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