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, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/netdevice.h>
24 #include <linux/etherdevice.h>
25 #include <linux/ethtool.h>
26 #include <linux/workqueue.h>
27 #include <linux/mii.h>
28 #include <linux/usb.h>
29 #include <linux/usb/usbnet.h>
30
31 enum cx82310_cmd {
32 CMD_START = 0x84, /* no effect? */
33 CMD_STOP = 0x85, /* no effect? */
34 CMD_GET_STATUS = 0x90, /* returns nothing? */
35 CMD_GET_MAC_ADDR = 0x91, /* read MAC address */
36 CMD_GET_LINK_STATUS = 0x92, /* not useful, link is always up */
37 CMD_ETHERNET_MODE = 0x99, /* unknown, needed during init */
38 };
39
40 enum cx82310_status {
41 STATUS_UNDEFINED,
42 STATUS_SUCCESS,
43 STATUS_ERROR,
44 STATUS_UNSUPPORTED,
45 STATUS_UNIMPLEMENTED,
46 STATUS_PARAMETER_ERROR,
47 STATUS_DBG_LOOPBACK,
48 };
49
50 #define CMD_PACKET_SIZE 64
51 /* first command after power on can take around 8 seconds */
52 #define CMD_TIMEOUT 15000
53 #define CMD_REPLY_RETRY 5
54
55 #define CX82310_MTU 1514
56 #define CMD_EP 0x01
57
58 /*
59 * execute control command
60 * - optionally send some data (command parameters)
61 * - optionally wait for the reply
62 * - optionally read some data from the reply
63 */
cx82310_cmd(struct usbnet * dev,enum cx82310_cmd cmd,bool reply,u8 * wdata,int wlen,u8 * rdata,int rlen)64 static int cx82310_cmd(struct usbnet *dev, enum cx82310_cmd cmd, bool reply,
65 u8 *wdata, int wlen, u8 *rdata, int rlen)
66 {
67 int actual_len, retries, ret;
68 struct usb_device *udev = dev->udev;
69 u8 *buf = kzalloc(CMD_PACKET_SIZE, GFP_KERNEL);
70
71 if (!buf)
72 return -ENOMEM;
73
74 /* create command packet */
75 buf[0] = cmd;
76 if (wdata)
77 memcpy(buf + 4, wdata, min_t(int, wlen, CMD_PACKET_SIZE - 4));
78
79 /* send command packet */
80 ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, CMD_EP), buf,
81 CMD_PACKET_SIZE, &actual_len, CMD_TIMEOUT);
82 if (ret < 0) {
83 dev_err(&dev->udev->dev, "send command %#x: error %d\n",
84 cmd, ret);
85 goto end;
86 }
87
88 if (reply) {
89 /* wait for reply, retry if it's empty */
90 for (retries = 0; retries < CMD_REPLY_RETRY; retries++) {
91 ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, CMD_EP),
92 buf, CMD_PACKET_SIZE, &actual_len,
93 CMD_TIMEOUT);
94 if (ret < 0) {
95 dev_err(&dev->udev->dev,
96 "reply receive error %d\n", 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
140 /* avoid ADSL modems - continue only if iProduct is "USB NET CARD" */
141 if (usb_string(udev, udev->descriptor.iProduct, buf, sizeof(buf)) > 0
142 && strcmp(buf, "USB NET CARD")) {
143 dev_info(&udev->dev, "ignoring: probably an ADSL modem\n");
144 return -ENODEV;
145 }
146
147 ret = usbnet_get_endpoints(dev, intf);
148 if (ret)
149 return ret;
150
151 /*
152 * this must not include ethernet header as the device can send partial
153 * packets with no header (and sometimes even empty URBs)
154 */
155 dev->net->hard_header_len = 0;
156 /* we can send at most 1514 bytes of data (+ 2-byte header) per URB */
157 dev->hard_mtu = CX82310_MTU + 2;
158 /* we can receive URBs up to 4KB from the device */
159 dev->rx_urb_size = 4096;
160
161 dev->partial_data = (unsigned long) kmalloc(dev->hard_mtu, GFP_KERNEL);
162 if (!dev->partial_data)
163 return -ENOMEM;
164
165 /* enable ethernet mode (?) */
166 ret = cx82310_cmd(dev, CMD_ETHERNET_MODE, true, "\x01", 1, NULL, 0);
167 if (ret) {
168 dev_err(&udev->dev, "unable to enable ethernet mode: %d\n",
169 ret);
170 goto err;
171 }
172
173 /* get the MAC address */
174 ret = cx82310_cmd(dev, CMD_GET_MAC_ADDR, true, NULL, 0,
175 dev->net->dev_addr, ETH_ALEN);
176 if (ret) {
177 dev_err(&udev->dev, "unable to read MAC address: %d\n", ret);
178 goto err;
179 }
180
181 /* start (does not seem to have any effect?) */
182 ret = cx82310_cmd(dev, CMD_START, false, NULL, 0, NULL, 0);
183 if (ret)
184 goto err;
185
186 return 0;
187 err:
188 kfree((void *)dev->partial_data);
189 return ret;
190 }
191
cx82310_unbind(struct usbnet * dev,struct usb_interface * intf)192 static void cx82310_unbind(struct usbnet *dev, struct usb_interface *intf)
193 {
194 kfree((void *)dev->partial_data);
195 }
196
197 /*
198 * RX is NOT easy - we can receive multiple packets per skb, each having 2-byte
199 * packet length at the beginning.
200 * The last packet might be incomplete (when it crosses the 4KB URB size),
201 * continuing in the next skb (without any headers).
202 * If a packet has odd length, there is one extra byte at the end (before next
203 * packet or at the end of the URB).
204 */
cx82310_rx_fixup(struct usbnet * dev,struct sk_buff * skb)205 static int cx82310_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
206 {
207 int len;
208 struct sk_buff *skb2;
209
210 /*
211 * If the last skb ended with an incomplete packet, this skb contains
212 * end of that packet at the beginning.
213 */
214 if (dev->partial_rem) {
215 len = dev->partial_len + dev->partial_rem;
216 skb2 = alloc_skb(len, GFP_ATOMIC);
217 if (!skb2)
218 return 0;
219 skb_put(skb2, len);
220 memcpy(skb2->data, (void *)dev->partial_data,
221 dev->partial_len);
222 memcpy(skb2->data + dev->partial_len, skb->data,
223 dev->partial_rem);
224 usbnet_skb_return(dev, skb2);
225 skb_pull(skb, (dev->partial_rem + 1) & ~1);
226 dev->partial_rem = 0;
227 if (skb->len < 2)
228 return 1;
229 }
230
231 /* a skb can contain multiple packets */
232 while (skb->len > 1) {
233 /* first two bytes are packet length */
234 len = skb->data[0] | (skb->data[1] << 8);
235 skb_pull(skb, 2);
236
237 /* if last packet in the skb, let usbnet to process it */
238 if (len == skb->len || len + 1 == skb->len) {
239 skb_trim(skb, len);
240 break;
241 }
242
243 if (len > CX82310_MTU) {
244 dev_err(&dev->udev->dev, "RX packet too long: %d B\n",
245 len);
246 return 0;
247 }
248
249 /* incomplete packet, save it for the next skb */
250 if (len > skb->len) {
251 dev->partial_len = skb->len;
252 dev->partial_rem = len - skb->len;
253 memcpy((void *)dev->partial_data, skb->data,
254 dev->partial_len);
255 skb_pull(skb, skb->len);
256 break;
257 }
258
259 skb2 = alloc_skb(len, GFP_ATOMIC);
260 if (!skb2)
261 return 0;
262 skb_put(skb2, len);
263 memcpy(skb2->data, skb->data, len);
264 /* process the packet */
265 usbnet_skb_return(dev, skb2);
266
267 skb_pull(skb, (len + 1) & ~1);
268 }
269
270 /* let usbnet process the last packet */
271 return 1;
272 }
273
274 /* 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)275 static struct sk_buff *cx82310_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
276 gfp_t flags)
277 {
278 int len = skb->len;
279
280 if (skb_headroom(skb) < 2) {
281 struct sk_buff *skb2 = skb_copy_expand(skb, 2, 0, flags);
282 dev_kfree_skb_any(skb);
283 skb = skb2;
284 if (!skb)
285 return NULL;
286 }
287 skb_push(skb, 2);
288
289 skb->data[0] = len;
290 skb->data[1] = len >> 8;
291
292 return skb;
293 }
294
295
296 static const struct driver_info cx82310_info = {
297 .description = "Conexant CX82310 USB ethernet",
298 .flags = FLAG_ETHER,
299 .bind = cx82310_bind,
300 .unbind = cx82310_unbind,
301 .rx_fixup = cx82310_rx_fixup,
302 .tx_fixup = cx82310_tx_fixup,
303 };
304
305 #define USB_DEVICE_CLASS(vend, prod, cl, sc, pr) \
306 .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
307 USB_DEVICE_ID_MATCH_DEV_INFO, \
308 .idVendor = (vend), \
309 .idProduct = (prod), \
310 .bDeviceClass = (cl), \
311 .bDeviceSubClass = (sc), \
312 .bDeviceProtocol = (pr)
313
314 static const struct usb_device_id products[] = {
315 {
316 USB_DEVICE_CLASS(0x0572, 0xcb01, 0xff, 0, 0),
317 .driver_info = (unsigned long) &cx82310_info
318 },
319 { },
320 };
321 MODULE_DEVICE_TABLE(usb, products);
322
323 static struct usb_driver cx82310_driver = {
324 .name = "cx82310_eth",
325 .id_table = products,
326 .probe = usbnet_probe,
327 .disconnect = usbnet_disconnect,
328 .suspend = usbnet_suspend,
329 .resume = usbnet_resume,
330 };
331
332 module_usb_driver(cx82310_driver);
333
334 MODULE_AUTHOR("Ondrej Zary");
335 MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver");
336 MODULE_LICENSE("GPL");
337