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