linux/drivers/net/usb/ipheth.c
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   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
  79static 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};
  85MODULE_DEVICE_TABLE(usb, ipheth_table);
  86
  87struct 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
 102static int ipheth_rx_submit(struct ipheth_device *dev, gfp_t mem_flags);
 103
 104static 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 + IPHETH_IP_ALIGN,
 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
 136free_tx_buf:
 137        usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, tx_buf,
 138                          tx_urb->transfer_dma);
 139free_rx_urb:
 140        usb_free_urb(rx_urb);
 141free_tx_urb:
 142        usb_free_urb(tx_urb);
 143error_nomem:
 144        return -ENOMEM;
 145}
 146
 147static void ipheth_free_urbs(struct ipheth_device *iphone)
 148{
 149        usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE + IPHETH_IP_ALIGN, 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
 157static 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
 163static 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
 216static 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
 239static 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
 273static 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
 282static 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
 313static 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 + IPHETH_IP_ALIGN,
 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
 332static 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
 352static 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
 361static 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
 403static 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
 412static 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
 418static const struct ethtool_ops ops = {
 419        .get_link = ipheth_ethtool_op_get_link
 420};
 421
 422static 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
 429static 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
 509err_register_netdev:
 510        ipheth_free_urbs(dev);
 511err_alloc_urbs:
 512err_get_macaddr:
 513err_alloc_ctrl_buf:
 514        kfree(dev->ctrl_buf);
 515err_endpoints:
 516        free_netdev(netdev);
 517        return retval;
 518}
 519
 520static 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
 536static 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
 544module_usb_driver(ipheth_driver);
 545
 546MODULE_AUTHOR("Diego Giagio <diego@giagio.com>");
 547MODULE_DESCRIPTION("Apple iPhone USB Ethernet driver");
 548MODULE_LICENSE("Dual BSD/GPL");
 549