xref: /linux/drivers/net/ethernet/ezchip/nps_enet.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * Copyright(c) 2015 EZchip Technologies.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * The full GNU General Public License is included in this distribution in
14  * the file called "COPYING".
15  */
16 
17 #include <linux/module.h>
18 #include <linux/etherdevice.h>
19 #include <linux/of_address.h>
20 #include <linux/of_irq.h>
21 #include <linux/of_net.h>
22 #include <linux/of_platform.h>
23 #include "nps_enet.h"
24 
25 #define DRV_NAME			"nps_mgt_enet"
26 
27 static void nps_enet_clean_rx_fifo(struct net_device *ndev, u32 frame_len)
28 {
29 	struct nps_enet_priv *priv = netdev_priv(ndev);
30 	u32 i, len = DIV_ROUND_UP(frame_len, sizeof(u32));
31 
32 	/* Empty Rx FIFO buffer by reading all words */
33 	for (i = 0; i < len; i++)
34 		nps_enet_reg_get(priv, NPS_ENET_REG_RX_BUF);
35 }
36 
37 static void nps_enet_read_rx_fifo(struct net_device *ndev,
38 				  unsigned char *dst, u32 length)
39 {
40 	struct nps_enet_priv *priv = netdev_priv(ndev);
41 	s32 i, last = length & (sizeof(u32) - 1);
42 	u32 *reg = (u32 *)dst, len = length / sizeof(u32);
43 	bool dst_is_aligned = IS_ALIGNED((unsigned long)dst, sizeof(u32));
44 
45 	/* In case dst is not aligned we need an intermediate buffer */
46 	if (dst_is_aligned)
47 		for (i = 0; i < len; i++, reg++)
48 			*reg = nps_enet_reg_get(priv, NPS_ENET_REG_RX_BUF);
49 	else { /* !dst_is_aligned */
50 		for (i = 0; i < len; i++, reg++) {
51 			u32 buf =
52 				nps_enet_reg_get(priv, NPS_ENET_REG_RX_BUF);
53 
54 			/* to accommodate word-unaligned address of "reg"
55 			 * we have to do memcpy_toio() instead of simple "=".
56 			 */
57 			memcpy_toio((void __iomem *)reg, &buf, sizeof(buf));
58 		}
59 	}
60 
61 	/* copy last bytes (if any) */
62 	if (last) {
63 		u32 buf = nps_enet_reg_get(priv, NPS_ENET_REG_RX_BUF);
64 
65 		memcpy_toio((void __iomem *)reg, &buf, last);
66 	}
67 }
68 
69 static u32 nps_enet_rx_handler(struct net_device *ndev)
70 {
71 	u32 frame_len, err = 0;
72 	u32 work_done = 0;
73 	struct nps_enet_priv *priv = netdev_priv(ndev);
74 	struct sk_buff *skb;
75 	struct nps_enet_rx_ctl rx_ctrl;
76 
77 	rx_ctrl.value = nps_enet_reg_get(priv, NPS_ENET_REG_RX_CTL);
78 	frame_len = rx_ctrl.nr;
79 
80 	/* Check if we got RX */
81 	if (!rx_ctrl.cr)
82 		return work_done;
83 
84 	/* If we got here there is a work for us */
85 	work_done++;
86 
87 	/* Check Rx error */
88 	if (rx_ctrl.er) {
89 		ndev->stats.rx_errors++;
90 		err = 1;
91 	}
92 
93 	/* Check Rx CRC error */
94 	if (rx_ctrl.crc) {
95 		ndev->stats.rx_crc_errors++;
96 		ndev->stats.rx_dropped++;
97 		err = 1;
98 	}
99 
100 	/* Check Frame length Min 64b */
101 	if (unlikely(frame_len < ETH_ZLEN)) {
102 		ndev->stats.rx_length_errors++;
103 		ndev->stats.rx_dropped++;
104 		err = 1;
105 	}
106 
107 	if (err)
108 		goto rx_irq_clean;
109 
110 	/* Skb allocation */
111 	skb = netdev_alloc_skb_ip_align(ndev, frame_len);
112 	if (unlikely(!skb)) {
113 		ndev->stats.rx_errors++;
114 		ndev->stats.rx_dropped++;
115 		goto rx_irq_clean;
116 	}
117 
118 	/* Copy frame from Rx fifo into the skb */
119 	nps_enet_read_rx_fifo(ndev, skb->data, frame_len);
120 
121 	skb_put(skb, frame_len);
122 	skb->protocol = eth_type_trans(skb, ndev);
123 	skb->ip_summed = CHECKSUM_UNNECESSARY;
124 
125 	ndev->stats.rx_packets++;
126 	ndev->stats.rx_bytes += frame_len;
127 	netif_receive_skb(skb);
128 
129 	goto rx_irq_frame_done;
130 
131 rx_irq_clean:
132 	/* Clean Rx fifo */
133 	nps_enet_clean_rx_fifo(ndev, frame_len);
134 
135 rx_irq_frame_done:
136 	/* Ack Rx ctrl register */
137 	nps_enet_reg_set(priv, NPS_ENET_REG_RX_CTL, 0);
138 
139 	return work_done;
140 }
141 
142 static void nps_enet_tx_handler(struct net_device *ndev)
143 {
144 	struct nps_enet_priv *priv = netdev_priv(ndev);
145 	struct nps_enet_tx_ctl tx_ctrl;
146 
147 	tx_ctrl.value = nps_enet_reg_get(priv, NPS_ENET_REG_TX_CTL);
148 
149 	/* Check if we got TX */
150 	if (!priv->tx_packet_sent || tx_ctrl.ct)
151 		return;
152 
153 	/* Ack Tx ctrl register */
154 	nps_enet_reg_set(priv, NPS_ENET_REG_TX_CTL, 0);
155 
156 	/* Check Tx transmit error */
157 	if (unlikely(tx_ctrl.et)) {
158 		ndev->stats.tx_errors++;
159 	} else {
160 		ndev->stats.tx_packets++;
161 		ndev->stats.tx_bytes += tx_ctrl.nt;
162 	}
163 
164 	dev_kfree_skb(priv->tx_skb);
165 	priv->tx_packet_sent = false;
166 
167 	if (netif_queue_stopped(ndev))
168 		netif_wake_queue(ndev);
169 }
170 
171 /**
172  * nps_enet_poll - NAPI poll handler.
173  * @napi:       Pointer to napi_struct structure.
174  * @budget:     How many frames to process on one call.
175  *
176  * returns:     Number of processed frames
177  */
178 static int nps_enet_poll(struct napi_struct *napi, int budget)
179 {
180 	struct net_device *ndev = napi->dev;
181 	struct nps_enet_priv *priv = netdev_priv(ndev);
182 	u32 work_done;
183 
184 	nps_enet_tx_handler(ndev);
185 	work_done = nps_enet_rx_handler(ndev);
186 	if (work_done < budget) {
187 		struct nps_enet_buf_int_enable buf_int_enable;
188 
189 		napi_complete(napi);
190 		buf_int_enable.rx_rdy = NPS_ENET_ENABLE;
191 		buf_int_enable.tx_done = NPS_ENET_ENABLE;
192 		nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE,
193 				 buf_int_enable.value);
194 	}
195 
196 	return work_done;
197 }
198 
199 /**
200  * nps_enet_irq_handler - Global interrupt handler for ENET.
201  * @irq:                irq number.
202  * @dev_instance:       device instance.
203  *
204  * returns: IRQ_HANDLED for all cases.
205  *
206  * EZchip ENET has 2 interrupt causes, and depending on bits raised in
207  * CTRL registers we may tell what is a reason for interrupt to fire up.
208  * We got one for RX and the other for TX (completion).
209  */
210 static irqreturn_t nps_enet_irq_handler(s32 irq, void *dev_instance)
211 {
212 	struct net_device *ndev = dev_instance;
213 	struct nps_enet_priv *priv = netdev_priv(ndev);
214 	struct nps_enet_rx_ctl rx_ctrl;
215 	struct nps_enet_tx_ctl tx_ctrl;
216 
217 	rx_ctrl.value = nps_enet_reg_get(priv, NPS_ENET_REG_RX_CTL);
218 	tx_ctrl.value = nps_enet_reg_get(priv, NPS_ENET_REG_TX_CTL);
219 
220 	if ((!tx_ctrl.ct && priv->tx_packet_sent) || rx_ctrl.cr)
221 		if (likely(napi_schedule_prep(&priv->napi))) {
222 			nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE, 0);
223 			__napi_schedule(&priv->napi);
224 		}
225 
226 	return IRQ_HANDLED;
227 }
228 
229 static void nps_enet_set_hw_mac_address(struct net_device *ndev)
230 {
231 	struct nps_enet_priv *priv = netdev_priv(ndev);
232 	struct nps_enet_ge_mac_cfg_1 ge_mac_cfg_1;
233 	struct nps_enet_ge_mac_cfg_2 *ge_mac_cfg_2 = &priv->ge_mac_cfg_2;
234 
235 	/* set MAC address in HW */
236 	ge_mac_cfg_1.octet_0 = ndev->dev_addr[0];
237 	ge_mac_cfg_1.octet_1 = ndev->dev_addr[1];
238 	ge_mac_cfg_1.octet_2 = ndev->dev_addr[2];
239 	ge_mac_cfg_1.octet_3 = ndev->dev_addr[3];
240 	ge_mac_cfg_2->octet_4 = ndev->dev_addr[4];
241 	ge_mac_cfg_2->octet_5 = ndev->dev_addr[5];
242 
243 	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_1,
244 			 ge_mac_cfg_1.value);
245 
246 	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_2,
247 			 ge_mac_cfg_2->value);
248 }
249 
250 /**
251  * nps_enet_hw_reset - Reset the network device.
252  * @ndev:       Pointer to the network device.
253  *
254  * This function reset the PCS and TX fifo.
255  * The programming model is to set the relevant reset bits
256  * wait for some time for this to propagate and then unset
257  * the reset bits. This way we ensure that reset procedure
258  * is done successfully by device.
259  */
260 static void nps_enet_hw_reset(struct net_device *ndev)
261 {
262 	struct nps_enet_priv *priv = netdev_priv(ndev);
263 	struct nps_enet_ge_rst ge_rst;
264 	struct nps_enet_phase_fifo_ctl phase_fifo_ctl;
265 
266 	ge_rst.value = 0;
267 	phase_fifo_ctl.value = 0;
268 	/* Pcs reset sequence*/
269 	ge_rst.gmac_0 = NPS_ENET_ENABLE;
270 	nps_enet_reg_set(priv, NPS_ENET_REG_GE_RST, ge_rst.value);
271 	usleep_range(10, 20);
272 	ge_rst.value = 0;
273 	nps_enet_reg_set(priv, NPS_ENET_REG_GE_RST, ge_rst.value);
274 
275 	/* Tx fifo reset sequence */
276 	phase_fifo_ctl.rst = NPS_ENET_ENABLE;
277 	phase_fifo_ctl.init = NPS_ENET_ENABLE;
278 	nps_enet_reg_set(priv, NPS_ENET_REG_PHASE_FIFO_CTL,
279 			 phase_fifo_ctl.value);
280 	usleep_range(10, 20);
281 	phase_fifo_ctl.value = 0;
282 	nps_enet_reg_set(priv, NPS_ENET_REG_PHASE_FIFO_CTL,
283 			 phase_fifo_ctl.value);
284 }
285 
286 static void nps_enet_hw_enable_control(struct net_device *ndev)
287 {
288 	struct nps_enet_priv *priv = netdev_priv(ndev);
289 	struct nps_enet_ge_mac_cfg_0 ge_mac_cfg_0;
290 	struct nps_enet_buf_int_enable buf_int_enable;
291 	struct nps_enet_ge_mac_cfg_2 *ge_mac_cfg_2 = &priv->ge_mac_cfg_2;
292 	struct nps_enet_ge_mac_cfg_3 *ge_mac_cfg_3 = &priv->ge_mac_cfg_3;
293 	s32 max_frame_length;
294 
295 	ge_mac_cfg_0.value = 0;
296 	buf_int_enable.value = 0;
297 	/* Enable Rx and Tx statistics */
298 	ge_mac_cfg_2->stat_en = NPS_ENET_GE_MAC_CFG_2_STAT_EN;
299 
300 	/* Discard packets with different MAC address */
301 	ge_mac_cfg_2->disc_da = NPS_ENET_ENABLE;
302 
303 	/* Discard multicast packets */
304 	ge_mac_cfg_2->disc_mc = NPS_ENET_ENABLE;
305 
306 	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_2,
307 			 ge_mac_cfg_2->value);
308 
309 	/* Discard Packets bigger than max frame length */
310 	max_frame_length = ETH_HLEN + ndev->mtu + ETH_FCS_LEN;
311 	if (max_frame_length <= NPS_ENET_MAX_FRAME_LENGTH)
312 		ge_mac_cfg_3->max_len = max_frame_length;
313 
314 	/* Enable interrupts */
315 	buf_int_enable.rx_rdy = NPS_ENET_ENABLE;
316 	buf_int_enable.tx_done = NPS_ENET_ENABLE;
317 	nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE,
318 			 buf_int_enable.value);
319 
320 	/* Write device MAC address to HW */
321 	nps_enet_set_hw_mac_address(ndev);
322 
323 	/* Rx and Tx HW features */
324 	ge_mac_cfg_0.tx_pad_en = NPS_ENET_ENABLE;
325 	ge_mac_cfg_0.tx_crc_en = NPS_ENET_ENABLE;
326 	ge_mac_cfg_0.rx_crc_strip = NPS_ENET_ENABLE;
327 
328 	/* IFG configuration */
329 	ge_mac_cfg_0.rx_ifg = NPS_ENET_GE_MAC_CFG_0_RX_IFG;
330 	ge_mac_cfg_0.tx_ifg = NPS_ENET_GE_MAC_CFG_0_TX_IFG;
331 
332 	/* preamble configuration */
333 	ge_mac_cfg_0.rx_pr_check_en = NPS_ENET_ENABLE;
334 	ge_mac_cfg_0.tx_pr_len = NPS_ENET_GE_MAC_CFG_0_TX_PR_LEN;
335 
336 	/* enable flow control frames */
337 	ge_mac_cfg_0.tx_fc_en = NPS_ENET_ENABLE;
338 	ge_mac_cfg_0.rx_fc_en = NPS_ENET_ENABLE;
339 	ge_mac_cfg_0.tx_fc_retr = NPS_ENET_GE_MAC_CFG_0_TX_FC_RETR;
340 	ge_mac_cfg_3->cf_drop = NPS_ENET_ENABLE;
341 
342 	/* Enable Rx and Tx */
343 	ge_mac_cfg_0.rx_en = NPS_ENET_ENABLE;
344 	ge_mac_cfg_0.tx_en = NPS_ENET_ENABLE;
345 
346 	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_3,
347 			 ge_mac_cfg_3->value);
348 	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_0,
349 			 ge_mac_cfg_0.value);
350 }
351 
352 static void nps_enet_hw_disable_control(struct net_device *ndev)
353 {
354 	struct nps_enet_priv *priv = netdev_priv(ndev);
355 
356 	/* Disable interrupts */
357 	nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE, 0);
358 
359 	/* Disable Rx and Tx */
360 	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_0, 0);
361 }
362 
363 static void nps_enet_send_frame(struct net_device *ndev,
364 				struct sk_buff *skb)
365 {
366 	struct nps_enet_priv *priv = netdev_priv(ndev);
367 	struct nps_enet_tx_ctl tx_ctrl;
368 	short length = skb->len;
369 	u32 i, len = DIV_ROUND_UP(length, sizeof(u32));
370 	u32 *src = (u32 *)virt_to_phys(skb->data);
371 	bool src_is_aligned = IS_ALIGNED((unsigned long)src, sizeof(u32));
372 
373 	tx_ctrl.value = 0;
374 	/* In case src is not aligned we need an intermediate buffer */
375 	if (src_is_aligned)
376 		for (i = 0; i < len; i++, src++)
377 			nps_enet_reg_set(priv, NPS_ENET_REG_TX_BUF, *src);
378 	else { /* !src_is_aligned */
379 		for (i = 0; i < len; i++, src++) {
380 			u32 buf;
381 
382 			/* to accommodate word-unaligned address of "src"
383 			 * we have to do memcpy_fromio() instead of simple "="
384 			 */
385 			memcpy_fromio(&buf, (void __iomem *)src, sizeof(buf));
386 			nps_enet_reg_set(priv, NPS_ENET_REG_TX_BUF, buf);
387 		}
388 	}
389 	/* Write the length of the Frame */
390 	tx_ctrl.nt = length;
391 
392 	/* Indicate SW is done */
393 	priv->tx_packet_sent = true;
394 	tx_ctrl.ct = NPS_ENET_ENABLE;
395 
396 	/* Send Frame */
397 	nps_enet_reg_set(priv, NPS_ENET_REG_TX_CTL, tx_ctrl.value);
398 }
399 
400 /**
401  * nps_enet_set_mac_address - Set the MAC address for this device.
402  * @ndev:       Pointer to net_device structure.
403  * @p:          6 byte Address to be written as MAC address.
404  *
405  * This function copies the HW address from the sockaddr structure to the
406  * net_device structure and updates the address in HW.
407  *
408  * returns:     -EBUSY if the net device is busy or 0 if the address is set
409  *              successfully.
410  */
411 static s32 nps_enet_set_mac_address(struct net_device *ndev, void *p)
412 {
413 	struct sockaddr *addr = p;
414 	s32 res;
415 
416 	if (netif_running(ndev))
417 		return -EBUSY;
418 
419 	res = eth_mac_addr(ndev, p);
420 	if (!res) {
421 		ether_addr_copy(ndev->dev_addr, addr->sa_data);
422 		nps_enet_set_hw_mac_address(ndev);
423 	}
424 
425 	return res;
426 }
427 
428 /**
429  * nps_enet_set_rx_mode - Change the receive filtering mode.
430  * @ndev:       Pointer to the network device.
431  *
432  * This function enables/disables promiscuous mode
433  */
434 static void nps_enet_set_rx_mode(struct net_device *ndev)
435 {
436 	struct nps_enet_priv *priv = netdev_priv(ndev);
437 	struct nps_enet_ge_mac_cfg_2 ge_mac_cfg_2;
438 
439 	ge_mac_cfg_2.value = priv->ge_mac_cfg_2.value;
440 
441 	if (ndev->flags & IFF_PROMISC) {
442 		ge_mac_cfg_2.disc_da = NPS_ENET_DISABLE;
443 		ge_mac_cfg_2.disc_mc = NPS_ENET_DISABLE;
444 	} else {
445 		ge_mac_cfg_2.disc_da = NPS_ENET_ENABLE;
446 		ge_mac_cfg_2.disc_mc = NPS_ENET_ENABLE;
447 	}
448 
449 	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_2, ge_mac_cfg_2.value);
450 }
451 
452 /**
453  * nps_enet_open - Open the network device.
454  * @ndev:       Pointer to the network device.
455  *
456  * returns: 0, on success or non-zero error value on failure.
457  *
458  * This function sets the MAC address, requests and enables an IRQ
459  * for the ENET device and starts the Tx queue.
460  */
461 static s32 nps_enet_open(struct net_device *ndev)
462 {
463 	struct nps_enet_priv *priv = netdev_priv(ndev);
464 	s32 err;
465 
466 	/* Reset private variables */
467 	priv->tx_packet_sent = false;
468 	priv->ge_mac_cfg_2.value = 0;
469 	priv->ge_mac_cfg_3.value = 0;
470 
471 	/* ge_mac_cfg_3 default values */
472 	priv->ge_mac_cfg_3.rx_ifg_th = NPS_ENET_GE_MAC_CFG_3_RX_IFG_TH;
473 	priv->ge_mac_cfg_3.max_len = NPS_ENET_GE_MAC_CFG_3_MAX_LEN;
474 
475 	/* Disable HW device */
476 	nps_enet_hw_disable_control(ndev);
477 
478 	/* irq Rx allocation */
479 	err = request_irq(priv->irq, nps_enet_irq_handler,
480 			  0, "enet-rx-tx", ndev);
481 	if (err)
482 		return err;
483 
484 	napi_enable(&priv->napi);
485 
486 	/* Enable HW device */
487 	nps_enet_hw_reset(ndev);
488 	nps_enet_hw_enable_control(ndev);
489 
490 	netif_start_queue(ndev);
491 
492 	return 0;
493 }
494 
495 /**
496  * nps_enet_stop - Close the network device.
497  * @ndev:       Pointer to the network device.
498  *
499  * This function stops the Tx queue, disables interrupts for the ENET device.
500  */
501 static s32 nps_enet_stop(struct net_device *ndev)
502 {
503 	struct nps_enet_priv *priv = netdev_priv(ndev);
504 
505 	napi_disable(&priv->napi);
506 	netif_stop_queue(ndev);
507 	nps_enet_hw_disable_control(ndev);
508 	free_irq(priv->irq, ndev);
509 
510 	return 0;
511 }
512 
513 /**
514  * nps_enet_start_xmit - Starts the data transmission.
515  * @skb:        sk_buff pointer that contains data to be Transmitted.
516  * @ndev:       Pointer to net_device structure.
517  *
518  * returns: NETDEV_TX_OK, on success
519  *              NETDEV_TX_BUSY, if any of the descriptors are not free.
520  *
521  * This function is invoked from upper layers to initiate transmission.
522  */
523 static netdev_tx_t nps_enet_start_xmit(struct sk_buff *skb,
524 				       struct net_device *ndev)
525 {
526 	struct nps_enet_priv *priv = netdev_priv(ndev);
527 
528 	/* This driver handles one frame at a time  */
529 	netif_stop_queue(ndev);
530 
531 	priv->tx_skb = skb;
532 
533 	nps_enet_send_frame(ndev, skb);
534 
535 	return NETDEV_TX_OK;
536 }
537 
538 #ifdef CONFIG_NET_POLL_CONTROLLER
539 static void nps_enet_poll_controller(struct net_device *ndev)
540 {
541 	disable_irq(ndev->irq);
542 	nps_enet_irq_handler(ndev->irq, ndev);
543 	enable_irq(ndev->irq);
544 }
545 #endif
546 
547 static const struct net_device_ops nps_netdev_ops = {
548 	.ndo_open		= nps_enet_open,
549 	.ndo_stop		= nps_enet_stop,
550 	.ndo_start_xmit		= nps_enet_start_xmit,
551 	.ndo_set_mac_address	= nps_enet_set_mac_address,
552 	.ndo_set_rx_mode        = nps_enet_set_rx_mode,
553 #ifdef CONFIG_NET_POLL_CONTROLLER
554 	.ndo_poll_controller	= nps_enet_poll_controller,
555 #endif
556 };
557 
558 static s32 nps_enet_probe(struct platform_device *pdev)
559 {
560 	struct device *dev = &pdev->dev;
561 	struct net_device *ndev;
562 	struct nps_enet_priv *priv;
563 	s32 err = 0;
564 	const char *mac_addr;
565 	struct resource *res_regs;
566 
567 	if (!dev->of_node)
568 		return -ENODEV;
569 
570 	ndev = alloc_etherdev(sizeof(struct nps_enet_priv));
571 	if (!ndev)
572 		return -ENOMEM;
573 
574 	platform_set_drvdata(pdev, ndev);
575 	SET_NETDEV_DEV(ndev, dev);
576 	priv = netdev_priv(ndev);
577 
578 	/* The EZ NET specific entries in the device structure. */
579 	ndev->netdev_ops = &nps_netdev_ops;
580 	ndev->watchdog_timeo = (400 * HZ / 1000);
581 	/* FIXME :: no multicast support yet */
582 	ndev->flags &= ~IFF_MULTICAST;
583 
584 	res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
585 	priv->regs_base = devm_ioremap_resource(dev, res_regs);
586 	if (IS_ERR(priv->regs_base)) {
587 		err = PTR_ERR(priv->regs_base);
588 		goto out_netdev;
589 	}
590 	dev_dbg(dev, "Registers base address is 0x%p\n", priv->regs_base);
591 
592 	/* set kernel MAC address to dev */
593 	mac_addr = of_get_mac_address(dev->of_node);
594 	if (mac_addr)
595 		ether_addr_copy(ndev->dev_addr, mac_addr);
596 	else
597 		eth_hw_addr_random(ndev);
598 
599 	/* Get IRQ number */
600 	priv->irq = platform_get_irq(pdev, 0);
601 	if (!priv->irq) {
602 		dev_err(dev, "failed to retrieve <irq Rx-Tx> value from device tree\n");
603 		err = -ENODEV;
604 		goto out_netdev;
605 	}
606 
607 	netif_napi_add(ndev, &priv->napi, nps_enet_poll,
608 		       NPS_ENET_NAPI_POLL_WEIGHT);
609 
610 	/* Register the driver. Should be the last thing in probe */
611 	err = register_netdev(ndev);
612 	if (err) {
613 		dev_err(dev, "Failed to register ndev for %s, err = 0x%08x\n",
614 			ndev->name, (s32)err);
615 		goto out_netif_api;
616 	}
617 
618 	dev_info(dev, "(rx/tx=%d)\n", priv->irq);
619 	return 0;
620 
621 out_netif_api:
622 	netif_napi_del(&priv->napi);
623 out_netdev:
624 	if (err)
625 		free_netdev(ndev);
626 
627 	return err;
628 }
629 
630 static s32 nps_enet_remove(struct platform_device *pdev)
631 {
632 	struct net_device *ndev = platform_get_drvdata(pdev);
633 	struct nps_enet_priv *priv = netdev_priv(ndev);
634 
635 	unregister_netdev(ndev);
636 	free_netdev(ndev);
637 	netif_napi_del(&priv->napi);
638 
639 	return 0;
640 }
641 
642 static const struct of_device_id nps_enet_dt_ids[] = {
643 	{ .compatible = "ezchip,nps-mgt-enet" },
644 	{ /* Sentinel */ }
645 };
646 
647 static struct platform_driver nps_enet_driver = {
648 	.probe = nps_enet_probe,
649 	.remove = nps_enet_remove,
650 	.driver = {
651 		.name = DRV_NAME,
652 		.of_match_table  = nps_enet_dt_ids,
653 	},
654 };
655 
656 module_platform_driver(nps_enet_driver);
657 
658 MODULE_AUTHOR("EZchip Semiconductor");
659 MODULE_LICENSE("GPL v2");
660