  * @stat:	buffer statistics
225  * @addr:	physical memory address
226  */
227 struct ethoc_bd {
228 	u32 stat;
229 	u32 addr;
230 };
231 
232 static inline u32 ethoc_read(struct ethoc *dev, loff_t offset)
233 {
234 	return ioread32(dev->iobase + offset);
235 }
236 
237 static inline void ethoc_write(struct ethoc *dev, loff_t offset, u32 data)
238 {
239 	iowrite32(data, dev->iobase + offset);
240 }
241 
242 static inline void ethoc_read_bd(struct ethoc *dev, int index,
243 		struct ethoc_bd *bd)
244 {
245 	loff_t offset = ETHOC_BD_BASE + (index * sizeof(struct ethoc_bd));
246 	bd->stat = ethoc_read(dev, offset + 0);
247 	bd->addr = ethoc_read(dev, offset + 4);
248 }
249 
250 static inline void ethoc_write_bd(struct ethoc *dev, int index,
251 		const struct ethoc_bd *bd)
252 {
253 	loff_t offset = ETHOC_BD_BASE + (index * sizeof(struct ethoc_bd));
254 	ethoc_write(dev, offset + 0, bd->stat);
255 	ethoc_write(dev, offset + 4, bd->addr);
256 }
257 
258 static inline void ethoc_enable_irq(struct ethoc *dev, u32 mask)
259 {
260 	u32 imask = ethoc_read(dev, INT_MASK);
261 	imask |= mask;
262 	ethoc_write(dev, INT_MASK, imask);
263 }
264 
265 static inline void ethoc_disable_irq(struct ethoc *dev, u32 mask)
266 {
267 	u32 imask = ethoc_read(dev, INT_MASK);
268 	imask &= ~mask;
269 	ethoc_write(dev, INT_MASK, imask);
270 }
271 
272 static inline void ethoc_ack_irq(struct ethoc *dev, u32 mask)
273 {
274 	ethoc_write(dev, INT_SOURCE, mask);
275 }
276 
277 static inline void ethoc_enable_rx_and_tx(struct ethoc *dev)
278 {
279 	u32 mode = ethoc_read(dev, MODER);
280 	mode |= MODER_RXEN | MODER_TXEN;
281 	ethoc_write(dev, MODER, mode);
282 }
283 
284 static inline void ethoc_disable_rx_and_tx(struct ethoc *dev)
285 {
286 	u32 mode = ethoc_read(dev, MODER);
287 	mode &= ~(MODER_RXEN | MODER_TXEN);
288 	ethoc_write(dev, MODER, mode);
289 }
290 
291 static int ethoc_init_ring(struct ethoc *dev, unsigned long mem_start)
292 {
293 	struct ethoc_bd bd;
294 	int i;
295 	void *vma;
296 
297 	dev->cur_tx = 0;
298 	dev->dty_tx = 0;
299 	dev->cur_rx = 0;
300 
301 	ethoc_write(dev, TX_BD_NUM, dev->num_tx);
302 
303 	/* setup transmission buffers */
304 	bd.addr = mem_start;
305 	bd.stat = TX_BD_IRQ | TX_BD_CRC;
306 	vma = dev->membase;
307 
308 	for (i = 0; i < dev->num_tx; i++) {
309 		if (i == dev->num_tx - 1)
310 			bd.stat |= TX_BD_WRAP;
311 
312 		ethoc_write_bd(dev, i, &bd);
313 		bd.addr += ETHOC_BUFSIZ;
314 
315 		dev->vma[i] = vma;
316 		vma += ETHOC_BUFSIZ;
317 	}
318 
319 	bd.stat = RX_BD_EMPTY | RX_BD_IRQ;
320 
321 	for (i = 0; i < dev->num_rx; i++) {
322 		if (i == dev->num_rx - 1)
323 			bd.stat |= RX_BD_WRAP;
324 
325 		ethoc_write_bd(dev, dev->num_tx + i, &bd);
326 		bd.addr += ETHOC_BUFSIZ;
327 
328 		dev->vma[dev->num_tx + i] = vma;
329 		vma += ETHOC_BUFSIZ;
330 	}
331 
332 	return 0;
333 }
334 
335 static int ethoc_reset(struct ethoc *dev)
336 {
337 	u32 mode;
338 
339 	/* TODO: reset controller? */
340 
341 	ethoc_disable_rx_and_tx(dev);
342 
343 	/* TODO: setup registers */
344 
345 	/* enable FCS generation and automatic padding */
346 	mode = ethoc_read(dev, MODER);
347 	mode |= MODER_CRC | MODER_PAD;
348 	ethoc_write(dev, MODER, mode);
349 
350 	/* set full-duplex mode */
351 	mode = ethoc_read(dev, MODER);
352 	mode |= MODER_FULLD;
353 	ethoc_write(dev, MODER, mode);
354 	ethoc_write(dev, IPGT, 0x15);
355 
356 	ethoc_ack_irq(dev, INT_MASK_ALL);
357 	ethoc_enable_irq(dev, INT_MASK_ALL);
358 	ethoc_enable_rx_and_tx(dev);
359 	return 0;
360 }
361 
362 static unsigned int ethoc_update_rx_stats(struct ethoc *dev,
363 		struct ethoc_bd *bd)
364 {
365 	struct net_device *netdev = dev->netdev;
366 	unsigned int ret = 0;
367 
368 	if (bd->stat & RX_BD_TL) {
369 		dev_err(&netdev->dev, "RX: frame too long\n");
370 		netdev->stats.rx_length_errors++;
371 		ret++;
372 	}
373 
374 	if (bd->stat & RX_BD_SF) {
375 		dev_err(&netdev->dev, "RX: frame too short\n");
376 		netdev->stats.rx_length_errors++;
377 		ret++;
378 	}
379 
380 	if (bd->stat & RX_BD_DN) {
381 		dev_err(&netdev->dev, "RX: dribble nibble\n");
382 		netdev->stats.rx_frame_errors++;
383 	}
384 
385 	if (bd->stat & RX_BD_CRC) {
386 		dev_err(&netdev->dev, "RX: wrong CRC\n");
387 		netdev->stats.rx_crc_errors++;
388 		ret++;
389 	}
390 
391 	if (bd->stat & RX_BD_OR) {
392 		dev_err(&netdev->dev, "RX: overrun\n");
393 		netdev->stats.rx_over_errors++;
394 		ret++;
395 	}
396 
397 	if (bd->stat & RX_BD_MISS)
398 		netdev->stats.rx_missed_errors++;
399 
400 	if (bd->stat & RX_BD_LC) {
401 		dev_err(&netdev->dev, "RX: late collision\n");
402 		netdev->stats.collisions++;
403 		ret++;
404 	}
405 
406 	return ret;
407 }
408 
409 static int ethoc_rx(struct net_device *dev, int limit)
410 {
411 	struct ethoc *priv = netdev_priv(dev);
412 	int count;
413 
414 	for (count = 0; count < limit; ++count) {
415 		unsigned int entry;
416 		struct ethoc_bd bd;
417 
418 		entry = priv->num_tx + priv->cur_rx;
419 		ethoc_read_bd(priv, entry, &bd);
420 		if (bd.stat & RX_BD_EMPTY) {
421 			ethoc_ack_irq(priv, INT_MASK_RX);
422 			/* If packet (interrupt) came in between checking
423 			 * BD_EMTPY and clearing the interrupt source, then we
424 			 * risk missing the packet as the RX interrupt won't
425 			 * trigger right away when we reenable it; hence, check
426 			 * BD_EMTPY here again to make sure there isn't such a
427 			 * packet waiting for us...
428 			 */
429 			ethoc_read_bd(priv, entry, &bd);
430 			if (bd.stat & RX_BD_EMPTY)
431 				break;
432 		}
433 
434 		if (ethoc_update_rx_stats(priv, &bd) == 0) {
435 			int size = bd.stat >> 16;
436 			struct sk_buff *skb;
437 
438 			size -= 4; /* strip the CRC */
439 			skb = netdev_alloc_skb_ip_align(dev, size);
440 
441 			if (likely(skb)) {
442 				void *src = priv->vma[entry];
443 				memcpy_fromio(skb_put(skb, size), src, size);
444 				skb->protocol = eth_type_trans(skb, dev);
445 				dev->stats.rx_packets++;
446 				dev->stats.rx_bytes += size;
447 				netif_receive_skb(skb);
448 			} else {
449 				if (net_ratelimit())
450 					dev_warn(&dev->dev,
451 					    "low on memory - packet dropped\n");
452 
453 				dev->stats.rx_dropped++;
454 				break;
455 			}
456 		}
457 
458 		/* clear the buffer descriptor so it can be reused */
459 		bd.stat &= ~RX_BD_STATS;
460 		bd.stat |=  RX_BD_EMPTY;
461 		ethoc_write_bd(priv, entry, &bd);
462 		if (++priv->cur_rx == priv->num_rx)
463 			priv->cur_rx = 0;
464 	}
465 
466 	return count;
467 }
468 
469 static void ethoc_update_tx_stats(struct ethoc *dev, struct ethoc_bd *bd)
470 {
471 	struct net_device *netdev = dev->netdev;
472 
473 	if (bd->stat & TX_BD_LC) {
474 		dev_err(&netdev->dev, "TX: late collision\n");
475 		netdev->stats.tx_window_errors++;
476 	}
477 
478 	if (bd->stat & TX_BD_RL) {
479 		dev_err(&netdev->dev, "TX: retransmit limit\n");
480 		netdev->stats.tx_aborted_errors++;
481 	}
482 
483 	if (bd->stat & TX_BD_UR) {
484 		dev_err(&netdev->dev, "TX: underrun\n");
485 		netdev->stats.tx_fifo_errors++;
486 	}
487 
488 	if (bd->stat & TX_BD_CS) {
489 		dev_err(&netdev->dev, "TX: carrier sense lost\n");
490 		netdev->stats.tx_carrier_errors++;
491 	}
492 
493 	if (bd->stat & TX_BD_STATS)
494 		netdev->stats.tx_errors++;
495 
496 	netdev->stats.collisions += (bd->stat >> 4) & 0xf;
497 	netdev->stats.tx_bytes += bd->stat >> 16;
498 	netdev->stats.tx_packets++;
499 }
500 
501 static int ethoc_tx(struct net_device *dev, int limit)
502 {
503 	struct ethoc *priv = netdev_priv(dev);
504 	int count;
505 	struct ethoc_bd bd;
506 
507 	for (count = 0; count < limit; ++count) {
508 		unsigned int entry;
509 
510 		entry = priv->dty_tx & (priv->num_tx-1);
511 
512 		ethoc_read_bd(priv, entry, &bd);
513 
514 		if (bd.stat & TX_BD_READY || (priv->dty_tx == priv->cur_tx)) {
515 			ethoc_ack_irq(priv, INT_MASK_TX);
516 			/* If interrupt came in between reading in the BD
517 			 * and clearing the interrupt source, then we risk
518 			 * missing the event as the TX interrupt won't trigger
519 			 * right away when we reenable it; hence, check
520 			 * BD_EMPTY here again to make sure there isn't such an
521 			 * event pending...
522 			 */
523 			ethoc_read_bd(priv, entry, &bd);
524 			if (bd.stat & TX_BD_READY ||
525 			    (priv->dty_tx == priv->cur_tx))
526 				break;
527 		}
528 
529 		ethoc_update_tx_stats(priv, &bd);
530 		priv->dty_tx++;
531 	}
532 
533 	if ((priv->cur_tx - priv->dty_tx) <= (priv->num_tx / 2))
534 		netif_wake_queue(dev);
535 
536 	return count;
537 }
538 
539 static irqreturn_t ethoc_interrupt(int irq, void *dev_id)
540 {
541 	struct net_device *dev = dev_id;
542 	struct ethoc *priv = netdev_priv(dev);
543 	u32 pending;
544 	u32 mask;
545 
546 	/* Figure out what triggered the interrupt...
547 	 * The tricky bit here is that the interrupt source bits get
548 	 * set in INT_SOURCE for an event regardless of whether that
549 	 * event is masked or not.  Thus, in order to figure out what
550 	 * triggered the interrupt, we need to remove the sources
551 	 * for all events that are currently masked.  This behaviour
552 	 * is not particularly well documented but reasonable...
553 	 */
554 	mask = ethoc_read(priv, INT_MASK);
555 	pending = ethoc_read(priv, INT_SOURCE);
556 	pending &= mask;
557 
558 	if (unlikely(pending == 0))
559 		return IRQ_NONE;
560 
561 	ethoc_ack_irq(priv, pending);
562 
563 	/* We always handle the dropped packet interrupt */
564 	if (pending & INT_MASK_BUSY) {
565 		dev_err(&dev->dev, "packet dropped\n");
566 		dev->stats.rx_dropped++;
567 	}
568 
569 	/* Handle receive/transmit event by switching to polling */
570 	if (pending & (INT_MASK_TX | INT_MASK_RX)) {
571 		ethoc_disable_irq(priv, INT_MASK_TX | INT_MASK_RX);
572 		napi_schedule(&priv->napi);
573 	}
574 
575 	return IRQ_HANDLED;
576 }
577 
578 static int ethoc_get_mac_address(struct net_device *dev, void *addr)
579 {
580 	struct ethoc *priv = netdev_priv(dev);
581 	u8 *mac = (u8 *)addr;
582 	u32 reg;
583 
584 	reg = ethoc_read(priv, MAC_ADDR0);
585 	mac[2] = (reg >> 24) & 0xff;
586 	mac[3] = (reg >> 16) & 0xff;
587 	mac[4] = (reg >>  8) & 0xff;
588 	mac[5] = (reg >>  0) & 0xff;
589 
590 	reg = ethoc_read(priv, MAC_ADDR1);
591 	mac[0] = (reg >>  8) & 0xff;
592 	mac[1] = (reg >>  0) & 0xff;
593 
594 	return 0;
595 }
596 
597 static int ethoc_poll(struct napi_struct *napi, int budget)
598 {
599 	struct ethoc *priv = container_of(napi, struct ethoc, napi);
600 	int rx_work_done = 0;
601 	int tx_work_done = 0;
602 
603 	rx_work_done = ethoc_rx(priv->netdev, budget);
604 	tx_work_done = ethoc_tx(priv->netdev, budget);
605 
606 	if (rx_work_done < budget && tx_work_done < budget) {
607 		napi_complete(napi);
608 		ethoc_enable_irq(priv, INT_MASK_TX | INT_MASK_RX);
609 	}
610 
611 	return rx_work_done;
612 }
613 
614 static int ethoc_mdio_read(struct mii_bus *bus, int phy, int reg)
615 {
616 	struct ethoc *priv = bus->priv;
617 	int i;
618 
619 	ethoc_write(priv, MIIADDRESS, MIIADDRESS_ADDR(phy, reg));
620 	ethoc_write(priv, MIICOMMAND, MIICOMMAND_READ);
621 
622 	for (i = 0; i < 5; i++) {
623 		u32 status = ethoc_read(priv, MIISTATUS);
624 		if (!(status & MIISTATUS_BUSY)) {
625 			u32 data = ethoc_read(priv, MIIRX_DATA);
626 			/* reset MII command register */
627 			ethoc_write(priv, MIICOMMAND, 0);
628 			return data;
629 		}
630 		usleep_range(100, 200);
631 	}
632 
633 	return -EBUSY;
634 }
635 
636 static int ethoc_mdio_write(struct mii_bus *bus, int phy, int reg, u16 val)
637 {
638 	struct ethoc *priv = bus->priv;
639 	int i;
640 
641 	ethoc_write(priv, MIIADDRESS, MIIADDRESS_ADDR(phy, reg));
642 	ethoc_write(priv, MIITX_DATA, val);
643 	ethoc_write(priv, MIICOMMAND, MIICOMMAND_WRITE);
644 
645 	for (i = 0; i < 5; i++) {
646 		u32 stat = ethoc_read(priv, MIISTATUS);
647 		if (!(stat & MIISTATUS_BUSY)) {
648 			/* reset MII command register */
649 			ethoc_write(priv, MIICOMMAND, 0);
650 			return 0;
651 		}
652 		usleep_range(100, 200);
653 	}
654 
655 	return -EBUSY;
656 }
657 
658 static int ethoc_mdio_reset(struct mii_bus *bus)
659 {
660 	return 0;
661 }
662 
663 static void ethoc_mdio_poll(struct net_device *dev)
664 {
665 }
666 
667 static int ethoc_mdio_probe(struct net_device *dev)
668 {
669 	struct ethoc *priv = netdev_priv(dev);
670 	struct phy_device *phy;
671 	int err;
672 
673 	if (priv->phy_id != -1)
674 		phy = priv->mdio->phy_map[priv->phy_id];
675 	else
676 		phy = phy_find_first(priv->mdio);
677 
678 	if (!phy) {
679 		dev_err(&dev->dev, "no PHY found\n");
680 		return -ENXIO;
681 	}
682 
683 	err = phy_connect_direct(dev, phy, ethoc_mdio_poll,
684 				 PHY_INTERFACE_MODE_GMII);
685 	if (err) {
686 		dev_err(&dev->dev, "could not attach to PHY\n");
687 		return err;
688 	}
689 
690 	priv->phy = phy;
691 	return 0;
692 }
693 
694 static int ethoc_open(struct net_device *dev)
695 {
696 	struct ethoc *priv = netdev_priv(dev);
697 	int ret;
698 
699 	ret = request_irq(dev->irq, ethoc_interrupt, IRQF_SHARED,
700 			dev->name, dev);
701 	if (ret)
702 		return ret;
703 
704 	ethoc_init_ring(priv, dev->mem_start);
705 	ethoc_reset(priv);
706 
707 	if (netif_queue_stopped(dev)) {
708 		dev_dbg(&dev->dev, " resuming queue\n");
709 		netif_wake_queue(dev);
710 	} else {
711 		dev_dbg(&dev->dev, " starting queue\n");
712 		netif_start_queue(dev);
713 	}
714 
715 	phy_start(priv->phy);
716 	napi_enable(&priv->napi);
717 
718 	if (netif_msg_ifup(priv)) {
719 		dev_info(&dev->dev, "I/O: %08lx Memory: %08lx-%08lx\n",
720 				dev->base_addr, dev->mem_start, dev->mem_end);
721 	}
722 
723 	return 0;
724 }
725 
726 static int ethoc_stop(struct net_device *dev)
727 {
728 	struct ethoc *priv = netdev_priv(dev);
729 
730 	napi_disable(&priv->napi);
731 
732 	if (priv->phy)
733 		phy_stop(priv->phy);
734 
735 	ethoc_disable_rx_and_tx(priv);
736 	free_irq(dev->irq, dev);
737 
738 	if (!netif_queue_stopped(dev))
739 		netif_stop_queue(dev);
740 
741 	return 0;
742 }
743 
744 static int ethoc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
745 {
746 	struct ethoc *priv = netdev_priv(dev);
747 	struct mii_ioctl_data *mdio = if_mii(ifr);
748 	struct phy_device *phy = NULL;
749 
750 	if (!netif_running(dev))
751 		return -EINVAL;
752 
753 	if (cmd != SIOCGMIIPHY) {
754 		if (mdio->phy_id >= PHY_MAX_ADDR)
755 			return -ERANGE;
756 
757 		phy = priv->mdio->phy_map[mdio->phy_id];
758 		if (!phy)
759 			return -ENODEV;
760 	} else {
761 		phy = priv->phy;
762 	}
763 
764 	return phy_mii_ioctl(phy, ifr, cmd);
765 }
766 
767 static int ethoc_config(struct net_device *dev, struct ifmap *map)
768 {
769 	return -ENOSYS;
770 }
771 
772 static void ethoc_do_set_mac_address(struct net_device *dev)
773 {
774 	struct ethoc *priv = netdev_priv(dev);
775 	unsigned char *mac = dev->dev_addr;
776 
777 	ethoc_write(priv, MAC_ADDR0, (mac[2] << 24) | (mac[3] << 16) |
778 				     (mac[4] <<  8) | (mac[5] <<  0));
779 	ethoc_write(priv, MAC_ADDR1, (mac[0] <<  8) | (mac[1] <<  0));
780 }
781 
782 static int ethoc_set_mac_address(struct net_device *dev, void *p)
783 {
784 	const struct sockaddr *addr = p;
785 
786 	if (!is_valid_ether_addr(addr->sa_data))
787 		return -EADDRNOTAVAIL;
788 	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
789 	ethoc_do_set_mac_address(dev);
790 	return 0;
791 }
792 
793 static void ethoc_set_multicast_list(struct net_device *dev)
794 {
795 	struct ethoc *priv = netdev_priv(dev);
796 	u32 mode = ethoc_read(priv, MODER);
797 	struct netdev_hw_addr *ha;
798 	u32 hash[2] = { 0, 0 };
799 
800 	/* set loopback mode if requested */
801 	if (dev->flags & IFF_LOOPBACK)
802 		mode |=  MODER_LOOP;
803 	else
804 		mode &= ~MODER_LOOP;
805 
806 	/* receive broadcast frames if requested */
807 	if (dev->flags & IFF_BROADCAST)
808 		mode &= ~MODER_BRO;
809 	else
810 		mode |=  MODER_BRO;
811 
812 	/* enable promiscuous mode if requested */
813 	if (dev->flags & IFF_PROMISC)
814 		mode |=  MODER_PRO;
815 	else
816 		mode &= ~MODER_PRO;
817 
818 	ethoc_write(priv, MODER, mode);
819 
820 	/* receive multicast frames */
821 	if (dev->flags & IFF_ALLMULTI) {
822 		hash[0] = 0xffffffff;
823 		hash[1] = 0xffffffff;
824 	} else {
825 		netdev_for_each_mc_addr(ha, dev) {
826 			u32 crc = ether_crc(ETH_ALEN, ha->addr);
827 			int bit = (crc >> 26) & 0x3f;
828 			hash[bit >> 5] |= 1 << (bit & 0x1f);
829 		}
830 	}
831 
832 	ethoc_write(priv, ETH_HASH0, hash[0]);
833 	ethoc_write(priv, ETH_HASH1, hash[1]);
834 }
835 
836 static int ethoc_change_mtu(struct net_device *dev, int new_mtu)
837 {
838 	return -ENOSYS;
839 }
840 
841 static void ethoc_tx_timeout(struct net_device *dev)
842 {
843 	struct ethoc *priv = netdev_priv(dev);
844 	u32 pending = ethoc_read(priv, INT_SOURCE);
845 	if (likely(pending))
846 		ethoc_interrupt(dev->irq, dev);
847 }
848 
849 static netdev_tx_t ethoc_start_xmit(struct sk_buff *skb, struct net_device *dev)
850 {
851 	struct ethoc *priv = netdev_priv(dev);
852 	struct ethoc_bd bd;
853 	unsigned int entry;
854 	void *dest;
855 
856 	if (unlikely(skb->len > ETHOC_BUFSIZ)) {
857 		dev->stats.tx_errors++;
858 		goto out;
859 	}
860 
861 	entry = priv->cur_tx % priv->num_tx;
862 	spin_lock_irq(&priv->lock);
863 	priv->cur_tx++;
864 
865 	ethoc_read_bd(priv, entry, &bd);
866 	if (unlikely(skb->len < ETHOC_ZLEN))
867 		bd.stat |=  TX_BD_PAD;
868 	else
869 		bd.stat &= ~TX_BD_PAD;
870 
871 	dest = priv->vma[entry];
872 	memcpy_toio(dest, skb->data, skb->len);
873 
874 	bd.stat &= ~(TX_BD_STATS | TX_BD_LEN_MASK);
875 	bd.stat |= TX_BD_LEN(skb->len);
876 	ethoc_write_bd(priv, entry, &bd);
877 
878 	bd.stat |= TX_BD_READY;
879 	ethoc_write_bd(priv, entry, &bd);
880 
881 	if (priv->cur_tx == (priv->dty_tx + priv->num_tx)) {
882 		dev_dbg(&dev->dev, "stopping queue\n");
883 		netif_stop_queue(dev);
884 	}
885 
886 	spin_unlock_irq(&priv->lock);
887 	skb_tx_timestamp(skb);
888 out:
889 	dev_kfree_skb(skb);
890 	return NETDEV_TX_OK;
891 }
892 
893 static const struct net_device_ops ethoc_netdev_ops = {
894 	.ndo_open = ethoc_open,
895 	.ndo_stop = ethoc_stop,
896 	.ndo_do_ioctl = ethoc_ioctl,
897 	.ndo_set_config = ethoc_config,
898 	.ndo_set_mac_address = ethoc_set_mac_address,
899 	.ndo_set_rx_mode = ethoc_set_multicast_list,
900 	.ndo_change_mtu = ethoc_change_mtu,
901 	.ndo_tx_timeout = ethoc_tx_timeout,
902 	.ndo_start_xmit = ethoc_start_xmit,
903 };
904 
905 /**
906  * ethoc_probe - initialize OpenCores ethernet MAC
907  * pdev:	platform device
908  */
909 static int ethoc_probe(struct platform_device *pdev)
910 {
911 	struct net_device *netdev = NULL;
912 	struct resource *res = NULL;
913 	struct resource *mmio = NULL;
914 	struct resource *mem = NULL;
915 	struct ethoc *priv = NULL;
916 	unsigned int phy;
917 	int num_bd;
918 	int ret = 0;
919 	bool random_mac = false;
920 
921 	/* allocate networking device */
922 	netdev = alloc_etherdev(sizeof(struct ethoc));
923 	if (!netdev) {
924 		ret = -ENOMEM;
925 		goto out;
926 	}
927 
928 	SET_NETDEV_DEV(netdev, &pdev->dev);
929 	platform_set_drvdata(pdev, netdev);
930 
931 	/* obtain I/O memory space */
932 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
933 	if (!res) {
934 		dev_err(&pdev->dev, "cannot obtain I/O memory space\n");
935 		ret = -ENXIO;
936 		goto free;
937 	}
938 
939 	mmio = devm_request_mem_region(&pdev->dev, res->start,
940 			resource_size(res), res->name);
941 	if (!mmio) {
942 		dev_err(&pdev->dev, "cannot request I/O memory space\n");
943 		ret = -ENXIO;
944 		goto free;
945 	}
946 
947 	netdev->base_addr = mmio->start;
948 
949 	/* obtain buffer memory space */
950 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
951 	if (res) {
952 		mem = devm_request_mem_region(&pdev->dev, res->start,
953 			resource_size(res), res->name);
954 		if (!mem) {
955 			dev_err(&pdev->dev, "cannot request memory space\n");
956 			ret = -ENXIO;
957 			goto free;
958 		}
959 
960 		netdev->mem_start = mem->start;
961 		netdev->mem_end   = mem->end;
962 	}
963 
964 
965 	/* obtain device IRQ number */
966 	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
967 	if (!res) {
968 		dev_err(&pdev->dev, "cannot obtain IRQ\n");
969 		ret = -ENXIO;
970 		goto free;
971 	}
972 
973 	netdev->irq = res->start;
974 
975 	/* setup driver-private data */
976 	priv = netdev_priv(netdev);
977 	priv->netdev = netdev;
978 	priv->dma_alloc = 0;
979 	priv->io_region_size = resource_size(mmio);
980 
981 	priv->iobase = devm_ioremap_nocache(&pdev->dev, netdev->base_addr,
982 			resource_size(mmio));
983 	if (!priv->iobase) {
984 		dev_err(&pdev->dev, "cannot remap I/O memory space\n");
985 		ret = -ENXIO;
986 		goto error;
987 	}
988 
989 	if (netdev->mem_end) {
990 		priv->membase = devm_ioremap_nocache(&pdev->dev,
991 			netdev->mem_start, resource_size(mem));
992 		if (!priv->membase) {
993 			dev_err(&pdev->dev, "cannot remap memory space\n");
994 			ret = -ENXIO;
995 			goto error;
996 		}
997 	} else {
998 		/* Allocate buffer memory */
999 		priv->membase = dmam_alloc_coherent(&pdev->dev,
1000 			buffer_size, (void *)&netdev->mem_start,
1001 			GFP_KERNEL);
1002 		if (!priv->membase) {
1003 			dev_err(&pdev->dev, "cannot allocate %dB buffer\n",
1004 				buffer_size);
1005 			ret = -ENOMEM;
1006 			goto error;
1007 		}
1008 		netdev->mem_end = netdev->mem_start + buffer_size;
1009 		priv->dma_alloc = buffer_size;
1010 	}
1011 
1012 	/* calculate the number of TX/RX buffers, maximum 128 supported */
1013 	num_bd = min_t(unsigned int,
1014 		128, (netdev->mem_end - netdev->mem_start + 1) / ETHOC_BUFSIZ);
1015 	if (num_bd < 4) {
1016 		ret = -ENODEV;
1017 		goto error;
1018 	}
1019 	/* num_tx must be a power of two */
1020 	priv->num_tx = rounddown_pow_of_two(num_bd >> 1);
1021 	priv->num_rx = num_bd - priv->num_tx;
1022 
1023 	dev_dbg(&pdev->dev, "ethoc: num_tx: %d num_rx: %d\n",
1024 		priv->num_tx, priv->num_rx);
1025 
1026 	priv->vma = devm_kzalloc(&pdev->dev, num_bd*sizeof(void *), GFP_KERNEL);
1027 	if (!priv->vma) {
1028 		ret = -ENOMEM;
1029 		goto error;
1030 	}
1031 
1032 	/* Allow the platform setup code to pass in a MAC address. */
1033 	if (dev_get_platdata(&pdev->dev)) {
1034 		struct ethoc_platform_data *pdata = dev_get_platdata(&pdev->dev);
1035 		memcpy(netdev->dev_addr, pdata->hwaddr, IFHWADDRLEN);
1036 		priv->phy_id = pdata->phy_id;
1037 	} else {
1038 		priv->phy_id = -1;
1039 
1040 #ifdef CONFIG_OF
1041 		{
1042 		const uint8_t *mac;
1043 
1044 		mac = of_get_property(pdev->dev.of_node,
1045 				      "local-mac-address",
1046 				      NULL);
1047 		if (mac)
1048 			memcpy(netdev->dev_addr, mac, IFHWADDRLEN);
1049 		}
1050 #endif
1051 	}
1052 
1053 	/* Check that the given MAC address is valid. If it isn't, read the
1054 	 * current MAC from the controller.
1055 	 */
1056 	if (!is_valid_ether_addr(netdev->dev_addr))
1057 		ethoc_get_mac_address(netdev, netdev->dev_addr);
1058 
1059 	/* Check the MAC again for validity, if it still isn't choose and
1060 	 * program a random one.
1061 	 */
1062 	if (!is_valid_ether_addr(netdev->dev_addr)) {
1063 		eth_random_addr(netdev->dev_addr);
1064 		random_mac = true;
1065 	}
1066 
1067 	ethoc_do_set_mac_address(netdev);
1068 
1069 	if (random_mac)
1070 		netdev->addr_assign_type = NET_ADDR_RANDOM;
1071 
1072 	/* register MII bus */
1073 	priv->mdio = mdiobus_alloc();
1074 	if (!priv->mdio) {
1075 		ret = -ENOMEM;
1076 		goto free;
1077 	}
1078 
1079 	priv->mdio->name = "ethoc-mdio";
1080 	snprintf(priv->mdio->id, MII_BUS_ID_SIZE, "%s-%d",
1081 			priv->mdio->name, pdev->id);
1082 	priv->mdio->read = ethoc_mdio_read;
1083 	priv->mdio->write = ethoc_mdio_write;
1084 	priv->mdio->reset = ethoc_mdio_reset;
1085 	priv->mdio->priv = priv;
1086 
1087 	priv->mdio->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
1088 	if (!priv->mdio->irq) {
1089 		ret = -ENOMEM;
1090 		goto free_mdio;
1091 	}
1092 
1093 	for (phy = 0; phy < PHY_MAX_ADDR; phy++)
1094 		priv->mdio->irq[phy] = PHY_POLL;
1095 
1096 	ret = mdiobus_register(priv->mdio);
1097 	if (ret) {
1098 		dev_err(&netdev->dev, "failed to register MDIO bus\n");
1099 		goto free_mdio;
1100 	}
1101 
1102 	ret = ethoc_mdio_probe(netdev);
1103 	if (ret) {
1104 		dev_err(&netdev->dev, "failed to probe MDIO bus\n");
1105 		goto error;
1106 	}
1107 
1108 	ether_setup(netdev);
1109 
1110 	/* setup the net_device structure */
1111 	netdev->netdev_ops = &ethoc_netdev_ops;
1112 	netdev->watchdog_timeo = ETHOC_TIMEOUT;
1113 	netdev->features |= 0;
1114 
1115 	/* setup NAPI */
1116 	netif_napi_add(netdev, &priv->napi, ethoc_poll, 64);
1117 
1118 	spin_lock_init(&priv->lock);
1119 
1120 	ret = register_netdev(netdev);
1121 	if (ret < 0) {
1122 		dev_err(&netdev->dev, "failed to register interface\n");
1123 		goto error2;
1124 	}
1125 
1126 	goto out;
1127 
1128 error2:
1129 	netif_napi_del(&priv->napi);
1130 error:
1131 	mdiobus_unregister(priv->mdio);
1132 free_mdio:
1133 	kfree(priv->mdio->irq);
1134 	mdiobus_free(priv->mdio);
1135 free:
1136 	free_netdev(netdev);
1137 out:
1138 	return ret;
1139 }
1140 
1141 /**
1142  * ethoc_remove - shutdown OpenCores ethernet MAC
1143  * @pdev:	platform device
1144  */
1145 static int ethoc_remove(struct platform_device *pdev)
1146 {
1147 	struct net_device *netdev = platform_get_drvdata(pdev);
1148 	struct ethoc *priv = netdev_priv(netdev);
1149 
1150 	if (netdev) {
1151 		netif_napi_del(&priv->napi);
1152 		phy_disconnect(priv->phy);
1153 		priv->phy = NULL;
1154 
1155 		if (priv->mdio) {
1156 			mdiobus_unregister(priv->mdio);
1157 			kfree(priv->mdio->irq);
1158 			mdiobus_free(priv->mdio);
1159 		}
1160 		unregister_netdev(netdev);
1161 		free_netdev(netdev);
1162 	}
1163 
1164 	return 0;
1165 }
1166 
1167 #ifdef CONFIG_PM
1168 static int ethoc_suspend(struct platform_device *pdev, pm_message_t state)
1169 {
1170 	return -ENOSYS;
1171 }
1172 
1173 static int ethoc_resume(struct platform_device *pdev)
1174 {
1175 	return -ENOSYS;
1176 }
1177 #else
1178 # define ethoc_suspend NULL
1179 # define ethoc_resume  NULL
1180 #endif
1181 
1182 static struct of_device_id ethoc_match[] = {
1183 	{ .compatible = "opencores,ethoc", },
1184 	{},
1185 };
1186 MODULE_DEVICE_TABLE(of, ethoc_match);
1187 
1188 static struct platform_driver ethoc_driver = {
1189 	.probe   = ethoc_probe,
1190 	.remove  = ethoc_remove,
1191 	.suspend = ethoc_suspend,
1192 	.resume  = ethoc_resume,
1193 	.driver  = {
1194 		.name = "ethoc",
1195 		.owner = THIS_MODULE,
1196 		.of_match_table = ethoc_match,
1197 	},
1198 };
1199 
1200 module_platform_driver(ethoc_driver);
1201 
1202 MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
1203 MODULE_DESCRIPTION("OpenCores Ethernet MAC driver");
1204 MODULE_LICENSE("GPL v2");
1205 
1206