xref: /linux/drivers/net/ethernet/allwinner/sun4i-emac.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
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 MAC */
272 	/* set MAC CTL0 */
273 	reg_val = readl(db->membase + EMAC_MAC_CTL0_REG);
274 	writel(reg_val | EMAC_MAC_CTL0_RX_FLOW_CTL_EN |
275 		EMAC_MAC_CTL0_TX_FLOW_CTL_EN,
276 		db->membase + EMAC_MAC_CTL0_REG);
277 
278 	/* set MAC CTL1 */
279 	reg_val = readl(db->membase + EMAC_MAC_CTL1_REG);
280 	reg_val |= EMAC_MAC_CTL1_LEN_CHECK_EN;
281 	reg_val |= EMAC_MAC_CTL1_CRC_EN;
282 	reg_val |= EMAC_MAC_CTL1_PAD_EN;
283 	writel(reg_val, db->membase + EMAC_MAC_CTL1_REG);
284 
285 	/* set up IPGT */
286 	writel(EMAC_MAC_IPGT_FULL_DUPLEX, db->membase + EMAC_MAC_IPGT_REG);
287 
288 	/* set up IPGR */
289 	writel((EMAC_MAC_IPGR_IPG1 << 8) | EMAC_MAC_IPGR_IPG2,
290 		db->membase + EMAC_MAC_IPGR_REG);
291 
292 	/* set up Collison window */
293 	writel((EMAC_MAC_CLRT_COLLISION_WINDOW << 8) | EMAC_MAC_CLRT_RM,
294 		db->membase + EMAC_MAC_CLRT_REG);
295 
296 	/* set up Max Frame Length */
297 	writel(EMAC_MAX_FRAME_LEN,
298 		db->membase + EMAC_MAC_MAXF_REG);
299 
300 	return 0;
301 }
302 
303 static void emac_set_rx_mode(struct net_device *ndev)
304 {
305 	struct emac_board_info *db = netdev_priv(ndev);
306 	unsigned int reg_val;
307 
308 	/* set up RX */
309 	reg_val = readl(db->membase + EMAC_RX_CTL_REG);
310 
311 	if (ndev->flags & IFF_PROMISC)
312 		reg_val |= EMAC_RX_CTL_PASS_ALL_EN;
313 	else
314 		reg_val &= ~EMAC_RX_CTL_PASS_ALL_EN;
315 
316 	writel(reg_val | EMAC_RX_CTL_PASS_LEN_OOR_EN |
317 		EMAC_RX_CTL_ACCEPT_UNICAST_EN | EMAC_RX_CTL_DA_FILTER_EN |
318 		EMAC_RX_CTL_ACCEPT_MULTICAST_EN |
319 		EMAC_RX_CTL_ACCEPT_BROADCAST_EN,
320 		db->membase + EMAC_RX_CTL_REG);
321 }
322 
323 static unsigned int emac_powerup(struct net_device *ndev)
324 {
325 	struct emac_board_info *db = netdev_priv(ndev);
326 	unsigned int reg_val;
327 
328 	/* initial EMAC */
329 	/* flush RX FIFO */
330 	reg_val = readl(db->membase + EMAC_RX_CTL_REG);
331 	reg_val |= 0x8;
332 	writel(reg_val, db->membase + EMAC_RX_CTL_REG);
333 	udelay(1);
334 
335 	/* initial MAC */
336 	/* soft reset MAC */
337 	reg_val = readl(db->membase + EMAC_MAC_CTL0_REG);
338 	reg_val &= ~EMAC_MAC_CTL0_SOFT_RESET;
339 	writel(reg_val, db->membase + EMAC_MAC_CTL0_REG);
340 
341 	/* set MII clock */
342 	reg_val = readl(db->membase + EMAC_MAC_MCFG_REG);
343 	reg_val &= (~(0xf << 2));
344 	reg_val |= (0xD << 2);
345 	writel(reg_val, db->membase + EMAC_MAC_MCFG_REG);
346 
347 	/* clear RX counter */
348 	writel(0x0, db->membase + EMAC_RX_FBC_REG);
349 
350 	/* disable all interrupt and clear interrupt status */
351 	writel(0, db->membase + EMAC_INT_CTL_REG);
352 	reg_val = readl(db->membase + EMAC_INT_STA_REG);
353 	writel(reg_val, db->membase + EMAC_INT_STA_REG);
354 
355 	udelay(1);
356 
357 	/* set up EMAC */
358 	emac_setup(ndev);
359 
360 	/* set mac_address to chip */
361 	writel(ndev->dev_addr[0] << 16 | ndev->dev_addr[1] << 8 | ndev->
362 	       dev_addr[2], db->membase + EMAC_MAC_A1_REG);
363 	writel(ndev->dev_addr[3] << 16 | ndev->dev_addr[4] << 8 | ndev->
364 	       dev_addr[5], db->membase + EMAC_MAC_A0_REG);
365 
366 	mdelay(1);
367 
368 	return 0;
369 }
370 
371 static int emac_set_mac_address(struct net_device *dev, void *p)
372 {
373 	struct sockaddr *addr = p;
374 	struct emac_board_info *db = netdev_priv(dev);
375 
376 	if (netif_running(dev))
377 		return -EBUSY;
378 
379 	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
380 
381 	writel(dev->dev_addr[0] << 16 | dev->dev_addr[1] << 8 | dev->
382 	       dev_addr[2], db->membase + EMAC_MAC_A1_REG);
383 	writel(dev->dev_addr[3] << 16 | dev->dev_addr[4] << 8 | dev->
384 	       dev_addr[5], db->membase + EMAC_MAC_A0_REG);
385 
386 	return 0;
387 }
388 
389 /* Initialize emac board */
390 static void emac_init_device(struct net_device *dev)
391 {
392 	struct emac_board_info *db = netdev_priv(dev);
393 	unsigned long flags;
394 	unsigned int reg_val;
395 
396 	spin_lock_irqsave(&db->lock, flags);
397 
398 	emac_update_speed(dev);
399 	emac_update_duplex(dev);
400 
401 	/* enable RX/TX */
402 	reg_val = readl(db->membase + EMAC_CTL_REG);
403 	writel(reg_val | EMAC_CTL_RESET | EMAC_CTL_TX_EN | EMAC_CTL_RX_EN,
404 		db->membase + EMAC_CTL_REG);
405 
406 	/* enable RX/TX0/RX Hlevel interrup */
407 	reg_val = readl(db->membase + EMAC_INT_CTL_REG);
408 	reg_val |= (0xf << 0) | (0x01 << 8);
409 	writel(reg_val, db->membase + EMAC_INT_CTL_REG);
410 
411 	spin_unlock_irqrestore(&db->lock, flags);
412 }
413 
414 /* Our watchdog timed out. Called by the networking layer */
415 static void emac_timeout(struct net_device *dev)
416 {
417 	struct emac_board_info *db = netdev_priv(dev);
418 	unsigned long flags;
419 
420 	if (netif_msg_timer(db))
421 		dev_err(db->dev, "tx time out.\n");
422 
423 	/* Save previous register address */
424 	spin_lock_irqsave(&db->lock, flags);
425 
426 	netif_stop_queue(dev);
427 	emac_reset(db);
428 	emac_init_device(dev);
429 	/* We can accept TX packets again */
430 	dev->trans_start = jiffies;
431 	netif_wake_queue(dev);
432 
433 	/* Restore previous register address */
434 	spin_unlock_irqrestore(&db->lock, flags);
435 }
436 
437 /* Hardware start transmission.
438  * Send a packet to media from the upper layer.
439  */
440 static int emac_start_xmit(struct sk_buff *skb, struct net_device *dev)
441 {
442 	struct emac_board_info *db = netdev_priv(dev);
443 	unsigned long channel;
444 	unsigned long flags;
445 
446 	channel = db->tx_fifo_stat & 3;
447 	if (channel == 3)
448 		return 1;
449 
450 	channel = (channel == 1 ? 1 : 0);
451 
452 	spin_lock_irqsave(&db->lock, flags);
453 
454 	writel(channel, db->membase + EMAC_TX_INS_REG);
455 
456 	emac_outblk_32bit(db->membase + EMAC_TX_IO_DATA_REG,
457 			skb->data, skb->len);
458 	dev->stats.tx_bytes += skb->len;
459 
460 	db->tx_fifo_stat |= 1 << channel;
461 	/* TX control: First packet immediately send, second packet queue */
462 	if (channel == 0) {
463 		/* set TX len */
464 		writel(skb->len, db->membase + EMAC_TX_PL0_REG);
465 		/* start translate from fifo to phy */
466 		writel(readl(db->membase + EMAC_TX_CTL0_REG) | 1,
467 		       db->membase + EMAC_TX_CTL0_REG);
468 
469 		/* save the time stamp */
470 		dev->trans_start = jiffies;
471 	} else if (channel == 1) {
472 		/* set TX len */
473 		writel(skb->len, db->membase + EMAC_TX_PL1_REG);
474 		/* start translate from fifo to phy */
475 		writel(readl(db->membase + EMAC_TX_CTL1_REG) | 1,
476 		       db->membase + EMAC_TX_CTL1_REG);
477 
478 		/* save the time stamp */
479 		dev->trans_start = jiffies;
480 	}
481 
482 	if ((db->tx_fifo_stat & 3) == 3) {
483 		/* Second packet */
484 		netif_stop_queue(dev);
485 	}
486 
487 	spin_unlock_irqrestore(&db->lock, flags);
488 
489 	/* free this SKB */
490 	dev_consume_skb_any(skb);
491 
492 	return NETDEV_TX_OK;
493 }
494 
495 /* EMAC interrupt handler
496  * receive the packet to upper layer, free the transmitted packet
497  */
498 static void emac_tx_done(struct net_device *dev, struct emac_board_info *db,
499 			  unsigned int tx_status)
500 {
501 	/* One packet sent complete */
502 	db->tx_fifo_stat &= ~(tx_status & 3);
503 	if (3 == (tx_status & 3))
504 		dev->stats.tx_packets += 2;
505 	else
506 		dev->stats.tx_packets++;
507 
508 	if (netif_msg_tx_done(db))
509 		dev_dbg(db->dev, "tx done, NSR %02x\n", tx_status);
510 
511 	netif_wake_queue(dev);
512 }
513 
514 /* Received a packet and pass to upper layer
515  */
516 static void emac_rx(struct net_device *dev)
517 {
518 	struct emac_board_info *db = netdev_priv(dev);
519 	struct sk_buff *skb;
520 	u8 *rdptr;
521 	bool good_packet;
522 	static int rxlen_last;
523 	unsigned int reg_val;
524 	u32 rxhdr, rxstatus, rxcount, rxlen;
525 
526 	/* Check packet ready or not */
527 	while (1) {
528 		/* race warning: the first packet might arrive with
529 		 * the interrupts disabled, but the second will fix
530 		 * it
531 		 */
532 		rxcount = readl(db->membase + EMAC_RX_FBC_REG);
533 
534 		if (netif_msg_rx_status(db))
535 			dev_dbg(db->dev, "RXCount: %x\n", rxcount);
536 
537 		if ((db->skb_last != NULL) && (rxlen_last > 0)) {
538 			dev->stats.rx_bytes += rxlen_last;
539 
540 			/* Pass to upper layer */
541 			db->skb_last->protocol = eth_type_trans(db->skb_last,
542 								dev);
543 			netif_rx(db->skb_last);
544 			dev->stats.rx_packets++;
545 			db->skb_last = NULL;
546 			rxlen_last = 0;
547 
548 			reg_val = readl(db->membase + EMAC_RX_CTL_REG);
549 			reg_val &= ~EMAC_RX_CTL_DMA_EN;
550 			writel(reg_val, db->membase + EMAC_RX_CTL_REG);
551 		}
552 
553 		if (!rxcount) {
554 			db->emacrx_completed_flag = 1;
555 			reg_val = readl(db->membase + EMAC_INT_CTL_REG);
556 			reg_val |= (0xf << 0) | (0x01 << 8);
557 			writel(reg_val, db->membase + EMAC_INT_CTL_REG);
558 
559 			/* had one stuck? */
560 			rxcount = readl(db->membase + EMAC_RX_FBC_REG);
561 			if (!rxcount)
562 				return;
563 		}
564 
565 		reg_val = readl(db->membase + EMAC_RX_IO_DATA_REG);
566 		if (netif_msg_rx_status(db))
567 			dev_dbg(db->dev, "receive header: %x\n", reg_val);
568 		if (reg_val != EMAC_UNDOCUMENTED_MAGIC) {
569 			/* disable RX */
570 			reg_val = readl(db->membase + EMAC_CTL_REG);
571 			writel(reg_val & ~EMAC_CTL_RX_EN,
572 			       db->membase + EMAC_CTL_REG);
573 
574 			/* Flush RX FIFO */
575 			reg_val = readl(db->membase + EMAC_RX_CTL_REG);
576 			writel(reg_val | (1 << 3),
577 			       db->membase + EMAC_RX_CTL_REG);
578 
579 			do {
580 				reg_val = readl(db->membase + EMAC_RX_CTL_REG);
581 			} while (reg_val & (1 << 3));
582 
583 			/* enable RX */
584 			reg_val = readl(db->membase + EMAC_CTL_REG);
585 			writel(reg_val | EMAC_CTL_RX_EN,
586 			       db->membase + EMAC_CTL_REG);
587 			reg_val = readl(db->membase + EMAC_INT_CTL_REG);
588 			reg_val |= (0xf << 0) | (0x01 << 8);
589 			writel(reg_val, db->membase + EMAC_INT_CTL_REG);
590 
591 			db->emacrx_completed_flag = 1;
592 
593 			return;
594 		}
595 
596 		/* A packet ready now  & Get status/length */
597 		good_packet = true;
598 
599 		emac_inblk_32bit(db->membase + EMAC_RX_IO_DATA_REG,
600 				&rxhdr, sizeof(rxhdr));
601 
602 		if (netif_msg_rx_status(db))
603 			dev_dbg(db->dev, "rxhdr: %x\n", *((int *)(&rxhdr)));
604 
605 		rxlen = EMAC_RX_IO_DATA_LEN(rxhdr);
606 		rxstatus = EMAC_RX_IO_DATA_STATUS(rxhdr);
607 
608 		if (netif_msg_rx_status(db))
609 			dev_dbg(db->dev, "RX: status %02x, length %04x\n",
610 				rxstatus, rxlen);
611 
612 		/* Packet Status check */
613 		if (rxlen < 0x40) {
614 			good_packet = false;
615 			if (netif_msg_rx_err(db))
616 				dev_dbg(db->dev, "RX: Bad Packet (runt)\n");
617 		}
618 
619 		if (unlikely(!(rxstatus & EMAC_RX_IO_DATA_STATUS_OK))) {
620 			good_packet = false;
621 
622 			if (rxstatus & EMAC_RX_IO_DATA_STATUS_CRC_ERR) {
623 				if (netif_msg_rx_err(db))
624 					dev_dbg(db->dev, "crc error\n");
625 				dev->stats.rx_crc_errors++;
626 			}
627 
628 			if (rxstatus & EMAC_RX_IO_DATA_STATUS_LEN_ERR) {
629 				if (netif_msg_rx_err(db))
630 					dev_dbg(db->dev, "length error\n");
631 				dev->stats.rx_length_errors++;
632 			}
633 		}
634 
635 		/* Move data from EMAC */
636 		if (good_packet) {
637 			skb = netdev_alloc_skb(dev, rxlen + 4);
638 			if (!skb)
639 				continue;
640 			skb_reserve(skb, 2);
641 			rdptr = (u8 *) skb_put(skb, rxlen - 4);
642 
643 			/* Read received packet from RX SRAM */
644 			if (netif_msg_rx_status(db))
645 				dev_dbg(db->dev, "RxLen %x\n", rxlen);
646 
647 			emac_inblk_32bit(db->membase + EMAC_RX_IO_DATA_REG,
648 					rdptr, rxlen);
649 			dev->stats.rx_bytes += rxlen;
650 
651 			/* Pass to upper layer */
652 			skb->protocol = eth_type_trans(skb, dev);
653 			netif_rx(skb);
654 			dev->stats.rx_packets++;
655 		}
656 	}
657 }
658 
659 static irqreturn_t emac_interrupt(int irq, void *dev_id)
660 {
661 	struct net_device *dev = dev_id;
662 	struct emac_board_info *db = netdev_priv(dev);
663 	int int_status;
664 	unsigned long flags;
665 	unsigned int reg_val;
666 
667 	/* A real interrupt coming */
668 
669 	/* holders of db->lock must always block IRQs */
670 	spin_lock_irqsave(&db->lock, flags);
671 
672 	/* Disable all interrupts */
673 	writel(0, db->membase + EMAC_INT_CTL_REG);
674 
675 	/* Got EMAC interrupt status */
676 	/* Got ISR */
677 	int_status = readl(db->membase + EMAC_INT_STA_REG);
678 	/* Clear ISR status */
679 	writel(int_status, db->membase + EMAC_INT_STA_REG);
680 
681 	if (netif_msg_intr(db))
682 		dev_dbg(db->dev, "emac interrupt %02x\n", int_status);
683 
684 	/* Received the coming packet */
685 	if ((int_status & 0x100) && (db->emacrx_completed_flag == 1)) {
686 		/* carrier lost */
687 		db->emacrx_completed_flag = 0;
688 		emac_rx(dev);
689 	}
690 
691 	/* Transmit Interrupt check */
692 	if (int_status & (0x01 | 0x02))
693 		emac_tx_done(dev, db, int_status);
694 
695 	if (int_status & (0x04 | 0x08))
696 		netdev_info(dev, " ab : %x\n", int_status);
697 
698 	/* Re-enable interrupt mask */
699 	if (db->emacrx_completed_flag == 1) {
700 		reg_val = readl(db->membase + EMAC_INT_CTL_REG);
701 		reg_val |= (0xf << 0) | (0x01 << 8);
702 		writel(reg_val, db->membase + EMAC_INT_CTL_REG);
703 	}
704 	spin_unlock_irqrestore(&db->lock, flags);
705 
706 	return IRQ_HANDLED;
707 }
708 
709 #ifdef CONFIG_NET_POLL_CONTROLLER
710 /*
711  * Used by netconsole
712  */
713 static void emac_poll_controller(struct net_device *dev)
714 {
715 	disable_irq(dev->irq);
716 	emac_interrupt(dev->irq, dev);
717 	enable_irq(dev->irq);
718 }
719 #endif
720 
721 /*  Open the interface.
722  *  The interface is opened whenever "ifconfig" actives it.
723  */
724 static int emac_open(struct net_device *dev)
725 {
726 	struct emac_board_info *db = netdev_priv(dev);
727 	int ret;
728 
729 	if (netif_msg_ifup(db))
730 		dev_dbg(db->dev, "enabling %s\n", dev->name);
731 
732 	if (request_irq(dev->irq, &emac_interrupt, 0, dev->name, dev))
733 		return -EAGAIN;
734 
735 	/* Initialize EMAC board */
736 	emac_reset(db);
737 	emac_init_device(dev);
738 
739 	ret = emac_mdio_probe(dev);
740 	if (ret < 0) {
741 		free_irq(dev->irq, dev);
742 		netdev_err(dev, "cannot probe MDIO bus\n");
743 		return ret;
744 	}
745 
746 	phy_start(db->phy_dev);
747 	netif_start_queue(dev);
748 
749 	return 0;
750 }
751 
752 static void emac_shutdown(struct net_device *dev)
753 {
754 	unsigned int reg_val;
755 	struct emac_board_info *db = netdev_priv(dev);
756 
757 	/* Disable all interrupt */
758 	writel(0, db->membase + EMAC_INT_CTL_REG);
759 
760 	/* clear interupt status */
761 	reg_val = readl(db->membase + EMAC_INT_STA_REG);
762 	writel(reg_val, db->membase + EMAC_INT_STA_REG);
763 
764 	/* Disable RX/TX */
765 	reg_val = readl(db->membase + EMAC_CTL_REG);
766 	reg_val &= ~(EMAC_CTL_TX_EN | EMAC_CTL_RX_EN | EMAC_CTL_RESET);
767 	writel(reg_val, db->membase + EMAC_CTL_REG);
768 }
769 
770 /* Stop the interface.
771  * The interface is stopped when it is brought.
772  */
773 static int emac_stop(struct net_device *ndev)
774 {
775 	struct emac_board_info *db = netdev_priv(ndev);
776 
777 	if (netif_msg_ifdown(db))
778 		dev_dbg(db->dev, "shutting down %s\n", ndev->name);
779 
780 	netif_stop_queue(ndev);
781 	netif_carrier_off(ndev);
782 
783 	phy_stop(db->phy_dev);
784 
785 	emac_mdio_remove(ndev);
786 
787 	emac_shutdown(ndev);
788 
789 	free_irq(ndev->irq, ndev);
790 
791 	return 0;
792 }
793 
794 static const struct net_device_ops emac_netdev_ops = {
795 	.ndo_open		= emac_open,
796 	.ndo_stop		= emac_stop,
797 	.ndo_start_xmit		= emac_start_xmit,
798 	.ndo_tx_timeout		= emac_timeout,
799 	.ndo_set_rx_mode	= emac_set_rx_mode,
800 	.ndo_do_ioctl		= emac_ioctl,
801 	.ndo_change_mtu		= eth_change_mtu,
802 	.ndo_validate_addr	= eth_validate_addr,
803 	.ndo_set_mac_address	= emac_set_mac_address,
804 #ifdef CONFIG_NET_POLL_CONTROLLER
805 	.ndo_poll_controller	= emac_poll_controller,
806 #endif
807 };
808 
809 /* Search EMAC board, allocate space and register it
810  */
811 static int emac_probe(struct platform_device *pdev)
812 {
813 	struct device_node *np = pdev->dev.of_node;
814 	struct emac_board_info *db;
815 	struct net_device *ndev;
816 	int ret = 0;
817 	const char *mac_addr;
818 
819 	ndev = alloc_etherdev(sizeof(struct emac_board_info));
820 	if (!ndev) {
821 		dev_err(&pdev->dev, "could not allocate device.\n");
822 		return -ENOMEM;
823 	}
824 
825 	SET_NETDEV_DEV(ndev, &pdev->dev);
826 
827 	db = netdev_priv(ndev);
828 	memset(db, 0, sizeof(*db));
829 
830 	db->dev = &pdev->dev;
831 	db->ndev = ndev;
832 	db->pdev = pdev;
833 
834 	spin_lock_init(&db->lock);
835 
836 	db->membase = of_iomap(np, 0);
837 	if (!db->membase) {
838 		dev_err(&pdev->dev, "failed to remap registers\n");
839 		ret = -ENOMEM;
840 		goto out;
841 	}
842 
843 	/* fill in parameters for net-dev structure */
844 	ndev->base_addr = (unsigned long)db->membase;
845 	ndev->irq = irq_of_parse_and_map(np, 0);
846 	if (ndev->irq == -ENXIO) {
847 		netdev_err(ndev, "No irq resource\n");
848 		ret = ndev->irq;
849 		goto out;
850 	}
851 
852 	db->clk = devm_clk_get(&pdev->dev, NULL);
853 	if (IS_ERR(db->clk)) {
854 		ret = PTR_ERR(db->clk);
855 		goto out;
856 	}
857 
858 	clk_prepare_enable(db->clk);
859 
860 	db->phy_node = of_parse_phandle(np, "phy", 0);
861 	if (!db->phy_node) {
862 		dev_err(&pdev->dev, "no associated PHY\n");
863 		ret = -ENODEV;
864 		goto out;
865 	}
866 
867 	/* Read MAC-address from DT */
868 	mac_addr = of_get_mac_address(np);
869 	if (mac_addr)
870 		memcpy(ndev->dev_addr, mac_addr, ETH_ALEN);
871 
872 	/* Check if the MAC address is valid, if not get a random one */
873 	if (!is_valid_ether_addr(ndev->dev_addr)) {
874 		eth_hw_addr_random(ndev);
875 		dev_warn(&pdev->dev, "using random MAC address %pM\n",
876 			 ndev->dev_addr);
877 	}
878 
879 	db->emacrx_completed_flag = 1;
880 	emac_powerup(ndev);
881 	emac_reset(db);
882 
883 	ndev->netdev_ops = &emac_netdev_ops;
884 	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
885 	ndev->ethtool_ops = &emac_ethtool_ops;
886 
887 	platform_set_drvdata(pdev, ndev);
888 
889 	/* Carrier starts down, phylib will bring it up */
890 	netif_carrier_off(ndev);
891 
892 	ret = register_netdev(ndev);
893 	if (ret) {
894 		dev_err(&pdev->dev, "Registering netdev failed!\n");
895 		ret = -ENODEV;
896 		goto out;
897 	}
898 
899 	dev_info(&pdev->dev, "%s: at %p, IRQ %d MAC: %pM\n",
900 		 ndev->name, db->membase, ndev->irq, ndev->dev_addr);
901 
902 	return 0;
903 
904 out:
905 	dev_err(db->dev, "not found (%d).\n", ret);
906 
907 	free_netdev(ndev);
908 
909 	return ret;
910 }
911 
912 static int emac_remove(struct platform_device *pdev)
913 {
914 	struct net_device *ndev = platform_get_drvdata(pdev);
915 
916 	unregister_netdev(ndev);
917 	free_netdev(ndev);
918 
919 	dev_dbg(&pdev->dev, "released and freed device\n");
920 	return 0;
921 }
922 
923 static int emac_suspend(struct platform_device *dev, pm_message_t state)
924 {
925 	struct net_device *ndev = platform_get_drvdata(dev);
926 
927 	netif_carrier_off(ndev);
928 	netif_device_detach(ndev);
929 	emac_shutdown(ndev);
930 
931 	return 0;
932 }
933 
934 static int emac_resume(struct platform_device *dev)
935 {
936 	struct net_device *ndev = platform_get_drvdata(dev);
937 	struct emac_board_info *db = netdev_priv(ndev);
938 
939 	emac_reset(db);
940 	emac_init_device(ndev);
941 	netif_device_attach(ndev);
942 
943 	return 0;
944 }
945 
946 static const struct of_device_id emac_of_match[] = {
947 	{.compatible = "allwinner,sun4i-a10-emac",},
948 
949 	/* Deprecated */
950 	{.compatible = "allwinner,sun4i-emac",},
951 	{},
952 };
953 
954 MODULE_DEVICE_TABLE(of, emac_of_match);
955 
956 static struct platform_driver emac_driver = {
957 	.driver = {
958 		.name = "sun4i-emac",
959 		.of_match_table = emac_of_match,
960 	},
961 	.probe = emac_probe,
962 	.remove = emac_remove,
963 	.suspend = emac_suspend,
964 	.resume = emac_resume,
965 };
966 
967 module_platform_driver(emac_driver);
968 
969 MODULE_AUTHOR("Stefan Roese <sr@denx.de>");
970 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
971 MODULE_DESCRIPTION("Allwinner A10 emac network driver");
972 MODULE_LICENSE("GPL");
973