xref: /linux/drivers/net/ethernet/allwinner/sun4i-emac.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 phy_device	*phy_dev;
81 	struct device_node	*phy_node;
82 	unsigned int		link;
83 	unsigned int		speed;
84 	unsigned int		duplex;
85 
86 	phy_interface_t		phy_interface;
87 };
88 
89 static void emac_update_speed(struct net_device *dev)
90 {
91 	struct emac_board_info *db = netdev_priv(dev);
92 	unsigned int reg_val;
93 
94 	/* set EMAC SPEED, depend on PHY  */
95 	reg_val = readl(db->membase + EMAC_MAC_SUPP_REG);
96 	reg_val &= ~(0x1 << 8);
97 	if (db->speed == SPEED_100)
98 		reg_val |= 1 << 8;
99 	writel(reg_val, db->membase + EMAC_MAC_SUPP_REG);
100 }
101 
102 static void emac_update_duplex(struct net_device *dev)
103 {
104 	struct emac_board_info *db = netdev_priv(dev);
105 	unsigned int reg_val;
106 
107 	/* set duplex depend on phy */
108 	reg_val = readl(db->membase + EMAC_MAC_CTL1_REG);
109 	reg_val &= ~EMAC_MAC_CTL1_DUPLEX_EN;
110 	if (db->duplex)
111 		reg_val |= EMAC_MAC_CTL1_DUPLEX_EN;
112 	writel(reg_val, db->membase + EMAC_MAC_CTL1_REG);
113 }
114 
115 static void emac_handle_link_change(struct net_device *dev)
116 {
117 	struct emac_board_info *db = netdev_priv(dev);
118 	struct phy_device *phydev = db->phy_dev;
119 	unsigned long flags;
120 	int status_change = 0;
121 
122 	if (phydev->link) {
123 		if (db->speed != phydev->speed) {
124 			spin_lock_irqsave(&db->lock, flags);
125 			db->speed = phydev->speed;
126 			emac_update_speed(dev);
127 			spin_unlock_irqrestore(&db->lock, flags);
128 			status_change = 1;
129 		}
130 
131 		if (db->duplex != phydev->duplex) {
132 			spin_lock_irqsave(&db->lock, flags);
133 			db->duplex = phydev->duplex;
134 			emac_update_duplex(dev);
135 			spin_unlock_irqrestore(&db->lock, flags);
136 			status_change = 1;
137 		}
138 	}
139 
140 	if (phydev->link != db->link) {
141 		if (!phydev->link) {
142 			db->speed = 0;
143 			db->duplex = -1;
144 		}
145 		db->link = phydev->link;
146 
147 		status_change = 1;
148 	}
149 
150 	if (status_change)
151 		phy_print_status(phydev);
152 }
153 
154 static int emac_mdio_probe(struct net_device *dev)
155 {
156 	struct emac_board_info *db = netdev_priv(dev);
157 
158 	/* to-do: PHY interrupts are currently not supported */
159 
160 	/* attach the mac to the phy */
161 	db->phy_dev = of_phy_connect(db->ndev, db->phy_node,
162 				     &emac_handle_link_change, 0,
163 				     db->phy_interface);
164 	if (!db->phy_dev) {
165 		netdev_err(db->ndev, "could not find the PHY\n");
166 		return -ENODEV;
167 	}
168 
169 	/* mask with MAC supported features */
170 	db->phy_dev->supported &= PHY_BASIC_FEATURES;
171 	db->phy_dev->advertising = db->phy_dev->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 	struct emac_board_info *db = netdev_priv(dev);
183 
184 	phy_disconnect(db->phy_dev);
185 	db->phy_dev = NULL;
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 static int emac_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
210 {
211 	struct emac_board_info *dm = netdev_priv(dev);
212 	struct phy_device *phydev = dm->phy_dev;
213 
214 	if (!netif_running(dev))
215 		return -EINVAL;
216 
217 	if (!phydev)
218 		return -ENODEV;
219 
220 	return phy_mii_ioctl(phydev, rq, cmd);
221 }
222 
223 /* ethtool ops */
224 static void emac_get_drvinfo(struct net_device *dev,
225 			      struct ethtool_drvinfo *info)
226 {
227 	strlcpy(info->driver, DRV_NAME, sizeof(DRV_NAME));
228 	strlcpy(info->version, DRV_VERSION, sizeof(DRV_VERSION));
229 	strlcpy(info->bus_info, dev_name(&dev->dev), sizeof(info->bus_info));
230 }
231 
232 static int emac_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
233 {
234 	struct emac_board_info *dm = netdev_priv(dev);
235 	struct phy_device *phydev = dm->phy_dev;
236 
237 	if (!phydev)
238 		return -ENODEV;
239 
240 	return phy_ethtool_gset(phydev, cmd);
241 }
242 
243 static int emac_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
244 {
245 	struct emac_board_info *dm = netdev_priv(dev);
246 	struct phy_device *phydev = dm->phy_dev;
247 
248 	if (!phydev)
249 		return -ENODEV;
250 
251 	return phy_ethtool_sset(phydev, cmd);
252 }
253 
254 static const struct ethtool_ops emac_ethtool_ops = {
255 	.get_drvinfo	= emac_get_drvinfo,
256 	.get_settings	= emac_get_settings,
257 	.set_settings	= emac_set_settings,
258 	.get_link	= ethtool_op_get_link,
259 };
260 
261 static unsigned int emac_setup(struct net_device *ndev)
262 {
263 	struct emac_board_info *db = netdev_priv(ndev);
264 	unsigned int reg_val;
265 
266 	/* set up TX */
267 	reg_val = readl(db->membase + EMAC_TX_MODE_REG);
268 
269 	writel(reg_val | EMAC_TX_MODE_ABORTED_FRAME_EN,
270 		db->membase + EMAC_TX_MODE_REG);
271 
272 	/* set MAC */
273 	/* set MAC CTL0 */
274 	reg_val = readl(db->membase + EMAC_MAC_CTL0_REG);
275 	writel(reg_val | EMAC_MAC_CTL0_RX_FLOW_CTL_EN |
276 		EMAC_MAC_CTL0_TX_FLOW_CTL_EN,
277 		db->membase + EMAC_MAC_CTL0_REG);
278 
279 	/* set MAC CTL1 */
280 	reg_val = readl(db->membase + EMAC_MAC_CTL1_REG);
281 	reg_val |= EMAC_MAC_CTL1_LEN_CHECK_EN;
282 	reg_val |= EMAC_MAC_CTL1_CRC_EN;
283 	reg_val |= EMAC_MAC_CTL1_PAD_EN;
284 	writel(reg_val, db->membase + EMAC_MAC_CTL1_REG);
285 
286 	/* set up IPGT */
287 	writel(EMAC_MAC_IPGT_FULL_DUPLEX, db->membase + EMAC_MAC_IPGT_REG);
288 
289 	/* set up IPGR */
290 	writel((EMAC_MAC_IPGR_IPG1 << 8) | EMAC_MAC_IPGR_IPG2,
291 		db->membase + EMAC_MAC_IPGR_REG);
292 
293 	/* set up Collison window */
294 	writel((EMAC_MAC_CLRT_COLLISION_WINDOW << 8) | EMAC_MAC_CLRT_RM,
295 		db->membase + EMAC_MAC_CLRT_REG);
296 
297 	/* set up Max Frame Length */
298 	writel(EMAC_MAX_FRAME_LEN,
299 		db->membase + EMAC_MAC_MAXF_REG);
300 
301 	return 0;
302 }
303 
304 static void emac_set_rx_mode(struct net_device *ndev)
305 {
306 	struct emac_board_info *db = netdev_priv(ndev);
307 	unsigned int reg_val;
308 
309 	/* set up RX */
310 	reg_val = readl(db->membase + EMAC_RX_CTL_REG);
311 
312 	if (ndev->flags & IFF_PROMISC)
313 		reg_val |= EMAC_RX_CTL_PASS_ALL_EN;
314 	else
315 		reg_val &= ~EMAC_RX_CTL_PASS_ALL_EN;
316 
317 	writel(reg_val | EMAC_RX_CTL_PASS_LEN_OOR_EN |
318 		EMAC_RX_CTL_ACCEPT_UNICAST_EN | EMAC_RX_CTL_DA_FILTER_EN |
319 		EMAC_RX_CTL_ACCEPT_MULTICAST_EN |
320 		EMAC_RX_CTL_ACCEPT_BROADCAST_EN,
321 		db->membase + EMAC_RX_CTL_REG);
322 }
323 
324 static unsigned int emac_powerup(struct net_device *ndev)
325 {
326 	struct emac_board_info *db = netdev_priv(ndev);
327 	unsigned int reg_val;
328 
329 	/* initial EMAC */
330 	/* flush RX FIFO */
331 	reg_val = readl(db->membase + EMAC_RX_CTL_REG);
332 	reg_val |= 0x8;
333 	writel(reg_val, db->membase + EMAC_RX_CTL_REG);
334 	udelay(1);
335 
336 	/* initial MAC */
337 	/* soft reset MAC */
338 	reg_val = readl(db->membase + EMAC_MAC_CTL0_REG);
339 	reg_val &= ~EMAC_MAC_CTL0_SOFT_RESET;
340 	writel(reg_val, db->membase + EMAC_MAC_CTL0_REG);
341 
342 	/* set MII clock */
343 	reg_val = readl(db->membase + EMAC_MAC_MCFG_REG);
344 	reg_val &= (~(0xf << 2));
345 	reg_val |= (0xD << 2);
346 	writel(reg_val, db->membase + EMAC_MAC_MCFG_REG);
347 
348 	/* clear RX counter */
349 	writel(0x0, db->membase + EMAC_RX_FBC_REG);
350 
351 	/* disable all interrupt and clear interrupt status */
352 	writel(0, db->membase + EMAC_INT_CTL_REG);
353 	reg_val = readl(db->membase + EMAC_INT_STA_REG);
354 	writel(reg_val, db->membase + EMAC_INT_STA_REG);
355 
356 	udelay(1);
357 
358 	/* set up EMAC */
359 	emac_setup(ndev);
360 
361 	/* set mac_address to chip */
362 	writel(ndev->dev_addr[0] << 16 | ndev->dev_addr[1] << 8 | ndev->
363 	       dev_addr[2], db->membase + EMAC_MAC_A1_REG);
364 	writel(ndev->dev_addr[3] << 16 | ndev->dev_addr[4] << 8 | ndev->
365 	       dev_addr[5], db->membase + EMAC_MAC_A0_REG);
366 
367 	mdelay(1);
368 
369 	return 0;
370 }
371 
372 static int emac_set_mac_address(struct net_device *dev, void *p)
373 {
374 	struct sockaddr *addr = p;
375 	struct emac_board_info *db = netdev_priv(dev);
376 
377 	if (netif_running(dev))
378 		return -EBUSY;
379 
380 	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
381 
382 	writel(dev->dev_addr[0] << 16 | dev->dev_addr[1] << 8 | dev->
383 	       dev_addr[2], db->membase + EMAC_MAC_A1_REG);
384 	writel(dev->dev_addr[3] << 16 | dev->dev_addr[4] << 8 | dev->
385 	       dev_addr[5], db->membase + EMAC_MAC_A0_REG);
386 
387 	return 0;
388 }
389 
390 /* Initialize emac board */
391 static void emac_init_device(struct net_device *dev)
392 {
393 	struct emac_board_info *db = netdev_priv(dev);
394 	unsigned long flags;
395 	unsigned int reg_val;
396 
397 	spin_lock_irqsave(&db->lock, flags);
398 
399 	emac_update_speed(dev);
400 	emac_update_duplex(dev);
401 
402 	/* enable RX/TX */
403 	reg_val = readl(db->membase + EMAC_CTL_REG);
404 	writel(reg_val | EMAC_CTL_RESET | EMAC_CTL_TX_EN | EMAC_CTL_RX_EN,
405 		db->membase + EMAC_CTL_REG);
406 
407 	/* enable RX/TX0/RX Hlevel interrup */
408 	reg_val = readl(db->membase + EMAC_INT_CTL_REG);
409 	reg_val |= (0xf << 0) | (0x01 << 8);
410 	writel(reg_val, db->membase + EMAC_INT_CTL_REG);
411 
412 	spin_unlock_irqrestore(&db->lock, flags);
413 }
414 
415 /* Our watchdog timed out. Called by the networking layer */
416 static void emac_timeout(struct net_device *dev)
417 {
418 	struct emac_board_info *db = netdev_priv(dev);
419 	unsigned long flags;
420 
421 	if (netif_msg_timer(db))
422 		dev_err(db->dev, "tx time out.\n");
423 
424 	/* Save previous register address */
425 	spin_lock_irqsave(&db->lock, flags);
426 
427 	netif_stop_queue(dev);
428 	emac_reset(db);
429 	emac_init_device(dev);
430 	/* We can accept TX packets again */
431 	dev->trans_start = jiffies;
432 	netif_wake_queue(dev);
433 
434 	/* Restore previous register address */
435 	spin_unlock_irqrestore(&db->lock, flags);
436 }
437 
438 /* Hardware start transmission.
439  * Send a packet to media from the upper layer.
440  */
441 static int emac_start_xmit(struct sk_buff *skb, struct net_device *dev)
442 {
443 	struct emac_board_info *db = netdev_priv(dev);
444 	unsigned long channel;
445 	unsigned long flags;
446 
447 	channel = db->tx_fifo_stat & 3;
448 	if (channel == 3)
449 		return 1;
450 
451 	channel = (channel == 1 ? 1 : 0);
452 
453 	spin_lock_irqsave(&db->lock, flags);
454 
455 	writel(channel, db->membase + EMAC_TX_INS_REG);
456 
457 	emac_outblk_32bit(db->membase + EMAC_TX_IO_DATA_REG,
458 			skb->data, skb->len);
459 	dev->stats.tx_bytes += skb->len;
460 
461 	db->tx_fifo_stat |= 1 << channel;
462 	/* TX control: First packet immediately send, second packet queue */
463 	if (channel == 0) {
464 		/* set TX len */
465 		writel(skb->len, db->membase + EMAC_TX_PL0_REG);
466 		/* start translate from fifo to phy */
467 		writel(readl(db->membase + EMAC_TX_CTL0_REG) | 1,
468 		       db->membase + EMAC_TX_CTL0_REG);
469 
470 		/* save the time stamp */
471 		dev->trans_start = jiffies;
472 	} else if (channel == 1) {
473 		/* set TX len */
474 		writel(skb->len, db->membase + EMAC_TX_PL1_REG);
475 		/* start translate from fifo to phy */
476 		writel(readl(db->membase + EMAC_TX_CTL1_REG) | 1,
477 		       db->membase + EMAC_TX_CTL1_REG);
478 
479 		/* save the time stamp */
480 		dev->trans_start = jiffies;
481 	}
482 
483 	if ((db->tx_fifo_stat & 3) == 3) {
484 		/* Second packet */
485 		netif_stop_queue(dev);
486 	}
487 
488 	spin_unlock_irqrestore(&db->lock, flags);
489 
490 	/* free this SKB */
491 	dev_consume_skb_any(skb);
492 
493 	return NETDEV_TX_OK;
494 }
495 
496 /* EMAC interrupt handler
497  * receive the packet to upper layer, free the transmitted packet
498  */
499 static void emac_tx_done(struct net_device *dev, struct emac_board_info *db,
500 			  unsigned int tx_status)
501 {
502 	/* One packet sent complete */
503 	db->tx_fifo_stat &= ~(tx_status & 3);
504 	if (3 == (tx_status & 3))
505 		dev->stats.tx_packets += 2;
506 	else
507 		dev->stats.tx_packets++;
508 
509 	if (netif_msg_tx_done(db))
510 		dev_dbg(db->dev, "tx done, NSR %02x\n", tx_status);
511 
512 	netif_wake_queue(dev);
513 }
514 
515 /* Received a packet and pass to upper layer
516  */
517 static void emac_rx(struct net_device *dev)
518 {
519 	struct emac_board_info *db = netdev_priv(dev);
520 	struct sk_buff *skb;
521 	u8 *rdptr;
522 	bool good_packet;
523 	static int rxlen_last;
524 	unsigned int reg_val;
525 	u32 rxhdr, rxstatus, rxcount, rxlen;
526 
527 	/* Check packet ready or not */
528 	while (1) {
529 		/* race warning: the first packet might arrive with
530 		 * the interrupts disabled, but the second will fix
531 		 * it
532 		 */
533 		rxcount = readl(db->membase + EMAC_RX_FBC_REG);
534 
535 		if (netif_msg_rx_status(db))
536 			dev_dbg(db->dev, "RXCount: %x\n", rxcount);
537 
538 		if ((db->skb_last != NULL) && (rxlen_last > 0)) {
539 			dev->stats.rx_bytes += rxlen_last;
540 
541 			/* Pass to upper layer */
542 			db->skb_last->protocol = eth_type_trans(db->skb_last,
543 								dev);
544 			netif_rx(db->skb_last);
545 			dev->stats.rx_packets++;
546 			db->skb_last = NULL;
547 			rxlen_last = 0;
548 
549 			reg_val = readl(db->membase + EMAC_RX_CTL_REG);
550 			reg_val &= ~EMAC_RX_CTL_DMA_EN;
551 			writel(reg_val, db->membase + EMAC_RX_CTL_REG);
552 		}
553 
554 		if (!rxcount) {
555 			db->emacrx_completed_flag = 1;
556 			reg_val = readl(db->membase + EMAC_INT_CTL_REG);
557 			reg_val |= (0xf << 0) | (0x01 << 8);
558 			writel(reg_val, db->membase + EMAC_INT_CTL_REG);
559 
560 			/* had one stuck? */
561 			rxcount = readl(db->membase + EMAC_RX_FBC_REG);
562 			if (!rxcount)
563 				return;
564 		}
565 
566 		reg_val = readl(db->membase + EMAC_RX_IO_DATA_REG);
567 		if (netif_msg_rx_status(db))
568 			dev_dbg(db->dev, "receive header: %x\n", reg_val);
569 		if (reg_val != EMAC_UNDOCUMENTED_MAGIC) {
570 			/* disable RX */
571 			reg_val = readl(db->membase + EMAC_CTL_REG);
572 			writel(reg_val & ~EMAC_CTL_RX_EN,
573 			       db->membase + EMAC_CTL_REG);
574 
575 			/* Flush RX FIFO */
576 			reg_val = readl(db->membase + EMAC_RX_CTL_REG);
577 			writel(reg_val | (1 << 3),
578 			       db->membase + EMAC_RX_CTL_REG);
579 
580 			do {
581 				reg_val = readl(db->membase + EMAC_RX_CTL_REG);
582 			} while (reg_val & (1 << 3));
583 
584 			/* enable RX */
585 			reg_val = readl(db->membase + EMAC_CTL_REG);
586 			writel(reg_val | EMAC_CTL_RX_EN,
587 			       db->membase + EMAC_CTL_REG);
588 			reg_val = readl(db->membase + EMAC_INT_CTL_REG);
589 			reg_val |= (0xf << 0) | (0x01 << 8);
590 			writel(reg_val, db->membase + EMAC_INT_CTL_REG);
591 
592 			db->emacrx_completed_flag = 1;
593 
594 			return;
595 		}
596 
597 		/* A packet ready now  & Get status/length */
598 		good_packet = true;
599 
600 		emac_inblk_32bit(db->membase + EMAC_RX_IO_DATA_REG,
601 				&rxhdr, sizeof(rxhdr));
602 
603 		if (netif_msg_rx_status(db))
604 			dev_dbg(db->dev, "rxhdr: %x\n", *((int *)(&rxhdr)));
605 
606 		rxlen = EMAC_RX_IO_DATA_LEN(rxhdr);
607 		rxstatus = EMAC_RX_IO_DATA_STATUS(rxhdr);
608 
609 		if (netif_msg_rx_status(db))
610 			dev_dbg(db->dev, "RX: status %02x, length %04x\n",
611 				rxstatus, rxlen);
612 
613 		/* Packet Status check */
614 		if (rxlen < 0x40) {
615 			good_packet = false;
616 			if (netif_msg_rx_err(db))
617 				dev_dbg(db->dev, "RX: Bad Packet (runt)\n");
618 		}
619 
620 		if (unlikely(!(rxstatus & EMAC_RX_IO_DATA_STATUS_OK))) {
621 			good_packet = false;
622 
623 			if (rxstatus & EMAC_RX_IO_DATA_STATUS_CRC_ERR) {
624 				if (netif_msg_rx_err(db))
625 					dev_dbg(db->dev, "crc error\n");
626 				dev->stats.rx_crc_errors++;
627 			}
628 
629 			if (rxstatus & EMAC_RX_IO_DATA_STATUS_LEN_ERR) {
630 				if (netif_msg_rx_err(db))
631 					dev_dbg(db->dev, "length error\n");
632 				dev->stats.rx_length_errors++;
633 			}
634 		}
635 
636 		/* Move data from EMAC */
637 		if (good_packet) {
638 			skb = netdev_alloc_skb(dev, rxlen + 4);
639 			if (!skb)
640 				continue;
641 			skb_reserve(skb, 2);
642 			rdptr = (u8 *) skb_put(skb, rxlen - 4);
643 
644 			/* Read received packet from RX SRAM */
645 			if (netif_msg_rx_status(db))
646 				dev_dbg(db->dev, "RxLen %x\n", rxlen);
647 
648 			emac_inblk_32bit(db->membase + EMAC_RX_IO_DATA_REG,
649 					rdptr, rxlen);
650 			dev->stats.rx_bytes += rxlen;
651 
652 			/* Pass to upper layer */
653 			skb->protocol = eth_type_trans(skb, dev);
654 			netif_rx(skb);
655 			dev->stats.rx_packets++;
656 		}
657 	}
658 }
659 
660 static irqreturn_t emac_interrupt(int irq, void *dev_id)
661 {
662 	struct net_device *dev = dev_id;
663 	struct emac_board_info *db = netdev_priv(dev);
664 	int int_status;
665 	unsigned long flags;
666 	unsigned int reg_val;
667 
668 	/* A real interrupt coming */
669 
670 	/* holders of db->lock must always block IRQs */
671 	spin_lock_irqsave(&db->lock, flags);
672 
673 	/* Disable all interrupts */
674 	writel(0, db->membase + EMAC_INT_CTL_REG);
675 
676 	/* Got EMAC interrupt status */
677 	/* Got ISR */
678 	int_status = readl(db->membase + EMAC_INT_STA_REG);
679 	/* Clear ISR status */
680 	writel(int_status, db->membase + EMAC_INT_STA_REG);
681 
682 	if (netif_msg_intr(db))
683 		dev_dbg(db->dev, "emac interrupt %02x\n", int_status);
684 
685 	/* Received the coming packet */
686 	if ((int_status & 0x100) && (db->emacrx_completed_flag == 1)) {
687 		/* carrier lost */
688 		db->emacrx_completed_flag = 0;
689 		emac_rx(dev);
690 	}
691 
692 	/* Transmit Interrupt check */
693 	if (int_status & (0x01 | 0x02))
694 		emac_tx_done(dev, db, int_status);
695 
696 	if (int_status & (0x04 | 0x08))
697 		netdev_info(dev, " ab : %x\n", int_status);
698 
699 	/* Re-enable interrupt mask */
700 	if (db->emacrx_completed_flag == 1) {
701 		reg_val = readl(db->membase + EMAC_INT_CTL_REG);
702 		reg_val |= (0xf << 0) | (0x01 << 8);
703 		writel(reg_val, db->membase + EMAC_INT_CTL_REG);
704 	}
705 	spin_unlock_irqrestore(&db->lock, flags);
706 
707 	return IRQ_HANDLED;
708 }
709 
710 #ifdef CONFIG_NET_POLL_CONTROLLER
711 /*
712  * Used by netconsole
713  */
714 static void emac_poll_controller(struct net_device *dev)
715 {
716 	disable_irq(dev->irq);
717 	emac_interrupt(dev->irq, dev);
718 	enable_irq(dev->irq);
719 }
720 #endif
721 
722 /*  Open the interface.
723  *  The interface is opened whenever "ifconfig" actives it.
724  */
725 static int emac_open(struct net_device *dev)
726 {
727 	struct emac_board_info *db = netdev_priv(dev);
728 	int ret;
729 
730 	if (netif_msg_ifup(db))
731 		dev_dbg(db->dev, "enabling %s\n", dev->name);
732 
733 	if (request_irq(dev->irq, &emac_interrupt, 0, dev->name, dev))
734 		return -EAGAIN;
735 
736 	/* Initialize EMAC board */
737 	emac_reset(db);
738 	emac_init_device(dev);
739 
740 	ret = emac_mdio_probe(dev);
741 	if (ret < 0) {
742 		free_irq(dev->irq, dev);
743 		netdev_err(dev, "cannot probe MDIO bus\n");
744 		return ret;
745 	}
746 
747 	phy_start(db->phy_dev);
748 	netif_start_queue(dev);
749 
750 	return 0;
751 }
752 
753 static void emac_shutdown(struct net_device *dev)
754 {
755 	unsigned int reg_val;
756 	struct emac_board_info *db = netdev_priv(dev);
757 
758 	/* Disable all interrupt */
759 	writel(0, db->membase + EMAC_INT_CTL_REG);
760 
761 	/* clear interrupt status */
762 	reg_val = readl(db->membase + EMAC_INT_STA_REG);
763 	writel(reg_val, db->membase + EMAC_INT_STA_REG);
764 
765 	/* Disable RX/TX */
766 	reg_val = readl(db->membase + EMAC_CTL_REG);
767 	reg_val &= ~(EMAC_CTL_TX_EN | EMAC_CTL_RX_EN | EMAC_CTL_RESET);
768 	writel(reg_val, db->membase + EMAC_CTL_REG);
769 }
770 
771 /* Stop the interface.
772  * The interface is stopped when it is brought.
773  */
774 static int emac_stop(struct net_device *ndev)
775 {
776 	struct emac_board_info *db = netdev_priv(ndev);
777 
778 	if (netif_msg_ifdown(db))
779 		dev_dbg(db->dev, "shutting down %s\n", ndev->name);
780 
781 	netif_stop_queue(ndev);
782 	netif_carrier_off(ndev);
783 
784 	phy_stop(db->phy_dev);
785 
786 	emac_mdio_remove(ndev);
787 
788 	emac_shutdown(ndev);
789 
790 	free_irq(ndev->irq, ndev);
791 
792 	return 0;
793 }
794 
795 static const struct net_device_ops emac_netdev_ops = {
796 	.ndo_open		= emac_open,
797 	.ndo_stop		= emac_stop,
798 	.ndo_start_xmit		= emac_start_xmit,
799 	.ndo_tx_timeout		= emac_timeout,
800 	.ndo_set_rx_mode	= emac_set_rx_mode,
801 	.ndo_do_ioctl		= emac_ioctl,
802 	.ndo_change_mtu		= eth_change_mtu,
803 	.ndo_validate_addr	= eth_validate_addr,
804 	.ndo_set_mac_address	= emac_set_mac_address,
805 #ifdef CONFIG_NET_POLL_CONTROLLER
806 	.ndo_poll_controller	= emac_poll_controller,
807 #endif
808 };
809 
810 /* Search EMAC board, allocate space and register it
811  */
812 static int emac_probe(struct platform_device *pdev)
813 {
814 	struct device_node *np = pdev->dev.of_node;
815 	struct emac_board_info *db;
816 	struct net_device *ndev;
817 	int ret = 0;
818 	const char *mac_addr;
819 
820 	ndev = alloc_etherdev(sizeof(struct emac_board_info));
821 	if (!ndev) {
822 		dev_err(&pdev->dev, "could not allocate device.\n");
823 		return -ENOMEM;
824 	}
825 
826 	SET_NETDEV_DEV(ndev, &pdev->dev);
827 
828 	db = netdev_priv(ndev);
829 	memset(db, 0, sizeof(*db));
830 
831 	db->dev = &pdev->dev;
832 	db->ndev = ndev;
833 	db->pdev = pdev;
834 
835 	spin_lock_init(&db->lock);
836 
837 	db->membase = of_iomap(np, 0);
838 	if (!db->membase) {
839 		dev_err(&pdev->dev, "failed to remap registers\n");
840 		ret = -ENOMEM;
841 		goto out;
842 	}
843 
844 	/* fill in parameters for net-dev structure */
845 	ndev->base_addr = (unsigned long)db->membase;
846 	ndev->irq = irq_of_parse_and_map(np, 0);
847 	if (ndev->irq == -ENXIO) {
848 		netdev_err(ndev, "No irq resource\n");
849 		ret = ndev->irq;
850 		goto out_iounmap;
851 	}
852 
853 	db->clk = devm_clk_get(&pdev->dev, NULL);
854 	if (IS_ERR(db->clk)) {
855 		ret = PTR_ERR(db->clk);
856 		goto out_iounmap;
857 	}
858 
859 	ret = clk_prepare_enable(db->clk);
860 	if (ret) {
861 		dev_err(&pdev->dev, "Error couldn't enable clock (%d)\n", ret);
862 		goto out_iounmap;
863 	}
864 
865 	ret = sunxi_sram_claim(&pdev->dev);
866 	if (ret) {
867 		dev_err(&pdev->dev, "Error couldn't map SRAM to device\n");
868 		goto out_clk_disable_unprepare;
869 	}
870 
871 	db->phy_node = of_parse_phandle(np, "phy", 0);
872 	if (!db->phy_node) {
873 		dev_err(&pdev->dev, "no associated PHY\n");
874 		ret = -ENODEV;
875 		goto out_release_sram;
876 	}
877 
878 	/* Read MAC-address from DT */
879 	mac_addr = of_get_mac_address(np);
880 	if (mac_addr)
881 		memcpy(ndev->dev_addr, mac_addr, ETH_ALEN);
882 
883 	/* Check if the MAC address is valid, if not get a random one */
884 	if (!is_valid_ether_addr(ndev->dev_addr)) {
885 		eth_hw_addr_random(ndev);
886 		dev_warn(&pdev->dev, "using random MAC address %pM\n",
887 			 ndev->dev_addr);
888 	}
889 
890 	db->emacrx_completed_flag = 1;
891 	emac_powerup(ndev);
892 	emac_reset(db);
893 
894 	ndev->netdev_ops = &emac_netdev_ops;
895 	ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
896 	ndev->ethtool_ops = &emac_ethtool_ops;
897 
898 	platform_set_drvdata(pdev, ndev);
899 
900 	/* Carrier starts down, phylib will bring it up */
901 	netif_carrier_off(ndev);
902 
903 	ret = register_netdev(ndev);
904 	if (ret) {
905 		dev_err(&pdev->dev, "Registering netdev failed!\n");
906 		ret = -ENODEV;
907 		goto out_release_sram;
908 	}
909 
910 	dev_info(&pdev->dev, "%s: at %p, IRQ %d MAC: %pM\n",
911 		 ndev->name, db->membase, ndev->irq, ndev->dev_addr);
912 
913 	return 0;
914 
915 out_release_sram:
916 	sunxi_sram_release(&pdev->dev);
917 out_clk_disable_unprepare:
918 	clk_disable_unprepare(db->clk);
919 out_iounmap:
920 	iounmap(db->membase);
921 out:
922 	dev_err(db->dev, "not found (%d).\n", ret);
923 
924 	free_netdev(ndev);
925 
926 	return ret;
927 }
928 
929 static int emac_remove(struct platform_device *pdev)
930 {
931 	struct net_device *ndev = platform_get_drvdata(pdev);
932 	struct emac_board_info *db = netdev_priv(ndev);
933 
934 	unregister_netdev(ndev);
935 	sunxi_sram_release(&pdev->dev);
936 	clk_disable_unprepare(db->clk);
937 	iounmap(db->membase);
938 	free_netdev(ndev);
939 
940 	dev_dbg(&pdev->dev, "released and freed device\n");
941 	return 0;
942 }
943 
944 static int emac_suspend(struct platform_device *dev, pm_message_t state)
945 {
946 	struct net_device *ndev = platform_get_drvdata(dev);
947 
948 	netif_carrier_off(ndev);
949 	netif_device_detach(ndev);
950 	emac_shutdown(ndev);
951 
952 	return 0;
953 }
954 
955 static int emac_resume(struct platform_device *dev)
956 {
957 	struct net_device *ndev = platform_get_drvdata(dev);
958 	struct emac_board_info *db = netdev_priv(ndev);
959 
960 	emac_reset(db);
961 	emac_init_device(ndev);
962 	netif_device_attach(ndev);
963 
964 	return 0;
965 }
966 
967 static const struct of_device_id emac_of_match[] = {
968 	{.compatible = "allwinner,sun4i-a10-emac",},
969 
970 	/* Deprecated */
971 	{.compatible = "allwinner,sun4i-emac",},
972 	{},
973 };
974 
975 MODULE_DEVICE_TABLE(of, emac_of_match);
976 
977 static struct platform_driver emac_driver = {
978 	.driver = {
979 		.name = "sun4i-emac",
980 		.of_match_table = emac_of_match,
981 	},
982 	.probe = emac_probe,
983 	.remove = emac_remove,
984 	.suspend = emac_suspend,
985 	.resume = emac_resume,
986 };
987 
988 module_platform_driver(emac_driver);
989 
990 MODULE_AUTHOR("Stefan Roese <sr@denx.de>");
991 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
992 MODULE_DESCRIPTION("Allwinner A10 emac network driver");
993 MODULE_LICENSE("GPL");
994