xref: /openbmc/linux/drivers/net/ethernet/xilinx/xilinx_emaclite.c (revision f677b30b487ca3763c3de3f1b4d8c976c2961cd1)
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/init.h>
18 #include <linux/netdevice.h>
19 #include <linux/etherdevice.h>
20 #include <linux/skbuff.h>
21 #include <linux/io.h>
22 #include <linux/slab.h>
23 #include <linux/of_address.h>
24 #include <linux/of_device.h>
25 #include <linux/of_platform.h>
26 #include <linux/of_mdio.h>
27 #include <linux/of_net.h>
28 #include <linux/phy.h>
29 #include <linux/interrupt.h>
30 
31 #define DRIVER_NAME "xilinx_emaclite"
32 
33 /* Register offsets for the EmacLite Core */
34 #define XEL_TXBUFF_OFFSET	0x0		/* Transmit Buffer */
35 #define XEL_MDIOADDR_OFFSET	0x07E4		/* MDIO Address Register */
36 #define XEL_MDIOWR_OFFSET	0x07E8		/* MDIO Write Data Register */
37 #define XEL_MDIORD_OFFSET	0x07EC		/* MDIO Read Data Register */
38 #define XEL_MDIOCTRL_OFFSET	0x07F0		/* MDIO Control Register */
39 #define XEL_GIER_OFFSET		0x07F8		/* GIE Register */
40 #define XEL_TSR_OFFSET		0x07FC		/* Tx status */
41 #define XEL_TPLR_OFFSET		0x07F4		/* Tx packet length */
42 
43 #define XEL_RXBUFF_OFFSET	0x1000		/* Receive Buffer */
44 #define XEL_RPLR_OFFSET		0x100C		/* Rx packet length */
45 #define XEL_RSR_OFFSET		0x17FC		/* Rx status */
46 
47 #define XEL_BUFFER_OFFSET	0x0800		/* Next Tx/Rx buffer's offset */
48 
49 /* MDIO Address Register Bit Masks */
50 #define XEL_MDIOADDR_REGADR_MASK  0x0000001F	/* Register Address */
51 #define XEL_MDIOADDR_PHYADR_MASK  0x000003E0	/* PHY Address */
52 #define XEL_MDIOADDR_PHYADR_SHIFT 5
53 #define XEL_MDIOADDR_OP_MASK	  0x00000400	/* RD/WR Operation */
54 
55 /* MDIO Write Data Register Bit Masks */
56 #define XEL_MDIOWR_WRDATA_MASK	  0x0000FFFF	/* Data to be Written */
57 
58 /* MDIO Read Data Register Bit Masks */
59 #define XEL_MDIORD_RDDATA_MASK	  0x0000FFFF	/* Data to be Read */
60 
61 /* MDIO Control Register Bit Masks */
62 #define XEL_MDIOCTRL_MDIOSTS_MASK 0x00000001	/* MDIO Status Mask */
63 #define XEL_MDIOCTRL_MDIOEN_MASK  0x00000008	/* MDIO Enable */
64 
65 /* Global Interrupt Enable Register (GIER) Bit Masks */
66 #define XEL_GIER_GIE_MASK	0x80000000	/* Global Enable */
67 
68 /* Transmit Status Register (TSR) Bit Masks */
69 #define XEL_TSR_XMIT_BUSY_MASK	 0x00000001	/* Tx complete */
70 #define XEL_TSR_PROGRAM_MASK	 0x00000002	/* Program the MAC address */
71 #define XEL_TSR_XMIT_IE_MASK	 0x00000008	/* Tx interrupt enable bit */
72 #define XEL_TSR_XMIT_ACTIVE_MASK 0x80000000	/* Buffer is active, SW bit
73 						 * only. This is not documented
74 						 * in the HW spec */
75 
76 /* Define for programming the MAC address into the EmacLite */
77 #define XEL_TSR_PROG_MAC_ADDR	(XEL_TSR_XMIT_BUSY_MASK | XEL_TSR_PROGRAM_MASK)
78 
79 /* Receive Status Register (RSR) */
80 #define XEL_RSR_RECV_DONE_MASK	0x00000001	/* Rx complete */
81 #define XEL_RSR_RECV_IE_MASK	0x00000008	/* Rx interrupt enable bit */
82 
83 /* Transmit Packet Length Register (TPLR) */
84 #define XEL_TPLR_LENGTH_MASK	0x0000FFFF	/* Tx packet length */
85 
86 /* Receive Packet Length Register (RPLR) */
87 #define XEL_RPLR_LENGTH_MASK	0x0000FFFF	/* Rx packet length */
88 
89 #define XEL_HEADER_OFFSET	12		/* Offset to length field */
90 #define XEL_HEADER_SHIFT	16		/* Shift value for length */
91 
92 /* General Ethernet Definitions */
93 #define XEL_ARP_PACKET_SIZE		28	/* Max ARP packet size */
94 #define XEL_HEADER_IP_LENGTH_OFFSET	16	/* IP Length Offset */
95 
96 
97 
98 #define TX_TIMEOUT		(60*HZ)		/* Tx timeout is 60 seconds. */
99 #define ALIGNMENT		4
100 
101 /* BUFFER_ALIGN(adr) calculates the number of bytes to the next alignment. */
102 #define BUFFER_ALIGN(adr) ((ALIGNMENT - ((u32) adr)) % ALIGNMENT)
103 
104 /**
105  * struct net_local - Our private per device data
106  * @ndev:		instance of the network device
107  * @tx_ping_pong:	indicates whether Tx Pong buffer is configured in HW
108  * @rx_ping_pong:	indicates whether Rx Pong buffer is configured in HW
109  * @next_tx_buf_to_use:	next Tx buffer to write to
110  * @next_rx_buf_to_use:	next Rx buffer to read from
111  * @base_addr:		base address of the Emaclite device
112  * @reset_lock:		lock used for synchronization
113  * @deferred_skb:	holds an skb (for transmission at a later time) when the
114  *			Tx buffer is not free
115  * @phy_dev:		pointer to the PHY device
116  * @phy_node:		pointer to the PHY device node
117  * @mii_bus:		pointer to the MII bus
118  * @mdio_irqs:		IRQs table for MDIO bus
119  * @last_link:		last link status
120  * @has_mdio:		indicates whether MDIO is included in the HW
121  */
122 struct net_local {
123 
124 	struct net_device *ndev;
125 
126 	bool tx_ping_pong;
127 	bool rx_ping_pong;
128 	u32 next_tx_buf_to_use;
129 	u32 next_rx_buf_to_use;
130 	void __iomem *base_addr;
131 
132 	spinlock_t reset_lock;
133 	struct sk_buff *deferred_skb;
134 
135 	struct phy_device *phy_dev;
136 	struct device_node *phy_node;
137 
138 	struct mii_bus *mii_bus;
139 	int mdio_irqs[PHY_MAX_ADDR];
140 
141 	int last_link;
142 	bool has_mdio;
143 };
144 
145 
146 /*************************/
147 /* EmacLite driver calls */
148 /*************************/
149 
150 /**
151  * xemaclite_enable_interrupts - Enable the interrupts for the EmacLite device
152  * @drvdata:	Pointer to the Emaclite device private data
153  *
154  * This function enables the Tx and Rx interrupts for the Emaclite device along
155  * with the Global Interrupt Enable.
156  */
157 static void xemaclite_enable_interrupts(struct net_local *drvdata)
158 {
159 	u32 reg_data;
160 
161 	/* Enable the Tx interrupts for the first Buffer */
162 	reg_data = __raw_readl(drvdata->base_addr + XEL_TSR_OFFSET);
163 	__raw_writel(reg_data | XEL_TSR_XMIT_IE_MASK,
164 		     drvdata->base_addr + XEL_TSR_OFFSET);
165 
166 	/* Enable the Rx interrupts for the first buffer */
167 	__raw_writel(XEL_RSR_RECV_IE_MASK, drvdata->base_addr + XEL_RSR_OFFSET);
168 
169 	/* Enable the Global Interrupt Enable */
170 	__raw_writel(XEL_GIER_GIE_MASK, drvdata->base_addr + XEL_GIER_OFFSET);
171 }
172 
173 /**
174  * xemaclite_disable_interrupts - Disable the interrupts for the EmacLite device
175  * @drvdata:	Pointer to the Emaclite device private data
176  *
177  * This function disables the Tx and Rx interrupts for the Emaclite device,
178  * along with the Global Interrupt Enable.
179  */
180 static void xemaclite_disable_interrupts(struct net_local *drvdata)
181 {
182 	u32 reg_data;
183 
184 	/* Disable the Global Interrupt Enable */
185 	__raw_writel(XEL_GIER_GIE_MASK, drvdata->base_addr + XEL_GIER_OFFSET);
186 
187 	/* Disable the Tx interrupts for the first buffer */
188 	reg_data = __raw_readl(drvdata->base_addr + XEL_TSR_OFFSET);
189 	__raw_writel(reg_data & (~XEL_TSR_XMIT_IE_MASK),
190 		     drvdata->base_addr + XEL_TSR_OFFSET);
191 
192 	/* Disable the Rx interrupts for the first buffer */
193 	reg_data = __raw_readl(drvdata->base_addr + XEL_RSR_OFFSET);
194 	__raw_writel(reg_data & (~XEL_RSR_RECV_IE_MASK),
195 		     drvdata->base_addr + XEL_RSR_OFFSET);
196 }
197 
198 /**
199  * xemaclite_aligned_write - Write from 16-bit aligned to 32-bit aligned address
200  * @src_ptr:	Void pointer to the 16-bit aligned source address
201  * @dest_ptr:	Pointer to the 32-bit aligned destination address
202  * @length:	Number bytes to write from source to destination
203  *
204  * This function writes data from a 16-bit aligned buffer to a 32-bit aligned
205  * address in the EmacLite device.
206  */
207 static void xemaclite_aligned_write(void *src_ptr, u32 *dest_ptr,
208 				    unsigned length)
209 {
210 	u32 align_buffer;
211 	u32 *to_u32_ptr;
212 	u16 *from_u16_ptr, *to_u16_ptr;
213 
214 	to_u32_ptr = dest_ptr;
215 	from_u16_ptr = src_ptr;
216 	align_buffer = 0;
217 
218 	for (; length > 3; length -= 4) {
219 		to_u16_ptr = (u16 *)&align_buffer;
220 		*to_u16_ptr++ = *from_u16_ptr++;
221 		*to_u16_ptr++ = *from_u16_ptr++;
222 
223 		/* This barrier resolves occasional issues seen around
224 		 * cases where the data is not properly flushed out
225 		 * from the processor store buffers to the destination
226 		 * memory locations.
227 		 */
228 		wmb();
229 
230 		/* Output a word */
231 		*to_u32_ptr++ = align_buffer;
232 	}
233 	if (length) {
234 		u8 *from_u8_ptr, *to_u8_ptr;
235 
236 		/* Set up to output the remaining data */
237 		align_buffer = 0;
238 		to_u8_ptr = (u8 *) &align_buffer;
239 		from_u8_ptr = (u8 *) from_u16_ptr;
240 
241 		/* Output the remaining data */
242 		for (; length > 0; length--)
243 			*to_u8_ptr++ = *from_u8_ptr++;
244 
245 		/* This barrier resolves occasional issues seen around
246 		 * cases where the data is not properly flushed out
247 		 * from the processor store buffers to the destination
248 		 * memory locations.
249 		 */
250 		wmb();
251 		*to_u32_ptr = align_buffer;
252 	}
253 }
254 
255 /**
256  * xemaclite_aligned_read - Read from 32-bit aligned to 16-bit aligned buffer
257  * @src_ptr:	Pointer to the 32-bit aligned source address
258  * @dest_ptr:	Pointer to the 16-bit aligned destination address
259  * @length:	Number bytes to read from source to destination
260  *
261  * This function reads data from a 32-bit aligned address in the EmacLite device
262  * to a 16-bit aligned buffer.
263  */
264 static void xemaclite_aligned_read(u32 *src_ptr, u8 *dest_ptr,
265 				   unsigned length)
266 {
267 	u16 *to_u16_ptr, *from_u16_ptr;
268 	u32 *from_u32_ptr;
269 	u32 align_buffer;
270 
271 	from_u32_ptr = src_ptr;
272 	to_u16_ptr = (u16 *) dest_ptr;
273 
274 	for (; length > 3; length -= 4) {
275 		/* Copy each word into the temporary buffer */
276 		align_buffer = *from_u32_ptr++;
277 		from_u16_ptr = (u16 *)&align_buffer;
278 
279 		/* Read data from source */
280 		*to_u16_ptr++ = *from_u16_ptr++;
281 		*to_u16_ptr++ = *from_u16_ptr++;
282 	}
283 
284 	if (length) {
285 		u8 *to_u8_ptr, *from_u8_ptr;
286 
287 		/* Set up to read the remaining data */
288 		to_u8_ptr = (u8 *) to_u16_ptr;
289 		align_buffer = *from_u32_ptr++;
290 		from_u8_ptr = (u8 *) &align_buffer;
291 
292 		/* Read the remaining data */
293 		for (; length > 0; length--)
294 			*to_u8_ptr = *from_u8_ptr;
295 	}
296 }
297 
298 /**
299  * xemaclite_send_data - Send an Ethernet frame
300  * @drvdata:	Pointer to the Emaclite device private data
301  * @data:	Pointer to the data to be sent
302  * @byte_count:	Total frame size, including header
303  *
304  * This function checks if the Tx buffer of the Emaclite device is free to send
305  * data. If so, it fills the Tx buffer with data for transmission. Otherwise, it
306  * returns an error.
307  *
308  * Return:	0 upon success or -1 if the buffer(s) are full.
309  *
310  * Note:	The maximum Tx packet size can not be more than Ethernet header
311  *		(14 Bytes) + Maximum MTU (1500 bytes). This is excluding FCS.
312  */
313 static int xemaclite_send_data(struct net_local *drvdata, u8 *data,
314 			       unsigned int byte_count)
315 {
316 	u32 reg_data;
317 	void __iomem *addr;
318 
319 	/* Determine the expected Tx buffer address */
320 	addr = drvdata->base_addr + drvdata->next_tx_buf_to_use;
321 
322 	/* If the length is too large, truncate it */
323 	if (byte_count > ETH_FRAME_LEN)
324 		byte_count = ETH_FRAME_LEN;
325 
326 	/* Check if the expected buffer is available */
327 	reg_data = __raw_readl(addr + XEL_TSR_OFFSET);
328 	if ((reg_data & (XEL_TSR_XMIT_BUSY_MASK |
329 	     XEL_TSR_XMIT_ACTIVE_MASK)) == 0) {
330 
331 		/* Switch to next buffer if configured */
332 		if (drvdata->tx_ping_pong != 0)
333 			drvdata->next_tx_buf_to_use ^= XEL_BUFFER_OFFSET;
334 	} else if (drvdata->tx_ping_pong != 0) {
335 		/* If the expected buffer is full, try the other buffer,
336 		 * if it is configured in HW */
337 
338 		addr = (void __iomem __force *)((u32 __force)addr ^
339 						 XEL_BUFFER_OFFSET);
340 		reg_data = __raw_readl(addr + XEL_TSR_OFFSET);
341 
342 		if ((reg_data & (XEL_TSR_XMIT_BUSY_MASK |
343 		     XEL_TSR_XMIT_ACTIVE_MASK)) != 0)
344 			return -1; /* Buffers were full, return failure */
345 	} else
346 		return -1; /* Buffer was full, return failure */
347 
348 	/* Write the frame to the buffer */
349 	xemaclite_aligned_write(data, (u32 __force *) addr, byte_count);
350 
351 	__raw_writel((byte_count & XEL_TPLR_LENGTH_MASK),
352 		     addr + XEL_TPLR_OFFSET);
353 
354 	/* Update the Tx Status Register to indicate that there is a
355 	 * frame to send. Set the XEL_TSR_XMIT_ACTIVE_MASK flag which
356 	 * is used by the interrupt handler to check whether a frame
357 	 * has been transmitted */
358 	reg_data = __raw_readl(addr + XEL_TSR_OFFSET);
359 	reg_data |= (XEL_TSR_XMIT_BUSY_MASK | XEL_TSR_XMIT_ACTIVE_MASK);
360 	__raw_writel(reg_data, addr + XEL_TSR_OFFSET);
361 
362 	return 0;
363 }
364 
365 /**
366  * xemaclite_recv_data - Receive a frame
367  * @drvdata:	Pointer to the Emaclite device private data
368  * @data:	Address where the data is to be received
369  *
370  * This function is intended to be called from the interrupt context or
371  * with a wrapper which waits for the receive frame to be available.
372  *
373  * Return:	Total number of bytes received
374  */
375 static u16 xemaclite_recv_data(struct net_local *drvdata, u8 *data)
376 {
377 	void __iomem *addr;
378 	u16 length, proto_type;
379 	u32 reg_data;
380 
381 	/* Determine the expected buffer address */
382 	addr = (drvdata->base_addr + drvdata->next_rx_buf_to_use);
383 
384 	/* Verify which buffer has valid data */
385 	reg_data = __raw_readl(addr + XEL_RSR_OFFSET);
386 
387 	if ((reg_data & XEL_RSR_RECV_DONE_MASK) == XEL_RSR_RECV_DONE_MASK) {
388 		if (drvdata->rx_ping_pong != 0)
389 			drvdata->next_rx_buf_to_use ^= XEL_BUFFER_OFFSET;
390 	} else {
391 		/* The instance is out of sync, try other buffer if other
392 		 * buffer is configured, return 0 otherwise. If the instance is
393 		 * out of sync, do not update the 'next_rx_buf_to_use' since it
394 		 * will correct on subsequent calls */
395 		if (drvdata->rx_ping_pong != 0)
396 			addr = (void __iomem __force *)((u32 __force)addr ^
397 							 XEL_BUFFER_OFFSET);
398 		else
399 			return 0;	/* No data was available */
400 
401 		/* Verify that buffer has valid data */
402 		reg_data = __raw_readl(addr + XEL_RSR_OFFSET);
403 		if ((reg_data & XEL_RSR_RECV_DONE_MASK) !=
404 		     XEL_RSR_RECV_DONE_MASK)
405 			return 0;	/* No data was available */
406 	}
407 
408 	/* Get the protocol type of the ethernet frame that arrived */
409 	proto_type = ((ntohl(__raw_readl(addr + XEL_HEADER_OFFSET +
410 			XEL_RXBUFF_OFFSET)) >> XEL_HEADER_SHIFT) &
411 			XEL_RPLR_LENGTH_MASK);
412 
413 	/* Check if received ethernet frame is a raw ethernet frame
414 	 * or an IP packet or an ARP packet */
415 	if (proto_type > (ETH_FRAME_LEN + ETH_FCS_LEN)) {
416 
417 		if (proto_type == ETH_P_IP) {
418 			length = ((ntohl(__raw_readl(addr +
419 					XEL_HEADER_IP_LENGTH_OFFSET +
420 					XEL_RXBUFF_OFFSET)) >>
421 					XEL_HEADER_SHIFT) &
422 					XEL_RPLR_LENGTH_MASK);
423 			length += ETH_HLEN + ETH_FCS_LEN;
424 
425 		} else if (proto_type == ETH_P_ARP)
426 			length = XEL_ARP_PACKET_SIZE + ETH_HLEN + ETH_FCS_LEN;
427 		else
428 			/* Field contains type other than IP or ARP, use max
429 			 * frame size and let user parse it */
430 			length = ETH_FRAME_LEN + ETH_FCS_LEN;
431 	} else
432 		/* Use the length in the frame, plus the header and trailer */
433 		length = proto_type + ETH_HLEN + ETH_FCS_LEN;
434 
435 	/* Read from the EmacLite device */
436 	xemaclite_aligned_read((u32 __force *) (addr + XEL_RXBUFF_OFFSET),
437 				data, length);
438 
439 	/* Acknowledge the frame */
440 	reg_data = __raw_readl(addr + XEL_RSR_OFFSET);
441 	reg_data &= ~XEL_RSR_RECV_DONE_MASK;
442 	__raw_writel(reg_data, addr + XEL_RSR_OFFSET);
443 
444 	return length;
445 }
446 
447 /**
448  * xemaclite_update_address - Update the MAC address in the device
449  * @drvdata:	Pointer to the Emaclite device private data
450  * @address_ptr:Pointer to the MAC address (MAC address is a 48-bit value)
451  *
452  * Tx must be idle and Rx should be idle for deterministic results.
453  * It is recommended that this function should be called after the
454  * initialization and before transmission of any packets from the device.
455  * The MAC address can be programmed using any of the two transmit
456  * buffers (if configured).
457  */
458 static void xemaclite_update_address(struct net_local *drvdata,
459 				     u8 *address_ptr)
460 {
461 	void __iomem *addr;
462 	u32 reg_data;
463 
464 	/* Determine the expected Tx buffer address */
465 	addr = drvdata->base_addr + drvdata->next_tx_buf_to_use;
466 
467 	xemaclite_aligned_write(address_ptr, (u32 __force *) addr, ETH_ALEN);
468 
469 	__raw_writel(ETH_ALEN, addr + XEL_TPLR_OFFSET);
470 
471 	/* Update the MAC address in the EmacLite */
472 	reg_data = __raw_readl(addr + XEL_TSR_OFFSET);
473 	__raw_writel(reg_data | XEL_TSR_PROG_MAC_ADDR, addr + XEL_TSR_OFFSET);
474 
475 	/* Wait for EmacLite to finish with the MAC address update */
476 	while ((__raw_readl(addr + XEL_TSR_OFFSET) &
477 		XEL_TSR_PROG_MAC_ADDR) != 0)
478 		;
479 }
480 
481 /**
482  * xemaclite_set_mac_address - Set the MAC address for this device
483  * @dev:	Pointer to the network device instance
484  * @addr:	Void pointer to the sockaddr structure
485  *
486  * This function copies the HW address from the sockaddr strucutre to the
487  * net_device structure and updates the address in HW.
488  *
489  * Return:	Error if the net device is busy or 0 if the addr is set
490  *		successfully
491  */
492 static int xemaclite_set_mac_address(struct net_device *dev, void *address)
493 {
494 	struct net_local *lp = netdev_priv(dev);
495 	struct sockaddr *addr = address;
496 
497 	if (netif_running(dev))
498 		return -EBUSY;
499 
500 	memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
501 	xemaclite_update_address(lp, dev->dev_addr);
502 	return 0;
503 }
504 
505 /**
506  * xemaclite_tx_timeout - Callback for Tx Timeout
507  * @dev:	Pointer to the network device
508  *
509  * This function is called when Tx time out occurs for Emaclite device.
510  */
511 static void xemaclite_tx_timeout(struct net_device *dev)
512 {
513 	struct net_local *lp = netdev_priv(dev);
514 	unsigned long flags;
515 
516 	dev_err(&lp->ndev->dev, "Exceeded transmit timeout of %lu ms\n",
517 		TX_TIMEOUT * 1000UL / HZ);
518 
519 	dev->stats.tx_errors++;
520 
521 	/* Reset the device */
522 	spin_lock_irqsave(&lp->reset_lock, flags);
523 
524 	/* Shouldn't really be necessary, but shouldn't hurt */
525 	netif_stop_queue(dev);
526 
527 	xemaclite_disable_interrupts(lp);
528 	xemaclite_enable_interrupts(lp);
529 
530 	if (lp->deferred_skb) {
531 		dev_kfree_skb(lp->deferred_skb);
532 		lp->deferred_skb = NULL;
533 		dev->stats.tx_errors++;
534 	}
535 
536 	/* To exclude tx timeout */
537 	dev->trans_start = jiffies; /* prevent tx timeout */
538 
539 	/* We're all ready to go. Start the queue */
540 	netif_wake_queue(dev);
541 	spin_unlock_irqrestore(&lp->reset_lock, flags);
542 }
543 
544 /**********************/
545 /* Interrupt Handlers */
546 /**********************/
547 
548 /**
549  * xemaclite_tx_handler - Interrupt handler for frames sent
550  * @dev:	Pointer to the network device
551  *
552  * This function updates the number of packets transmitted and handles the
553  * deferred skb, if there is one.
554  */
555 static void xemaclite_tx_handler(struct net_device *dev)
556 {
557 	struct net_local *lp = netdev_priv(dev);
558 
559 	dev->stats.tx_packets++;
560 	if (lp->deferred_skb) {
561 		if (xemaclite_send_data(lp,
562 					(u8 *) lp->deferred_skb->data,
563 					lp->deferred_skb->len) != 0)
564 			return;
565 		else {
566 			dev->stats.tx_bytes += lp->deferred_skb->len;
567 			dev_kfree_skb_irq(lp->deferred_skb);
568 			lp->deferred_skb = NULL;
569 			dev->trans_start = jiffies; /* prevent tx timeout */
570 			netif_wake_queue(dev);
571 		}
572 	}
573 }
574 
575 /**
576  * xemaclite_rx_handler- Interrupt handler for frames received
577  * @dev:	Pointer to the network device
578  *
579  * This function allocates memory for a socket buffer, fills it with data
580  * received and hands it over to the TCP/IP stack.
581  */
582 static void xemaclite_rx_handler(struct net_device *dev)
583 {
584 	struct net_local *lp = netdev_priv(dev);
585 	struct sk_buff *skb;
586 	unsigned int align;
587 	u32 len;
588 
589 	len = ETH_FRAME_LEN + ETH_FCS_LEN;
590 	skb = netdev_alloc_skb(dev, len + ALIGNMENT);
591 	if (!skb) {
592 		/* Couldn't get memory. */
593 		dev->stats.rx_dropped++;
594 		dev_err(&lp->ndev->dev, "Could not allocate receive buffer\n");
595 		return;
596 	}
597 
598 	/*
599 	 * A new skb should have the data halfword aligned, but this code is
600 	 * here just in case that isn't true. Calculate how many
601 	 * bytes we should reserve to get the data to start on a word
602 	 * boundary */
603 	align = BUFFER_ALIGN(skb->data);
604 	if (align)
605 		skb_reserve(skb, align);
606 
607 	skb_reserve(skb, 2);
608 
609 	len = xemaclite_recv_data(lp, (u8 *) skb->data);
610 
611 	if (!len) {
612 		dev->stats.rx_errors++;
613 		dev_kfree_skb_irq(skb);
614 		return;
615 	}
616 
617 	skb_put(skb, len);	/* Tell the skb how much data we got */
618 
619 	skb->protocol = eth_type_trans(skb, dev);
620 	skb_checksum_none_assert(skb);
621 
622 	dev->stats.rx_packets++;
623 	dev->stats.rx_bytes += len;
624 
625 	if (!skb_defer_rx_timestamp(skb))
626 		netif_rx(skb);	/* Send the packet upstream */
627 }
628 
629 /**
630  * xemaclite_interrupt - Interrupt handler for this driver
631  * @irq:	Irq of the Emaclite device
632  * @dev_id:	Void pointer to the network device instance used as callback
633  *		reference
634  *
635  * This function handles the Tx and Rx interrupts of the EmacLite device.
636  */
637 static irqreturn_t xemaclite_interrupt(int irq, void *dev_id)
638 {
639 	bool tx_complete = false;
640 	struct net_device *dev = dev_id;
641 	struct net_local *lp = netdev_priv(dev);
642 	void __iomem *base_addr = lp->base_addr;
643 	u32 tx_status;
644 
645 	/* Check if there is Rx Data available */
646 	if ((__raw_readl(base_addr + XEL_RSR_OFFSET) &
647 			 XEL_RSR_RECV_DONE_MASK) ||
648 	    (__raw_readl(base_addr + XEL_BUFFER_OFFSET + XEL_RSR_OFFSET)
649 			 & XEL_RSR_RECV_DONE_MASK))
650 
651 		xemaclite_rx_handler(dev);
652 
653 	/* Check if the Transmission for the first buffer is completed */
654 	tx_status = __raw_readl(base_addr + XEL_TSR_OFFSET);
655 	if (((tx_status & XEL_TSR_XMIT_BUSY_MASK) == 0) &&
656 		(tx_status & XEL_TSR_XMIT_ACTIVE_MASK) != 0) {
657 
658 		tx_status &= ~XEL_TSR_XMIT_ACTIVE_MASK;
659 		__raw_writel(tx_status, base_addr + XEL_TSR_OFFSET);
660 
661 		tx_complete = true;
662 	}
663 
664 	/* Check if the Transmission for the second buffer is completed */
665 	tx_status = __raw_readl(base_addr + XEL_BUFFER_OFFSET + XEL_TSR_OFFSET);
666 	if (((tx_status & XEL_TSR_XMIT_BUSY_MASK) == 0) &&
667 		(tx_status & XEL_TSR_XMIT_ACTIVE_MASK) != 0) {
668 
669 		tx_status &= ~XEL_TSR_XMIT_ACTIVE_MASK;
670 		__raw_writel(tx_status, base_addr + XEL_BUFFER_OFFSET +
671 			     XEL_TSR_OFFSET);
672 
673 		tx_complete = true;
674 	}
675 
676 	/* If there was a Tx interrupt, call the Tx Handler */
677 	if (tx_complete != 0)
678 		xemaclite_tx_handler(dev);
679 
680 	return IRQ_HANDLED;
681 }
682 
683 /**********************/
684 /* MDIO Bus functions */
685 /**********************/
686 
687 /**
688  * xemaclite_mdio_wait - Wait for the MDIO to be ready to use
689  * @lp:		Pointer to the Emaclite device private data
690  *
691  * This function waits till the device is ready to accept a new MDIO
692  * request.
693  *
694  * Return:	0 for success or ETIMEDOUT for a timeout
695  */
696 
697 static int xemaclite_mdio_wait(struct net_local *lp)
698 {
699 	long end = jiffies + 2;
700 
701 	/* wait for the MDIO interface to not be busy or timeout
702 	   after some time.
703 	*/
704 	while (__raw_readl(lp->base_addr + XEL_MDIOCTRL_OFFSET) &
705 			XEL_MDIOCTRL_MDIOSTS_MASK) {
706 		if (end - jiffies <= 0) {
707 			WARN_ON(1);
708 			return -ETIMEDOUT;
709 		}
710 		msleep(1);
711 	}
712 	return 0;
713 }
714 
715 /**
716  * xemaclite_mdio_read - Read from a given MII management register
717  * @bus:	the mii_bus struct
718  * @phy_id:	the phy address
719  * @reg:	register number to read from
720  *
721  * This function waits till the device is ready to accept a new MDIO
722  * request and then writes the phy address to the MDIO Address register
723  * and reads data from MDIO Read Data register, when its available.
724  *
725  * Return:	Value read from the MII management register
726  */
727 static int xemaclite_mdio_read(struct mii_bus *bus, int phy_id, int reg)
728 {
729 	struct net_local *lp = bus->priv;
730 	u32 ctrl_reg;
731 	u32 rc;
732 
733 	if (xemaclite_mdio_wait(lp))
734 		return -ETIMEDOUT;
735 
736 	/* Write the PHY address, register number and set the OP bit in the
737 	 * MDIO Address register. Set the Status bit in the MDIO Control
738 	 * register to start a MDIO read transaction.
739 	 */
740 	ctrl_reg = __raw_readl(lp->base_addr + XEL_MDIOCTRL_OFFSET);
741 	__raw_writel(XEL_MDIOADDR_OP_MASK |
742 		     ((phy_id << XEL_MDIOADDR_PHYADR_SHIFT) | reg),
743 		     lp->base_addr + XEL_MDIOADDR_OFFSET);
744 	__raw_writel(ctrl_reg | XEL_MDIOCTRL_MDIOSTS_MASK,
745 		     lp->base_addr + XEL_MDIOCTRL_OFFSET);
746 
747 	if (xemaclite_mdio_wait(lp))
748 		return -ETIMEDOUT;
749 
750 	rc = __raw_readl(lp->base_addr + XEL_MDIORD_OFFSET);
751 
752 	dev_dbg(&lp->ndev->dev,
753 		"xemaclite_mdio_read(phy_id=%i, reg=%x) == %x\n",
754 		phy_id, reg, rc);
755 
756 	return rc;
757 }
758 
759 /**
760  * xemaclite_mdio_write - Write to a given MII management register
761  * @bus:	the mii_bus struct
762  * @phy_id:	the phy address
763  * @reg:	register number to write to
764  * @val:	value to write to the register number specified by reg
765  *
766  * This function waits till the device is ready to accept a new MDIO
767  * request and then writes the val to the MDIO Write Data register.
768  */
769 static int xemaclite_mdio_write(struct mii_bus *bus, int phy_id, int reg,
770 				u16 val)
771 {
772 	struct net_local *lp = bus->priv;
773 	u32 ctrl_reg;
774 
775 	dev_dbg(&lp->ndev->dev,
776 		"xemaclite_mdio_write(phy_id=%i, reg=%x, val=%x)\n",
777 		phy_id, reg, val);
778 
779 	if (xemaclite_mdio_wait(lp))
780 		return -ETIMEDOUT;
781 
782 	/* Write the PHY address, register number and clear the OP bit in the
783 	 * MDIO Address register and then write the value into the MDIO Write
784 	 * Data register. Finally, set the Status bit in the MDIO Control
785 	 * register to start a MDIO write transaction.
786 	 */
787 	ctrl_reg = __raw_readl(lp->base_addr + XEL_MDIOCTRL_OFFSET);
788 	__raw_writel(~XEL_MDIOADDR_OP_MASK &
789 		     ((phy_id << XEL_MDIOADDR_PHYADR_SHIFT) | reg),
790 		     lp->base_addr + XEL_MDIOADDR_OFFSET);
791 	__raw_writel(val, lp->base_addr + XEL_MDIOWR_OFFSET);
792 	__raw_writel(ctrl_reg | XEL_MDIOCTRL_MDIOSTS_MASK,
793 		     lp->base_addr + XEL_MDIOCTRL_OFFSET);
794 
795 	return 0;
796 }
797 
798 /**
799  * xemaclite_mdio_reset - Reset the mdio bus.
800  * @bus:	Pointer to the MII bus
801  *
802  * This function is required(?) as per Documentation/networking/phy.txt.
803  * There is no reset in this device; this function always returns 0.
804  */
805 static int xemaclite_mdio_reset(struct mii_bus *bus)
806 {
807 	return 0;
808 }
809 
810 /**
811  * xemaclite_mdio_setup - Register mii_bus for the Emaclite device
812  * @lp:		Pointer to the Emaclite device private data
813  * @ofdev:	Pointer to OF device structure
814  *
815  * This function enables MDIO bus in the Emaclite device and registers a
816  * mii_bus.
817  *
818  * Return:	0 upon success or a negative error upon failure
819  */
820 static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
821 {
822 	struct mii_bus *bus;
823 	int rc;
824 	struct resource res;
825 	struct device_node *np = of_get_parent(lp->phy_node);
826 	struct device_node *npp;
827 
828 	/* Don't register the MDIO bus if the phy_node or its parent node
829 	 * can't be found.
830 	 */
831 	if (!np) {
832 		dev_err(dev, "Failed to register mdio bus.\n");
833 		return -ENODEV;
834 	}
835 	npp = of_get_parent(np);
836 
837 	of_address_to_resource(npp, 0, &res);
838 	if (lp->ndev->mem_start != res.start) {
839 		struct phy_device *phydev;
840 		phydev = of_phy_find_device(lp->phy_node);
841 		if (!phydev)
842 			dev_info(dev,
843 				 "MDIO of the phy is not registered yet\n");
844 		return 0;
845 	}
846 
847 	/* Enable the MDIO bus by asserting the enable bit in MDIO Control
848 	 * register.
849 	 */
850 	__raw_writel(XEL_MDIOCTRL_MDIOEN_MASK,
851 		     lp->base_addr + XEL_MDIOCTRL_OFFSET);
852 
853 	bus = mdiobus_alloc();
854 	if (!bus) {
855 		dev_err(dev, "Failed to allocate mdiobus\n");
856 		return -ENOMEM;
857 	}
858 
859 	snprintf(bus->id, MII_BUS_ID_SIZE, "%.8llx",
860 		 (unsigned long long)res.start);
861 	bus->priv = lp;
862 	bus->name = "Xilinx Emaclite MDIO";
863 	bus->read = xemaclite_mdio_read;
864 	bus->write = xemaclite_mdio_write;
865 	bus->reset = xemaclite_mdio_reset;
866 	bus->parent = dev;
867 	bus->irq = lp->mdio_irqs; /* preallocated IRQ table */
868 
869 	lp->mii_bus = bus;
870 
871 	rc = of_mdiobus_register(bus, np);
872 	if (rc) {
873 		dev_err(dev, "Failed to register mdio bus.\n");
874 		goto err_register;
875 	}
876 
877 	return 0;
878 
879 err_register:
880 	mdiobus_free(bus);
881 	return rc;
882 }
883 
884 /**
885  * xemaclite_adjust_link - Link state callback for the Emaclite device
886  * @ndev: pointer to net_device struct
887  *
888  * There's nothing in the Emaclite device to be configured when the link
889  * state changes. We just print the status.
890  */
891 static void xemaclite_adjust_link(struct net_device *ndev)
892 {
893 	struct net_local *lp = netdev_priv(ndev);
894 	struct phy_device *phy = lp->phy_dev;
895 	int link_state;
896 
897 	/* hash together the state values to decide if something has changed */
898 	link_state = phy->speed | (phy->duplex << 1) | phy->link;
899 
900 	if (lp->last_link != link_state) {
901 		lp->last_link = link_state;
902 		phy_print_status(phy);
903 	}
904 }
905 
906 /**
907  * xemaclite_open - Open the network device
908  * @dev:	Pointer to the network device
909  *
910  * This function sets the MAC address, requests an IRQ and enables interrupts
911  * for the Emaclite device and starts the Tx queue.
912  * It also connects to the phy device, if MDIO is included in Emaclite device.
913  */
914 static int xemaclite_open(struct net_device *dev)
915 {
916 	struct net_local *lp = netdev_priv(dev);
917 	int retval;
918 
919 	/* Just to be safe, stop the device first */
920 	xemaclite_disable_interrupts(lp);
921 
922 	if (lp->phy_node) {
923 		u32 bmcr;
924 
925 		lp->phy_dev = of_phy_connect(lp->ndev, lp->phy_node,
926 					     xemaclite_adjust_link, 0,
927 					     PHY_INTERFACE_MODE_MII);
928 		if (!lp->phy_dev) {
929 			dev_err(&lp->ndev->dev, "of_phy_connect() failed\n");
930 			return -ENODEV;
931 		}
932 
933 		/* EmacLite doesn't support giga-bit speeds */
934 		lp->phy_dev->supported &= (PHY_BASIC_FEATURES);
935 		lp->phy_dev->advertising = lp->phy_dev->supported;
936 
937 		/* Don't advertise 1000BASE-T Full/Half duplex speeds */
938 		phy_write(lp->phy_dev, MII_CTRL1000, 0);
939 
940 		/* Advertise only 10 and 100mbps full/half duplex speeds */
941 		phy_write(lp->phy_dev, MII_ADVERTISE, ADVERTISE_ALL |
942 			  ADVERTISE_CSMA);
943 
944 		/* Restart auto negotiation */
945 		bmcr = phy_read(lp->phy_dev, MII_BMCR);
946 		bmcr |= (BMCR_ANENABLE | BMCR_ANRESTART);
947 		phy_write(lp->phy_dev, MII_BMCR, bmcr);
948 
949 		phy_start(lp->phy_dev);
950 	}
951 
952 	/* Set the MAC address each time opened */
953 	xemaclite_update_address(lp, dev->dev_addr);
954 
955 	/* Grab the IRQ */
956 	retval = request_irq(dev->irq, xemaclite_interrupt, 0, dev->name, dev);
957 	if (retval) {
958 		dev_err(&lp->ndev->dev, "Could not allocate interrupt %d\n",
959 			dev->irq);
960 		if (lp->phy_dev)
961 			phy_disconnect(lp->phy_dev);
962 		lp->phy_dev = NULL;
963 
964 		return retval;
965 	}
966 
967 	/* Enable Interrupts */
968 	xemaclite_enable_interrupts(lp);
969 
970 	/* We're ready to go */
971 	netif_start_queue(dev);
972 
973 	return 0;
974 }
975 
976 /**
977  * xemaclite_close - Close the network device
978  * @dev:	Pointer to the network device
979  *
980  * This function stops the Tx queue, disables interrupts and frees the IRQ for
981  * the Emaclite device.
982  * It also disconnects the phy device associated with the Emaclite device.
983  */
984 static int xemaclite_close(struct net_device *dev)
985 {
986 	struct net_local *lp = netdev_priv(dev);
987 
988 	netif_stop_queue(dev);
989 	xemaclite_disable_interrupts(lp);
990 	free_irq(dev->irq, dev);
991 
992 	if (lp->phy_dev)
993 		phy_disconnect(lp->phy_dev);
994 	lp->phy_dev = NULL;
995 
996 	return 0;
997 }
998 
999 /**
1000  * xemaclite_send - Transmit a frame
1001  * @orig_skb:	Pointer to the socket buffer to be transmitted
1002  * @dev:	Pointer to the network device
1003  *
1004  * This function checks if the Tx buffer of the Emaclite device is free to send
1005  * data. If so, it fills the Tx buffer with data from socket buffer data,
1006  * updates the stats and frees the socket buffer. The Tx completion is signaled
1007  * by an interrupt. If the Tx buffer isn't free, then the socket buffer is
1008  * deferred and the Tx queue is stopped so that the deferred socket buffer can
1009  * be transmitted when the Emaclite device is free to transmit data.
1010  *
1011  * Return:	0, always.
1012  */
1013 static int xemaclite_send(struct sk_buff *orig_skb, struct net_device *dev)
1014 {
1015 	struct net_local *lp = netdev_priv(dev);
1016 	struct sk_buff *new_skb;
1017 	unsigned int len;
1018 	unsigned long flags;
1019 
1020 	len = orig_skb->len;
1021 
1022 	new_skb = orig_skb;
1023 
1024 	spin_lock_irqsave(&lp->reset_lock, flags);
1025 	if (xemaclite_send_data(lp, (u8 *) new_skb->data, len) != 0) {
1026 		/* If the Emaclite Tx buffer is busy, stop the Tx queue and
1027 		 * defer the skb for transmission during the ISR, after the
1028 		 * current transmission is complete */
1029 		netif_stop_queue(dev);
1030 		lp->deferred_skb = new_skb;
1031 		/* Take the time stamp now, since we can't do this in an ISR. */
1032 		skb_tx_timestamp(new_skb);
1033 		spin_unlock_irqrestore(&lp->reset_lock, flags);
1034 		return 0;
1035 	}
1036 	spin_unlock_irqrestore(&lp->reset_lock, flags);
1037 
1038 	skb_tx_timestamp(new_skb);
1039 
1040 	dev->stats.tx_bytes += len;
1041 	dev_kfree_skb(new_skb);
1042 
1043 	return 0;
1044 }
1045 
1046 /**
1047  * xemaclite_remove_ndev - Free the network device
1048  * @ndev:	Pointer to the network device to be freed
1049  *
1050  * This function un maps the IO region of the Emaclite device and frees the net
1051  * device.
1052  */
1053 static void xemaclite_remove_ndev(struct net_device *ndev)
1054 {
1055 	if (ndev) {
1056 		free_netdev(ndev);
1057 	}
1058 }
1059 
1060 /**
1061  * get_bool - Get a parameter from the OF device
1062  * @ofdev:	Pointer to OF device structure
1063  * @s:		Property to be retrieved
1064  *
1065  * This function looks for a property in the device node and returns the value
1066  * of the property if its found or 0 if the property is not found.
1067  *
1068  * Return:	Value of the parameter if the parameter is found, or 0 otherwise
1069  */
1070 static bool get_bool(struct platform_device *ofdev, const char *s)
1071 {
1072 	u32 *p = (u32 *)of_get_property(ofdev->dev.of_node, s, NULL);
1073 
1074 	if (p) {
1075 		return (bool)*p;
1076 	} else {
1077 		dev_warn(&ofdev->dev, "Parameter %s not found,"
1078 			"defaulting to false\n", s);
1079 		return 0;
1080 	}
1081 }
1082 
1083 static struct net_device_ops xemaclite_netdev_ops;
1084 
1085 /**
1086  * xemaclite_of_probe - Probe method for the Emaclite device.
1087  * @ofdev:	Pointer to OF device structure
1088  * @match:	Pointer to the structure used for matching a device
1089  *
1090  * This function probes for the Emaclite device in the device tree.
1091  * It initializes the driver data structure and the hardware, sets the MAC
1092  * address and registers the network device.
1093  * It also registers a mii_bus for the Emaclite device, if MDIO is included
1094  * in the device.
1095  *
1096  * Return:	0, if the driver is bound to the Emaclite device, or
1097  *		a negative error if there is failure.
1098  */
1099 static int xemaclite_of_probe(struct platform_device *ofdev)
1100 {
1101 	struct resource *res;
1102 	struct net_device *ndev = NULL;
1103 	struct net_local *lp = NULL;
1104 	struct device *dev = &ofdev->dev;
1105 	const void *mac_address;
1106 
1107 	int rc = 0;
1108 
1109 	dev_info(dev, "Device Tree Probing\n");
1110 
1111 	/* Create an ethernet device instance */
1112 	ndev = alloc_etherdev(sizeof(struct net_local));
1113 	if (!ndev)
1114 		return -ENOMEM;
1115 
1116 	dev_set_drvdata(dev, ndev);
1117 	SET_NETDEV_DEV(ndev, &ofdev->dev);
1118 
1119 	lp = netdev_priv(ndev);
1120 	lp->ndev = ndev;
1121 
1122 	/* Get IRQ for the device */
1123 	res = platform_get_resource(ofdev, IORESOURCE_IRQ, 0);
1124 	if (!res) {
1125 		dev_err(dev, "no IRQ found\n");
1126 		goto error;
1127 	}
1128 
1129 	ndev->irq = res->start;
1130 
1131 	res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
1132 	lp->base_addr = devm_ioremap_resource(&ofdev->dev, res);
1133 	if (IS_ERR(lp->base_addr)) {
1134 		rc = PTR_ERR(lp->base_addr);
1135 		goto error;
1136 	}
1137 
1138 	ndev->mem_start = res->start;
1139 	ndev->mem_end = res->end;
1140 
1141 	spin_lock_init(&lp->reset_lock);
1142 	lp->next_tx_buf_to_use = 0x0;
1143 	lp->next_rx_buf_to_use = 0x0;
1144 	lp->tx_ping_pong = get_bool(ofdev, "xlnx,tx-ping-pong");
1145 	lp->rx_ping_pong = get_bool(ofdev, "xlnx,rx-ping-pong");
1146 	mac_address = of_get_mac_address(ofdev->dev.of_node);
1147 
1148 	if (mac_address)
1149 		/* Set the MAC address. */
1150 		memcpy(ndev->dev_addr, mac_address, ETH_ALEN);
1151 	else
1152 		dev_warn(dev, "No MAC address found\n");
1153 
1154 	/* Clear the Tx CSR's in case this is a restart */
1155 	__raw_writel(0, lp->base_addr + XEL_TSR_OFFSET);
1156 	__raw_writel(0, lp->base_addr + XEL_BUFFER_OFFSET + XEL_TSR_OFFSET);
1157 
1158 	/* Set the MAC address in the EmacLite device */
1159 	xemaclite_update_address(lp, ndev->dev_addr);
1160 
1161 	lp->phy_node = of_parse_phandle(ofdev->dev.of_node, "phy-handle", 0);
1162 	rc = xemaclite_mdio_setup(lp, &ofdev->dev);
1163 	if (rc)
1164 		dev_warn(&ofdev->dev, "error registering MDIO bus\n");
1165 
1166 	dev_info(dev, "MAC address is now %pM\n", ndev->dev_addr);
1167 
1168 	ndev->netdev_ops = &xemaclite_netdev_ops;
1169 	ndev->flags &= ~IFF_MULTICAST;
1170 	ndev->watchdog_timeo = TX_TIMEOUT;
1171 
1172 	/* Finally, register the device */
1173 	rc = register_netdev(ndev);
1174 	if (rc) {
1175 		dev_err(dev,
1176 			"Cannot register network device, aborting\n");
1177 		goto error;
1178 	}
1179 
1180 	dev_info(dev,
1181 		 "Xilinx EmacLite at 0x%08X mapped to 0x%08X, irq=%d\n",
1182 		 (unsigned int __force)ndev->mem_start,
1183 		 (unsigned int __force)lp->base_addr, ndev->irq);
1184 	return 0;
1185 
1186 error:
1187 	xemaclite_remove_ndev(ndev);
1188 	return rc;
1189 }
1190 
1191 /**
1192  * xemaclite_of_remove - Unbind the driver from the Emaclite device.
1193  * @of_dev:	Pointer to OF device structure
1194  *
1195  * This function is called if a device is physically removed from the system or
1196  * if the driver module is being unloaded. It frees any resources allocated to
1197  * the device.
1198  *
1199  * Return:	0, always.
1200  */
1201 static int xemaclite_of_remove(struct platform_device *of_dev)
1202 {
1203 	struct net_device *ndev = platform_get_drvdata(of_dev);
1204 
1205 	struct net_local *lp = netdev_priv(ndev);
1206 
1207 	/* Un-register the mii_bus, if configured */
1208 	if (lp->has_mdio) {
1209 		mdiobus_unregister(lp->mii_bus);
1210 		kfree(lp->mii_bus->irq);
1211 		mdiobus_free(lp->mii_bus);
1212 		lp->mii_bus = NULL;
1213 	}
1214 
1215 	unregister_netdev(ndev);
1216 
1217 	if (lp->phy_node)
1218 		of_node_put(lp->phy_node);
1219 	lp->phy_node = NULL;
1220 
1221 	xemaclite_remove_ndev(ndev);
1222 
1223 	return 0;
1224 }
1225 
1226 #ifdef CONFIG_NET_POLL_CONTROLLER
1227 static void
1228 xemaclite_poll_controller(struct net_device *ndev)
1229 {
1230 	disable_irq(ndev->irq);
1231 	xemaclite_interrupt(ndev->irq, ndev);
1232 	enable_irq(ndev->irq);
1233 }
1234 #endif
1235 
1236 static struct net_device_ops xemaclite_netdev_ops = {
1237 	.ndo_open		= xemaclite_open,
1238 	.ndo_stop		= xemaclite_close,
1239 	.ndo_start_xmit		= xemaclite_send,
1240 	.ndo_set_mac_address	= xemaclite_set_mac_address,
1241 	.ndo_tx_timeout		= xemaclite_tx_timeout,
1242 #ifdef CONFIG_NET_POLL_CONTROLLER
1243 	.ndo_poll_controller = xemaclite_poll_controller,
1244 #endif
1245 };
1246 
1247 /* Match table for OF platform binding */
1248 static struct of_device_id xemaclite_of_match[] = {
1249 	{ .compatible = "xlnx,opb-ethernetlite-1.01.a", },
1250 	{ .compatible = "xlnx,opb-ethernetlite-1.01.b", },
1251 	{ .compatible = "xlnx,xps-ethernetlite-1.00.a", },
1252 	{ .compatible = "xlnx,xps-ethernetlite-2.00.a", },
1253 	{ .compatible = "xlnx,xps-ethernetlite-2.01.a", },
1254 	{ .compatible = "xlnx,xps-ethernetlite-3.00.a", },
1255 	{ /* end of list */ },
1256 };
1257 MODULE_DEVICE_TABLE(of, xemaclite_of_match);
1258 
1259 static struct platform_driver xemaclite_of_driver = {
1260 	.driver = {
1261 		.name = DRIVER_NAME,
1262 		.owner = THIS_MODULE,
1263 		.of_match_table = xemaclite_of_match,
1264 	},
1265 	.probe		= xemaclite_of_probe,
1266 	.remove		= xemaclite_of_remove,
1267 };
1268 
1269 module_platform_driver(xemaclite_of_driver);
1270 
1271 MODULE_AUTHOR("Xilinx, Inc.");
1272 MODULE_DESCRIPTION("Xilinx Ethernet MAC Lite driver");
1273 MODULE_LICENSE("GPL");
1274