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 */ 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 */ 133 134 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 } 191 192 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 */ 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 */ 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 static const struct usb_device_id products[] = { 306 { 307 USB_DEVICE_AND_INTERFACE_INFO(0x0572, 0xcb01, 0xff, 0, 0), 308 .driver_info = (unsigned long) &cx82310_info 309 }, 310 { }, 311 }; 312 MODULE_DEVICE_TABLE(usb, products); 313 314 static struct usb_driver cx82310_driver = { 315 .name = "cx82310_eth", 316 .id_table = products, 317 .probe = usbnet_probe, 318 .disconnect = usbnet_disconnect, 319 .suspend = usbnet_suspend, 320 .resume = usbnet_resume, 321 .disable_hub_initiated_lpm = 1, 322 }; 323 324 module_usb_driver(cx82310_driver); 325 326 MODULE_AUTHOR("Ondrej Zary"); 327 MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver"); 328 MODULE_LICENSE("GPL"); 329