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 */ 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 */ 131 132 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 } 189 190 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 */ 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 */ 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 static const struct usb_device_id products[] = { 304 { 305 USB_DEVICE_AND_INTERFACE_INFO(0x0572, 0xcb01, 0xff, 0, 0), 306 .driver_info = (unsigned long) &cx82310_info 307 }, 308 { }, 309 }; 310 MODULE_DEVICE_TABLE(usb, products); 311 312 static struct usb_driver cx82310_driver = { 313 .name = "cx82310_eth", 314 .id_table = products, 315 .probe = usbnet_probe, 316 .disconnect = usbnet_disconnect, 317 .suspend = usbnet_suspend, 318 .resume = usbnet_resume, 319 .disable_hub_initiated_lpm = 1, 320 }; 321 322 module_usb_driver(cx82310_driver); 323 324 MODULE_AUTHOR("Ondrej Zary"); 325 MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver"); 326 MODULE_LICENSE("GPL"); 327