1 /*
2  * Allwinner EMAC Fast Ethernet driver for Linux.
3  *
4  * Copyright 2012-2013 Stefan Roese <sr@denx.de>
5  * Copyright 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
6  *
7  * Based on the Linux driver provided by Allwinner:
8  * Copyright (C) 1997  Sten Wang
9  *
10  * This file is licensed under the terms of the GNU General Public
11  * License version 2. This program is licensed "as is" without any
12  * warranty of any kind, whether express or implied.
13  */
14 
15 #include <linux/clk.h>
16 #include <linux/etherdevice.h>
17 #include <linux/ethtool.h>
18 #include <linux/gpio.h>
19 #include <linux/interrupt.h>
20 #include <linux/irq.h>
21 #include <linux/mii.h>
22 #include <linux/module.h>
23 #include <linux/netdevice.h>
24 #include <linux/of_address.h>
25 #include <linux/of_irq.h>
26 #include <linux/of_mdio.h>
27 #include <linux/of_net.h>
28 #include <linux/of_platform.h>
29 #include <linux/platform_device.h>
30 #include <linux/phy.h>
31 
32 #include "sun4i-emac.h"
33 
34 #define DRV_NAME		"sun4i-emac"
35 #define DRV_VERSION		"1.02"
36 
37 #define EMAC_MAX_FRAME_LEN	0x0600
38 
39 /* Transmit timeout, default 5 seconds. */
40 static int watchdog = 5000;
41 module_param(watchdog, int, 0400);
42 MODULE_PARM_DESC(watchdog, "transmit timeout in milliseconds");
43 
44 /* EMAC register address locking.
45  *
46  * The EMAC uses an address register to control where data written
47  * to the data register goes. This means that the address register
48  * must be preserved over interrupts or similar calls.
49  *
50  * During interrupt and other critical calls, a spinlock is used to
51  * protect the system, but the calls themselves save the address
52  * in the address register in case they are interrupting another
53  * access to the device.
54  *
55  * For general accesses a lock is provided so that calls which are
56  * allowed to sleep are serialised so that the address register does
57  * not need to be saved. This lock also serves to serialise access
58  * to the EEPROM and PHY access registers which are shared between
59  * these two devices.
60  */
61 
62 /* The driver supports the original EMACE, and now the two newer
63  * devices, EMACA and EMACB.
64  */
65 
66 struct emac_board_info {
67 	struct clk		*clk;
68 	struct device		*dev;
69 	struct platform_device	*pdev;
70 	spinlock_t		lock;
71 	void __iomem		*membase;
72 	u32			msg_enable;
73 	struct net_device	*ndev;
74 	struct sk_buff		*skb_last;
75 	u16			tx_fifo_stat;
76 
77 	int			emacrx_completed_flag;
78 
79 	struct phy_device	*phy_dev;
80 	struct device_node	*phy_node;
81 	unsigned int		link;
82 	unsigned int		speed;
83 	unsigned int		duplex;
84 
85 	phy_interface_t		phy_interface;
86 };
87 
88 static void emac_update_speed(struct net_device *dev)
89 {
90 	struct emac_board_info *db = netdev_priv(dev);
91 	unsigned int reg_val;
92 
93 	/* set EMAC SPEED, depend on PHY  */
94 	reg_val = readl(db->membase + EMAC_MAC_SUPP_REG);
95 	reg_val &= ~(0x1 << 8);
96 	if (db->speed == SPEED_100)
97 		reg_val |= 1 << 8;
98 	writel(reg_val, db->membase + EMAC_MAC_SUPP_REG);
99 }
100 
101 static void emac_update_duplex(struct net_device *dev)
102 {
103 	struct emac_board_info *db = netdev_priv(dev);
104 	unsigned int reg_val;
105 
106 	/* set duplex depend on phy */
107 	reg_val = readl(db->membase + EMAC_MAC_CTL1_REG);
108 	reg_val &= ~EMAC_MAC_CTL1_DUPLEX_EN;
109 	if (db->duplex)
110 		reg_val |= EMAC_MAC_CTL1_DUPLEX_EN;
111 	writel(reg_val, db->membase + EMAC_MAC_CTL1_REG);
112 }
113 
114 static void emac_handle_link_change(struct net_device *dev)
115 {
116 	struct emac_board_info *db = netdev_priv(dev);
117 	struct phy_device *phydev = db->phy_dev;
118 	unsigned long flags;
119 	int status_change = 0;
120 
121 	if (phydev->link) {
122 		if (db->speed != phydev->speed) {
123 			spin_lock_irqsave(&db->lock, flags);
124 			db->speed = phydev->speed;
125 			emac_update_speed(dev);
126 			spin_unlock_irqrestore(&db->lock, flags);
127 			status_change = 1;
128 		}
129 
130 		if (db->duplex != phydev->duplex) {
131 			spin_lock_irqsave(&db->lock, flags);
132 			db->duplex = phydev->duplex;
133 			emac_update_duplex(dev);
134 			spin_unlock_irqrestore(&db->lock, flags);
135 			status_change = 1;
136 		}
137 	}
138 
139 	if (phydev->link != db->link) {
140 		if (!phydev->link) {
141 			db->speed = 0;
142 			db->duplex = -1;
143 		}
144 		db->link = phydev->link;
145 
146 		status_change = 1;
147 	}
148 
149 	if (status_change)
150 		phy_print_status(phydev);
151 }
152 
153 static int emac_mdio_probe(struct net_device *dev)
154 {
155 	struct emac_board_info *db = netdev_priv(dev);
156 
157 	/* to-do: PHY interrupts are currently not supported */
158 
159 	/* attach the mac to the phy */
160 	db->phy_dev = of_phy_connect(db->ndev, db->phy_node,
161 				     &emac_handle_link_change, 0,
162 				     db->phy_interface);
163 	if (!db->phy_dev) {
164 		netdev_err(db->ndev, "could not find the PHY\n");
165 		return -ENODEV;
166 	}
167 
168 	/* mask with MAC supported features */
169 	db->phy_dev->supported &= PHY_BASIC_FEATURES;
170 	db->phy_dev->advertising = db->phy_dev->supported;
171 
172 	db->link = 0;
173 	db->speed = 0;
174 	db->duplex = -1;
175 
176 	return 0;
177 }
178 
179 static void emac_mdio_remove(struct net_device *dev)
180 {
181 	struct emac_board_info *db = netdev_priv(dev);
182 
183 	phy_disconnect(db->phy_dev);
184 	db->phy_dev = NULL;
185 }
186 
187 static void emac_reset(struct emac_board_info *db)
188 {
189 	dev_dbg(db->dev, "resetting device\n");
190 
191 	/* RESET device */
192 	writel(0, db->membase + EMAC_CTL_REG);
193 	udelay(200);
194 	writel(EMAC_CTL_RESET, db->membase + EMAC_CTL_REG);
195 	udelay(200);
196 }
197 
198 static void emac_outblk_32bit(void __iomem *reg, void *data, int count)
199 {
200 	writesl(reg, data, round_up(count, 4) / 4);
201 }
202 
203 static void emac_inblk_32bit(void __iomem *reg, void *data, int count)
204 {
205 	readsl(reg, data, round_up(count, 4) / 4);
206 }
207 
208 static int emac_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
209 {
210 	struct emac_board_info *dm = netdev_priv(dev);
211 	struct phy_device *phydev = dm->phy_dev;
212 
213 	if (!netif_running(dev))
214 		return -EINVAL;
215 
216 	if (!phydev)
217 		return -ENODEV;
218 
219 	return phy_mii_ioctl(phydev, rq, cmd);
220 }
221 
222 /* ethtool ops */
223 static void emac_get_drvinfo(struct net_device *dev,
224 			      struct ethtool_drvinfo *info)
225 {
226 	strlcpy(info->driver, DRV_NAME, sizeof(DRV_NAME));
227 	strlcpy(info->version, DRV_VERSION, sizeof(DRV_VERSION));
228 	strlcpy(info->bus_info, dev_name(&dev->dev), sizeof(info->bus_info));
229 }
230 
231 static int emac_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
232 {
233 	struct emac_board_info *dm = netdev_priv(dev);
234 	struct phy_device *phydev = dm->phy_dev;
235 
236 	if (!phydev)
237 		return -ENODEV;
238 
239 	return phy_ethtool_gset(phydev, cmd);
240 }
241 
242 static int emac_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
243 {
244 	struct emac_board_info *dm = netdev_priv(dev);
245 	struct phy_device *phydev = dm->phy_dev;
246 
247 	if (!phydev)
248 		return -ENODEV;
249 
250 	return phy_ethtool_sset(phydev, cmd);
251 }
252 
253 static const struct ethtool_ops emac_ethtool_ops = {
254 	.get_drvinfo	= emac_get_drvinfo,
255 	.get_settings	= emac_get_settings,
256 	.set_settings	= emac_set_settings,
257 	.get_link	= ethtool_op_get_link,
258 };
259 
260 static unsigned int emac_setup(struct net_device *ndev)
261 {
262 	struct emac_board_info *db = netdev_priv(ndev);
263 	unsigned int reg_val;
264 
265 	/* set up TX */
266 	reg_val = readl(db->membase + EMAC_TX_MODE_REG);
267 
268 	writel(reg_val | EMAC_TX_MODE_ABORTED_FRAME_EN,
269 		db->membase + EMAC_TX_MODE_REG);
270 
271 	/* set up RX */
272 	reg_val = readl(db->membase + EMAC_RX_CTL_REG);
273 
274 	writel(reg_val | EMAC_RX_CTL_PASS_LEN_OOR_EN |
275 		EMAC_RX_CTL_ACCEPT_UNICAST_EN | EMAC_RX_CTL_DA_FILTER_EN |
276 		EMAC_RX_CTL_ACCEPT_MULTICAST_EN |
277 		EMAC_RX_CTL_ACCEPT_BROADCAST_EN,
278 		db->membase + EMAC_RX_CTL_REG);
279 
280 	/* set MAC */
281 	/* set MAC CTL0 */
282 	reg_val = readl(db->membase + EMAC_MAC_CTL0_REG);
283 	writel(reg_val | EMAC_MAC_CTL0_RX_FLOW_CTL_EN |
284 		EMAC_MAC_CTL0_TX_FLOW_CTL_EN,
285 		db->membase + EMAC_MAC_CTL0_REG);
286 
287 	/* set MAC CTL1 */
288 	reg_val = readl(db->membase + EMAC_MAC_CTL1_REG);
289 	reg_val |= EMAC_MAC_CTL1_LEN_CHECK_EN;
290 	reg_val |= EMAC_MAC_CTL1_CRC_EN;
291 	reg_val |= EMAC_MAC_CTL1_PAD_EN;
292 	writel(reg_val, db->membase + EMAC_MAC_CTL1_REG);
293 
294 	/* set up IPGT */
295 	writel(EMAC_MAC_IPGT_FULL_DUPLEX, db->membase + EMAC_MAC_IPGT_REG);
296 
297 	/* set up IPGR */
298 	writel((EMAC_MAC_IPGR_IPG1 << 8) | EMAC_MAC_IPGR_IPG2,
299 		db->membase + EMAC_MAC_IPGR_REG);
300 
301 	/* set up Collison window */
302 	writel((EMAC_MAC_CLRT_COLLISION_WINDOW << 8) | EMAC_MAC_CLRT_RM,
303 		db->membase + EMAC_MAC_CLRT_REG);
304 
305 	/* set up Max Frame Length */
306 	writel(EMAC_MAX_FRAME_LEN,
307 		db->membase + EMAC_MAC_MAXF_REG);
308 
309 	return 0;
310 }
311 
312 static unsigned int emac_powerup(struct net_device *ndev)
313 {
314 	struct emac_board_info *db = netdev_priv(ndev);
315 	unsigned int reg_val;
316 
317 	/* initial EMAC */
318 	/* flush RX FIFO */
319 	reg_val = readl(db->membase + EMAC_RX_CTL_REG);
320 	reg_val |= 0x8;
321 	writel(reg_val, db->membase + EMAC_RX_CTL_REG);
322 	udelay(1);
323 
324 	/* initial MAC */
325 	/* soft reset MAC */
326 	reg_val = readl(db->membase + EMAC_MAC_CTL0_REG);
327 	reg_val &= ~EMAC_MAC_CTL0_SOFT_RESET;
328 	writel(reg_val, db->membase + EMAC_MAC_CTL0_REG);
329 
330 	/* set MII clock */
331 	reg_val = readl(db->membase + EMAC_MAC_MCFG_REG);
332 	reg_val &= (~(0xf << 2));
333 	reg_val |= (0xD << 2);
334 	writel(reg_val, db->membase + EMAC_MAC_MCFG_REG);
335 
336 	/* clear RX counter */
337 	writel(0x0, db->membase + EMAC_RX_FBC_REG);
338 
339 	/* disable all interrupt and clear interrupt status */
340 	writel(0, db->membase + EMAC_INT_CTL_REG);
341 	reg_val = readl(db->membase + EMAC_INT_STA_REG);
342 	writel(reg_val, db->membase + EMAC_INT_STA_REG);
343 
344 	udelay(1);
345 
346 	/* set up EMAC */
347 	emac_setup(ndev);
348 
349 	/* set mac_address to chip */
350 	writel(ndev->dev_addr[0] << 16 | ndev->dev_addr[1] << 8 | ndev->
351 	       dev_addr[2], db->membase + EMAC_MAC_A1_REG);
352 	writel(ndev->dev_addr[3] << 16 | ndev->dev_addr[4] << 8 | ndev->
353 	       dev_addr[5], db->membase + EMAC_MAC_A0_REG);
354 
355 	mdelay(1);
356 
357 	return 0;
358 }
359 
360 static int emac_set_mac_address(struct net_device *dev, void *p)
361 {
362 	struct sockaddr *addr = p;
363 	struct emac_board_info *db = netdev_priv(dev);
364 
365 	if (netif_running(dev))
366 		return -EBUSY;
367 
368 	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
369 
370 	writel(dev->dev_addr[0] << 16 | dev->dev_addr[1] << 8 | dev->
371 	       dev_addr[2], db->membase + EMAC_MAC_A1_REG);
372 	writel(dev->dev_addr[3] << 16 | dev->dev_addr[4] << 8 | dev->
373 	       dev_addr[5], db->membase + EMAC_MAC_A0_REG);
374 
375 	return 0;
376 }
377 
378 /* Initialize emac board */
379 static void emac_init_device(struct net_device *dev)
380 {
381 	struct emac_board_info *db = netdev_priv(dev);
382 	unsigned long flags;
383 	unsigned int reg_val;
384 
385 	spin_lock_irqsave(&db->lock, flags);
386 
387 	emac_update_speed(dev);
388 	emac_update_duplex(dev);
389 
390 	/* enable RX/TX */
391 	reg_val = readl(db->membase + EMAC_CTL_REG);
392 	writel(reg_val | EMAC_CTL_RESET | EMAC_CTL_TX_EN | EMAC_CTL_RX_EN,
393 		db->membase + EMAC_CTL_REG);
394 
395 	/* enable RX/TX0/RX Hlevel interrup */
396 	reg_val = readl(db->membase + EMAC_INT_CTL_REG);
397 	reg_val |= (0xf << 0) | (0x01 << 8);
398 	writel(reg_val, db->membase + EMAC_INT_CTL_REG);
399 
400 	spin_unlock_irqrestore(&db->lock, flags);
401 }
402 
403 /* Our watchdog timed out. Called by the networking layer */
404 static void emac_timeout(struct net_device *dev)
405 {
406 	struct emac_board_info *db = netdev_priv(dev);
407 	unsigned long flags;
408 
409 	if (netif_msg_timer(db))
410 		dev_err(db->dev, "tx time out.\n");
411 
412 	/* Save previous register address */
413 	spin_lock_irqsave(&db->lock, flags);
414 
415 	netif_stop_queue(dev);
416 	emac_reset(db);
417 	emac_init_device(dev);
418 	/* We can accept TX packets again */
419 	dev->trans_start = jiffies;
420 	netif_wake_queue(dev);
421 
422 	/* Restore previous register address */
423 	spin_unlock_irqrestore(&db->lock, flags);
424 }
425 
426 /* Hardware start transmission.
427  * Send a packet to media from the upper layer.
428  */
429 static int emac_start_xmit(struct sk_buff *skb, struct net_device *dev)
430 {
431 	struct emac_board_info *db = netdev_priv(dev);
432 	unsigned long channel;
433 	unsigned long flags;
434 
435 	channel = db->tx_fifo_stat & 3;
436 	if (channel == 3)
437 		return 1;
438 
439 	channel = (channel == 1 ? 1 : 0);
440 
441 	spin_lock_irqsave(&db->lock, flags);
442 
443 	writel(channel, db->membase + EMAC_TX_INS_REG);
444 
445 	emac_outblk_32bit(db->membase + EMAC_TX_IO_DATA_REG,
446 			skb->data, skb->len);
447 	dev->stats.tx_bytes += skb->len;
448 
449 	db->tx_fifo_stat |= 1 << channel;
450 	/* TX control: First packet immediately send, second packet queue */
451 	if (channel == 0) {
452 		/* set TX len */
453 		writel(skb->len, db->membase + EMAC_TX_PL0_REG);
454 		/* start translate from fifo to phy */
455 		writel(readl(db->membase + EMAC_TX_CTL0_REG) | 1,
456 		       db->membase + EMAC_TX_CTL0_REG);
457 
458 		/* save the time stamp */
459 		dev->trans_start = jiffies;
460 	} else if (channel == 1) {
461 		/* set TX len */
462 		writel(skb->len, db->membase + EMAC_TX_PL1_REG);
463 		/* start translate from fifo to phy */
464 		writel(readl(db->membase + EMAC_TX_CTL1_REG) | 1,
465 		       db->membase + EMAC_TX_CTL1_REG);
466 
467 		/* save the time stamp */
468 		dev->trans_start = jiffies;
469 	}
470 
471 	if ((db->tx_fifo_stat & 3) == 3) {
472 		/* Second packet */
473 		netif_stop_queue(dev);
474 	}
475 
476 	spin_unlock_irqrestore(&db->lock, flags);
477 
478 	/* free this SKB */
479 	dev_kfree_skb(skb);
480 
481 	return NETDEV_TX_OK;
482 }
483 
484 /* EMAC interrupt handler
485  * receive the packet to upper layer, free the transmitted packet
486  */
487 static void emac_tx_done(struct net_device *dev, struct emac_board_info *db,
488 			  unsigned int tx_status)
489 {
490 	/* One packet sent complete */
491 	db->tx_fifo_stat &= ~(tx_status & 3);
492 	if (3 == (tx_status & 3))
493 		dev->stats.tx_packets += 2;
494 	else
495 		dev->stats.tx_packets++;
496 
497 	if (netif_msg_tx_done(db))
498 		dev_dbg(db->dev, "tx done, NSR %02x\n", tx_status);
499 
500 	netif_wake_queue(dev);
501 }
502 
503 /* Received a packet and pass to upper layer
504  */
505 static void emac_rx(struct net_device *dev)
506 {
507 	struct emac_board_info *db = netdev_priv(dev);
508 	struct sk_buff *skb;
509 	u8 *rdptr;
510 	bool good_packet;
511 	static int rxlen_last;
512 	unsigned int reg_val;
513 	u32 rxhdr, rxstatus, rxcount, rxlen;
514 
515 	/* Check packet ready or not */
516 	while (1) {
517 		/* race warning: the first packet might arrive with
518 		 * the interrupts disabled, but the second will fix
519 		 * it
520 		 */
521 		rxcount = readl(db->membase + EMAC_RX_FBC_REG);
522 
523 		if (netif_msg_rx_status(db))
524 			dev_dbg(db->dev, "RXCount: %x\n", rxcount);
525 
526 		if ((db->skb_last != NULL) && (rxlen_last > 0)) {
527 			dev->stats.rx_bytes += rxlen_last;
528 
529 			/* Pass to upper layer */
530 			db->skb_last->protocol = eth_type_trans(db->skb_last,
531 								dev);
532 			netif_rx(db->skb_last);
533 			dev->stats.rx_packets++;
534 			db->skb_last = NULL;
535 			rxlen_last = 0;
536 
537 			reg_val = readl(db->membase + EMAC_RX_CTL_REG);
538 			reg_val &= ~EMAC_RX_CTL_DMA_EN;
539 			writel(reg_val, db->membase + EMAC_RX_CTL_REG);
540 		}
541 
542 		if (!rxcount) {
543 			db->emacrx_completed_flag = 1;
544 			reg_val = readl(db->membase + EMAC_INT_CTL_REG);
545 			reg_val |= (0xf << 0) | (0x01 << 8);
546 			writel(reg_val, db->membase + EMAC_INT_CTL_REG);
547 
548 			/* had one stuck? */
549 			rxcount = readl(db->membase + EMAC_RX_FBC_REG);
550 			if (!rxcount)
551 				return;
552 		}
553 
554 		reg_val = readl(db->membase + EMAC_RX_IO_DATA_REG);
555 		if (netif_msg_rx_status(db))
556 			dev_dbg(db->dev, "receive header: %x\n", reg_val);
557 		if (reg_val != EMAC_UNDOCUMENTED_MAGIC) {
558 			/* disable RX */
559 			reg_val = readl(db->membase + EMAC_CTL_REG);
560 			writel(reg_val & ~EMAC_CTL_RX_EN,
561 			       db->membase + EMAC_CTL_REG);
562 
563 			/* Flush RX FIFO */
564 			reg_val = readl(db->membase + EMAC_RX_CTL_REG);
565 			writel(reg_val | (1 << 3),
566 			       db->membase + EMAC_RX_CTL_REG);
567 
568 			do {
569 				reg_val = readl(db->membase + EMAC_RX_CTL_REG);
570 			} while (reg_val & (1 << 3));
571 
572 			/* enable RX */
573 			reg_val = readl(db->membase + EMAC_CTL_REG);
574 			writel(reg_val | EMAC_CTL_RX_EN,
575 			       db->membase + EMAC_CTL_REG);
576 			reg_val = readl(db->membase + EMAC_INT_CTL_REG);
577 			reg_val |= (0xf << 0) | (0x01 << 8);
578 			writel(reg_val, db->membase + EMAC_INT_CTL_REG);
579 
580 			db->emacrx_completed_flag = 1;
581 
582 			return;
583 		}
584 
585 		/* A packet ready now  & Get status/length */
586 		good_packet = true;
587 
588 		emac_inblk_32bit(db->membase + EMAC_RX_IO_DATA_REG,
589 				&rxhdr, sizeof(rxhdr));
590 
591 		if (netif_msg_rx_status(db))
592 			dev_dbg(db->dev, "rxhdr: %x\n", *((int *)(&rxhdr)));
593 
594 		rxlen = EMAC_RX_IO_DATA_LEN(rxhdr);
595 		rxstatus = EMAC_RX_IO_DATA_STATUS(rxhdr);
596 
597 		if (netif_msg_rx_status(db))
598 			dev_dbg(db->dev, "RX: status %02x, length %04x\n",
599 				rxstatus, rxlen);
600 
601 		/* Packet Status check */
602 		if (rxlen < 0x40) {
603 			good_packet = false;
604 			if (netif_msg_rx_err(db))
605 				dev_dbg(db->dev, "RX: Bad Packet (runt)\n");
606 		}
607 
608 		if (unlikely(!(rxstatus & EMAC_RX_IO_DATA_STATUS_OK))) {
609 			good_packet = false;
610 
611 			if (rxstatus & EMAC_RX_IO_DATA_STATUS_CRC_ERR) {
612 				if (netif_msg_rx_err(db))
613 					dev_dbg(db->dev, "crc error\n");
614 				dev->stats.rx_crc_errors++;
615 			}
616 
617 			if (rxstatus & EMAC_RX_IO_DATA_STATUS_LEN_ERR) {
618 				if (netif_msg_rx_err(db))
619 					dev_dbg(db->dev, "length error\n");
620 				dev->stats.rx_length_errors++;
621 			}
622 		}
623 
624 		/* Move data from EMAC */
625 		skb = dev_alloc_skb(rxlen + 4);
626 		if (good_packet && skb) {
627 			skb_reserve(skb, 2);
628 			rdptr = (u8 *) skb_put(skb, rxlen - 4);
629 
630 			/* Read received packet from RX SRAM */
631 			if (netif_msg_rx_status(db))
632 				dev_dbg(db->dev, "RxLen %x\n", rxlen);
633 
634 			emac_inblk_32bit(db->membase + EMAC_RX_IO_DATA_REG,
635 					rdptr, rxlen);
636 			dev->stats.rx_bytes += rxlen;
637 
638 			/* Pass to upper layer */
639 			skb->protocol = eth_type_trans(skb, dev);
640 			netif_rx(skb);
641 			dev->stats.rx_packets++;
642 		}
643 	}
644 }
645 
646 static irqreturn_t emac_interrupt(int irq, void *dev_id)
647 {
648 	struct net_device *dev = dev_id;
649 	struct emac_board_info *db = netdev_priv(dev);
650 	int int_status;
651 	unsigned long flags;
652 	unsigned int reg_val;
653 
654 	/* A real interrupt coming */
655 
656 	/* holders of db->lock must always block IRQs */
657 	spin_lock_irqsave(&db->lock, flags);
658 
659 	/* Disable all interrupts */
660 	writel(0, db->membase + EMAC_INT_CTL_REG);
661 
662 	/* Got EMAC interrupt status */
663 	/* Got ISR */
664 	int_status = readl(db->membase + EMAC_INT_STA_REG);
665 	/* Clear ISR status */
666 	writel(int_status, db->membase + EMAC_INT_STA_REG);
667 
668 	if (netif_msg_intr(db))
669 		dev_dbg(db->dev, "emac interrupt %02x\n", int_status);
670 
671 	/* Received the coming packet */
672 	if ((int_status & 0x100) && (db->emacrx_completed_flag == 1)) {
673 		/* carrier lost */
674 		db->emacrx_completed_flag = 0;
675 		emac_rx(dev);
676 	}
677 
678 	/* Transmit Interrupt check */
679 	if (int_status & (0x01 | 0x02))
680 		emac_tx_done(dev, db, int_status);
681 
682 	if (int_status & (0x04 | 0x08))
683 		netdev_info(dev, " ab : %x\n", int_status);
684 
685 	/* Re-enable interrupt mask */
686 	if (db->emacrx_completed_flag == 1) {
687 		reg_val = readl(db->membase + EMAC_INT_CTL_REG);
688 		reg_val |= (0xf << 0) | (0x01 << 8);
689 		writel(reg_val, db->membase + EMAC_INT_CTL_REG);
690 	}
691 	spin_unlock_irqrestore(&db->lock, flags);
692 
693 	return IRQ_HANDLED;
694 }
695 
696 #ifdef CONFIG_NET_POLL_CONTROLLER
697 /*
698  * Used by netconsole
699  */
700 static void emac_poll_controller(struct net_device *dev)
701 {
702 	disable_irq(dev->irq);
703 	emac_interrupt(dev->irq, dev);
704 	enable_irq(dev->irq);
705 }
706 #endif
707 
708 /*  Open the interface.
709  *  The interface is opened whenever "ifconfig" actives it.
710  */
711 static int emac_open(struct net_device *dev)
712 {
713 	struct emac_board_info *db = netdev_priv(dev);
714 	int ret;
715 
716 	if (netif_msg_ifup(db))
717 		dev_dbg(db->dev, "enabling %s\n", dev->name);
718 
719 	if (request_irq(dev->irq, &emac_interrupt, 0, dev->name, dev))
720 		return -EAGAIN;
721 
722 	/* Initialize EMAC board */
723 	emac_reset(db);
724 	emac_init_device(dev);
725 
726 	ret = emac_mdio_probe(dev);
727 	if (ret < 0) {
728 		netdev_err(dev, "cannot probe MDIO bus\n");
729 		return ret;
730 	}
731 
732 	phy_start(db->phy_dev);
733 	netif_start_queue(dev);
734 
735 	return 0;
736 }
737 
738 static void emac_shutdown(struct net_device *dev)
739 {
740 	unsigned int reg_val;
741 	struct emac_board_info *db = netdev_priv(dev);
742 
743 	/* Disable all interrupt */
744 	writel(0, db->membase + EMAC_INT_CTL_REG);
745 
746 	/* clear interupt status */
747 	reg_val = readl(db->membase + EMAC_INT_STA_REG);
748 	writel(reg_val, db->membase + EMAC_INT_STA_REG);
749 
750 	/* Disable RX/TX */
751 	reg_val = readl(db->membase + EMAC_CTL_REG);
752 	reg_val &= ~(EMAC_CTL_TX_EN | EMAC_CTL_RX_EN | EMAC_CTL_RESET);
753 	writel(reg_val, db->membase + EMAC_CTL_REG);
754 }
755 
756 /* Stop the interface.
757  * The interface is stopped when it is brought.
758  */
759 static int emac_stop(struct net_device *ndev)
760 {
761 	struct emac_board_info *db = netdev_priv(ndev);
762 
763 	if (netif_msg_ifdown(db))
764 		dev_dbg(db->dev, "shutting down %s\n", ndev->name);
765 
766 	netif_stop_queue(ndev);
767 	netif_carrier_off(ndev);
768 
769 	phy_stop(db->phy_dev);
770 
771 	emac_mdio_remove(ndev);
772 
773 	emac_shutdown(ndev);
774 
775 	free_irq(ndev->irq, ndev);
776 
777 	return 0;
778 }
779 
780 static const struct net_device_ops emac_netdev_ops = {
781 	.ndo_open		= emac_open,
782 	.ndo_stop		= emac_stop,
783 	.ndo_start_xmit		= emac_start_xmit,
784 	.ndo_tx_timeout		= emac_timeout,
785 	.ndo_do_ioctl		= emac_ioctl,
786 	.ndo_change_mtu		= eth_change_mtu,
787 	.ndo_validate_addr	= eth_validate_addr,
788 	.ndo_set_mac_address	= emac_set_mac_address,
789 #ifdef CONFIG_NET_POLL_CONTROLLER
790 	.ndo_poll_controller	= emac_poll_controller,
791 #endif
792 };
793 
794 /* Search EMAC board, allocate space and register it
795  */
796 static int emac_probe(struct platform_device *pdev)
797 {
798 	struct device_node *np = pdev->dev.of_node;
799 	struct emac_board_info *db;
800 	struct net_device *ndev;
801 	int ret = 0;
802 	const char *mac_addr;
803 
804 	ndev = alloc_etherdev(sizeof(struct emac_board_info));
805 	if (!ndev) {
806 		dev_err(&pdev->dev, "could not allocate device.\n");
807 		return -ENOMEM;
808 	}
809 
810 	SET_NETDEV_DEV(ndev, &pdev->dev);
811 
812 	db = netdev_priv(ndev);
813 	memset(db, 0, sizeof(*db));
814 
815 	db->dev = &pdev->dev;
816 	db->ndev = ndev;
817 	db->pdev = pdev;
818 
819 	spin_lock_init(&db->lock);
820 
821 	db->membase = of_iomap(np, 0);
822 	if (!db->membase) {
823 		dev_err(&pdev->dev, "failed to remap registers\n");
824 		ret = -ENOMEM;
825 		goto out;
826 	}
827 
828 	/* fill in parameters for net-dev structure */
829 	ndev->base_addr = (unsigned long)db->membase;
830 	ndev->irq = irq_of_parse_and_map(np, 0);
831 	if (ndev->irq == -ENXIO) {
832 		netdev_err(ndev, "No irq resource\n");
833 		ret = ndev->irq;
834 		goto out;
835 	}
836 
837 	db->clk = devm_clk_get(&pdev->dev, NULL);
838 	if (IS_ERR(db->clk))
839 		goto out;
840 
841 	clk_prepare_enable(db->clk);
842 
843 	db->phy_node = of_parse_phandle(np, "phy", 0);
844 	if (!db->phy_node) {
845 		dev_err(&pdev->dev, "no associated PHY\n");
846 		ret = -ENODEV;
847 		goto out;
848 	}
849 
850 	/* Read MAC-address from DT */
851 	mac_addr = of_get_mac_address(np);
852 	if (mac_addr)
853 		memcpy(ndev->dev_addr, mac_addr, ETH_ALEN);
854 
855 	/* Check if the MAC address is valid, if not get a random one */
856 	if (!is_valid_ether_addr(ndev->dev_addr)) {
857 		eth_hw_addr_random(ndev);
858 		dev_warn(&pdev->dev, "using random MAC address %pM\n",
859 			 ndev->dev_addr);
860 	}
861 
862 	db->emacrx_completed_flag = 1;
863 	emac_powerup(ndev);
864 	emac_reset(db);
865 
866 	ether_setup(ndev);
867 
868 	ndev->netdev_ops = &emac_netdev_ops;
869 	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
870 	ndev->ethtool_ops = &emac_ethtool_ops;
871 
872 	platform_set_drvdata(pdev, ndev);
873 
874 	/* Carrier starts down, phylib will bring it up */
875 	netif_carrier_off(ndev);
876 
877 	ret = register_netdev(ndev);
878 	if (ret) {
879 		dev_err(&pdev->dev, "Registering netdev failed!\n");
880 		ret = -ENODEV;
881 		goto out;
882 	}
883 
884 	dev_info(&pdev->dev, "%s: at %p, IRQ %d MAC: %pM\n",
885 		 ndev->name, db->membase, ndev->irq, ndev->dev_addr);
886 
887 	return 0;
888 
889 out:
890 	dev_err(db->dev, "not found (%d).\n", ret);
891 
892 	free_netdev(ndev);
893 
894 	return ret;
895 }
896 
897 static int emac_remove(struct platform_device *pdev)
898 {
899 	struct net_device *ndev = platform_get_drvdata(pdev);
900 
901 	unregister_netdev(ndev);
902 	free_netdev(ndev);
903 
904 	dev_dbg(&pdev->dev, "released and freed device\n");
905 	return 0;
906 }
907 
908 static int emac_suspend(struct platform_device *dev, pm_message_t state)
909 {
910 	struct net_device *ndev = platform_get_drvdata(dev);
911 
912 	netif_carrier_off(ndev);
913 	netif_device_detach(ndev);
914 	emac_shutdown(ndev);
915 
916 	return 0;
917 }
918 
919 static int emac_resume(struct platform_device *dev)
920 {
921 	struct net_device *ndev = platform_get_drvdata(dev);
922 	struct emac_board_info *db = netdev_priv(ndev);
923 
924 	emac_reset(db);
925 	emac_init_device(ndev);
926 	netif_device_attach(ndev);
927 
928 	return 0;
929 }
930 
931 static const struct of_device_id emac_of_match[] = {
932 	{.compatible = "allwinner,sun4i-emac",},
933 	{},
934 };
935 
936 MODULE_DEVICE_TABLE(of, emac_of_match);
937 
938 static struct platform_driver emac_driver = {
939 	.driver = {
940 		.name = "sun4i-emac",
941 		.of_match_table = emac_of_match,
942 	},
943 	.probe = emac_probe,
944 	.remove = emac_remove,
945 	.suspend = emac_suspend,
946 	.resume = emac_resume,
947 };
948 
949 module_platform_driver(emac_driver);
950 
951 MODULE_AUTHOR("Stefan Roese <sr@denx.de>");
952 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
953 MODULE_DESCRIPTION("Allwinner A10 emac network driver");
954 MODULE_LICENSE("GPL");
955