xref: /openbmc/linux/drivers/net/usb/asix_common.c (revision e6e8c6c2)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * ASIX AX8817X based USB 2.0 Ethernet Devices
4  * Copyright (C) 2003-2006 David Hollis <dhollis@davehollis.com>
5  * Copyright (C) 2005 Phil Chang <pchang23@sbcglobal.net>
6  * Copyright (C) 2006 James Painter <jamie.painter@iname.com>
7  * Copyright (c) 2002-2003 TiVo Inc.
8  */
9 
10 #include "asix.h"
11 
12 #define AX_HOST_EN_RETRIES	30
13 
14 int __must_check asix_read_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
15 			       u16 size, void *data, int in_pm)
16 {
17 	int ret;
18 	int (*fn)(struct usbnet *, u8, u8, u16, u16, void *, u16);
19 
20 	BUG_ON(!dev);
21 
22 	if (!in_pm)
23 		fn = usbnet_read_cmd;
24 	else
25 		fn = usbnet_read_cmd_nopm;
26 
27 	ret = fn(dev, cmd, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
28 		 value, index, data, size);
29 
30 	if (unlikely(ret < size)) {
31 		ret = ret < 0 ? ret : -ENODATA;
32 
33 		netdev_warn(dev->net, "Failed to read reg index 0x%04x: %d\n",
34 			    index, ret);
35 	}
36 
37 	return ret;
38 }
39 
40 int asix_write_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
41 		   u16 size, void *data, int in_pm)
42 {
43 	int ret;
44 	int (*fn)(struct usbnet *, u8, u8, u16, u16, const void *, u16);
45 
46 	BUG_ON(!dev);
47 
48 	if (!in_pm)
49 		fn = usbnet_write_cmd;
50 	else
51 		fn = usbnet_write_cmd_nopm;
52 
53 	ret = fn(dev, cmd, USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
54 		 value, index, data, size);
55 
56 	if (unlikely(ret < 0))
57 		netdev_warn(dev->net, "Failed to write reg index 0x%04x: %d\n",
58 			    index, ret);
59 
60 	return ret;
61 }
62 
63 void asix_write_cmd_async(struct usbnet *dev, u8 cmd, u16 value, u16 index,
64 			  u16 size, void *data)
65 {
66 	usbnet_write_cmd_async(dev, cmd,
67 			       USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
68 			       value, index, data, size);
69 }
70 
71 static int asix_set_sw_mii(struct usbnet *dev, int in_pm)
72 {
73 	int ret;
74 
75 	ret = asix_write_cmd(dev, AX_CMD_SET_SW_MII, 0x0000, 0, 0, NULL, in_pm);
76 
77 	if (ret < 0)
78 		netdev_err(dev->net, "Failed to enable software MII access\n");
79 	return ret;
80 }
81 
82 static int asix_set_hw_mii(struct usbnet *dev, int in_pm)
83 {
84 	int ret;
85 
86 	ret = asix_write_cmd(dev, AX_CMD_SET_HW_MII, 0x0000, 0, 0, NULL, in_pm);
87 	if (ret < 0)
88 		netdev_err(dev->net, "Failed to enable hardware MII access\n");
89 	return ret;
90 }
91 
92 static int asix_check_host_enable(struct usbnet *dev, int in_pm)
93 {
94 	int i, ret;
95 	u8 smsr;
96 
97 	for (i = 0; i < AX_HOST_EN_RETRIES; ++i) {
98 		ret = asix_set_sw_mii(dev, in_pm);
99 		if (ret == -ENODEV || ret == -ETIMEDOUT)
100 			break;
101 		usleep_range(1000, 1100);
102 		ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG,
103 				    0, 0, 1, &smsr, in_pm);
104 		if (ret == -ENODEV)
105 			break;
106 		else if (ret < 0)
107 			continue;
108 		else if (smsr & AX_HOST_EN)
109 			break;
110 	}
111 
112 	return i >= AX_HOST_EN_RETRIES ? -ETIMEDOUT : ret;
113 }
114 
115 static void reset_asix_rx_fixup_info(struct asix_rx_fixup_info *rx)
116 {
117 	/* Reset the variables that have a lifetime outside of
118 	 * asix_rx_fixup_internal() so that future processing starts from a
119 	 * known set of initial conditions.
120 	 */
121 
122 	if (rx->ax_skb) {
123 		/* Discard any incomplete Ethernet frame in the netdev buffer */
124 		kfree_skb(rx->ax_skb);
125 		rx->ax_skb = NULL;
126 	}
127 
128 	/* Assume the Data header 32-bit word is at the start of the current
129 	 * or next URB socket buffer so reset all the state variables.
130 	 */
131 	rx->remaining = 0;
132 	rx->split_head = false;
133 	rx->header = 0;
134 }
135 
136 int asix_rx_fixup_internal(struct usbnet *dev, struct sk_buff *skb,
137 			   struct asix_rx_fixup_info *rx)
138 {
139 	int offset = 0;
140 	u16 size;
141 
142 	/* When an Ethernet frame spans multiple URB socket buffers,
143 	 * do a sanity test for the Data header synchronisation.
144 	 * Attempt to detect the situation of the previous socket buffer having
145 	 * been truncated or a socket buffer was missing. These situations
146 	 * cause a discontinuity in the data stream and therefore need to avoid
147 	 * appending bad data to the end of the current netdev socket buffer.
148 	 * Also avoid unnecessarily discarding a good current netdev socket
149 	 * buffer.
150 	 */
151 	if (rx->remaining && (rx->remaining + sizeof(u32) <= skb->len)) {
152 		offset = ((rx->remaining + 1) & 0xfffe);
153 		rx->header = get_unaligned_le32(skb->data + offset);
154 		offset = 0;
155 
156 		size = (u16)(rx->header & 0x7ff);
157 		if (size != ((~rx->header >> 16) & 0x7ff)) {
158 			netdev_err(dev->net, "asix_rx_fixup() Data Header synchronisation was lost, remaining %d\n",
159 				   rx->remaining);
160 			reset_asix_rx_fixup_info(rx);
161 		}
162 	}
163 
164 	while (offset + sizeof(u16) <= skb->len) {
165 		u16 copy_length;
166 
167 		if (!rx->remaining) {
168 			if (skb->len - offset == sizeof(u16)) {
169 				rx->header = get_unaligned_le16(
170 						skb->data + offset);
171 				rx->split_head = true;
172 				offset += sizeof(u16);
173 				break;
174 			}
175 
176 			if (rx->split_head == true) {
177 				rx->header |= (get_unaligned_le16(
178 						skb->data + offset) << 16);
179 				rx->split_head = false;
180 				offset += sizeof(u16);
181 			} else {
182 				rx->header = get_unaligned_le32(skb->data +
183 								offset);
184 				offset += sizeof(u32);
185 			}
186 
187 			/* take frame length from Data header 32-bit word */
188 			size = (u16)(rx->header & 0x7ff);
189 			if (size != ((~rx->header >> 16) & 0x7ff)) {
190 				netdev_err(dev->net, "asix_rx_fixup() Bad Header Length 0x%x, offset %d\n",
191 					   rx->header, offset);
192 				reset_asix_rx_fixup_info(rx);
193 				return 0;
194 			}
195 			if (size > dev->net->mtu + ETH_HLEN + VLAN_HLEN) {
196 				netdev_dbg(dev->net, "asix_rx_fixup() Bad RX Length %d\n",
197 					   size);
198 				reset_asix_rx_fixup_info(rx);
199 				return 0;
200 			}
201 
202 			/* Sometimes may fail to get a netdev socket buffer but
203 			 * continue to process the URB socket buffer so that
204 			 * synchronisation of the Ethernet frame Data header
205 			 * word is maintained.
206 			 */
207 			rx->ax_skb = netdev_alloc_skb_ip_align(dev->net, size);
208 
209 			rx->remaining = size;
210 		}
211 
212 		if (rx->remaining > skb->len - offset) {
213 			copy_length = skb->len - offset;
214 			rx->remaining -= copy_length;
215 		} else {
216 			copy_length = rx->remaining;
217 			rx->remaining = 0;
218 		}
219 
220 		if (rx->ax_skb) {
221 			skb_put_data(rx->ax_skb, skb->data + offset,
222 				     copy_length);
223 			if (!rx->remaining) {
224 				usbnet_skb_return(dev, rx->ax_skb);
225 				rx->ax_skb = NULL;
226 			}
227 		}
228 
229 		offset += (copy_length + 1) & 0xfffe;
230 	}
231 
232 	if (skb->len != offset) {
233 		netdev_err(dev->net, "asix_rx_fixup() Bad SKB Length %d, %d\n",
234 			   skb->len, offset);
235 		reset_asix_rx_fixup_info(rx);
236 		return 0;
237 	}
238 
239 	return 1;
240 }
241 
242 int asix_rx_fixup_common(struct usbnet *dev, struct sk_buff *skb)
243 {
244 	struct asix_common_private *dp = dev->driver_priv;
245 	struct asix_rx_fixup_info *rx = &dp->rx_fixup_info;
246 
247 	return asix_rx_fixup_internal(dev, skb, rx);
248 }
249 
250 void asix_rx_fixup_common_free(struct asix_common_private *dp)
251 {
252 	struct asix_rx_fixup_info *rx;
253 
254 	if (!dp)
255 		return;
256 
257 	rx = &dp->rx_fixup_info;
258 
259 	if (rx->ax_skb) {
260 		kfree_skb(rx->ax_skb);
261 		rx->ax_skb = NULL;
262 	}
263 }
264 
265 struct sk_buff *asix_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
266 			      gfp_t flags)
267 {
268 	int padlen;
269 	int headroom = skb_headroom(skb);
270 	int tailroom = skb_tailroom(skb);
271 	u32 packet_len;
272 	u32 padbytes = 0xffff0000;
273 	void *ptr;
274 
275 	padlen = ((skb->len + 4) & (dev->maxpacket - 1)) ? 0 : 4;
276 
277 	/* We need to push 4 bytes in front of frame (packet_len)
278 	 * and maybe add 4 bytes after the end (if padlen is 4)
279 	 *
280 	 * Avoid skb_copy_expand() expensive call, using following rules :
281 	 * - We are allowed to push 4 bytes in headroom if skb_header_cloned()
282 	 *   is false (and if we have 4 bytes of headroom)
283 	 * - We are allowed to put 4 bytes at tail if skb_cloned()
284 	 *   is false (and if we have 4 bytes of tailroom)
285 	 *
286 	 * TCP packets for example are cloned, but __skb_header_release()
287 	 * was called in tcp stack, allowing us to use headroom for our needs.
288 	 */
289 	if (!skb_header_cloned(skb) &&
290 	    !(padlen && skb_cloned(skb)) &&
291 	    headroom + tailroom >= 4 + padlen) {
292 		/* following should not happen, but better be safe */
293 		if (headroom < 4 ||
294 		    tailroom < padlen) {
295 			skb->data = memmove(skb->head + 4, skb->data, skb->len);
296 			skb_set_tail_pointer(skb, skb->len);
297 		}
298 	} else {
299 		struct sk_buff *skb2;
300 
301 		skb2 = skb_copy_expand(skb, 4, padlen, flags);
302 		dev_kfree_skb_any(skb);
303 		skb = skb2;
304 		if (!skb)
305 			return NULL;
306 	}
307 
308 	packet_len = ((skb->len ^ 0x0000ffff) << 16) + skb->len;
309 	ptr = skb_push(skb, 4);
310 	put_unaligned_le32(packet_len, ptr);
311 
312 	if (padlen) {
313 		put_unaligned_le32(padbytes, skb_tail_pointer(skb));
314 		skb_put(skb, sizeof(padbytes));
315 	}
316 
317 	usbnet_set_skb_tx_stats(skb, 1, 0);
318 	return skb;
319 }
320 
321 int asix_read_phy_addr(struct usbnet *dev, bool internal)
322 {
323 	int ret, offset;
324 	u8 buf[2];
325 
326 	ret = asix_read_cmd(dev, AX_CMD_READ_PHY_ID, 0, 0, 2, buf, 0);
327 	if (ret < 0)
328 		goto error;
329 
330 	if (ret < 2) {
331 		ret = -EIO;
332 		goto error;
333 	}
334 
335 	offset = (internal ? 1 : 0);
336 	ret = buf[offset];
337 
338 	netdev_dbg(dev->net, "%s PHY address 0x%x\n",
339 		   internal ? "internal" : "external", ret);
340 
341 	return ret;
342 
343 error:
344 	netdev_err(dev->net, "Error reading PHY_ID register: %02x\n", ret);
345 
346 	return ret;
347 }
348 
349 int asix_sw_reset(struct usbnet *dev, u8 flags, int in_pm)
350 {
351 	int ret;
352 
353 	ret = asix_write_cmd(dev, AX_CMD_SW_RESET, flags, 0, 0, NULL, in_pm);
354 	if (ret < 0)
355 		netdev_err(dev->net, "Failed to send software reset: %02x\n", ret);
356 
357 	return ret;
358 }
359 
360 u16 asix_read_rx_ctl(struct usbnet *dev, int in_pm)
361 {
362 	__le16 v;
363 	int ret = asix_read_cmd(dev, AX_CMD_READ_RX_CTL, 0, 0, 2, &v, in_pm);
364 
365 	if (ret < 0) {
366 		netdev_err(dev->net, "Error reading RX_CTL register: %02x\n", ret);
367 		goto out;
368 	}
369 	ret = le16_to_cpu(v);
370 out:
371 	return ret;
372 }
373 
374 int asix_write_rx_ctl(struct usbnet *dev, u16 mode, int in_pm)
375 {
376 	int ret;
377 
378 	netdev_dbg(dev->net, "asix_write_rx_ctl() - mode = 0x%04x\n", mode);
379 	ret = asix_write_cmd(dev, AX_CMD_WRITE_RX_CTL, mode, 0, 0, NULL, in_pm);
380 	if (ret < 0)
381 		netdev_err(dev->net, "Failed to write RX_CTL mode to 0x%04x: %02x\n",
382 			   mode, ret);
383 
384 	return ret;
385 }
386 
387 u16 asix_read_medium_status(struct usbnet *dev, int in_pm)
388 {
389 	__le16 v;
390 	int ret = asix_read_cmd(dev, AX_CMD_READ_MEDIUM_STATUS,
391 				0, 0, 2, &v, in_pm);
392 
393 	if (ret < 0) {
394 		netdev_err(dev->net, "Error reading Medium Status register: %02x\n",
395 			   ret);
396 		return ret;	/* TODO: callers not checking for error ret */
397 	}
398 
399 	return le16_to_cpu(v);
400 
401 }
402 
403 int asix_write_medium_mode(struct usbnet *dev, u16 mode, int in_pm)
404 {
405 	int ret;
406 
407 	netdev_dbg(dev->net, "asix_write_medium_mode() - mode = 0x%04x\n", mode);
408 	ret = asix_write_cmd(dev, AX_CMD_WRITE_MEDIUM_MODE,
409 			     mode, 0, 0, NULL, in_pm);
410 	if (ret < 0)
411 		netdev_err(dev->net, "Failed to write Medium Mode mode to 0x%04x: %02x\n",
412 			   mode, ret);
413 
414 	return ret;
415 }
416 
417 /* set MAC link settings according to information from phylib */
418 void asix_adjust_link(struct net_device *netdev)
419 {
420 	struct phy_device *phydev = netdev->phydev;
421 	struct usbnet *dev = netdev_priv(netdev);
422 	u16 mode = 0;
423 
424 	if (phydev->link) {
425 		mode = AX88772_MEDIUM_DEFAULT;
426 
427 		if (phydev->duplex == DUPLEX_HALF)
428 			mode &= ~AX_MEDIUM_FD;
429 
430 		if (phydev->speed != SPEED_100)
431 			mode &= ~AX_MEDIUM_PS;
432 	}
433 
434 	asix_write_medium_mode(dev, mode, 0);
435 	phy_print_status(phydev);
436 	usbnet_link_change(dev, phydev->link, 0);
437 }
438 
439 int asix_write_gpio(struct usbnet *dev, u16 value, int sleep, int in_pm)
440 {
441 	int ret;
442 
443 	netdev_dbg(dev->net, "asix_write_gpio() - value = 0x%04x\n", value);
444 	ret = asix_write_cmd(dev, AX_CMD_WRITE_GPIOS, value, 0, 0, NULL, in_pm);
445 	if (ret < 0)
446 		netdev_err(dev->net, "Failed to write GPIO value 0x%04x: %02x\n",
447 			   value, ret);
448 
449 	if (sleep)
450 		msleep(sleep);
451 
452 	return ret;
453 }
454 
455 /*
456  * AX88772 & AX88178 have a 16-bit RX_CTL value
457  */
458 void asix_set_multicast(struct net_device *net)
459 {
460 	struct usbnet *dev = netdev_priv(net);
461 	struct asix_data *data = (struct asix_data *)&dev->data;
462 	u16 rx_ctl = AX_DEFAULT_RX_CTL;
463 
464 	if (net->flags & IFF_PROMISC) {
465 		rx_ctl |= AX_RX_CTL_PRO;
466 	} else if (net->flags & IFF_ALLMULTI ||
467 		   netdev_mc_count(net) > AX_MAX_MCAST) {
468 		rx_ctl |= AX_RX_CTL_AMALL;
469 	} else if (netdev_mc_empty(net)) {
470 		/* just broadcast and directed */
471 	} else {
472 		/* We use the 20 byte dev->data
473 		 * for our 8 byte filter buffer
474 		 * to avoid allocating memory that
475 		 * is tricky to free later */
476 		struct netdev_hw_addr *ha;
477 		u32 crc_bits;
478 
479 		memset(data->multi_filter, 0, AX_MCAST_FILTER_SIZE);
480 
481 		/* Build the multicast hash filter. */
482 		netdev_for_each_mc_addr(ha, net) {
483 			crc_bits = ether_crc(ETH_ALEN, ha->addr) >> 26;
484 			data->multi_filter[crc_bits >> 3] |=
485 			    1 << (crc_bits & 7);
486 		}
487 
488 		asix_write_cmd_async(dev, AX_CMD_WRITE_MULTI_FILTER, 0, 0,
489 				   AX_MCAST_FILTER_SIZE, data->multi_filter);
490 
491 		rx_ctl |= AX_RX_CTL_AM;
492 	}
493 
494 	asix_write_cmd_async(dev, AX_CMD_WRITE_RX_CTL, rx_ctl, 0, 0, NULL);
495 }
496 
497 static int __asix_mdio_read(struct net_device *netdev, int phy_id, int loc,
498 			    bool in_pm)
499 {
500 	struct usbnet *dev = netdev_priv(netdev);
501 	__le16 res;
502 	int ret;
503 
504 	mutex_lock(&dev->phy_mutex);
505 
506 	ret = asix_check_host_enable(dev, in_pm);
507 	if (ret == -ENODEV || ret == -ETIMEDOUT) {
508 		mutex_unlock(&dev->phy_mutex);
509 		return ret;
510 	}
511 
512 	ret = asix_read_cmd(dev, AX_CMD_READ_MII_REG, phy_id, (__u16)loc, 2,
513 			    &res, in_pm);
514 	if (ret < 0)
515 		goto out;
516 
517 	ret = asix_set_hw_mii(dev, in_pm);
518 out:
519 	mutex_unlock(&dev->phy_mutex);
520 
521 	netdev_dbg(dev->net, "asix_mdio_read() phy_id=0x%02x, loc=0x%02x, returns=0x%04x\n",
522 			phy_id, loc, le16_to_cpu(res));
523 
524 	return ret < 0 ? ret : le16_to_cpu(res);
525 }
526 
527 int asix_mdio_read(struct net_device *netdev, int phy_id, int loc)
528 {
529 	return __asix_mdio_read(netdev, phy_id, loc, false);
530 }
531 
532 static int __asix_mdio_write(struct net_device *netdev, int phy_id, int loc,
533 			     int val, bool in_pm)
534 {
535 	struct usbnet *dev = netdev_priv(netdev);
536 	__le16 res = cpu_to_le16(val);
537 	int ret;
538 
539 	netdev_dbg(dev->net, "asix_mdio_write() phy_id=0x%02x, loc=0x%02x, val=0x%04x\n",
540 			phy_id, loc, val);
541 
542 	mutex_lock(&dev->phy_mutex);
543 
544 	ret = asix_check_host_enable(dev, in_pm);
545 	if (ret == -ENODEV)
546 		goto out;
547 
548 	ret = asix_write_cmd(dev, AX_CMD_WRITE_MII_REG, phy_id, (__u16)loc, 2,
549 			     &res, in_pm);
550 	if (ret < 0)
551 		goto out;
552 
553 	ret = asix_set_hw_mii(dev, in_pm);
554 out:
555 	mutex_unlock(&dev->phy_mutex);
556 
557 	return ret < 0 ? ret : 0;
558 }
559 
560 void asix_mdio_write(struct net_device *netdev, int phy_id, int loc, int val)
561 {
562 	__asix_mdio_write(netdev, phy_id, loc, val, false);
563 }
564 
565 /* MDIO read and write wrappers for phylib */
566 int asix_mdio_bus_read(struct mii_bus *bus, int phy_id, int regnum)
567 {
568 	struct usbnet *priv = bus->priv;
569 
570 	return __asix_mdio_read(priv->net, phy_id, regnum, false);
571 }
572 
573 int asix_mdio_bus_write(struct mii_bus *bus, int phy_id, int regnum, u16 val)
574 {
575 	struct usbnet *priv = bus->priv;
576 
577 	return __asix_mdio_write(priv->net, phy_id, regnum, val, false);
578 }
579 
580 int asix_mdio_read_nopm(struct net_device *netdev, int phy_id, int loc)
581 {
582 	return __asix_mdio_read(netdev, phy_id, loc, true);
583 }
584 
585 void
586 asix_mdio_write_nopm(struct net_device *netdev, int phy_id, int loc, int val)
587 {
588 	__asix_mdio_write(netdev, phy_id, loc, val, true);
589 }
590 
591 void asix_get_wol(struct net_device *net, struct ethtool_wolinfo *wolinfo)
592 {
593 	struct usbnet *dev = netdev_priv(net);
594 	u8 opt;
595 
596 	if (asix_read_cmd(dev, AX_CMD_READ_MONITOR_MODE,
597 			  0, 0, 1, &opt, 0) < 0) {
598 		wolinfo->supported = 0;
599 		wolinfo->wolopts = 0;
600 		return;
601 	}
602 	wolinfo->supported = WAKE_PHY | WAKE_MAGIC;
603 	wolinfo->wolopts = 0;
604 	if (opt & AX_MONITOR_LINK)
605 		wolinfo->wolopts |= WAKE_PHY;
606 	if (opt & AX_MONITOR_MAGIC)
607 		wolinfo->wolopts |= WAKE_MAGIC;
608 }
609 
610 int asix_set_wol(struct net_device *net, struct ethtool_wolinfo *wolinfo)
611 {
612 	struct usbnet *dev = netdev_priv(net);
613 	u8 opt = 0;
614 
615 	if (wolinfo->wolopts & ~(WAKE_PHY | WAKE_MAGIC))
616 		return -EINVAL;
617 
618 	if (wolinfo->wolopts & WAKE_PHY)
619 		opt |= AX_MONITOR_LINK;
620 	if (wolinfo->wolopts & WAKE_MAGIC)
621 		opt |= AX_MONITOR_MAGIC;
622 
623 	if (asix_write_cmd(dev, AX_CMD_WRITE_MONITOR_MODE,
624 			      opt, 0, 0, NULL, 0) < 0)
625 		return -EINVAL;
626 
627 	return 0;
628 }
629 
630 int asix_get_eeprom_len(struct net_device *net)
631 {
632 	return AX_EEPROM_LEN;
633 }
634 
635 int asix_get_eeprom(struct net_device *net, struct ethtool_eeprom *eeprom,
636 		    u8 *data)
637 {
638 	struct usbnet *dev = netdev_priv(net);
639 	u16 *eeprom_buff;
640 	int first_word, last_word;
641 	int i;
642 
643 	if (eeprom->len == 0)
644 		return -EINVAL;
645 
646 	eeprom->magic = AX_EEPROM_MAGIC;
647 
648 	first_word = eeprom->offset >> 1;
649 	last_word = (eeprom->offset + eeprom->len - 1) >> 1;
650 
651 	eeprom_buff = kmalloc_array(last_word - first_word + 1, sizeof(u16),
652 				    GFP_KERNEL);
653 	if (!eeprom_buff)
654 		return -ENOMEM;
655 
656 	/* ax8817x returns 2 bytes from eeprom on read */
657 	for (i = first_word; i <= last_word; i++) {
658 		if (asix_read_cmd(dev, AX_CMD_READ_EEPROM, i, 0, 2,
659 				  &eeprom_buff[i - first_word], 0) < 0) {
660 			kfree(eeprom_buff);
661 			return -EIO;
662 		}
663 	}
664 
665 	memcpy(data, (u8 *)eeprom_buff + (eeprom->offset & 1), eeprom->len);
666 	kfree(eeprom_buff);
667 	return 0;
668 }
669 
670 int asix_set_eeprom(struct net_device *net, struct ethtool_eeprom *eeprom,
671 		    u8 *data)
672 {
673 	struct usbnet *dev = netdev_priv(net);
674 	u16 *eeprom_buff;
675 	int first_word, last_word;
676 	int i;
677 	int ret;
678 
679 	netdev_dbg(net, "write EEPROM len %d, offset %d, magic 0x%x\n",
680 		   eeprom->len, eeprom->offset, eeprom->magic);
681 
682 	if (eeprom->len == 0)
683 		return -EINVAL;
684 
685 	if (eeprom->magic != AX_EEPROM_MAGIC)
686 		return -EINVAL;
687 
688 	first_word = eeprom->offset >> 1;
689 	last_word = (eeprom->offset + eeprom->len - 1) >> 1;
690 
691 	eeprom_buff = kmalloc_array(last_word - first_word + 1, sizeof(u16),
692 				    GFP_KERNEL);
693 	if (!eeprom_buff)
694 		return -ENOMEM;
695 
696 	/* align data to 16 bit boundaries, read the missing data from
697 	   the EEPROM */
698 	if (eeprom->offset & 1) {
699 		ret = asix_read_cmd(dev, AX_CMD_READ_EEPROM, first_word, 0, 2,
700 				    &eeprom_buff[0], 0);
701 		if (ret < 0) {
702 			netdev_err(net, "Failed to read EEPROM at offset 0x%02x.\n", first_word);
703 			goto free;
704 		}
705 	}
706 
707 	if ((eeprom->offset + eeprom->len) & 1) {
708 		ret = asix_read_cmd(dev, AX_CMD_READ_EEPROM, last_word, 0, 2,
709 				    &eeprom_buff[last_word - first_word], 0);
710 		if (ret < 0) {
711 			netdev_err(net, "Failed to read EEPROM at offset 0x%02x.\n", last_word);
712 			goto free;
713 		}
714 	}
715 
716 	memcpy((u8 *)eeprom_buff + (eeprom->offset & 1), data, eeprom->len);
717 
718 	/* write data to EEPROM */
719 	ret = asix_write_cmd(dev, AX_CMD_WRITE_ENABLE, 0x0000, 0, 0, NULL, 0);
720 	if (ret < 0) {
721 		netdev_err(net, "Failed to enable EEPROM write\n");
722 		goto free;
723 	}
724 	msleep(20);
725 
726 	for (i = first_word; i <= last_word; i++) {
727 		netdev_dbg(net, "write to EEPROM at offset 0x%02x, data 0x%04x\n",
728 			   i, eeprom_buff[i - first_word]);
729 		ret = asix_write_cmd(dev, AX_CMD_WRITE_EEPROM, i,
730 				     eeprom_buff[i - first_word], 0, NULL, 0);
731 		if (ret < 0) {
732 			netdev_err(net, "Failed to write EEPROM at offset 0x%02x.\n",
733 				   i);
734 			goto free;
735 		}
736 		msleep(20);
737 	}
738 
739 	ret = asix_write_cmd(dev, AX_CMD_WRITE_DISABLE, 0x0000, 0, 0, NULL, 0);
740 	if (ret < 0) {
741 		netdev_err(net, "Failed to disable EEPROM write\n");
742 		goto free;
743 	}
744 
745 	ret = 0;
746 free:
747 	kfree(eeprom_buff);
748 	return ret;
749 }
750 
751 void asix_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *info)
752 {
753 	/* Inherit standard device info */
754 	usbnet_get_drvinfo(net, info);
755 	strlcpy(info->driver, DRIVER_NAME, sizeof(info->driver));
756 	strlcpy(info->version, DRIVER_VERSION, sizeof(info->version));
757 }
758 
759 int asix_set_mac_address(struct net_device *net, void *p)
760 {
761 	struct usbnet *dev = netdev_priv(net);
762 	struct asix_data *data = (struct asix_data *)&dev->data;
763 	struct sockaddr *addr = p;
764 
765 	if (netif_running(net))
766 		return -EBUSY;
767 	if (!is_valid_ether_addr(addr->sa_data))
768 		return -EADDRNOTAVAIL;
769 
770 	eth_hw_addr_set(net, addr->sa_data);
771 
772 	/* We use the 20 byte dev->data
773 	 * for our 6 byte mac buffer
774 	 * to avoid allocating memory that
775 	 * is tricky to free later */
776 	memcpy(data->mac_addr, addr->sa_data, ETH_ALEN);
777 	asix_write_cmd_async(dev, AX_CMD_WRITE_NODE_ID, 0, 0, ETH_ALEN,
778 							data->mac_addr);
779 
780 	return 0;
781 }
782