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 #include <linux/soc/sunxi/sunxi_sram.h>
32 
33 #include "sun4i-emac.h"
34 
35 #define DRV_NAME		"sun4i-emac"
36 #define DRV_VERSION		"1.02"
37 
38 #define EMAC_MAX_FRAME_LEN	0x0600
39 
40 #define EMAC_DEFAULT_MSG_ENABLE 0x0000
41 static int debug = -1;     /* defaults above */;
42 module_param(debug, int, 0);
43 MODULE_PARM_DESC(debug, "debug message flags");
44 
45 /* Transmit timeout, default 5 seconds. */
46 static int watchdog = 5000;
47 module_param(watchdog, int, 0400);
48 MODULE_PARM_DESC(watchdog, "transmit timeout in milliseconds");
49 
50 /* EMAC register address locking.
51  *
52  * The EMAC uses an address register to control where data written
53  * to the data register goes. This means that the address register
54  * must be preserved over interrupts or similar calls.
55  *
56  * During interrupt and other critical calls, a spinlock is used to
57  * protect the system, but the calls themselves save the address
58  * in the address register in case they are interrupting another
59  * access to the device.
60  *
61  * For general accesses a lock is provided so that calls which are
62  * allowed to sleep are serialised so that the address register does
63  * not need to be saved. This lock also serves to serialise access
64  * to the EEPROM and PHY access registers which are shared between
65  * these two devices.
66  */
67 
68 /* The driver supports the original EMACE, and now the two newer
69  * devices, EMACA and EMACB.
70  */
71 
72 struct emac_board_info {
73 	struct clk		*clk;
74 	struct device		*dev;
75 	struct platform_device	*pdev;
76 	spinlock_t		lock;
77 	void __iomem		*membase;
78 	u32			msg_enable;
79 	struct net_device	*ndev;
80 	struct sk_buff		*skb_last;
81 	u16			tx_fifo_stat;
82 
83 	int			emacrx_completed_flag;
84 
85 	struct device_node	*phy_node;
86 	unsigned int		link;
87 	unsigned int		speed;
88 	unsigned int		duplex;
89 
90 	phy_interface_t		phy_interface;
91 };
92 
93 static void emac_update_speed(struct net_device *dev)
94 {
95 	struct emac_board_info *db = netdev_priv(dev);
96 	unsigned int reg_val;
97 
98 	/* set EMAC SPEED, depend on PHY  */
99 	reg_val = readl(db->membase + EMAC_MAC_SUPP_REG);
100 	reg_val &= ~(0x1 << 8);
101 	if (db->speed == SPEED_100)
102 		reg_val |= 1 << 8;
103 	writel(reg_val, db->membase + EMAC_MAC_SUPP_REG);
104 }
105 
106 static void emac_update_duplex(struct net_device *dev)
107 {
108 	struct emac_board_info *db = netdev_priv(dev);
109 	unsigned int reg_val;
110 
111 	/* set duplex depend on phy */
112 	reg_val = readl(db->membase + EMAC_MAC_CTL1_REG);
113 	reg_val &= ~EMAC_MAC_CTL1_DUPLEX_EN;
114 	if (db->duplex)
115 		reg_val |= EMAC_MAC_CTL1_DUPLEX_EN;
116 	writel(reg_val, db->membase + EMAC_MAC_CTL1_REG);
117 }
118 
119 static void emac_handle_link_change(struct net_device *dev)
120 {
121 	struct emac_board_info *db = netdev_priv(dev);
122 	struct phy_device *phydev = dev->phydev;
123 	unsigned long flags;
124 	int status_change = 0;
125 
126 	if (phydev->link) {
127 		if (db->speed != phydev->speed) {
128 			spin_lock_irqsave(&db->lock, flags);
129 			db->speed = phydev->speed;
130 			emac_update_speed(dev);
131 			spin_unlock_irqrestore(&db->lock, flags);
132 			status_change = 1;
133 		}
134 
135 		if (db->duplex != phydev->duplex) {
136 			spin_lock_irqsave(&db->lock, flags);
137 			db->duplex = phydev->duplex;
138 			emac_update_duplex(dev);
139 			spin_unlock_irqrestore(&db->lock, flags);
140 			status_change = 1;
141 		}
142 	}
143 
144 	if (phydev->link != db->link) {
145 		if (!phydev->link) {
146 			db->speed = 0;
147 			db->duplex = -1;
148 		}
149 		db->link = phydev->link;
150 
151 		status_change = 1;
152 	}
153 
154 	if (status_change)
155 		phy_print_status(phydev);
156 }
157 
158 static int emac_mdio_probe(struct net_device *dev)
159 {
160 	struct emac_board_info *db = netdev_priv(dev);
161 	struct phy_device *phydev;
162 
163 	/* to-do: PHY interrupts are currently not supported */
164 
165 	/* attach the mac to the phy */
166 	phydev = of_phy_connect(db->ndev, db->phy_node,
167 				&emac_handle_link_change, 0,
168 				db->phy_interface);
169 	if (!phydev) {
170 		netdev_err(db->ndev, "could not find the PHY\n");
171 		return -ENODEV;
172 	}
173 
174 	/* mask with MAC supported features */
175 	phydev->supported &= PHY_BASIC_FEATURES;
176 	phydev->advertising = phydev->supported;
177 
178 	db->link = 0;
179 	db->speed = 0;
180 	db->duplex = -1;
181 
182 	return 0;
183 }
184 
185 static void emac_mdio_remove(struct net_device *dev)
186 {
187 	phy_disconnect(dev->phydev);
188 }
189 
190 static void emac_reset(struct emac_board_info *db)
191 {
192 	dev_dbg(db->dev, "resetting device\n");
193 
194 	/* RESET device */
195 	writel(0, db->membase + EMAC_CTL_REG);
196 	udelay(200);
197 	writel(EMAC_CTL_RESET, db->membase + EMAC_CTL_REG);
198 	udelay(200);
199 }
200 
201 static void emac_outblk_32bit(void __iomem *reg, void *data, int count)
202 {
203 	writesl(reg, data, round_up(count, 4) / 4);
204 }
205 
206 static void emac_inblk_32bit(void __iomem *reg, void *data, int count)
207 {
208 	readsl(reg, data, round_up(count, 4) / 4);
209 }
210 
211 static int emac_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
212 {
213 	struct phy_device *phydev = dev->phydev;
214 
215 	if (!netif_running(dev))
216 		return -EINVAL;
217 
218 	if (!phydev)
219 		return -ENODEV;
220 
221 	return phy_mii_ioctl(phydev, rq, cmd);
222 }
223 
224 /* ethtool ops */
225 static void emac_get_drvinfo(struct net_device *dev,
226 			      struct ethtool_drvinfo *info)
227 {
228 	strlcpy(info->driver, DRV_NAME, sizeof(DRV_NAME));
229 	strlcpy(info->version, DRV_VERSION, sizeof(DRV_VERSION));
230 	strlcpy(info->bus_info, dev_name(&dev->dev), sizeof(info->bus_info));
231 }
232 
233 static u32 emac_get_msglevel(struct net_device *dev)
234 {
235 	struct emac_board_info *db = netdev_priv(dev);
236 
237 	return db->msg_enable;
238 }
239 
240 static void emac_set_msglevel(struct net_device *dev, u32 value)
241 {
242 	struct emac_board_info *db = netdev_priv(dev);
243 
244 	db->msg_enable = value;
245 }
246 
247 static const struct ethtool_ops emac_ethtool_ops = {
248 	.get_drvinfo	= emac_get_drvinfo,
249 	.get_link	= ethtool_op_get_link,
250 	.get_link_ksettings = phy_ethtool_get_link_ksettings,
251 	.set_link_ksettings = phy_ethtool_set_link_ksettings,
252 	.get_msglevel	= emac_get_msglevel,
253 	.set_msglevel	= emac_set_msglevel,
254 };
255 
256 static unsigned int emac_setup(struct net_device *ndev)
257 {
258 	struct emac_board_info *db = netdev_priv(ndev);
259 	unsigned int reg_val;
260 
261 	/* set up TX */
262 	reg_val = readl(db->membase + EMAC_TX_MODE_REG);
263 
264 	writel(reg_val | EMAC_TX_MODE_ABORTED_FRAME_EN,
265 		db->membase + EMAC_TX_MODE_REG);
266 
267 	/* set MAC */
268 	/* set MAC CTL0 */
269 	reg_val = readl(db->membase + EMAC_MAC_CTL0_REG);
270 	writel(reg_val | EMAC_MAC_CTL0_RX_FLOW_CTL_EN |
271 		EMAC_MAC_CTL0_TX_FLOW_CTL_EN,
272 		db->membase + EMAC_MAC_CTL0_REG);
273 
274 	/* set MAC CTL1 */
275 	reg_val = readl(db->membase + EMAC_MAC_CTL1_REG);
276 	reg_val |= EMAC_MAC_CTL1_LEN_CHECK_EN;
277 	reg_val |= EMAC_MAC_CTL1_CRC_EN;
278 	reg_val |= EMAC_MAC_CTL1_PAD_EN;
279 	writel(reg_val, db->membase + EMAC_MAC_CTL1_REG);
280 
281 	/* set up IPGT */
282 	writel(EMAC_MAC_IPGT_FULL_DUPLEX, db->membase + EMAC_MAC_IPGT_REG);
283 
284 	/* set up IPGR */
285 	writel((EMAC_MAC_IPGR_IPG1 << 8) | EMAC_MAC_IPGR_IPG2,
286 		db->membase + EMAC_MAC_IPGR_REG);
287 
288 	/* set up Collison window */
289 	writel((EMAC_MAC_CLRT_COLLISION_WINDOW << 8) | EMAC_MAC_CLRT_RM,
290 		db->membase + EMAC_MAC_CLRT_REG);
291 
292 	/* set up Max Frame Length */
293 	writel(EMAC_MAX_FRAME_LEN,
294 		db->membase + EMAC_MAC_MAXF_REG);
295 
296 	return 0;
297 }
298 
299 static void emac_set_rx_mode(struct net_device *ndev)
300 {
301 	struct emac_board_info *db = netdev_priv(ndev);
302 	unsigned int reg_val;
303 
304 	/* set up RX */
305 	reg_val = readl(db->membase + EMAC_RX_CTL_REG);
306 
307 	if (ndev->flags & IFF_PROMISC)
308 		reg_val |= EMAC_RX_CTL_PASS_ALL_EN;
309 	else
310 		reg_val &= ~EMAC_RX_CTL_PASS_ALL_EN;
311 
312 	writel(reg_val | EMAC_RX_CTL_PASS_LEN_OOR_EN |
313 		EMAC_RX_CTL_ACCEPT_UNICAST_EN | EMAC_RX_CTL_DA_FILTER_EN |
314 		EMAC_RX_CTL_ACCEPT_MULTICAST_EN |
315 		EMAC_RX_CTL_ACCEPT_BROADCAST_EN,
316 		db->membase + EMAC_RX_CTL_REG);
317 }
318 
319 static unsigned int emac_powerup(struct net_device *ndev)
320 {
321 	struct emac_board_info *db = netdev_priv(ndev);
322 	unsigned int reg_val;
323 
324 	/* initial EMAC */
325 	/* flush RX FIFO */
326 	reg_val = readl(db->membase + EMAC_RX_CTL_REG);
327 	reg_val |= 0x8;
328 	writel(reg_val, db->membase + EMAC_RX_CTL_REG);
329 	udelay(1);
330 
331 	/* initial MAC */
332 	/* soft reset MAC */
333 	reg_val = readl(db->membase + EMAC_MAC_CTL0_REG);
334 	reg_val &= ~EMAC_MAC_CTL0_SOFT_RESET;
335 	writel(reg_val, db->membase + EMAC_MAC_CTL0_REG);
336 
337 	/* set MII clock */
338 	reg_val = readl(db->membase + EMAC_MAC_MCFG_REG);
339 	reg_val &= (~(0xf << 2));
340 	reg_val |= (0xD << 2);
341 	writel(reg_val, db->membase + EMAC_MAC_MCFG_REG);
342 
343 	/* clear RX counter */
344 	writel(0x0, db->membase + EMAC_RX_FBC_REG);
345 
346 	/* disable all interrupt and clear interrupt status */
347 	writel(0, db->membase + EMAC_INT_CTL_REG);
348 	reg_val = readl(db->membase + EMAC_INT_STA_REG);
349 	writel(reg_val, db->membase + EMAC_INT_STA_REG);
350 
351 	udelay(1);
352 
353 	/* set up EMAC */
354 	emac_setup(ndev);
355 
356 	/* set mac_address to chip */
357 	writel(ndev->dev_addr[0] << 16 | ndev->dev_addr[1] << 8 | ndev->
358 	       dev_addr[2], db->membase + EMAC_MAC_A1_REG);
359 	writel(ndev->dev_addr[3] << 16 | ndev->dev_addr[4] << 8 | ndev->
360 	       dev_addr[5], db->membase + EMAC_MAC_A0_REG);
361 
362 	mdelay(1);
363 
364 	return 0;
365 }
366 
367 static int emac_set_mac_address(struct net_device *dev, void *p)
368 {
369 	struct sockaddr *addr = p;
370 	struct emac_board_info *db = netdev_priv(dev);
371 
372 	if (netif_running(dev))
373 		return -EBUSY;
374 
375 	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
376 
377 	writel(dev->dev_addr[0] << 16 | dev->dev_addr[1] << 8 | dev->
378 	       dev_addr[2], db->membase + EMAC_MAC_A1_REG);
379 	writel(dev->dev_addr[3] << 16 | dev->dev_addr[4] << 8 | dev->
380 	       dev_addr[5], db->membase + EMAC_MAC_A0_REG);
381 
382 	return 0;
383 }
384 
385 /* Initialize emac board */
386 static void emac_init_device(struct net_device *dev)
387 {
388 	struct emac_board_info *db = netdev_priv(dev);
389 	unsigned long flags;
390 	unsigned int reg_val;
391 
392 	spin_lock_irqsave(&db->lock, flags);
393 
394 	emac_update_speed(dev);
395 	emac_update_duplex(dev);
396 
397 	/* enable RX/TX */
398 	reg_val = readl(db->membase + EMAC_CTL_REG);
399 	writel(reg_val | EMAC_CTL_RESET | EMAC_CTL_TX_EN | EMAC_CTL_RX_EN,
400 		db->membase + EMAC_CTL_REG);
401 
402 	/* enable RX/TX0/RX Hlevel interrup */
403 	reg_val = readl(db->membase + EMAC_INT_CTL_REG);
404 	reg_val |= (0xf << 0) | (0x01 << 8);
405 	writel(reg_val, db->membase + EMAC_INT_CTL_REG);
406 
407 	spin_unlock_irqrestore(&db->lock, flags);
408 }
409 
410 /* Our watchdog timed out. Called by the networking layer */
411 static void emac_timeout(struct net_device *dev)
412 {
413 	struct emac_board_info *db = netdev_priv(dev);
414 	unsigned long flags;
415 
416 	if (netif_msg_timer(db))
417 		dev_err(db->dev, "tx time out.\n");
418 
419 	/* Save previous register address */
420 	spin_lock_irqsave(&db->lock, flags);
421 
422 	netif_stop_queue(dev);
423 	emac_reset(db);
424 	emac_init_device(dev);
425 	/* We can accept TX packets again */
426 	netif_trans_update(dev);
427 	netif_wake_queue(dev);
428 
429 	/* Restore previous register address */
430 	spin_unlock_irqrestore(&db->lock, flags);
431 }
432 
433 /* Hardware start transmission.
434  * Send a packet to media from the upper layer.
435  */
436 static int emac_start_xmit(struct sk_buff *skb, struct net_device *dev)
437 {
438 	struct emac_board_info *db = netdev_priv(dev);
439 	unsigned long channel;
440 	unsigned long flags;
441 
442 	channel = db->tx_fifo_stat & 3;
443 	if (channel == 3)
444 		return 1;
445 
446 	channel = (channel == 1 ? 1 : 0);
447 
448 	spin_lock_irqsave(&db->lock, flags);
449 
450 	writel(channel, db->membase + EMAC_TX_INS_REG);
451 
452 	emac_outblk_32bit(db->membase + EMAC_TX_IO_DATA_REG,
453 			skb->data, skb->len);
454 	dev->stats.tx_bytes += skb->len;
455 
456 	db->tx_fifo_stat |= 1 << channel;
457 	/* TX control: First packet immediately send, second packet queue */
458 	if (channel == 0) {
459 		/* set TX len */
460 		writel(skb->len, db->membase + EMAC_TX_PL0_REG);
461 		/* start translate from fifo to phy */
462 		writel(readl(db->membase + EMAC_TX_CTL0_REG) | 1,
463 		       db->membase + EMAC_TX_CTL0_REG);
464 
465 		/* save the time stamp */
466 		netif_trans_update(dev);
467 	} else if (channel == 1) {
468 		/* set TX len */
469 		writel(skb->len, db->membase + EMAC_TX_PL1_REG);
470 		/* start translate from fifo to phy */
471 		writel(readl(db->membase + EMAC_TX_CTL1_REG) | 1,
472 		       db->membase + EMAC_TX_CTL1_REG);
473 
474 		/* save the time stamp */
475 		netif_trans_update(dev);
476 	}
477 
478 	if ((db->tx_fifo_stat & 3) == 3) {
479 		/* Second packet */
480 		netif_stop_queue(dev);
481 	}
482 
483 	spin_unlock_irqrestore(&db->lock, flags);
484 
485 	/* free this SKB */
486 	dev_consume_skb_any(skb);
487 
488 	return NETDEV_TX_OK;
489 }
490 
491 /* EMAC interrupt handler
492  * receive the packet to upper layer, free the transmitted packet
493  */
494 static void emac_tx_done(struct net_device *dev, struct emac_board_info *db,
495 			  unsigned int tx_status)
496 {
497 	/* One packet sent complete */
498 	db->tx_fifo_stat &= ~(tx_status & 3);
499 	if (3 == (tx_status & 3))
500 		dev->stats.tx_packets += 2;
501 	else
502 		dev->stats.tx_packets++;
503 
504 	if (netif_msg_tx_done(db))
505 		dev_dbg(db->dev, "tx done, NSR %02x\n", tx_status);
506 
507 	netif_wake_queue(dev);
508 }
509 
510 /* Received a packet and pass to upper layer
511  */
512 static void emac_rx(struct net_device *dev)
513 {
514 	struct emac_board_info *db = netdev_priv(dev);
515 	struct sk_buff *skb;
516 	u8 *rdptr;
517 	bool good_packet;
518 	static int rxlen_last;
519 	unsigned int reg_val;
520 	u32 rxhdr, rxstatus, rxcount, rxlen;
521 
522 	/* Check packet ready or not */
523 	while (1) {
524 		/* race warning: the first packet might arrive with
525 		 * the interrupts disabled, but the second will fix
526 		 * it
527 		 */
528 		rxcount = readl(db->membase + EMAC_RX_FBC_REG);
529 
530 		if (netif_msg_rx_status(db))
531 			dev_dbg(db->dev, "RXCount: %x\n", rxcount);
532 
533 		if ((db->skb_last != NULL) && (rxlen_last > 0)) {
534 			dev->stats.rx_bytes += rxlen_last;
535 
536 			/* Pass to upper layer */
537 			db->skb_last->protocol = eth_type_trans(db->skb_last,
538 								dev);
539 			netif_rx(db->skb_last);
540 			dev->stats.rx_packets++;
541 			db->skb_last = NULL;
542 			rxlen_last = 0;
543 
544 			reg_val = readl(db->membase + EMAC_RX_CTL_REG);
545 			reg_val &= ~EMAC_RX_CTL_DMA_EN;
546 			writel(reg_val, db->membase + EMAC_RX_CTL_REG);
547 		}
548 
549 		if (!rxcount) {
550 			db->emacrx_completed_flag = 1;
551 			reg_val = readl(db->membase + EMAC_INT_CTL_REG);
552 			reg_val |= (0xf << 0) | (0x01 << 8);
553 			writel(reg_val, db->membase + EMAC_INT_CTL_REG);
554 
555 			/* had one stuck? */
556 			rxcount = readl(db->membase + EMAC_RX_FBC_REG);
557 			if (!rxcount)
558 				return;
559 		}
560 
561 		reg_val = readl(db->membase + EMAC_RX_IO_DATA_REG);
562 		if (netif_msg_rx_status(db))
563 			dev_dbg(db->dev, "receive header: %x\n", reg_val);
564 		if (reg_val != EMAC_UNDOCUMENTED_MAGIC) {
565 			/* disable RX */
566 			reg_val = readl(db->membase + EMAC_CTL_REG);
567 			writel(reg_val & ~EMAC_CTL_RX_EN,
568 			       db->membase + EMAC_CTL_REG);
569 
570 			/* Flush RX FIFO */
571 			reg_val = readl(db->membase + EMAC_RX_CTL_REG);
572 			writel(reg_val | (1 << 3),
573 			       db->membase + EMAC_RX_CTL_REG);
574 
575 			do {
576 				reg_val = readl(db->membase + EMAC_RX_CTL_REG);
577 			} while (reg_val & (1 << 3));
578 
579 			/* enable RX */
580 			reg_val = readl(db->membase + EMAC_CTL_REG);
581 			writel(reg_val | EMAC_CTL_RX_EN,
582 			       db->membase + EMAC_CTL_REG);
583 			reg_val = readl(db->membase + EMAC_INT_CTL_REG);
584 			reg_val |= (0xf << 0) | (0x01 << 8);
585 			writel(reg_val, db->membase + EMAC_INT_CTL_REG);
586 
587 			db->emacrx_completed_flag = 1;
588 
589 			return;
590 		}
591 
592 		/* A packet ready now  & Get status/length */
593 		good_packet = true;
594 
595 		rxhdr = readl(db->membase + EMAC_RX_IO_DATA_REG);
596 
597 		if (netif_msg_rx_status(db))
598 			dev_dbg(db->dev, "rxhdr: %x\n", *((int *)(&rxhdr)));
599 
600 		rxlen = EMAC_RX_IO_DATA_LEN(rxhdr);
601 		rxstatus = EMAC_RX_IO_DATA_STATUS(rxhdr);
602 
603 		if (netif_msg_rx_status(db))
604 			dev_dbg(db->dev, "RX: status %02x, length %04x\n",
605 				rxstatus, rxlen);
606 
607 		/* Packet Status check */
608 		if (rxlen < 0x40) {
609 			good_packet = false;
610 			if (netif_msg_rx_err(db))
611 				dev_dbg(db->dev, "RX: Bad Packet (runt)\n");
612 		}
613 
614 		if (unlikely(!(rxstatus & EMAC_RX_IO_DATA_STATUS_OK))) {
615 			good_packet = false;
616 
617 			if (rxstatus & EMAC_RX_IO_DATA_STATUS_CRC_ERR) {
618 				if (netif_msg_rx_err(db))
619 					dev_dbg(db->dev, "crc error\n");
620 				dev->stats.rx_crc_errors++;
621 			}
622 
623 			if (rxstatus & EMAC_RX_IO_DATA_STATUS_LEN_ERR) {
624 				if (netif_msg_rx_err(db))
625 					dev_dbg(db->dev, "length error\n");
626 				dev->stats.rx_length_errors++;
627 			}
628 		}
629 
630 		/* Move data from EMAC */
631 		if (good_packet) {
632 			skb = netdev_alloc_skb(dev, rxlen + 4);
633 			if (!skb)
634 				continue;
635 			skb_reserve(skb, 2);
636 			rdptr = skb_put(skb, rxlen - 4);
637 
638 			/* Read received packet from RX SRAM */
639 			if (netif_msg_rx_status(db))
640 				dev_dbg(db->dev, "RxLen %x\n", rxlen);
641 
642 			emac_inblk_32bit(db->membase + EMAC_RX_IO_DATA_REG,
643 					rdptr, rxlen);
644 			dev->stats.rx_bytes += rxlen;
645 
646 			/* Pass to upper layer */
647 			skb->protocol = eth_type_trans(skb, dev);
648 			netif_rx(skb);
649 			dev->stats.rx_packets++;
650 		}
651 	}
652 }
653 
654 static irqreturn_t emac_interrupt(int irq, void *dev_id)
655 {
656 	struct net_device *dev = dev_id;
657 	struct emac_board_info *db = netdev_priv(dev);
658 	int int_status;
659 	unsigned long flags;
660 	unsigned int reg_val;
661 
662 	/* A real interrupt coming */
663 
664 	/* holders of db->lock must always block IRQs */
665 	spin_lock_irqsave(&db->lock, flags);
666 
667 	/* Disable all interrupts */
668 	writel(0, db->membase + EMAC_INT_CTL_REG);
669 
670 	/* Got EMAC interrupt status */
671 	/* Got ISR */
672 	int_status = readl(db->membase + EMAC_INT_STA_REG);
673 	/* Clear ISR status */
674 	writel(int_status, db->membase + EMAC_INT_STA_REG);
675 
676 	if (netif_msg_intr(db))
677 		dev_dbg(db->dev, "emac interrupt %02x\n", int_status);
678 
679 	/* Received the coming packet */
680 	if ((int_status & 0x100) && (db->emacrx_completed_flag == 1)) {
681 		/* carrier lost */
682 		db->emacrx_completed_flag = 0;
683 		emac_rx(dev);
684 	}
685 
686 	/* Transmit Interrupt check */
687 	if (int_status & (0x01 | 0x02))
688 		emac_tx_done(dev, db, int_status);
689 
690 	if (int_status & (0x04 | 0x08))
691 		netdev_info(dev, " ab : %x\n", int_status);
692 
693 	/* Re-enable interrupt mask */
694 	if (db->emacrx_completed_flag == 1) {
695 		reg_val = readl(db->membase + EMAC_INT_CTL_REG);
696 		reg_val |= (0xf << 0) | (0x01 << 8);
697 		writel(reg_val, db->membase + EMAC_INT_CTL_REG);
698 	}
699 	spin_unlock_irqrestore(&db->lock, flags);
700 
701 	return IRQ_HANDLED;
702 }
703 
704 #ifdef CONFIG_NET_POLL_CONTROLLER
705 /*
706  * Used by netconsole
707  */
708 static void emac_poll_controller(struct net_device *dev)
709 {
710 	disable_irq(dev->irq);
711 	emac_interrupt(dev->irq, dev);
712 	enable_irq(dev->irq);
713 }
714 #endif
715 
716 /*  Open the interface.
717  *  The interface is opened whenever "ifconfig" actives it.
718  */
719 static int emac_open(struct net_device *dev)
720 {
721 	struct emac_board_info *db = netdev_priv(dev);
722 	int ret;
723 
724 	if (netif_msg_ifup(db))
725 		dev_dbg(db->dev, "enabling %s\n", dev->name);
726 
727 	if (request_irq(dev->irq, &emac_interrupt, 0, dev->name, dev))
728 		return -EAGAIN;
729 
730 	/* Initialize EMAC board */
731 	emac_reset(db);
732 	emac_init_device(dev);
733 
734 	ret = emac_mdio_probe(dev);
735 	if (ret < 0) {
736 		free_irq(dev->irq, dev);
737 		netdev_err(dev, "cannot probe MDIO bus\n");
738 		return ret;
739 	}
740 
741 	phy_start(dev->phydev);
742 	netif_start_queue(dev);
743 
744 	return 0;
745 }
746 
747 static void emac_shutdown(struct net_device *dev)
748 {
749 	unsigned int reg_val;
750 	struct emac_board_info *db = netdev_priv(dev);
751 
752 	/* Disable all interrupt */
753 	writel(0, db->membase + EMAC_INT_CTL_REG);
754 
755 	/* clear interrupt status */
756 	reg_val = readl(db->membase + EMAC_INT_STA_REG);
757 	writel(reg_val, db->membase + EMAC_INT_STA_REG);
758 
759 	/* Disable RX/TX */
760 	reg_val = readl(db->membase + EMAC_CTL_REG);
761 	reg_val &= ~(EMAC_CTL_TX_EN | EMAC_CTL_RX_EN | EMAC_CTL_RESET);
762 	writel(reg_val, db->membase + EMAC_CTL_REG);
763 }
764 
765 /* Stop the interface.
766  * The interface is stopped when it is brought.
767  */
768 static int emac_stop(struct net_device *ndev)
769 {
770 	struct emac_board_info *db = netdev_priv(ndev);
771 
772 	if (netif_msg_ifdown(db))
773 		dev_dbg(db->dev, "shutting down %s\n", ndev->name);
774 
775 	netif_stop_queue(ndev);
776 	netif_carrier_off(ndev);
777 
778 	phy_stop(ndev->phydev);
779 
780 	emac_mdio_remove(ndev);
781 
782 	emac_shutdown(ndev);
783 
784 	free_irq(ndev->irq, ndev);
785 
786 	return 0;
787 }
788 
789 static const struct net_device_ops emac_netdev_ops = {
790 	.ndo_open		= emac_open,
791 	.ndo_stop		= emac_stop,
792 	.ndo_start_xmit		= emac_start_xmit,
793 	.ndo_tx_timeout		= emac_timeout,
794 	.ndo_set_rx_mode	= emac_set_rx_mode,
795 	.ndo_do_ioctl		= emac_ioctl,
796 	.ndo_validate_addr	= eth_validate_addr,
797 	.ndo_set_mac_address	= emac_set_mac_address,
798 #ifdef CONFIG_NET_POLL_CONTROLLER
799 	.ndo_poll_controller	= emac_poll_controller,
800 #endif
801 };
802 
803 /* Search EMAC board, allocate space and register it
804  */
805 static int emac_probe(struct platform_device *pdev)
806 {
807 	struct device_node *np = pdev->dev.of_node;
808 	struct emac_board_info *db;
809 	struct net_device *ndev;
810 	int ret = 0;
811 	const char *mac_addr;
812 
813 	ndev = alloc_etherdev(sizeof(struct emac_board_info));
814 	if (!ndev) {
815 		dev_err(&pdev->dev, "could not allocate device.\n");
816 		return -ENOMEM;
817 	}
818 
819 	SET_NETDEV_DEV(ndev, &pdev->dev);
820 
821 	db = netdev_priv(ndev);
822 	memset(db, 0, sizeof(*db));
823 
824 	db->dev = &pdev->dev;
825 	db->ndev = ndev;
826 	db->pdev = pdev;
827 	db->msg_enable = netif_msg_init(debug, EMAC_DEFAULT_MSG_ENABLE);
828 
829 	spin_lock_init(&db->lock);
830 
831 	db->membase = of_iomap(np, 0);
832 	if (!db->membase) {
833 		dev_err(&pdev->dev, "failed to remap registers\n");
834 		ret = -ENOMEM;
835 		goto out;
836 	}
837 
838 	/* fill in parameters for net-dev structure */
839 	ndev->base_addr = (unsigned long)db->membase;
840 	ndev->irq = irq_of_parse_and_map(np, 0);
841 	if (ndev->irq == -ENXIO) {
842 		netdev_err(ndev, "No irq resource\n");
843 		ret = ndev->irq;
844 		goto out_iounmap;
845 	}
846 
847 	db->clk = devm_clk_get(&pdev->dev, NULL);
848 	if (IS_ERR(db->clk)) {
849 		ret = PTR_ERR(db->clk);
850 		goto out_iounmap;
851 	}
852 
853 	ret = clk_prepare_enable(db->clk);
854 	if (ret) {
855 		dev_err(&pdev->dev, "Error couldn't enable clock (%d)\n", ret);
856 		goto out_iounmap;
857 	}
858 
859 	ret = sunxi_sram_claim(&pdev->dev);
860 	if (ret) {
861 		dev_err(&pdev->dev, "Error couldn't map SRAM to device\n");
862 		goto out_clk_disable_unprepare;
863 	}
864 
865 	db->phy_node = of_parse_phandle(np, "phy", 0);
866 	if (!db->phy_node) {
867 		dev_err(&pdev->dev, "no associated PHY\n");
868 		ret = -ENODEV;
869 		goto out_release_sram;
870 	}
871 
872 	/* Read MAC-address from DT */
873 	mac_addr = of_get_mac_address(np);
874 	if (mac_addr)
875 		memcpy(ndev->dev_addr, mac_addr, ETH_ALEN);
876 
877 	/* Check if the MAC address is valid, if not get a random one */
878 	if (!is_valid_ether_addr(ndev->dev_addr)) {
879 		eth_hw_addr_random(ndev);
880 		dev_warn(&pdev->dev, "using random MAC address %pM\n",
881 			 ndev->dev_addr);
882 	}
883 
884 	db->emacrx_completed_flag = 1;
885 	emac_powerup(ndev);
886 	emac_reset(db);
887 
888 	ndev->netdev_ops = &emac_netdev_ops;
889 	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
890 	ndev->ethtool_ops = &emac_ethtool_ops;
891 
892 	platform_set_drvdata(pdev, ndev);
893 
894 	/* Carrier starts down, phylib will bring it up */
895 	netif_carrier_off(ndev);
896 
897 	ret = register_netdev(ndev);
898 	if (ret) {
899 		dev_err(&pdev->dev, "Registering netdev failed!\n");
900 		ret = -ENODEV;
901 		goto out_release_sram;
902 	}
903 
904 	dev_info(&pdev->dev, "%s: at %p, IRQ %d MAC: %pM\n",
905 		 ndev->name, db->membase, ndev->irq, ndev->dev_addr);
906 
907 	return 0;
908 
909 out_release_sram:
910 	sunxi_sram_release(&pdev->dev);
911 out_clk_disable_unprepare:
912 	clk_disable_unprepare(db->clk);
913 out_iounmap:
914 	iounmap(db->membase);
915 out:
916 	dev_err(db->dev, "not found (%d).\n", ret);
917 
918 	free_netdev(ndev);
919 
920 	return ret;
921 }
922 
923 static int emac_remove(struct platform_device *pdev)
924 {
925 	struct net_device *ndev = platform_get_drvdata(pdev);
926 	struct emac_board_info *db = netdev_priv(ndev);
927 
928 	unregister_netdev(ndev);
929 	sunxi_sram_release(&pdev->dev);
930 	clk_disable_unprepare(db->clk);
931 	iounmap(db->membase);
932 	free_netdev(ndev);
933 
934 	dev_dbg(&pdev->dev, "released and freed device\n");
935 	return 0;
936 }
937 
938 static int emac_suspend(struct platform_device *dev, pm_message_t state)
939 {
940 	struct net_device *ndev = platform_get_drvdata(dev);
941 
942 	netif_carrier_off(ndev);
943 	netif_device_detach(ndev);
944 	emac_shutdown(ndev);
945 
946 	return 0;
947 }
948 
949 static int emac_resume(struct platform_device *dev)
950 {
951 	struct net_device *ndev = platform_get_drvdata(dev);
952 	struct emac_board_info *db = netdev_priv(ndev);
953 
954 	emac_reset(db);
955 	emac_init_device(ndev);
956 	netif_device_attach(ndev);
957 
958 	return 0;
959 }
960 
961 static const struct of_device_id emac_of_match[] = {
962 	{.compatible = "allwinner,sun4i-a10-emac",},
963 
964 	/* Deprecated */
965 	{.compatible = "allwinner,sun4i-emac",},
966 	{},
967 };
968 
969 MODULE_DEVICE_TABLE(of, emac_of_match);
970 
971 static struct platform_driver emac_driver = {
972 	.driver = {
973 		.name = "sun4i-emac",
974 		.of_match_table = emac_of_match,
975 	},
976 	.probe = emac_probe,
977 	.remove = emac_remove,
978 	.suspend = emac_suspend,
979 	.resume = emac_resume,
980 };
981 
982 module_platform_driver(emac_driver);
983 
984 MODULE_AUTHOR("Stefan Roese <sr@denx.de>");
985 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
986 MODULE_DESCRIPTION("Allwinner A10 emac network driver");
987 MODULE_LICENSE("GPL");
988