1 /*
2  * Xilinx EmacLite Linux driver for the Xilinx Ethernet MAC Lite device.
3  *
4  * This is a new flat driver which is based on the original emac_lite
5  * driver from John Williams <john.williams@xilinx.com>.
6  *
7  * 2007 - 2013 (c) Xilinx, Inc.
8  *
9  * This program is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU General Public License as published by the
11  * Free Software Foundation; either version 2 of the License, or (at your
12  * option) any later version.
13  */
14 
15 #include <linux/module.h>
16 #include <linux/uaccess.h>
17 #include <linux/netdevice.h>
18 #include <linux/etherdevice.h>
19 #include <linux/skbuff.h>
20 #include <linux/io.h>
21 #include <linux/slab.h>
22 #include <linux/of_address.h>
23 #include <linux/of_device.h>
24 #include <linux/of_platform.h>
25 #include <linux/of_mdio.h>
26 #include <linux/of_net.h>
27 #include <linux/phy.h>
28 #include <linux/interrupt.h>
29 
30 #define DRIVER_NAME "xilinx_emaclite"
31 
32 /* Register offsets for the EmacLite Core */
33 #define XEL_TXBUFF_OFFSET	0x0		/* Transmit Buffer */
34 #define XEL_MDIOADDR_OFFSET	0x07E4		/* MDIO Address Register */
35 #define XEL_MDIOWR_OFFSET	0x07E8		/* MDIO Write Data Register */
36 #define XEL_MDIORD_OFFSET	0x07EC		/* MDIO Read Data Register */
37 #define XEL_MDIOCTRL_OFFSET	0x07F0		/* MDIO Control Register */
38 #define XEL_GIER_OFFSET		0x07F8		/* GIE Register */
39 #define XEL_TSR_OFFSET		0x07FC		/* Tx status */
40 #define XEL_TPLR_OFFSET		0x07F4		/* Tx packet length */
41 
42 #define XEL_RXBUFF_OFFSET	0x1000		/* Receive Buffer */
43 #define XEL_RPLR_OFFSET		0x100C		/* Rx packet length */
44 #define XEL_RSR_OFFSET		0x17FC		/* Rx status */
45 
46 #define XEL_BUFFER_OFFSET	0x0800		/* Next Tx/Rx buffer's offset */
47 
48 /* MDIO Address Register Bit Masks */
49 #define XEL_MDIOADDR_REGADR_MASK  0x0000001F	/* Register Address */
50 #define XEL_MDIOADDR_PHYADR_MASK  0x000003E0	/* PHY Address */
51 #define XEL_MDIOADDR_PHYADR_SHIFT 5
52 #define XEL_MDIOADDR_OP_MASK	  0x00000400	/* RD/WR Operation */
53 
54 /* MDIO Write Data Register Bit Masks */
55 #define XEL_MDIOWR_WRDATA_MASK	  0x0000FFFF	/* Data to be Written */
56 
57 /* MDIO Read Data Register Bit Masks */
58 #define XEL_MDIORD_RDDATA_MASK	  0x0000FFFF	/* Data to be Read */
59 
60 /* MDIO Control Register Bit Masks */
61 #define XEL_MDIOCTRL_MDIOSTS_MASK 0x00000001	/* MDIO Status Mask */
62 #define XEL_MDIOCTRL_MDIOEN_MASK  0x00000008	/* MDIO Enable */
63 
64 /* Global Interrupt Enable Register (GIER) Bit Masks */
65 #define XEL_GIER_GIE_MASK	0x80000000	/* Global Enable */
66 
67 /* Transmit Status Register (TSR) Bit Masks */
68 #define XEL_TSR_XMIT_BUSY_MASK	 0x00000001	/* Tx complete */
69 #define XEL_TSR_PROGRAM_MASK	 0x00000002	/* Program the MAC address */
70 #define XEL_TSR_XMIT_IE_MASK	 0x00000008	/* Tx interrupt enable bit */
71 #define XEL_TSR_XMIT_ACTIVE_MASK 0x80000000	/* Buffer is active, SW bit
72 						 * only. This is not documented
73 						 * in the HW spec */
74 
75 /* Define for programming the MAC address into the EmacLite */
76 #define XEL_TSR_PROG_MAC_ADDR	(XEL_TSR_XMIT_BUSY_MASK | XEL_TSR_PROGRAM_MASK)
77 
78 /* Receive Status Register (RSR) */
79 #define XEL_RSR_RECV_DONE_MASK	0x00000001	/* Rx complete */
80 #define XEL_RSR_RECV_IE_MASK	0x00000008	/* Rx interrupt enable bit */
81 
82 /* Transmit Packet Length Register (TPLR) */
83 #define XEL_TPLR_LENGTH_MASK	0x0000FFFF	/* Tx packet length */
84 
85 /* Receive Packet Length Register (RPLR) */
86 #define XEL_RPLR_LENGTH_MASK	0x0000FFFF	/* Rx packet length */
87 
88 #define XEL_HEADER_OFFSET	12		/* Offset to length field */
89 #define XEL_HEADER_SHIFT	16		/* Shift value for length */
90 
91 /* General Ethernet Definitions */
92 #define XEL_ARP_PACKET_SIZE		28	/* Max ARP packet size */
93 #define XEL_HEADER_IP_LENGTH_OFFSET	16	/* IP Length Offset */
94 
95 
96 
97 #define TX_TIMEOUT		(60*HZ)		/* Tx timeout is 60 seconds. */
98 #define ALIGNMENT		4
99 
100 /* BUFFER_ALIGN(adr) calculates the number of bytes to the next alignment. */
101 #define BUFFER_ALIGN(adr) ((ALIGNMENT - ((u32) adr)) % ALIGNMENT)
102 
103 #ifdef __BIG_ENDIAN
104 #define xemaclite_readl		ioread32be
105 #define xemaclite_writel	iowrite32be
106 #else
107 #define xemaclite_readl		ioread32
108 #define xemaclite_writel	iowrite32
109 #endif
110 
111 /**
112  * struct net_local - Our private per device data
113  * @ndev:		instance of the network device
114  * @tx_ping_pong:	indicates whether Tx Pong buffer is configured in HW
115  * @rx_ping_pong:	indicates whether Rx Pong buffer is configured in HW
116  * @next_tx_buf_to_use:	next Tx buffer to write to
117  * @next_rx_buf_to_use:	next Rx buffer to read from
118  * @base_addr:		base address of the Emaclite device
119  * @reset_lock:		lock used for synchronization
120  * @deferred_skb:	holds an skb (for transmission at a later time) when the
121  *			Tx buffer is not free
122  * @phy_dev:		pointer to the PHY device
123  * @phy_node:		pointer to the PHY device node
124  * @mii_bus:		pointer to the MII bus
125  * @last_link:		last link status
126  * @has_mdio:		indicates whether MDIO is included in the HW
127  */
128 struct net_local {
129 
130 	struct net_device *ndev;
131 
132 	bool tx_ping_pong;
133 	bool rx_ping_pong;
134 	u32 next_tx_buf_to_use;
135 	u32 next_rx_buf_to_use;
136 	void __iomem *base_addr;
137 
138 	spinlock_t reset_lock;
139 	struct sk_buff *deferred_skb;
140 
141 	struct phy_device *phy_dev;
142 	struct device_node *phy_node;
143 
144 	struct mii_bus *mii_bus;
145 
146 	int last_link;
147 	bool has_mdio;
148 };
149 
150 
151 /*************************/
152 /* EmacLite driver calls */
153 /*************************/
154 
155 /**
156  * xemaclite_enable_interrupts - Enable the interrupts for the EmacLite device
157  * @drvdata:	Pointer to the Emaclite device private data
158  *
159  * This function enables the Tx and Rx interrupts for the Emaclite device along
160  * with the Global Interrupt Enable.
161  */
162 static void xemaclite_enable_interrupts(struct net_local *drvdata)
163 {
164 	u32 reg_data;
165 
166 	/* Enable the Tx interrupts for the first Buffer */
167 	reg_data = xemaclite_readl(drvdata->base_addr + XEL_TSR_OFFSET);
168 	xemaclite_writel(reg_data | XEL_TSR_XMIT_IE_MASK,
169 			 drvdata->base_addr + XEL_TSR_OFFSET);
170 
171 	/* Enable the Rx interrupts for the first buffer */
172 	xemaclite_writel(XEL_RSR_RECV_IE_MASK, drvdata->base_addr + XEL_RSR_OFFSET);
173 
174 	/* Enable the Global Interrupt Enable */
175 	xemaclite_writel(XEL_GIER_GIE_MASK, drvdata->base_addr + XEL_GIER_OFFSET);
176 }
177 
178 /**
179  * xemaclite_disable_interrupts - Disable the interrupts for the EmacLite device
180  * @drvdata:	Pointer to the Emaclite device private data
181  *
182  * This function disables the Tx and Rx interrupts for the Emaclite device,
183  * along with the Global Interrupt Enable.
184  */
185 static void xemaclite_disable_interrupts(struct net_local *drvdata)
186 {
187 	u32 reg_data;
188 
189 	/* Disable the Global Interrupt Enable */
190 	xemaclite_writel(XEL_GIER_GIE_MASK, drvdata->base_addr + XEL_GIER_OFFSET);
191 
192 	/* Disable the Tx interrupts for the first buffer */
193 	reg_data = xemaclite_readl(drvdata->base_addr + XEL_TSR_OFFSET);
194 	xemaclite_writel(reg_data & (~XEL_TSR_XMIT_IE_MASK),
195 			 drvdata->base_addr + XEL_TSR_OFFSET);
196 
197 	/* Disable the Rx interrupts for the first buffer */
198 	reg_data = xemaclite_readl(drvdata->base_addr + XEL_RSR_OFFSET);
199 	xemaclite_writel(reg_data & (~XEL_RSR_RECV_IE_MASK),
200 			 drvdata->base_addr + XEL_RSR_OFFSET);
201 }
202 
203 /**
204  * xemaclite_aligned_write - Write from 16-bit aligned to 32-bit aligned address
205  * @src_ptr:	Void pointer to the 16-bit aligned source address
206  * @dest_ptr:	Pointer to the 32-bit aligned destination address
207  * @length:	Number bytes to write from source to destination
208  *
209  * This function writes data from a 16-bit aligned buffer to a 32-bit aligned
210  * address in the EmacLite device.
211  */
212 static void xemaclite_aligned_write(void *src_ptr, u32 *dest_ptr,
213 				    unsigned length)
214 {
215 	u32 align_buffer;
216 	u32 *to_u32_ptr;
217 	u16 *from_u16_ptr, *to_u16_ptr;
218 
219 	to_u32_ptr = dest_ptr;
220 	from_u16_ptr = src_ptr;
221 	align_buffer = 0;
222 
223 	for (; length > 3; length -= 4) {
224 		to_u16_ptr = (u16 *)&align_buffer;
225 		*to_u16_ptr++ = *from_u16_ptr++;
226 		*to_u16_ptr++ = *from_u16_ptr++;
227 
228 		/* This barrier resolves occasional issues seen around
229 		 * cases where the data is not properly flushed out
230 		 * from the processor store buffers to the destination
231 		 * memory locations.
232 		 */
233 		wmb();
234 
235 		/* Output a word */
236 		*to_u32_ptr++ = align_buffer;
237 	}
238 	if (length) {
239 		u8 *from_u8_ptr, *to_u8_ptr;
240 
241 		/* Set up to output the remaining data */
242 		align_buffer = 0;
243 		to_u8_ptr = (u8 *) &align_buffer;
244 		from_u8_ptr = (u8 *) from_u16_ptr;
245 
246 		/* Output the remaining data */
247 		for (; length > 0; length--)
248 			*to_u8_ptr++ = *from_u8_ptr++;
249 
250 		/* This barrier resolves occasional issues seen around
251 		 * cases where the data is not properly flushed out
252 		 * from the processor store buffers to the destination
253 		 * memory locations.
254 		 */
255 		wmb();
256 		*to_u32_ptr = align_buffer;
257 	}
258 }
259 
260 /**
261  * xemaclite_aligned_read - Read from 32-bit aligned to 16-bit aligned buffer
262  * @src_ptr:	Pointer to the 32-bit aligned source address
263  * @dest_ptr:	Pointer to the 16-bit aligned destination address
264  * @length:	Number bytes to read from source to destination
265  *
266  * This function reads data from a 32-bit aligned address in the EmacLite device
267  * to a 16-bit aligned buffer.
268  */
269 static void xemaclite_aligned_read(u32 *src_ptr, u8 *dest_ptr,
270 				   unsigned length)
271 {
272 	u16 *to_u16_ptr, *from_u16_ptr;
273 	u32 *from_u32_ptr;
274 	u32 align_buffer;
275 
276 	from_u32_ptr = src_ptr;
277 	to_u16_ptr = (u16 *) dest_ptr;
278 
279 	for (; length > 3; length -= 4) {
280 		/* Copy each word into the temporary buffer */
281 		align_buffer = *from_u32_ptr++;
282 		from_u16_ptr = (u16 *)&align_buffer;
283 
284 		/* Read data from source */
285 		*to_u16_ptr++ = *from_u16_ptr++;
286 		*to_u16_ptr++ = *from_u16_ptr++;
287 	}
288 
289 	if (length) {
290 		u8 *to_u8_ptr, *from_u8_ptr;
291 
292 		/* Set up to read the remaining data */
293 		to_u8_ptr = (u8 *) to_u16_ptr;
294 		align_buffer = *from_u32_ptr++;
295 		from_u8_ptr = (u8 *) &align_buffer;
296 
297 		/* Read the remaining data */
298 		for (; length > 0; length--)
299 			*to_u8_ptr = *from_u8_ptr;
300 	}
301 }
302 
303 /**
304  * xemaclite_send_data - Send an Ethernet frame
305  * @drvdata:	Pointer to the Emaclite device private data
306  * @data:	Pointer to the data to be sent
307  * @byte_count:	Total frame size, including header
308  *
309  * This function checks if the Tx buffer of the Emaclite device is free to send
310  * data. If so, it fills the Tx buffer with data for transmission. Otherwise, it
311  * returns an error.
312  *
313  * Return:	0 upon success or -1 if the buffer(s) are full.
314  *
315  * Note:	The maximum Tx packet size can not be more than Ethernet header
316  *		(14 Bytes) + Maximum MTU (1500 bytes). This is excluding FCS.
317  */
318 static int xemaclite_send_data(struct net_local *drvdata, u8 *data,
319 			       unsigned int byte_count)
320 {
321 	u32 reg_data;
322 	void __iomem *addr;
323 
324 	/* Determine the expected Tx buffer address */
325 	addr = drvdata->base_addr + drvdata->next_tx_buf_to_use;
326 
327 	/* If the length is too large, truncate it */
328 	if (byte_count > ETH_FRAME_LEN)
329 		byte_count = ETH_FRAME_LEN;
330 
331 	/* Check if the expected buffer is available */
332 	reg_data = xemaclite_readl(addr + XEL_TSR_OFFSET);
333 	if ((reg_data & (XEL_TSR_XMIT_BUSY_MASK |
334 	     XEL_TSR_XMIT_ACTIVE_MASK)) == 0) {
335 
336 		/* Switch to next buffer if configured */
337 		if (drvdata->tx_ping_pong != 0)
338 			drvdata->next_tx_buf_to_use ^= XEL_BUFFER_OFFSET;
339 	} else if (drvdata->tx_ping_pong != 0) {
340 		/* If the expected buffer is full, try the other buffer,
341 		 * if it is configured in HW */
342 
343 		addr = (void __iomem __force *)((u32 __force)addr ^
344 						 XEL_BUFFER_OFFSET);
345 		reg_data = xemaclite_readl(addr + XEL_TSR_OFFSET);
346 
347 		if ((reg_data & (XEL_TSR_XMIT_BUSY_MASK |
348 		     XEL_TSR_XMIT_ACTIVE_MASK)) != 0)
349 			return -1; /* Buffers were full, return failure */
350 	} else
351 		return -1; /* Buffer was full, return failure */
352 
353 	/* Write the frame to the buffer */
354 	xemaclite_aligned_write(data, (u32 __force *) addr, byte_count);
355 
356 	xemaclite_writel((byte_count & XEL_TPLR_LENGTH_MASK),
357 			 addr + XEL_TPLR_OFFSET);
358 
359 	/* Update the Tx Status Register to indicate that there is a
360 	 * frame to send. Set the XEL_TSR_XMIT_ACTIVE_MASK flag which
361 	 * is used by the interrupt handler to check whether a frame
362 	 * has been transmitted */
363 	reg_data = xemaclite_readl(addr + XEL_TSR_OFFSET);
364 	reg_data |= (XEL_TSR_XMIT_BUSY_MASK | XEL_TSR_XMIT_ACTIVE_MASK);
365 	xemaclite_writel(reg_data, addr + XEL_TSR_OFFSET);
366 
367 	return 0;
368 }
369 
370 /**
371  * xemaclite_recv_data - Receive a frame
372  * @drvdata:	Pointer to the Emaclite device private data
373  * @data:	Address where the data is to be received
374  *
375  * This function is intended to be called from the interrupt context or
376  * with a wrapper which waits for the receive frame to be available.
377  *
378  * Return:	Total number of bytes received
379  */
380 static u16 xemaclite_recv_data(struct net_local *drvdata, u8 *data, int maxlen)
381 {
382 	void __iomem *addr;
383 	u16 length, proto_type;
384 	u32 reg_data;
385 
386 	/* Determine the expected buffer address */
387 	addr = (drvdata->base_addr + drvdata->next_rx_buf_to_use);
388 
389 	/* Verify which buffer has valid data */
390 	reg_data = xemaclite_readl(addr + XEL_RSR_OFFSET);
391 
392 	if ((reg_data & XEL_RSR_RECV_DONE_MASK) == XEL_RSR_RECV_DONE_MASK) {
393 		if (drvdata->rx_ping_pong != 0)
394 			drvdata->next_rx_buf_to_use ^= XEL_BUFFER_OFFSET;
395 	} else {
396 		/* The instance is out of sync, try other buffer if other
397 		 * buffer is configured, return 0 otherwise. If the instance is
398 		 * out of sync, do not update the 'next_rx_buf_to_use' since it
399 		 * will correct on subsequent calls */
400 		if (drvdata->rx_ping_pong != 0)
401 			addr = (void __iomem __force *)((u32 __force)addr ^
402 							 XEL_BUFFER_OFFSET);
403 		else
404 			return 0;	/* No data was available */
405 
406 		/* Verify that buffer has valid data */
407 		reg_data = xemaclite_readl(addr + XEL_RSR_OFFSET);
408 		if ((reg_data & XEL_RSR_RECV_DONE_MASK) !=
409 		     XEL_RSR_RECV_DONE_MASK)
410 			return 0;	/* No data was available */
411 	}
412 
413 	/* Get the protocol type of the ethernet frame that arrived */
414 	proto_type = ((ntohl(xemaclite_readl(addr + XEL_HEADER_OFFSET +
415 			XEL_RXBUFF_OFFSET)) >> XEL_HEADER_SHIFT) &
416 			XEL_RPLR_LENGTH_MASK);
417 
418 	/* Check if received ethernet frame is a raw ethernet frame
419 	 * or an IP packet or an ARP packet */
420 	if (proto_type > ETH_DATA_LEN) {
421 
422 		if (proto_type == ETH_P_IP) {
423 			length = ((ntohl(xemaclite_readl(addr +
424 					XEL_HEADER_IP_LENGTH_OFFSET +
425 					XEL_RXBUFF_OFFSET)) >>
426 					XEL_HEADER_SHIFT) &
427 					XEL_RPLR_LENGTH_MASK);
428 			length = min_t(u16, length, ETH_DATA_LEN);
429 			length += ETH_HLEN + ETH_FCS_LEN;
430 
431 		} else if (proto_type == ETH_P_ARP)
432 			length = XEL_ARP_PACKET_SIZE + ETH_HLEN + ETH_FCS_LEN;
433 		else
434 			/* Field contains type other than IP or ARP, use max
435 			 * frame size and let user parse it */
436 			length = ETH_FRAME_LEN + ETH_FCS_LEN;
437 	} else
438 		/* Use the length in the frame, plus the header and trailer */
439 		length = proto_type + ETH_HLEN + ETH_FCS_LEN;
440 
441 	if (WARN_ON(length > maxlen))
442 		length = maxlen;
443 
444 	/* Read from the EmacLite device */
445 	xemaclite_aligned_read((u32 __force *) (addr + XEL_RXBUFF_OFFSET),
446 				data, length);
447 
448 	/* Acknowledge the frame */
449 	reg_data = xemaclite_readl(addr + XEL_RSR_OFFSET);
450 	reg_data &= ~XEL_RSR_RECV_DONE_MASK;
451 	xemaclite_writel(reg_data, addr + XEL_RSR_OFFSET);
452 
453 	return length;
454 }
455 
456 /**
457  * xemaclite_update_address - Update the MAC address in the device
458  * @drvdata:	Pointer to the Emaclite device private data
459  * @address_ptr:Pointer to the MAC address (MAC address is a 48-bit value)
460  *
461  * Tx must be idle and Rx should be idle for deterministic results.
462  * It is recommended that this function should be called after the
463  * initialization and before transmission of any packets from the device.
464  * The MAC address can be programmed using any of the two transmit
465  * buffers (if configured).
466  */
467 static void xemaclite_update_address(struct net_local *drvdata,
468 				     u8 *address_ptr)
469 {
470 	void __iomem *addr;
471 	u32 reg_data;
472 
473 	/* Determine the expected Tx buffer address */
474 	addr = drvdata->base_addr + drvdata->next_tx_buf_to_use;
475 
476 	xemaclite_aligned_write(address_ptr, (u32 __force *) addr, ETH_ALEN);
477 
478 	xemaclite_writel(ETH_ALEN, addr + XEL_TPLR_OFFSET);
479 
480 	/* Update the MAC address in the EmacLite */
481 	reg_data = xemaclite_readl(addr + XEL_TSR_OFFSET);
482 	xemaclite_writel(reg_data | XEL_TSR_PROG_MAC_ADDR, addr + XEL_TSR_OFFSET);
483 
484 	/* Wait for EmacLite to finish with the MAC address update */
485 	while ((xemaclite_readl(addr + XEL_TSR_OFFSET) &
486 		XEL_TSR_PROG_MAC_ADDR) != 0)
487 		;
488 }
489 
490 /**
491  * xemaclite_set_mac_address - Set the MAC address for this device
492  * @dev:	Pointer to the network device instance
493  * @addr:	Void pointer to the sockaddr structure
494  *
495  * This function copies the HW address from the sockaddr strucutre to the
496  * net_device structure and updates the address in HW.
497  *
498  * Return:	Error if the net device is busy or 0 if the addr is set
499  *		successfully
500  */
501 static int xemaclite_set_mac_address(struct net_device *dev, void *address)
502 {
503 	struct net_local *lp = netdev_priv(dev);
504 	struct sockaddr *addr = address;
505 
506 	if (netif_running(dev))
507 		return -EBUSY;
508 
509 	memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
510 	xemaclite_update_address(lp, dev->dev_addr);
511 	return 0;
512 }
513 
514 /**
515  * xemaclite_tx_timeout - Callback for Tx Timeout
516  * @dev:	Pointer to the network device
517  *
518  * This function is called when Tx time out occurs for Emaclite device.
519  */
520 static void xemaclite_tx_timeout(struct net_device *dev)
521 {
522 	struct net_local *lp = netdev_priv(dev);
523 	unsigned long flags;
524 
525 	dev_err(&lp->ndev->dev, "Exceeded transmit timeout of %lu ms\n",
526 		TX_TIMEOUT * 1000UL / HZ);
527 
528 	dev->stats.tx_errors++;
529 
530 	/* Reset the device */
531 	spin_lock_irqsave(&lp->reset_lock, flags);
532 
533 	/* Shouldn't really be necessary, but shouldn't hurt */
534 	netif_stop_queue(dev);
535 
536 	xemaclite_disable_interrupts(lp);
537 	xemaclite_enable_interrupts(lp);
538 
539 	if (lp->deferred_skb) {
540 		dev_kfree_skb(lp->deferred_skb);
541 		lp->deferred_skb = NULL;
542 		dev->stats.tx_errors++;
543 	}
544 
545 	/* To exclude tx timeout */
546 	netif_trans_update(dev); /* prevent tx timeout */
547 
548 	/* We're all ready to go. Start the queue */
549 	netif_wake_queue(dev);
550 	spin_unlock_irqrestore(&lp->reset_lock, flags);
551 }
552 
553 /**********************/
554 /* Interrupt Handlers */
555 /**********************/
556 
557 /**
558  * xemaclite_tx_handler - Interrupt handler for frames sent
559  * @dev:	Pointer to the network device
560  *
561  * This function updates the number of packets transmitted and handles the
562  * deferred skb, if there is one.
563  */
564 static void xemaclite_tx_handler(struct net_device *dev)
565 {
566 	struct net_local *lp = netdev_priv(dev);
567 
568 	dev->stats.tx_packets++;
569 	if (lp->deferred_skb) {
570 		if (xemaclite_send_data(lp,
571 					(u8 *) lp->deferred_skb->data,
572 					lp->deferred_skb->len) != 0)
573 			return;
574 		else {
575 			dev->stats.tx_bytes += lp->deferred_skb->len;
576 			dev_kfree_skb_irq(lp->deferred_skb);
577 			lp->deferred_skb = NULL;
578 			netif_trans_update(dev); /* prevent tx timeout */
579 			netif_wake_queue(dev);
580 		}
581 	}
582 }
583 
584 /**
585  * xemaclite_rx_handler- Interrupt handler for frames received
586  * @dev:	Pointer to the network device
587  *
588  * This function allocates memory for a socket buffer, fills it with data
589  * received and hands it over to the TCP/IP stack.
590  */
591 static void xemaclite_rx_handler(struct net_device *dev)
592 {
593 	struct net_local *lp = netdev_priv(dev);
594 	struct sk_buff *skb;
595 	unsigned int align;
596 	u32 len;
597 
598 	len = ETH_FRAME_LEN + ETH_FCS_LEN;
599 	skb = netdev_alloc_skb(dev, len + ALIGNMENT);
600 	if (!skb) {
601 		/* Couldn't get memory. */
602 		dev->stats.rx_dropped++;
603 		dev_err(&lp->ndev->dev, "Could not allocate receive buffer\n");
604 		return;
605 	}
606 
607 	/*
608 	 * A new skb should have the data halfword aligned, but this code is
609 	 * here just in case that isn't true. Calculate how many
610 	 * bytes we should reserve to get the data to start on a word
611 	 * boundary */
612 	align = BUFFER_ALIGN(skb->data);
613 	if (align)
614 		skb_reserve(skb, align);
615 
616 	skb_reserve(skb, 2);
617 
618 	len = xemaclite_recv_data(lp, (u8 *) skb->data, len);
619 
620 	if (!len) {
621 		dev->stats.rx_errors++;
622 		dev_kfree_skb_irq(skb);
623 		return;
624 	}
625 
626 	skb_put(skb, len);	/* Tell the skb how much data we got */
627 
628 	skb->protocol = eth_type_trans(skb, dev);
629 	skb_checksum_none_assert(skb);
630 
631 	dev->stats.rx_packets++;
632 	dev->stats.rx_bytes += len;
633 
634 	if (!skb_defer_rx_timestamp(skb))
635 		netif_rx(skb);	/* Send the packet upstream */
636 }
637 
638 /**
639  * xemaclite_interrupt - Interrupt handler for this driver
640  * @irq:	Irq of the Emaclite device
641  * @dev_id:	Void pointer to the network device instance used as callback
642  *		reference
643  *
644  * This function handles the Tx and Rx interrupts of the EmacLite device.
645  */
646 static irqreturn_t xemaclite_interrupt(int irq, void *dev_id)
647 {
648 	bool tx_complete = false;
649 	struct net_device *dev = dev_id;
650 	struct net_local *lp = netdev_priv(dev);
651 	void __iomem *base_addr = lp->base_addr;
652 	u32 tx_status;
653 
654 	/* Check if there is Rx Data available */
655 	if ((xemaclite_readl(base_addr + XEL_RSR_OFFSET) &
656 			 XEL_RSR_RECV_DONE_MASK) ||
657 	    (xemaclite_readl(base_addr + XEL_BUFFER_OFFSET + XEL_RSR_OFFSET)
658 			 & XEL_RSR_RECV_DONE_MASK))
659 
660 		xemaclite_rx_handler(dev);
661 
662 	/* Check if the Transmission for the first buffer is completed */
663 	tx_status = xemaclite_readl(base_addr + XEL_TSR_OFFSET);
664 	if (((tx_status & XEL_TSR_XMIT_BUSY_MASK) == 0) &&
665 		(tx_status & XEL_TSR_XMIT_ACTIVE_MASK) != 0) {
666 
667 		tx_status &= ~XEL_TSR_XMIT_ACTIVE_MASK;
668 		xemaclite_writel(tx_status, base_addr + XEL_TSR_OFFSET);
669 
670 		tx_complete = true;
671 	}
672 
673 	/* Check if the Transmission for the second buffer is completed */
674 	tx_status = xemaclite_readl(base_addr + XEL_BUFFER_OFFSET + XEL_TSR_OFFSET);
675 	if (((tx_status & XEL_TSR_XMIT_BUSY_MASK) == 0) &&
676 		(tx_status & XEL_TSR_XMIT_ACTIVE_MASK) != 0) {
677 
678 		tx_status &= ~XEL_TSR_XMIT_ACTIVE_MASK;
679 		xemaclite_writel(tx_status, base_addr + XEL_BUFFER_OFFSET +
680 				 XEL_TSR_OFFSET);
681 
682 		tx_complete = true;
683 	}
684 
685 	/* If there was a Tx interrupt, call the Tx Handler */
686 	if (tx_complete != 0)
687 		xemaclite_tx_handler(dev);
688 
689 	return IRQ_HANDLED;
690 }
691 
692 /**********************/
693 /* MDIO Bus functions */
694 /**********************/
695 
696 /**
697  * xemaclite_mdio_wait - Wait for the MDIO to be ready to use
698  * @lp:		Pointer to the Emaclite device private data
699  *
700  * This function waits till the device is ready to accept a new MDIO
701  * request.
702  *
703  * Return:	0 for success or ETIMEDOUT for a timeout
704  */
705 
706 static int xemaclite_mdio_wait(struct net_local *lp)
707 {
708 	unsigned long end = jiffies + 2;
709 
710 	/* wait for the MDIO interface to not be busy or timeout
711 	   after some time.
712 	*/
713 	while (xemaclite_readl(lp->base_addr + XEL_MDIOCTRL_OFFSET) &
714 			XEL_MDIOCTRL_MDIOSTS_MASK) {
715 		if (time_before_eq(end, jiffies)) {
716 			WARN_ON(1);
717 			return -ETIMEDOUT;
718 		}
719 		msleep(1);
720 	}
721 	return 0;
722 }
723 
724 /**
725  * xemaclite_mdio_read - Read from a given MII management register
726  * @bus:	the mii_bus struct
727  * @phy_id:	the phy address
728  * @reg:	register number to read from
729  *
730  * This function waits till the device is ready to accept a new MDIO
731  * request and then writes the phy address to the MDIO Address register
732  * and reads data from MDIO Read Data register, when its available.
733  *
734  * Return:	Value read from the MII management register
735  */
736 static int xemaclite_mdio_read(struct mii_bus *bus, int phy_id, int reg)
737 {
738 	struct net_local *lp = bus->priv;
739 	u32 ctrl_reg;
740 	u32 rc;
741 
742 	if (xemaclite_mdio_wait(lp))
743 		return -ETIMEDOUT;
744 
745 	/* Write the PHY address, register number and set the OP bit in the
746 	 * MDIO Address register. Set the Status bit in the MDIO Control
747 	 * register to start a MDIO read transaction.
748 	 */
749 	ctrl_reg = xemaclite_readl(lp->base_addr + XEL_MDIOCTRL_OFFSET);
750 	xemaclite_writel(XEL_MDIOADDR_OP_MASK |
751 			 ((phy_id << XEL_MDIOADDR_PHYADR_SHIFT) | reg),
752 			 lp->base_addr + XEL_MDIOADDR_OFFSET);
753 	xemaclite_writel(ctrl_reg | XEL_MDIOCTRL_MDIOSTS_MASK,
754 			 lp->base_addr + XEL_MDIOCTRL_OFFSET);
755 
756 	if (xemaclite_mdio_wait(lp))
757 		return -ETIMEDOUT;
758 
759 	rc = xemaclite_readl(lp->base_addr + XEL_MDIORD_OFFSET);
760 
761 	dev_dbg(&lp->ndev->dev,
762 		"xemaclite_mdio_read(phy_id=%i, reg=%x) == %x\n",
763 		phy_id, reg, rc);
764 
765 	return rc;
766 }
767 
768 /**
769  * xemaclite_mdio_write - Write to a given MII management register
770  * @bus:	the mii_bus struct
771  * @phy_id:	the phy address
772  * @reg:	register number to write to
773  * @val:	value to write to the register number specified by reg
774  *
775  * This function waits till the device is ready to accept a new MDIO
776  * request and then writes the val to the MDIO Write Data register.
777  */
778 static int xemaclite_mdio_write(struct mii_bus *bus, int phy_id, int reg,
779 				u16 val)
780 {
781 	struct net_local *lp = bus->priv;
782 	u32 ctrl_reg;
783 
784 	dev_dbg(&lp->ndev->dev,
785 		"xemaclite_mdio_write(phy_id=%i, reg=%x, val=%x)\n",
786 		phy_id, reg, val);
787 
788 	if (xemaclite_mdio_wait(lp))
789 		return -ETIMEDOUT;
790 
791 	/* Write the PHY address, register number and clear the OP bit in the
792 	 * MDIO Address register and then write the value into the MDIO Write
793 	 * Data register. Finally, set the Status bit in the MDIO Control
794 	 * register to start a MDIO write transaction.
795 	 */
796 	ctrl_reg = xemaclite_readl(lp->base_addr + XEL_MDIOCTRL_OFFSET);
797 	xemaclite_writel(~XEL_MDIOADDR_OP_MASK &
798 			 ((phy_id << XEL_MDIOADDR_PHYADR_SHIFT) | reg),
799 			 lp->base_addr + XEL_MDIOADDR_OFFSET);
800 	xemaclite_writel(val, lp->base_addr + XEL_MDIOWR_OFFSET);
801 	xemaclite_writel(ctrl_reg | XEL_MDIOCTRL_MDIOSTS_MASK,
802 			 lp->base_addr + XEL_MDIOCTRL_OFFSET);
803 
804 	return 0;
805 }
806 
807 /**
808  * xemaclite_mdio_setup - Register mii_bus for the Emaclite device
809  * @lp:		Pointer to the Emaclite device private data
810  * @ofdev:	Pointer to OF device structure
811  *
812  * This function enables MDIO bus in the Emaclite device and registers a
813  * mii_bus.
814  *
815  * Return:	0 upon success or a negative error upon failure
816  */
817 static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
818 {
819 	struct mii_bus *bus;
820 	int rc;
821 	struct resource res;
822 	struct device_node *np = of_get_parent(lp->phy_node);
823 	struct device_node *npp;
824 
825 	/* Don't register the MDIO bus if the phy_node or its parent node
826 	 * can't be found.
827 	 */
828 	if (!np) {
829 		dev_err(dev, "Failed to register mdio bus.\n");
830 		return -ENODEV;
831 	}
832 	npp = of_get_parent(np);
833 
834 	of_address_to_resource(npp, 0, &res);
835 	if (lp->ndev->mem_start != res.start) {
836 		struct phy_device *phydev;
837 		phydev = of_phy_find_device(lp->phy_node);
838 		if (!phydev)
839 			dev_info(dev,
840 				 "MDIO of the phy is not registered yet\n");
841 		else
842 			put_device(&phydev->mdio.dev);
843 		return 0;
844 	}
845 
846 	/* Enable the MDIO bus by asserting the enable bit in MDIO Control
847 	 * register.
848 	 */
849 	xemaclite_writel(XEL_MDIOCTRL_MDIOEN_MASK,
850 			 lp->base_addr + XEL_MDIOCTRL_OFFSET);
851 
852 	bus = mdiobus_alloc();
853 	if (!bus) {
854 		dev_err(dev, "Failed to allocate mdiobus\n");
855 		return -ENOMEM;
856 	}
857 
858 	snprintf(bus->id, MII_BUS_ID_SIZE, "%.8llx",
859 		 (unsigned long long)res.start);
860 	bus->priv = lp;
861 	bus->name = "Xilinx Emaclite MDIO";
862 	bus->read = xemaclite_mdio_read;
863 	bus->write = xemaclite_mdio_write;
864 	bus->parent = dev;
865 
866 	lp->mii_bus = bus;
867 
868 	rc = of_mdiobus_register(bus, np);
869 	if (rc) {
870 		dev_err(dev, "Failed to register mdio bus.\n");
871 		goto err_register;
872 	}
873 
874 	return 0;
875 
876 err_register:
877 	mdiobus_free(bus);
878 	return rc;
879 }
880 
881 /**
882  * xemaclite_adjust_link - Link state callback for the Emaclite device
883  * @ndev: pointer to net_device struct
884  *
885  * There's nothing in the Emaclite device to be configured when the link
886  * state changes. We just print the status.
887  */
888 static void xemaclite_adjust_link(struct net_device *ndev)
889 {
890 	struct net_local *lp = netdev_priv(ndev);
891 	struct phy_device *phy = lp->phy_dev;
892 	int link_state;
893 
894 	/* hash together the state values to decide if something has changed */
895 	link_state = phy->speed | (phy->duplex << 1) | phy->link;
896 
897 	if (lp->last_link != link_state) {
898 		lp->last_link = link_state;
899 		phy_print_status(phy);
900 	}
901 }
902 
903 /**
904  * xemaclite_open - Open the network device
905  * @dev:	Pointer to the network device
906  *
907  * This function sets the MAC address, requests an IRQ and enables interrupts
908  * for the Emaclite device and starts the Tx queue.
909  * It also connects to the phy device, if MDIO is included in Emaclite device.
910  */
911 static int xemaclite_open(struct net_device *dev)
912 {
913 	struct net_local *lp = netdev_priv(dev);
914 	int retval;
915 
916 	/* Just to be safe, stop the device first */
917 	xemaclite_disable_interrupts(lp);
918 
919 	if (lp->phy_node) {
920 		u32 bmcr;
921 
922 		lp->phy_dev = of_phy_connect(lp->ndev, lp->phy_node,
923 					     xemaclite_adjust_link, 0,
924 					     PHY_INTERFACE_MODE_MII);
925 		if (!lp->phy_dev) {
926 			dev_err(&lp->ndev->dev, "of_phy_connect() failed\n");
927 			return -ENODEV;
928 		}
929 
930 		/* EmacLite doesn't support giga-bit speeds */
931 		lp->phy_dev->supported &= (PHY_BASIC_FEATURES);
932 		lp->phy_dev->advertising = lp->phy_dev->supported;
933 
934 		/* Don't advertise 1000BASE-T Full/Half duplex speeds */
935 		phy_write(lp->phy_dev, MII_CTRL1000, 0);
936 
937 		/* Advertise only 10 and 100mbps full/half duplex speeds */
938 		phy_write(lp->phy_dev, MII_ADVERTISE, ADVERTISE_ALL |
939 			  ADVERTISE_CSMA);
940 
941 		/* Restart auto negotiation */
942 		bmcr = phy_read(lp->phy_dev, MII_BMCR);
943 		bmcr |= (BMCR_ANENABLE | BMCR_ANRESTART);
944 		phy_write(lp->phy_dev, MII_BMCR, bmcr);
945 
946 		phy_start(lp->phy_dev);
947 	}
948 
949 	/* Set the MAC address each time opened */
950 	xemaclite_update_address(lp, dev->dev_addr);
951 
952 	/* Grab the IRQ */
953 	retval = request_irq(dev->irq, xemaclite_interrupt, 0, dev->name, dev);
954 	if (retval) {
955 		dev_err(&lp->ndev->dev, "Could not allocate interrupt %d\n",
956 			dev->irq);
957 		if (lp->phy_dev)
958 			phy_disconnect(lp->phy_dev);
959 		lp->phy_dev = NULL;
960 
961 		return retval;
962 	}
963 
964 	/* Enable Interrupts */
965 	xemaclite_enable_interrupts(lp);
966 
967 	/* We're ready to go */
968 	netif_start_queue(dev);
969 
970 	return 0;
971 }
972 
973 /**
974  * xemaclite_close - Close the network device
975  * @dev:	Pointer to the network device
976  *
977  * This function stops the Tx queue, disables interrupts and frees the IRQ for
978  * the Emaclite device.
979  * It also disconnects the phy device associated with the Emaclite device.
980  */
981 static int xemaclite_close(struct net_device *dev)
982 {
983 	struct net_local *lp = netdev_priv(dev);
984 
985 	netif_stop_queue(dev);
986 	xemaclite_disable_interrupts(lp);
987 	free_irq(dev->irq, dev);
988 
989 	if (lp->phy_dev)
990 		phy_disconnect(lp->phy_dev);
991 	lp->phy_dev = NULL;
992 
993 	return 0;
994 }
995 
996 /**
997  * xemaclite_send - Transmit a frame
998  * @orig_skb:	Pointer to the socket buffer to be transmitted
999  * @dev:	Pointer to the network device
1000  *
1001  * This function checks if the Tx buffer of the Emaclite device is free to send
1002  * data. If so, it fills the Tx buffer with data from socket buffer data,
1003  * updates the stats and frees the socket buffer. The Tx completion is signaled
1004  * by an interrupt. If the Tx buffer isn't free, then the socket buffer is
1005  * deferred and the Tx queue is stopped so that the deferred socket buffer can
1006  * be transmitted when the Emaclite device is free to transmit data.
1007  *
1008  * Return:	0, always.
1009  */
1010 static int xemaclite_send(struct sk_buff *orig_skb, struct net_device *dev)
1011 {
1012 	struct net_local *lp = netdev_priv(dev);
1013 	struct sk_buff *new_skb;
1014 	unsigned int len;
1015 	unsigned long flags;
1016 
1017 	len = orig_skb->len;
1018 
1019 	new_skb = orig_skb;
1020 
1021 	spin_lock_irqsave(&lp->reset_lock, flags);
1022 	if (xemaclite_send_data(lp, (u8 *) new_skb->data, len) != 0) {
1023 		/* If the Emaclite Tx buffer is busy, stop the Tx queue and
1024 		 * defer the skb for transmission during the ISR, after the
1025 		 * current transmission is complete */
1026 		netif_stop_queue(dev);
1027 		lp->deferred_skb = new_skb;
1028 		/* Take the time stamp now, since we can't do this in an ISR. */
1029 		skb_tx_timestamp(new_skb);
1030 		spin_unlock_irqrestore(&lp->reset_lock, flags);
1031 		return 0;
1032 	}
1033 	spin_unlock_irqrestore(&lp->reset_lock, flags);
1034 
1035 	skb_tx_timestamp(new_skb);
1036 
1037 	dev->stats.tx_bytes += len;
1038 	dev_consume_skb_any(new_skb);
1039 
1040 	return 0;
1041 }
1042 
1043 /**
1044  * get_bool - Get a parameter from the OF device
1045  * @ofdev:	Pointer to OF device structure
1046  * @s:		Property to be retrieved
1047  *
1048  * This function looks for a property in the device node and returns the value
1049  * of the property if its found or 0 if the property is not found.
1050  *
1051  * Return:	Value of the parameter if the parameter is found, or 0 otherwise
1052  */
1053 static bool get_bool(struct platform_device *ofdev, const char *s)
1054 {
1055 	u32 *p = (u32 *)of_get_property(ofdev->dev.of_node, s, NULL);
1056 
1057 	if (p) {
1058 		return (bool)*p;
1059 	} else {
1060 		dev_warn(&ofdev->dev, "Parameter %s not found,"
1061 			"defaulting to false\n", s);
1062 		return false;
1063 	}
1064 }
1065 
1066 static const struct net_device_ops xemaclite_netdev_ops;
1067 
1068 /**
1069  * xemaclite_of_probe - Probe method for the Emaclite device.
1070  * @ofdev:	Pointer to OF device structure
1071  * @match:	Pointer to the structure used for matching a device
1072  *
1073  * This function probes for the Emaclite device in the device tree.
1074  * It initializes the driver data structure and the hardware, sets the MAC
1075  * address and registers the network device.
1076  * It also registers a mii_bus for the Emaclite device, if MDIO is included
1077  * in the device.
1078  *
1079  * Return:	0, if the driver is bound to the Emaclite device, or
1080  *		a negative error if there is failure.
1081  */
1082 static int xemaclite_of_probe(struct platform_device *ofdev)
1083 {
1084 	struct resource *res;
1085 	struct net_device *ndev = NULL;
1086 	struct net_local *lp = NULL;
1087 	struct device *dev = &ofdev->dev;
1088 	const void *mac_address;
1089 
1090 	int rc = 0;
1091 
1092 	dev_info(dev, "Device Tree Probing\n");
1093 
1094 	/* Create an ethernet device instance */
1095 	ndev = alloc_etherdev(sizeof(struct net_local));
1096 	if (!ndev)
1097 		return -ENOMEM;
1098 
1099 	dev_set_drvdata(dev, ndev);
1100 	SET_NETDEV_DEV(ndev, &ofdev->dev);
1101 
1102 	lp = netdev_priv(ndev);
1103 	lp->ndev = ndev;
1104 
1105 	/* Get IRQ for the device */
1106 	res = platform_get_resource(ofdev, IORESOURCE_IRQ, 0);
1107 	if (!res) {
1108 		dev_err(dev, "no IRQ found\n");
1109 		rc = -ENXIO;
1110 		goto error;
1111 	}
1112 
1113 	ndev->irq = res->start;
1114 
1115 	res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
1116 	lp->base_addr = devm_ioremap_resource(&ofdev->dev, res);
1117 	if (IS_ERR(lp->base_addr)) {
1118 		rc = PTR_ERR(lp->base_addr);
1119 		goto error;
1120 	}
1121 
1122 	ndev->mem_start = res->start;
1123 	ndev->mem_end = res->end;
1124 
1125 	spin_lock_init(&lp->reset_lock);
1126 	lp->next_tx_buf_to_use = 0x0;
1127 	lp->next_rx_buf_to_use = 0x0;
1128 	lp->tx_ping_pong = get_bool(ofdev, "xlnx,tx-ping-pong");
1129 	lp->rx_ping_pong = get_bool(ofdev, "xlnx,rx-ping-pong");
1130 	mac_address = of_get_mac_address(ofdev->dev.of_node);
1131 
1132 	if (mac_address) {
1133 		/* Set the MAC address. */
1134 		memcpy(ndev->dev_addr, mac_address, ETH_ALEN);
1135 	} else {
1136 		dev_warn(dev, "No MAC address found, using random\n");
1137 		eth_hw_addr_random(ndev);
1138 	}
1139 
1140 	/* Clear the Tx CSR's in case this is a restart */
1141 	xemaclite_writel(0, lp->base_addr + XEL_TSR_OFFSET);
1142 	xemaclite_writel(0, lp->base_addr + XEL_BUFFER_OFFSET + XEL_TSR_OFFSET);
1143 
1144 	/* Set the MAC address in the EmacLite device */
1145 	xemaclite_update_address(lp, ndev->dev_addr);
1146 
1147 	lp->phy_node = of_parse_phandle(ofdev->dev.of_node, "phy-handle", 0);
1148 	rc = xemaclite_mdio_setup(lp, &ofdev->dev);
1149 	if (rc)
1150 		dev_warn(&ofdev->dev, "error registering MDIO bus\n");
1151 
1152 	dev_info(dev, "MAC address is now %pM\n", ndev->dev_addr);
1153 
1154 	ndev->netdev_ops = &xemaclite_netdev_ops;
1155 	ndev->flags &= ~IFF_MULTICAST;
1156 	ndev->watchdog_timeo = TX_TIMEOUT;
1157 
1158 	/* Finally, register the device */
1159 	rc = register_netdev(ndev);
1160 	if (rc) {
1161 		dev_err(dev,
1162 			"Cannot register network device, aborting\n");
1163 		goto error;
1164 	}
1165 
1166 	dev_info(dev,
1167 		 "Xilinx EmacLite at 0x%08X mapped to 0x%08X, irq=%d\n",
1168 		 (unsigned int __force)ndev->mem_start,
1169 		 (unsigned int __force)lp->base_addr, ndev->irq);
1170 	return 0;
1171 
1172 error:
1173 	free_netdev(ndev);
1174 	return rc;
1175 }
1176 
1177 /**
1178  * xemaclite_of_remove - Unbind the driver from the Emaclite device.
1179  * @of_dev:	Pointer to OF device structure
1180  *
1181  * This function is called if a device is physically removed from the system or
1182  * if the driver module is being unloaded. It frees any resources allocated to
1183  * the device.
1184  *
1185  * Return:	0, always.
1186  */
1187 static int xemaclite_of_remove(struct platform_device *of_dev)
1188 {
1189 	struct net_device *ndev = platform_get_drvdata(of_dev);
1190 
1191 	struct net_local *lp = netdev_priv(ndev);
1192 
1193 	/* Un-register the mii_bus, if configured */
1194 	if (lp->has_mdio) {
1195 		mdiobus_unregister(lp->mii_bus);
1196 		mdiobus_free(lp->mii_bus);
1197 		lp->mii_bus = NULL;
1198 	}
1199 
1200 	unregister_netdev(ndev);
1201 
1202 	of_node_put(lp->phy_node);
1203 	lp->phy_node = NULL;
1204 
1205 	free_netdev(ndev);
1206 
1207 	return 0;
1208 }
1209 
1210 #ifdef CONFIG_NET_POLL_CONTROLLER
1211 static void
1212 xemaclite_poll_controller(struct net_device *ndev)
1213 {
1214 	disable_irq(ndev->irq);
1215 	xemaclite_interrupt(ndev->irq, ndev);
1216 	enable_irq(ndev->irq);
1217 }
1218 #endif
1219 
1220 static const struct net_device_ops xemaclite_netdev_ops = {
1221 	.ndo_open		= xemaclite_open,
1222 	.ndo_stop		= xemaclite_close,
1223 	.ndo_start_xmit		= xemaclite_send,
1224 	.ndo_set_mac_address	= xemaclite_set_mac_address,
1225 	.ndo_tx_timeout		= xemaclite_tx_timeout,
1226 #ifdef CONFIG_NET_POLL_CONTROLLER
1227 	.ndo_poll_controller = xemaclite_poll_controller,
1228 #endif
1229 };
1230 
1231 /* Match table for OF platform binding */
1232 static const struct of_device_id xemaclite_of_match[] = {
1233 	{ .compatible = "xlnx,opb-ethernetlite-1.01.a", },
1234 	{ .compatible = "xlnx,opb-ethernetlite-1.01.b", },
1235 	{ .compatible = "xlnx,xps-ethernetlite-1.00.a", },
1236 	{ .compatible = "xlnx,xps-ethernetlite-2.00.a", },
1237 	{ .compatible = "xlnx,xps-ethernetlite-2.01.a", },
1238 	{ .compatible = "xlnx,xps-ethernetlite-3.00.a", },
1239 	{ /* end of list */ },
1240 };
1241 MODULE_DEVICE_TABLE(of, xemaclite_of_match);
1242 
1243 static struct platform_driver xemaclite_of_driver = {
1244 	.driver = {
1245 		.name = DRIVER_NAME,
1246 		.of_match_table = xemaclite_of_match,
1247 	},
1248 	.probe		= xemaclite_of_probe,
1249 	.remove		= xemaclite_of_remove,
1250 };
1251 
1252 module_platform_driver(xemaclite_of_driver);
1253 
1254 MODULE_AUTHOR("Xilinx, Inc.");
1255 MODULE_DESCRIPTION("Xilinx Ethernet MAC Lite driver");
1256 MODULE_LICENSE("GPL");
1257