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 /* first command after power on can take around 8 seconds */
50 #define CMD_TIMEOUT 15000
51 #define CMD_REPLY_RETRY 5
52
53 #define CX82310_MTU 1514
54 #define CMD_EP 0x01
55
56 /*
57 * execute control command
58 * - optionally send some data (command parameters)
59 * - optionally wait for the reply
60 * - optionally read some data from the reply
61 */
cx82310_cmd(struct usbnet * dev,enum cx82310_cmd cmd,bool reply,u8 * wdata,int wlen,u8 * rdata,int rlen)62 static int cx82310_cmd(struct usbnet *dev, enum cx82310_cmd cmd, bool reply,
63 u8 *wdata, int wlen, u8 *rdata, int rlen)
64 {
65 int actual_len, retries, ret;
66 struct usb_device *udev = dev->udev;
67 u8 *buf = kzalloc(CMD_PACKET_SIZE, GFP_KERNEL);
68
69 if (!buf)
70 return -ENOMEM;
71
72 /* create command packet */
73 buf[0] = cmd;
74 if (wdata)
75 memcpy(buf + 4, wdata, min_t(int, wlen, CMD_PACKET_SIZE - 4));
76
77 /* send command packet */
78 ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, CMD_EP), buf,
79 CMD_PACKET_SIZE, &actual_len, CMD_TIMEOUT);
80 if (ret < 0) {
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 dev_err(&dev->udev->dev,
94 "reply receive error %d\n", ret);
95 goto end;
96 }
97 if (actual_len > 0)
98 break;
99 }
100 if (actual_len == 0) {
101 dev_err(&dev->udev->dev, "no reply to command %#x\n",
102 cmd);
103 ret = -EIO;
104 goto end;
105 }
106 if (buf[0] != cmd) {
107 dev_err(&dev->udev->dev,
108 "got reply to command %#x, expected: %#x\n",
109 buf[0], cmd);
110 ret = -EIO;
111 goto end;
112 }
113 if (buf[1] != STATUS_SUCCESS) {
114 dev_err(&dev->udev->dev, "command %#x failed: %#x\n",
115 cmd, buf[1]);
116 ret = -EIO;
117 goto end;
118 }
119 if (rdata)
120 memcpy(rdata, buf + 4,
121 min_t(int, rlen, CMD_PACKET_SIZE - 4));
122 }
123 end:
124 kfree(buf);
125 return ret;
126 }
127
128 #define partial_len data[0] /* length of partial packet data */
129 #define partial_rem data[1] /* remaining (missing) data length */
130 #define partial_data data[2] /* partial packet data */
131
cx82310_bind(struct usbnet * dev,struct usb_interface * intf)132 static int cx82310_bind(struct usbnet *dev, struct usb_interface *intf)
133 {
134 int ret;
135 char buf[15];
136 struct usb_device *udev = dev->udev;
137
138 /* avoid ADSL modems - continue only if iProduct is "USB NET CARD" */
139 if (usb_string(udev, udev->descriptor.iProduct, buf, sizeof(buf)) > 0
140 && strcmp(buf, "USB NET CARD")) {
141 dev_info(&udev->dev, "ignoring: probably an ADSL modem\n");
142 return -ENODEV;
143 }
144
145 ret = usbnet_get_endpoints(dev, intf);
146 if (ret)
147 return ret;
148
149 /*
150 * this must not include ethernet header as the device can send partial
151 * packets with no header (and sometimes even empty URBs)
152 */
153 dev->net->hard_header_len = 0;
154 /* we can send at most 1514 bytes of data (+ 2-byte header) per URB */
155 dev->hard_mtu = CX82310_MTU + 2;
156 /* we can receive URBs up to 4KB from the device */
157 dev->rx_urb_size = 4096;
158
159 dev->partial_data = (unsigned long) kmalloc(dev->hard_mtu, GFP_KERNEL);
160 if (!dev->partial_data)
161 return -ENOMEM;
162
163 /* enable ethernet mode (?) */
164 ret = cx82310_cmd(dev, CMD_ETHERNET_MODE, true, "\x01", 1, NULL, 0);
165 if (ret) {
166 dev_err(&udev->dev, "unable to enable ethernet mode: %d\n",
167 ret);
168 goto err;
169 }
170
171 /* get the MAC address */
172 ret = cx82310_cmd(dev, CMD_GET_MAC_ADDR, true, NULL, 0,
173 dev->net->dev_addr, ETH_ALEN);
174 if (ret) {
175 dev_err(&udev->dev, "unable to read MAC address: %d\n", ret);
176 goto err;
177 }
178
179 /* start (does not seem to have any effect?) */
180 ret = cx82310_cmd(dev, CMD_START, false, NULL, 0, NULL, 0);
181 if (ret)
182 goto err;
183
184 return 0;
185 err:
186 kfree((void *)dev->partial_data);
187 return ret;
188 }
189
cx82310_unbind(struct usbnet * dev,struct usb_interface * intf)190 static void cx82310_unbind(struct usbnet *dev, struct usb_interface *intf)
191 {
192 kfree((void *)dev->partial_data);
193 }
194
195 /*
196 * RX is NOT easy - we can receive multiple packets per skb, each having 2-byte
197 * packet length at the beginning.
198 * The last packet might be incomplete (when it crosses the 4KB URB size),
199 * continuing in the next skb (without any headers).
200 * If a packet has odd length, there is one extra byte at the end (before next
201 * packet or at the end of the URB).
202 */
cx82310_rx_fixup(struct usbnet * dev,struct sk_buff * skb)203 static int cx82310_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
204 {
205 int len;
206 struct sk_buff *skb2;
207
208 /*
209 * If the last skb ended with an incomplete packet, this skb contains
210 * end of that packet at the beginning.
211 */
212 if (dev->partial_rem) {
213 len = dev->partial_len + dev->partial_rem;
214 skb2 = alloc_skb(len, GFP_ATOMIC);
215 if (!skb2)
216 return 0;
217 skb_put(skb2, len);
218 memcpy(skb2->data, (void *)dev->partial_data,
219 dev->partial_len);
220 memcpy(skb2->data + dev->partial_len, skb->data,
221 dev->partial_rem);
222 usbnet_skb_return(dev, skb2);
223 skb_pull(skb, (dev->partial_rem + 1) & ~1);
224 dev->partial_rem = 0;
225 if (skb->len < 2)
226 return 1;
227 }
228
229 /* a skb can contain multiple packets */
230 while (skb->len > 1) {
231 /* first two bytes are packet length */
232 len = skb->data[0] | (skb->data[1] << 8);
233 skb_pull(skb, 2);
234
235 /* if last packet in the skb, let usbnet to process it */
236 if (len == skb->len || len + 1 == skb->len) {
237 skb_trim(skb, len);
238 break;
239 }
240
241 if (len > CX82310_MTU) {
242 dev_err(&dev->udev->dev, "RX packet too long: %d B\n",
243 len);
244 return 0;
245 }
246
247 /* incomplete packet, save it for the next skb */
248 if (len > skb->len) {
249 dev->partial_len = skb->len;
250 dev->partial_rem = len - skb->len;
251 memcpy((void *)dev->partial_data, skb->data,
252 dev->partial_len);
253 skb_pull(skb, skb->len);
254 break;
255 }
256
257 skb2 = alloc_skb(len, GFP_ATOMIC);
258 if (!skb2)
259 return 0;
260 skb_put(skb2, len);
261 memcpy(skb2->data, skb->data, len);
262 /* process the packet */
263 usbnet_skb_return(dev, skb2);
264
265 skb_pull(skb, (len + 1) & ~1);
266 }
267
268 /* let usbnet process the last packet */
269 return 1;
270 }
271
272 /* 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)273 static struct sk_buff *cx82310_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
274 gfp_t flags)
275 {
276 int len = skb->len;
277
278 if (skb_headroom(skb) < 2) {
279 struct sk_buff *skb2 = skb_copy_expand(skb, 2, 0, flags);
280 dev_kfree_skb_any(skb);
281 skb = skb2;
282 if (!skb)
283 return NULL;
284 }
285 skb_push(skb, 2);
286
287 skb->data[0] = len;
288 skb->data[1] = len >> 8;
289
290 return skb;
291 }
292
293
294 static const struct driver_info cx82310_info = {
295 .description = "Conexant CX82310 USB ethernet",
296 .flags = FLAG_ETHER,
297 .bind = cx82310_bind,
298 .unbind = cx82310_unbind,
299 .rx_fixup = cx82310_rx_fixup,
300 .tx_fixup = cx82310_tx_fixup,
301 };
302
303 #define USB_DEVICE_CLASS(vend, prod, cl, sc, pr) \
304 .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
305 USB_DEVICE_ID_MATCH_DEV_INFO, \
306 .idVendor = (vend), \
307 .idProduct = (prod), \
308 .bDeviceClass = (cl), \
309 .bDeviceSubClass = (sc), \
310 .bDeviceProtocol = (pr)
311
312 static const struct usb_device_id products[] = {
313 {
314 USB_DEVICE_CLASS(0x0572, 0xcb01, 0xff, 0, 0),
315 .driver_info = (unsigned long) &cx82310_info
316 },
317 { },
318 };
319 MODULE_DEVICE_TABLE(usb, products);
320
321 static struct usb_driver cx82310_driver = {
322 .name = "cx82310_eth",
323 .id_table = products,
324 .probe = usbnet_probe,
325 .disconnect = usbnet_disconnect,
326 .suspend = usbnet_suspend,
327 .resume = usbnet_resume,
328 .disable_hub_initiated_lpm = 1,
329 };
330
331 module_usb_driver(cx82310_driver);
332
333 MODULE_AUTHOR("Ondrej Zary");
334 MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver");
335 MODULE_LICENSE("GPL");
336