drivers/net/usb/ipheth.c

   1 /*
   2  * ipheth.c - Apple iPhone USB Ethernet driver
   3  *
   4  * Copyright (c) 2009 Diego Giagio <diego@giagio.com>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of GIAGIO.COM nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * Alternatively, provided that this notice is retained in full, this
  20  * software may be distributed under the terms of the GNU General
  21  * Public License ("GPL") version 2, in which case the provisions of the
  22  * GPL apply INSTEAD OF those given above.
  23  *
  24  * The provided data structures and external interfaces from this code
  25  * are not restricted to be used by modules with a GPL compatible license.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  38  * DAMAGE.
  39  *
  40  *
  41  * Attention: iPhone device must be paired, otherwise it won't respond to our
  42  * driver. For more info: http://giagio.com/wiki/moin.cgi/iPhoneEthernetDriver
  43  *
  44  */
  45
  46 #include <linux/kernel.h>
  47 #include <linux/errno.h>
  48 #include <linux/slab.h>
  49 #include <linux/module.h>
  50 #include <linux/netdevice.h>
  51 #include <linux/etherdevice.h>
  52 #include <linux/ethtool.h>
  53 #include <linux/usb.h>
  54 #include <linux/workqueue.h>
  55
  56 #define USB_VENDOR_APPLE        0x05ac
  57
  58 #define IPHETH_USBINTF_CLASS    255
  59 #define IPHETH_USBINTF_SUBCLASS 253
  60 #define IPHETH_USBINTF_PROTO    1
  61
  62 #define IPHETH_BUF_SIZE         1514
  63 #define IPHETH_IP_ALIGN         2       /* padding at front of URB */
  64 #define IPHETH_TX_TIMEOUT       (5 * HZ)
  65
  66 #define IPHETH_INTFNUM          2
  67 #define IPHETH_ALT_INTFNUM      1
  68
  69 #define IPHETH_CTRL_ENDP        0x00
  70 #define IPHETH_CTRL_BUF_SIZE    0x40
  71 #define IPHETH_CTRL_TIMEOUT     (5 * HZ)
  72
  73 #define IPHETH_CMD_GET_MACADDR   0x00
  74 #define IPHETH_CMD_CARRIER_CHECK 0x45
  75
  76 #define IPHETH_CARRIER_CHECK_TIMEOUT round_jiffies_relative(1 * HZ)
  77 #define IPHETH_CARRIER_ON       0x04
  78
  79 static const struct usb_device_id ipheth_table[] = {
  80         { USB_VENDOR_AND_INTERFACE_INFO(USB_VENDOR_APPLE, IPHETH_USBINTF_CLASS,
  81                                         IPHETH_USBINTF_SUBCLASS,
  82                                         IPHETH_USBINTF_PROTO) },
  83         { }
  84 };
  85 MODULE_DEVICE_TABLE(usb, ipheth_table);
  86
  87 struct ipheth_device {
  88         struct usb_device *udev;
  89         struct usb_interface *intf;
  90         struct net_device *net;
  91         struct urb *tx_urb;
  92         struct urb *rx_urb;
  93         unsigned char *tx_buf;
  94         unsigned char *rx_buf;
  95         unsigned char *ctrl_buf;
  96         u8 bulk_in;
  97         u8 bulk_out;
  98         struct delayed_work carrier_work;
  99         bool confirmed_pairing;
 100 };
 101
 102 static int ipheth_rx_submit(struct ipheth_device *dev, gfp_t mem_flags);
 103
 104 static int ipheth_alloc_urbs(struct ipheth_device *iphone)
 105 {
 106         struct urb *tx_urb = NULL;
 107         struct urb *rx_urb = NULL;
 108         u8 *tx_buf = NULL;
 109         u8 *rx_buf = NULL;
 110
 111         tx_urb = usb_alloc_urb(0, GFP_KERNEL);
 112         if (tx_urb == NULL)
 113                 goto error_nomem;
 114
 115         rx_urb = usb_alloc_urb(0, GFP_KERNEL);
 116         if (rx_urb == NULL)
 117                 goto free_tx_urb;
 118
 119         tx_buf = usb_alloc_coherent(iphone->udev, IPHETH_BUF_SIZE,
 120                                     GFP_KERNEL, &tx_urb->transfer_dma);
 121         if (tx_buf == NULL)
 122                 goto free_rx_urb;
 123
 124         rx_buf = usb_alloc_coherent(iphone->udev, IPHETH_BUF_SIZE,
 125                                     GFP_KERNEL, &rx_urb->transfer_dma);
 126         if (rx_buf == NULL)
 127                 goto free_tx_buf;
 128
 129
 130         iphone->tx_urb = tx_urb;
 131         iphone->rx_urb = rx_urb;
 132         iphone->tx_buf = tx_buf;
 133         iphone->rx_buf = rx_buf;
 134         return 0;
 135
 136 free_tx_buf:
 137         usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, tx_buf,
 138                           tx_urb->transfer_dma);
 139 free_rx_urb:
 140         usb_free_urb(rx_urb);
 141 free_tx_urb:
 142         usb_free_urb(tx_urb);
 143 error_nomem:
 144         return -ENOMEM;
 145 }
 146
 147 static void ipheth_free_urbs(struct ipheth_device *iphone)
 148 {
 149         usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, iphone->rx_buf,
 150                           iphone->rx_urb->transfer_dma);
 151         usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, iphone->tx_buf,
 152                           iphone->tx_urb->transfer_dma);
 153         usb_free_urb(iphone->rx_urb);
 154         usb_free_urb(iphone->tx_urb);
 155 }
 156
 157 static void ipheth_kill_urbs(struct ipheth_device *dev)
 158 {
 159         usb_kill_urb(dev->tx_urb);
 160         usb_kill_urb(dev->rx_urb);
 161 }
 162
 163 static void ipheth_rcvbulk_callback(struct urb *urb)
 164 {
 165         struct ipheth_device *dev;
 166         struct sk_buff *skb;
 167         int status;
 168         char *buf;
 169         int len;
 170
 171         dev = urb->context;
 172         if (dev == NULL)
 173                 return;
 174
 175         status = urb->status;
 176         switch (status) {
 177         case -ENOENT:
 178         case -ECONNRESET:
 179         case -ESHUTDOWN:
 180         case -EPROTO:
 181                 return;
 182         case 0:
 183                 break;
 184         default:
 185                 dev_err(&dev->intf->dev, "%s: urb status: %d\n",
 186                         __func__, status);
 187                 return;
 188         }
 189
 190         if (urb->actual_length <= IPHETH_IP_ALIGN) {
 191                 dev->net->stats.rx_length_errors++;
 192                 return;
 193         }
 194         len = urb->actual_length - IPHETH_IP_ALIGN;
 195         buf = urb->transfer_buffer + IPHETH_IP_ALIGN;
 196
 197         skb = dev_alloc_skb(len);
 198         if (!skb) {
 199                 dev_err(&dev->intf->dev, "%s: dev_alloc_skb: -ENOMEM\n",
 200                         __func__);
 201                 dev->net->stats.rx_dropped++;
 202                 return;
 203         }
 204
 205         skb_put_data(skb, buf, len);
 206         skb->dev = dev->net;
 207         skb->protocol = eth_type_trans(skb, dev->net);
 208
 209         dev->net->stats.rx_packets++;
 210         dev->net->stats.rx_bytes += len;
 211         dev->confirmed_pairing = true;
 212         netif_rx(skb);
 213         ipheth_rx_submit(dev, GFP_ATOMIC);
 214 }
 215
 216 static void ipheth_sndbulk_callback(struct urb *urb)
 217 {
 218         struct ipheth_device *dev;
 219         int status = urb->status;
 220
 221         dev = urb->context;
 222         if (dev == NULL)
 223                 return;
 224
 225         if (status != 0 &&
 226             status != -ENOENT &&
 227             status != -ECONNRESET &&
 228             status != -ESHUTDOWN)
 229                 dev_err(&dev->intf->dev, "%s: urb status: %d\n",
 230                 __func__, status);
 231
 232         if (status == 0)
 233                 netif_wake_queue(dev->net);
 234         else
 235                 // on URB error, trigger immediate poll
 236                 schedule_delayed_work(&dev->carrier_work, 0);
 237 }
 238
 239 static int ipheth_carrier_set(struct ipheth_device *dev)
 240 {
 241         struct usb_device *udev;
 242         int retval;
 243
 244         if (!dev->confirmed_pairing)
 245                 return 0;
 246
 247         udev = dev->udev;
 248         retval = usb_control_msg(udev,
 249                         usb_rcvctrlpipe(udev, IPHETH_CTRL_ENDP),
 250                         IPHETH_CMD_CARRIER_CHECK, /* request */
 251                         0xc0, /* request type */
 252                         0x00, /* value */
 253                         0x02, /* index */
 254                         dev->ctrl_buf, IPHETH_CTRL_BUF_SIZE,
 255                         IPHETH_CTRL_TIMEOUT);
 256         if (retval < 0) {
 257                 dev_err(&dev->intf->dev, "%s: usb_control_msg: %d\n",
 258                         __func__, retval);
 259                 return retval;
 260         }
 261
 262         if (dev->ctrl_buf[0] == IPHETH_CARRIER_ON) {
 263                 netif_carrier_on(dev->net);
 264                 if (dev->tx_urb->status != -EINPROGRESS)
 265                         netif_wake_queue(dev->net);
 266         } else {
 267                 netif_carrier_off(dev->net);
 268                 netif_stop_queue(dev->net);
 269         }
 270         return 0;
 271 }
 272
 273 static void ipheth_carrier_check_work(struct work_struct *work)
 274 {
 275         struct ipheth_device *dev = container_of(work, struct ipheth_device,
 276                                                  carrier_work.work);
 277
 278         ipheth_carrier_set(dev);
 279         schedule_delayed_work(&dev->carrier_work, IPHETH_CARRIER_CHECK_TIMEOUT);
 280 }
 281
 282 static int ipheth_get_macaddr(struct ipheth_device *dev)
 283 {
 284         struct usb_device *udev = dev->udev;
 285         struct net_device *net = dev->net;
 286         int retval;
 287
 288         retval = usb_control_msg(udev,
 289                                  usb_rcvctrlpipe(udev, IPHETH_CTRL_ENDP),
 290                                  IPHETH_CMD_GET_MACADDR, /* request */
 291                                  0xc0, /* request type */
 292                                  0x00, /* value */
 293                                  0x02, /* index */
 294                                  dev->ctrl_buf,
 295                                  IPHETH_CTRL_BUF_SIZE,
 296                                  IPHETH_CTRL_TIMEOUT);
 297         if (retval < 0) {
 298                 dev_err(&dev->intf->dev, "%s: usb_control_msg: %d\n",
 299                         __func__, retval);
 300         } else if (retval < ETH_ALEN) {
 301                 dev_err(&dev->intf->dev,
 302                         "%s: usb_control_msg: short packet: %d bytes\n",
 303                         __func__, retval);
 304                 retval = -EINVAL;
 305         } else {
 306                 eth_hw_addr_set(net, dev->ctrl_buf);
 307                 retval = 0;
 308         }
 309
 310         return retval;
 311 }
 312
 313 static int ipheth_rx_submit(struct ipheth_device *dev, gfp_t mem_flags)
 314 {
 315         struct usb_device *udev = dev->udev;
 316         int retval;
 317
 318         usb_fill_bulk_urb(dev->rx_urb, udev,
 319                           usb_rcvbulkpipe(udev, dev->bulk_in),
 320                           dev->rx_buf, IPHETH_BUF_SIZE,
 321                           ipheth_rcvbulk_callback,
 322                           dev);
 323         dev->rx_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 324
 325         retval = usb_submit_urb(dev->rx_urb, mem_flags);
 326         if (retval)
 327                 dev_err(&dev->intf->dev, "%s: usb_submit_urb: %d\n",
 328                         __func__, retval);
 329         return retval;
 330 }
 331
 332 static int ipheth_open(struct net_device *net)
 333 {
 334         struct ipheth_device *dev = netdev_priv(net);
 335         struct usb_device *udev = dev->udev;
 336         int retval = 0;
 337
 338         usb_set_interface(udev, IPHETH_INTFNUM, IPHETH_ALT_INTFNUM);
 339
 340         retval = ipheth_carrier_set(dev);
 341         if (retval)
 342                 return retval;
 343
 344         retval = ipheth_rx_submit(dev, GFP_KERNEL);
 345         if (retval)
 346                 return retval;
 347
 348         schedule_delayed_work(&dev->carrier_work, IPHETH_CARRIER_CHECK_TIMEOUT);
 349         return retval;
 350 }
 351
 352 static int ipheth_close(struct net_device *net)
 353 {
 354         struct ipheth_device *dev = netdev_priv(net);
 355
 356         cancel_delayed_work_sync(&dev->carrier_work);
 357         netif_stop_queue(net);
 358         return 0;
 359 }
 360
 361 static netdev_tx_t ipheth_tx(struct sk_buff *skb, struct net_device *net)
 362 {
 363         struct ipheth_device *dev = netdev_priv(net);
 364         struct usb_device *udev = dev->udev;
 365         int retval;
 366
 367         /* Paranoid */
 368         if (skb->len > IPHETH_BUF_SIZE) {
 369                 WARN(1, "%s: skb too large: %d bytes\n", __func__, skb->len);
 370                 dev->net->stats.tx_dropped++;
 371                 dev_kfree_skb_any(skb);
 372                 return NETDEV_TX_OK;
 373         }
 374
 375         memcpy(dev->tx_buf, skb->data, skb->len);
 376         if (skb->len < IPHETH_BUF_SIZE)
 377                 memset(dev->tx_buf + skb->len, 0, IPHETH_BUF_SIZE - skb->len);
 378
 379         usb_fill_bulk_urb(dev->tx_urb, udev,
 380                           usb_sndbulkpipe(udev, dev->bulk_out),
 381                           dev->tx_buf, IPHETH_BUF_SIZE,
 382                           ipheth_sndbulk_callback,
 383                           dev);
 384         dev->tx_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 385
 386         netif_stop_queue(net);
 387         retval = usb_submit_urb(dev->tx_urb, GFP_ATOMIC);
 388         if (retval) {
 389                 dev_err(&dev->intf->dev, "%s: usb_submit_urb: %d\n",
 390                         __func__, retval);
 391                 dev->net->stats.tx_errors++;
 392                 dev_kfree_skb_any(skb);
 393                 netif_wake_queue(net);
 394         } else {
 395                 dev->net->stats.tx_packets++;
 396                 dev->net->stats.tx_bytes += skb->len;
 397                 dev_consume_skb_any(skb);
 398         }
 399
 400         return NETDEV_TX_OK;
 401 }
 402
 403 static void ipheth_tx_timeout(struct net_device *net, unsigned int txqueue)
 404 {
 405         struct ipheth_device *dev = netdev_priv(net);
 406
 407         dev_err(&dev->intf->dev, "%s: TX timeout\n", __func__);
 408         dev->net->stats.tx_errors++;
 409         usb_unlink_urb(dev->tx_urb);
 410 }
 411
 412 static u32 ipheth_ethtool_op_get_link(struct net_device *net)
 413 {
 414         struct ipheth_device *dev = netdev_priv(net);
 415         return netif_carrier_ok(dev->net);
 416 }
 417
 418 static const struct ethtool_ops ops = {
 419         .get_link = ipheth_ethtool_op_get_link
 420 };
 421
 422 static const struct net_device_ops ipheth_netdev_ops = {
 423         .ndo_open = ipheth_open,
 424         .ndo_stop = ipheth_close,
 425         .ndo_start_xmit = ipheth_tx,
 426         .ndo_tx_timeout = ipheth_tx_timeout,
 427 };
 428
 429 static int ipheth_probe(struct usb_interface *intf,
 430                         const struct usb_device_id *id)
 431 {
 432         struct usb_device *udev = interface_to_usbdev(intf);
 433         struct usb_host_interface *hintf;
 434         struct usb_endpoint_descriptor *endp;
 435         struct ipheth_device *dev;
 436         struct net_device *netdev;
 437         int i;
 438         int retval;
 439
 440         netdev = alloc_etherdev(sizeof(struct ipheth_device));
 441         if (!netdev)
 442                 return -ENOMEM;
 443
 444         netdev->netdev_ops = &ipheth_netdev_ops;
 445         netdev->watchdog_timeo = IPHETH_TX_TIMEOUT;
 446         strscpy(netdev->name, "eth%d", sizeof(netdev->name));
 447
 448         dev = netdev_priv(netdev);
 449         dev->udev = udev;
 450         dev->net = netdev;
 451         dev->intf = intf;
 452         dev->confirmed_pairing = false;
 453         /* Set up endpoints */
 454         hintf = usb_altnum_to_altsetting(intf, IPHETH_ALT_INTFNUM);
 455         if (hintf == NULL) {
 456                 retval = -ENODEV;
 457                 dev_err(&intf->dev, "Unable to find alternate settings interface\n");
 458                 goto err_endpoints;
 459         }
 460
 461         for (i = 0; i < hintf->desc.bNumEndpoints; i++) {
 462                 endp = &hintf->endpoint[i].desc;
 463                 if (usb_endpoint_is_bulk_in(endp))
 464                         dev->bulk_in = endp->bEndpointAddress;
 465                 else if (usb_endpoint_is_bulk_out(endp))
 466                         dev->bulk_out = endp->bEndpointAddress;
 467         }
 468         if (!(dev->bulk_in && dev->bulk_out)) {
 469                 retval = -ENODEV;
 470                 dev_err(&intf->dev, "Unable to find endpoints\n");
 471                 goto err_endpoints;
 472         }
 473
 474         dev->ctrl_buf = kmalloc(IPHETH_CTRL_BUF_SIZE, GFP_KERNEL);
 475         if (dev->ctrl_buf == NULL) {
 476                 retval = -ENOMEM;
 477                 goto err_alloc_ctrl_buf;
 478         }
 479
 480         retval = ipheth_get_macaddr(dev);
 481         if (retval)
 482                 goto err_get_macaddr;
 483
 484         INIT_DELAYED_WORK(&dev->carrier_work, ipheth_carrier_check_work);
 485
 486         retval = ipheth_alloc_urbs(dev);
 487         if (retval) {
 488                 dev_err(&intf->dev, "error allocating urbs: %d\n", retval);
 489                 goto err_alloc_urbs;
 490         }
 491
 492         usb_set_intfdata(intf, dev);
 493
 494         SET_NETDEV_DEV(netdev, &intf->dev);
 495         netdev->ethtool_ops = &ops;
 496
 497         retval = register_netdev(netdev);
 498         if (retval) {
 499                 dev_err(&intf->dev, "error registering netdev: %d\n", retval);
 500                 retval = -EIO;
 501                 goto err_register_netdev;
 502         }
 503         // carrier down and transmit queues stopped until packet from device
 504         netif_carrier_off(netdev);
 505         netif_tx_stop_all_queues(netdev);
 506         dev_info(&intf->dev, "Apple iPhone USB Ethernet device attached\n");
 507         return 0;
 508
 509 err_register_netdev:
 510         ipheth_free_urbs(dev);
 511 err_alloc_urbs:
 512 err_get_macaddr:
 513 err_alloc_ctrl_buf:
 514         kfree(dev->ctrl_buf);
 515 err_endpoints:
 516         free_netdev(netdev);
 517         return retval;
 518 }
 519
 520 static void ipheth_disconnect(struct usb_interface *intf)
 521 {
 522         struct ipheth_device *dev;
 523
 524         dev = usb_get_intfdata(intf);
 525         if (dev != NULL) {
 526                 unregister_netdev(dev->net);
 527                 ipheth_kill_urbs(dev);
 528                 ipheth_free_urbs(dev);
 529                 kfree(dev->ctrl_buf);
 530                 free_netdev(dev->net);
 531         }
 532         usb_set_intfdata(intf, NULL);
 533         dev_info(&intf->dev, "Apple iPhone USB Ethernet now disconnected\n");
 534 }
 535
 536 static struct usb_driver ipheth_driver = {
 537         .name =         "ipheth",
 538         .probe =        ipheth_probe,
 539         .disconnect =   ipheth_disconnect,
 540         .id_table =     ipheth_table,
 541         .disable_hub_initiated_lpm = 1,
 542 };
 543
 544 module_usb_driver(ipheth_driver);
 545
 546 MODULE_AUTHOR("Diego Giagio <diego@giagio.com>");
 547 MODULE_DESCRIPTION("Apple iPhone USB Ethernet driver");
 548 MODULE_LICENSE("Dual BSD/GPL");