1 /*
2 * Driver for USB ethernet port of Conexant CX82310-based ADSL routers
3 * Copyright (C) 2010 by Ondrej Zary
4 * some parts inspired by the cxacru driver
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
18 */
19
20 #include <linux/module.h>
21 #include <linux/netdevice.h>
22 #include <linux/etherdevice.h>
23 #include <linux/ethtool.h>
24 #include <linux/workqueue.h>
25 #include <linux/mii.h>
26 #include <linux/usb.h>
27 #include <linux/usb/usbnet.h>
28
29 enum cx82310_cmd {
30 CMD_START = 0x84, /* no effect? */
31 CMD_STOP = 0x85, /* no effect? */
32 CMD_GET_STATUS = 0x90, /* returns nothing? */
33 CMD_GET_MAC_ADDR = 0x91, /* read MAC address */
34 CMD_GET_LINK_STATUS = 0x92, /* not useful, link is always up */
35 CMD_ETHERNET_MODE = 0x99, /* unknown, needed during init */
36 };
37
38 enum cx82310_status {
39 STATUS_UNDEFINED,
40 STATUS_SUCCESS,
41 STATUS_ERROR,
42 STATUS_UNSUPPORTED,
43 STATUS_UNIMPLEMENTED,
44 STATUS_PARAMETER_ERROR,
45 STATUS_DBG_LOOPBACK,
46 };
47
48 #define CMD_PACKET_SIZE 64
49 #define CMD_TIMEOUT 100
50 #define CMD_REPLY_RETRY 5
51
52 #define CX82310_MTU 1514
53 #define CMD_EP 0x01
54
55 /*
56 * execute control command
57 * - optionally send some data (command parameters)
58 * - optionally wait for the reply
59 * - optionally read some data from the reply
60 */
cx82310_cmd(struct usbnet * dev,enum cx82310_cmd cmd,bool reply,u8 * wdata,int wlen,u8 * rdata,int rlen)61 static int cx82310_cmd(struct usbnet *dev, enum cx82310_cmd cmd, bool reply,
62 u8 *wdata, int wlen, u8 *rdata, int rlen)
63 {
64 int actual_len, retries, ret;
65 struct usb_device *udev = dev->udev;
66 u8 *buf = kzalloc(CMD_PACKET_SIZE, GFP_KERNEL);
67
68 if (!buf)
69 return -ENOMEM;
70
71 /* create command packet */
72 buf[0] = cmd;
73 if (wdata)
74 memcpy(buf + 4, wdata, min_t(int, wlen, CMD_PACKET_SIZE - 4));
75
76 /* send command packet */
77 ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, CMD_EP), buf,
78 CMD_PACKET_SIZE, &actual_len, CMD_TIMEOUT);
79 if (ret < 0) {
80 if (cmd != CMD_GET_LINK_STATUS)
81 dev_err(&dev->udev->dev, "send command %#x: error %d\n",
82 cmd, ret);
83 goto end;
84 }
85
86 if (reply) {
87 /* wait for reply, retry if it's empty */
88 for (retries = 0; retries < CMD_REPLY_RETRY; retries++) {
89 ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, CMD_EP),
90 buf, CMD_PACKET_SIZE, &actual_len,
91 CMD_TIMEOUT);
92 if (ret < 0) {
93 if (cmd != CMD_GET_LINK_STATUS)
94 dev_err(&dev->udev->dev,
95 "reply receive error %d\n",
96 ret);
97 goto end;
98 }
99 if (actual_len > 0)
100 break;
101 }
102 if (actual_len == 0) {
103 dev_err(&dev->udev->dev, "no reply to command %#x\n",
104 cmd);
105 ret = -EIO;
106 goto end;
107 }
108 if (buf[0] != cmd) {
109 dev_err(&dev->udev->dev,
110 "got reply to command %#x, expected: %#x\n",
111 buf[0], cmd);
112 ret = -EIO;
113 goto end;
114 }
115 if (buf[1] != STATUS_SUCCESS) {
116 dev_err(&dev->udev->dev, "command %#x failed: %#x\n",
117 cmd, buf[1]);
118 ret = -EIO;
119 goto end;
120 }
121 if (rdata)
122 memcpy(rdata, buf + 4,
123 min_t(int, rlen, CMD_PACKET_SIZE - 4));
124 }
125 end:
126 kfree(buf);
127 return ret;
128 }
129
130 #define partial_len data[0] /* length of partial packet data */
131 #define partial_rem data[1] /* remaining (missing) data length */
132 #define partial_data data[2] /* partial packet data */
133
cx82310_bind(struct usbnet * dev,struct usb_interface * intf)134 static int cx82310_bind(struct usbnet *dev, struct usb_interface *intf)
135 {
136 int ret;
137 char buf[15];
138 struct usb_device *udev = dev->udev;
139 u8 link[3];
140 int timeout = 50;
141
142 /* avoid ADSL modems - continue only if iProduct is "USB NET CARD" */
143 if (usb_string(udev, udev->descriptor.iProduct, buf, sizeof(buf)) > 0
144 && strcmp(buf, "USB NET CARD")) {
145 dev_info(&udev->dev, "ignoring: probably an ADSL modem\n");
146 return -ENODEV;
147 }
148
149 ret = usbnet_get_endpoints(dev, intf);
150 if (ret)
151 return ret;
152
153 /*
154 * this must not include ethernet header as the device can send partial
155 * packets with no header (and sometimes even empty URBs)
156 */
157 dev->net->hard_header_len = 0;
158 /* we can send at most 1514 bytes of data (+ 2-byte header) per URB */
159 dev->hard_mtu = CX82310_MTU + 2;
160 /* we can receive URBs up to 4KB from the device */
161 dev->rx_urb_size = 4096;
162
163 dev->partial_data = (unsigned long) kmalloc(dev->hard_mtu, GFP_KERNEL);
164 if (!dev->partial_data)
165 return -ENOMEM;
166
167 /* wait for firmware to become ready (indicated by the link being up) */
168 while (--timeout) {
169 ret = cx82310_cmd(dev, CMD_GET_LINK_STATUS, true, NULL, 0,
170 link, sizeof(link));
171 /* the command can time out during boot - it's not an error */
172 if (!ret && link[0] == 1 && link[2] == 1)
173 break;
174 msleep(500);
175 }
176 if (!timeout) {
177 dev_err(&udev->dev, "firmware not ready in time\n");
178 ret = -ETIMEDOUT;
179 goto err;
180 }
181
182 /* enable ethernet mode (?) */
183 ret = cx82310_cmd(dev, CMD_ETHERNET_MODE, true, "\x01", 1, NULL, 0);
184 if (ret) {
185 dev_err(&udev->dev, "unable to enable ethernet mode: %d\n",
186 ret);
187 goto err;
188 }
189
190 /* get the MAC address */
191 ret = cx82310_cmd(dev, CMD_GET_MAC_ADDR, true, NULL, 0,
192 dev->net->dev_addr, ETH_ALEN);
193 if (ret) {
194 dev_err(&udev->dev, "unable to read MAC address: %d\n", ret);
195 goto err;
196 }
197
198 /* start (does not seem to have any effect?) */
199 ret = cx82310_cmd(dev, CMD_START, false, NULL, 0, NULL, 0);
200 if (ret)
201 goto err;
202
203 return 0;
204 err:
205 kfree((void *)dev->partial_data);
206 return ret;
207 }
208
cx82310_unbind(struct usbnet * dev,struct usb_interface * intf)209 static void cx82310_unbind(struct usbnet *dev, struct usb_interface *intf)
210 {
211 kfree((void *)dev->partial_data);
212 }
213
214 /*
215 * RX is NOT easy - we can receive multiple packets per skb, each having 2-byte
216 * packet length at the beginning.
217 * The last packet might be incomplete (when it crosses the 4KB URB size),
218 * continuing in the next skb (without any headers).
219 * If a packet has odd length, there is one extra byte at the end (before next
220 * packet or at the end of the URB).
221 */
cx82310_rx_fixup(struct usbnet * dev,struct sk_buff * skb)222 static int cx82310_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
223 {
224 int len;
225 struct sk_buff *skb2;
226
227 /*
228 * If the last skb ended with an incomplete packet, this skb contains
229 * end of that packet at the beginning.
230 */
231 if (dev->partial_rem) {
232 len = dev->partial_len + dev->partial_rem;
233 skb2 = alloc_skb(len, GFP_ATOMIC);
234 if (!skb2)
235 return 0;
236 skb_put(skb2, len);
237 memcpy(skb2->data, (void *)dev->partial_data,
238 dev->partial_len);
239 memcpy(skb2->data + dev->partial_len, skb->data,
240 dev->partial_rem);
241 usbnet_skb_return(dev, skb2);
242 skb_pull(skb, (dev->partial_rem + 1) & ~1);
243 dev->partial_rem = 0;
244 if (skb->len < 2)
245 return 1;
246 }
247
248 /* a skb can contain multiple packets */
249 while (skb->len > 1) {
250 /* first two bytes are packet length */
251 len = skb->data[0] | (skb->data[1] << 8);
252 skb_pull(skb, 2);
253
254 /* if last packet in the skb, let usbnet to process it */
255 if (len == skb->len || len + 1 == skb->len) {
256 skb_trim(skb, len);
257 break;
258 }
259
260 if (len > CX82310_MTU) {
261 dev_err(&dev->udev->dev, "RX packet too long: %d B\n",
262 len);
263 return 0;
264 }
265
266 /* incomplete packet, save it for the next skb */
267 if (len > skb->len) {
268 dev->partial_len = skb->len;
269 dev->partial_rem = len - skb->len;
270 memcpy((void *)dev->partial_data, skb->data,
271 dev->partial_len);
272 skb_pull(skb, skb->len);
273 break;
274 }
275
276 skb2 = alloc_skb(len, GFP_ATOMIC);
277 if (!skb2)
278 return 0;
279 skb_put(skb2, len);
280 memcpy(skb2->data, skb->data, len);
281 /* process the packet */
282 usbnet_skb_return(dev, skb2);
283
284 skb_pull(skb, (len + 1) & ~1);
285 }
286
287 /* let usbnet process the last packet */
288 return 1;
289 }
290
291 /* TX is easy, just add 2 bytes of length at the beginning */
cx82310_tx_fixup(struct usbnet * dev,struct sk_buff * skb,gfp_t flags)292 static struct sk_buff *cx82310_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
293 gfp_t flags)
294 {
295 int len = skb->len;
296
297 if (skb_cow_head(skb, 2)) {
298 dev_kfree_skb_any(skb);
299 return NULL;
300 }
301 skb_push(skb, 2);
302
303 skb->data[0] = len;
304 skb->data[1] = len >> 8;
305
306 return skb;
307 }
308
309
310 static const struct driver_info cx82310_info = {
311 .description = "Conexant CX82310 USB ethernet",
312 .flags = FLAG_ETHER,
313 .bind = cx82310_bind,
314 .unbind = cx82310_unbind,
315 .rx_fixup = cx82310_rx_fixup,
316 .tx_fixup = cx82310_tx_fixup,
317 };
318
319 #define USB_DEVICE_CLASS(vend, prod, cl, sc, pr) \
320 .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
321 USB_DEVICE_ID_MATCH_DEV_INFO, \
322 .idVendor = (vend), \
323 .idProduct = (prod), \
324 .bDeviceClass = (cl), \
325 .bDeviceSubClass = (sc), \
326 .bDeviceProtocol = (pr)
327
328 static const struct usb_device_id products[] = {
329 {
330 USB_DEVICE_CLASS(0x0572, 0xcb01, 0xff, 0, 0),
331 .driver_info = (unsigned long) &cx82310_info
332 },
333 { },
334 };
335 MODULE_DEVICE_TABLE(usb, products);
336
337 static struct usb_driver cx82310_driver = {
338 .name = "cx82310_eth",
339 .id_table = products,
340 .probe = usbnet_probe,
341 .disconnect = usbnet_disconnect,
342 .suspend = usbnet_suspend,
343 .resume = usbnet_resume,
344 .disable_hub_initiated_lpm = 1,
345 };
346
347 module_usb_driver(cx82310_driver);
348
349 MODULE_AUTHOR("Ondrej Zary");
350 MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver");
351 MODULE_LICENSE("GPL");
352