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/init.h> 22 #include <linux/netdevice.h> 23 #include <linux/etherdevice.h> 24 #include <linux/ethtool.h> 25 #include <linux/workqueue.h> 26 #include <linux/mii.h> 27 #include <linux/usb.h> 28 #include <linux/usb/usbnet.h> 29 30 enum cx82310_cmd { 31 CMD_START = 0x84, /* no effect? */ 32 CMD_STOP = 0x85, /* no effect? */ 33 CMD_GET_STATUS = 0x90, /* returns nothing? */ 34 CMD_GET_MAC_ADDR = 0x91, /* read MAC address */ 35 CMD_GET_LINK_STATUS = 0x92, /* not useful, link is always up */ 36 CMD_ETHERNET_MODE = 0x99, /* unknown, needed during init */ 37 }; 38 39 enum cx82310_status { 40 STATUS_UNDEFINED, 41 STATUS_SUCCESS, 42 STATUS_ERROR, 43 STATUS_UNSUPPORTED, 44 STATUS_UNIMPLEMENTED, 45 STATUS_PARAMETER_ERROR, 46 STATUS_DBG_LOOPBACK, 47 }; 48 49 #define CMD_PACKET_SIZE 64 50 /* first command after power on can take around 8 seconds */ 51 #define CMD_TIMEOUT 15000 52 #define CMD_REPLY_RETRY 5 53 54 #define CX82310_MTU 1514 55 #define CMD_EP 0x01 56 57 /* 58 * execute control command 59 * - optionally send some data (command parameters) 60 * - optionally wait for the reply 61 * - optionally read some data from the reply 62 */ 63 static int cx82310_cmd(struct usbnet *dev, enum cx82310_cmd cmd, bool reply, 64 u8 *wdata, int wlen, u8 *rdata, int rlen) 65 { 66 int actual_len, retries, ret; 67 struct usb_device *udev = dev->udev; 68 u8 *buf = kzalloc(CMD_PACKET_SIZE, GFP_KERNEL); 69 70 if (!buf) 71 return -ENOMEM; 72 73 /* create command packet */ 74 buf[0] = cmd; 75 if (wdata) 76 memcpy(buf + 4, wdata, min_t(int, wlen, CMD_PACKET_SIZE - 4)); 77 78 /* send command packet */ 79 ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, CMD_EP), buf, 80 CMD_PACKET_SIZE, &actual_len, CMD_TIMEOUT); 81 if (ret < 0) { 82 dev_err(&dev->udev->dev, "send command %#x: error %d\n", 83 cmd, ret); 84 goto end; 85 } 86 87 if (reply) { 88 /* wait for reply, retry if it's empty */ 89 for (retries = 0; retries < CMD_REPLY_RETRY; retries++) { 90 ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, CMD_EP), 91 buf, CMD_PACKET_SIZE, &actual_len, 92 CMD_TIMEOUT); 93 if (ret < 0) { 94 dev_err(&dev->udev->dev, 95 "reply receive error %d\n", ret); 96 goto end; 97 } 98 if (actual_len > 0) 99 break; 100 } 101 if (actual_len == 0) { 102 dev_err(&dev->udev->dev, "no reply to command %#x\n", 103 cmd); 104 ret = -EIO; 105 goto end; 106 } 107 if (buf[0] != cmd) { 108 dev_err(&dev->udev->dev, 109 "got reply to command %#x, expected: %#x\n", 110 buf[0], cmd); 111 ret = -EIO; 112 goto end; 113 } 114 if (buf[1] != STATUS_SUCCESS) { 115 dev_err(&dev->udev->dev, "command %#x failed: %#x\n", 116 cmd, buf[1]); 117 ret = -EIO; 118 goto end; 119 } 120 if (rdata) 121 memcpy(rdata, buf + 4, 122 min_t(int, rlen, CMD_PACKET_SIZE - 4)); 123 } 124 end: 125 kfree(buf); 126 return ret; 127 } 128 129 #define partial_len data[0] /* length of partial packet data */ 130 #define partial_rem data[1] /* remaining (missing) data length */ 131 #define partial_data data[2] /* partial packet data */ 132 133 static int cx82310_bind(struct usbnet *dev, struct usb_interface *intf) 134 { 135 int ret; 136 char buf[15]; 137 struct usb_device *udev = dev->udev; 138 139 /* avoid ADSL modems - continue only if iProduct is "USB NET CARD" */ 140 if (usb_string(udev, udev->descriptor.iProduct, buf, sizeof(buf)) > 0 141 && strcmp(buf, "USB NET CARD")) { 142 dev_info(&udev->dev, "ignoring: probably an ADSL modem\n"); 143 return -ENODEV; 144 } 145 146 ret = usbnet_get_endpoints(dev, intf); 147 if (ret) 148 return ret; 149 150 /* 151 * this must not include ethernet header as the device can send partial 152 * packets with no header (and sometimes even empty URBs) 153 */ 154 dev->net->hard_header_len = 0; 155 /* we can send at most 1514 bytes of data (+ 2-byte header) per URB */ 156 dev->hard_mtu = CX82310_MTU + 2; 157 /* we can receive URBs up to 4KB from the device */ 158 dev->rx_urb_size = 4096; 159 160 dev->partial_data = (unsigned long) kmalloc(dev->hard_mtu, GFP_KERNEL); 161 if (!dev->partial_data) 162 return -ENOMEM; 163 164 /* enable ethernet mode (?) */ 165 ret = cx82310_cmd(dev, CMD_ETHERNET_MODE, true, "\x01", 1, NULL, 0); 166 if (ret) { 167 dev_err(&udev->dev, "unable to enable ethernet mode: %d\n", 168 ret); 169 goto err; 170 } 171 172 /* get the MAC address */ 173 ret = cx82310_cmd(dev, CMD_GET_MAC_ADDR, true, NULL, 0, 174 dev->net->dev_addr, ETH_ALEN); 175 if (ret) { 176 dev_err(&udev->dev, "unable to read MAC address: %d\n", ret); 177 goto err; 178 } 179 180 /* start (does not seem to have any effect?) */ 181 ret = cx82310_cmd(dev, CMD_START, false, NULL, 0, NULL, 0); 182 if (ret) 183 goto err; 184 185 return 0; 186 err: 187 kfree((void *)dev->partial_data); 188 return ret; 189 } 190 191 static void cx82310_unbind(struct usbnet *dev, struct usb_interface *intf) 192 { 193 kfree((void *)dev->partial_data); 194 } 195 196 /* 197 * RX is NOT easy - we can receive multiple packets per skb, each having 2-byte 198 * packet length at the beginning. 199 * The last packet might be incomplete (when it crosses the 4KB URB size), 200 * continuing in the next skb (without any headers). 201 * If a packet has odd length, there is one extra byte at the end (before next 202 * packet or at the end of the URB). 203 */ 204 static int cx82310_rx_fixup(struct usbnet *dev, struct sk_buff *skb) 205 { 206 int len; 207 struct sk_buff *skb2; 208 209 /* 210 * If the last skb ended with an incomplete packet, this skb contains 211 * end of that packet at the beginning. 212 */ 213 if (dev->partial_rem) { 214 len = dev->partial_len + dev->partial_rem; 215 skb2 = alloc_skb(len, GFP_ATOMIC); 216 if (!skb2) 217 return 0; 218 skb_put(skb2, len); 219 memcpy(skb2->data, (void *)dev->partial_data, 220 dev->partial_len); 221 memcpy(skb2->data + dev->partial_len, skb->data, 222 dev->partial_rem); 223 usbnet_skb_return(dev, skb2); 224 skb_pull(skb, (dev->partial_rem + 1) & ~1); 225 dev->partial_rem = 0; 226 if (skb->len < 2) 227 return 1; 228 } 229 230 /* a skb can contain multiple packets */ 231 while (skb->len > 1) { 232 /* first two bytes are packet length */ 233 len = skb->data[0] | (skb->data[1] << 8); 234 skb_pull(skb, 2); 235 236 /* if last packet in the skb, let usbnet to process it */ 237 if (len == skb->len || len + 1 == skb->len) { 238 skb_trim(skb, len); 239 break; 240 } 241 242 if (len > CX82310_MTU) { 243 dev_err(&dev->udev->dev, "RX packet too long: %d B\n", 244 len); 245 return 0; 246 } 247 248 /* incomplete packet, save it for the next skb */ 249 if (len > skb->len) { 250 dev->partial_len = skb->len; 251 dev->partial_rem = len - skb->len; 252 memcpy((void *)dev->partial_data, skb->data, 253 dev->partial_len); 254 skb_pull(skb, skb->len); 255 break; 256 } 257 258 skb2 = alloc_skb(len, GFP_ATOMIC); 259 if (!skb2) 260 return 0; 261 skb_put(skb2, len); 262 memcpy(skb2->data, skb->data, len); 263 /* process the packet */ 264 usbnet_skb_return(dev, skb2); 265 266 skb_pull(skb, (len + 1) & ~1); 267 } 268 269 /* let usbnet process the last packet */ 270 return 1; 271 } 272 273 /* TX is easy, just add 2 bytes of length at the beginning */ 274 static struct sk_buff *cx82310_tx_fixup(struct usbnet *dev, struct sk_buff *skb, 275 gfp_t flags) 276 { 277 int len = skb->len; 278 279 if (skb_headroom(skb) < 2) { 280 struct sk_buff *skb2 = skb_copy_expand(skb, 2, 0, flags); 281 dev_kfree_skb_any(skb); 282 skb = skb2; 283 if (!skb) 284 return NULL; 285 } 286 skb_push(skb, 2); 287 288 skb->data[0] = len; 289 skb->data[1] = len >> 8; 290 291 return skb; 292 } 293 294 295 static const struct driver_info cx82310_info = { 296 .description = "Conexant CX82310 USB ethernet", 297 .flags = FLAG_ETHER, 298 .bind = cx82310_bind, 299 .unbind = cx82310_unbind, 300 .rx_fixup = cx82310_rx_fixup, 301 .tx_fixup = cx82310_tx_fixup, 302 }; 303 304 static const struct usb_device_id products[] = { 305 { 306 USB_DEVICE_AND_INTERFACE_INFO(0x0572, 0xcb01, 0xff, 0, 0), 307 .driver_info = (unsigned long) &cx82310_info 308 }, 309 { }, 310 }; 311 MODULE_DEVICE_TABLE(usb, products); 312 313 static struct usb_driver cx82310_driver = { 314 .name = "cx82310_eth", 315 .id_table = products, 316 .probe = usbnet_probe, 317 .disconnect = usbnet_disconnect, 318 .suspend = usbnet_suspend, 319 .resume = usbnet_resume, 320 .disable_hub_initiated_lpm = 1, 321 }; 322 323 module_usb_driver(cx82310_driver); 324 325 MODULE_AUTHOR("Ondrej Zary"); 326 MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver"); 327 MODULE_LICENSE("GPL"); 328