drivers/net/usb/cdc-phonet.c

   1 /*
   2  * phonet.c -- USB CDC Phonet host driver
   3  *
   4  * Copyright (C) 2008-2009 Nokia Corporation. All rights reserved.
   5  *
   6  * Author: Rémi Denis-Courmont
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  20  * 02110-1301 USA
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/mm.h>
  25 #include <linux/module.h>
  26 #include <linux/gfp.h>
  27 #include <linux/usb.h>
  28 #include <linux/usb/cdc.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/if_arp.h>
  31 #include <linux/if_phonet.h>
  32 #include <linux/phonet.h>
  33
  34 #define PN_MEDIA_USB    0x1B
  35
  36 static const unsigned rxq_size = 17;
  37
  38 struct usbpn_dev {
  39         struct net_device       *dev;
  40
  41         struct usb_interface    *intf, *data_intf;
  42         struct usb_device       *usb;
  43         unsigned int            tx_pipe, rx_pipe;
  44         u8 active_setting;
  45         u8 disconnected;
  46
  47         unsigned                tx_queue;
  48         spinlock_t              tx_lock;
  49
  50         spinlock_t              rx_lock;
  51         struct sk_buff          *rx_skb;
  52         struct urb              *urbs[0];
  53 };
  54
  55 static void tx_complete(struct urb *req);
  56 static void rx_complete(struct urb *req);
  57
  58 /*
  59  * Network device callbacks
  60  */
  61 static netdev_tx_t usbpn_xmit(struct sk_buff *skb, struct net_device *dev)
  62 {
  63         struct usbpn_dev *pnd = netdev_priv(dev);
  64         struct urb *req = NULL;
  65         unsigned long flags;
  66         int err;
  67
  68         if (skb->protocol != htons(ETH_P_PHONET))
  69                 goto drop;
  70
  71         req = usb_alloc_urb(0, GFP_ATOMIC);
  72         if (!req)
  73                 goto drop;
  74         usb_fill_bulk_urb(req, pnd->usb, pnd->tx_pipe, skb->data, skb->len,
  75                                 tx_complete, skb);
  76         req->transfer_flags = URB_ZERO_PACKET;
  77         err = usb_submit_urb(req, GFP_ATOMIC);
  78         if (err) {
  79                 usb_free_urb(req);
  80                 goto drop;
  81         }
  82
  83         spin_lock_irqsave(&pnd->tx_lock, flags);
  84         pnd->tx_queue++;
  85         if (pnd->tx_queue >= dev->tx_queue_len)
  86                 netif_stop_queue(dev);
  87         spin_unlock_irqrestore(&pnd->tx_lock, flags);
  88         return NETDEV_TX_OK;
  89
  90 drop:
  91         dev_kfree_skb(skb);
  92         dev->stats.tx_dropped++;
  93         return NETDEV_TX_OK;
  94 }
  95
  96 static void tx_complete(struct urb *req)
  97 {
  98         struct sk_buff *skb = req->context;
  99         struct net_device *dev = skb->dev;
 100         struct usbpn_dev *pnd = netdev_priv(dev);
 101         int status = req->status;
 102
 103         switch (status) {
 104         case 0:
 105                 dev->stats.tx_bytes += skb->len;
 106                 break;
 107
 108         case -ENOENT:
 109         case -ECONNRESET:
 110         case -ESHUTDOWN:
 111                 dev->stats.tx_aborted_errors++;
 112         default:
 113                 dev->stats.tx_errors++;
 114                 dev_dbg(&dev->dev, "TX error (%d)\n", status);
 115         }
 116         dev->stats.tx_packets++;
 117
 118         spin_lock(&pnd->tx_lock);
 119         pnd->tx_queue--;
 120         netif_wake_queue(dev);
 121         spin_unlock(&pnd->tx_lock);
 122
 123         dev_kfree_skb_any(skb);
 124         usb_free_urb(req);
 125 }
 126
 127 static int rx_submit(struct usbpn_dev *pnd, struct urb *req, gfp_t gfp_flags)
 128 {
 129         struct net_device *dev = pnd->dev;
 130         struct page *page;
 131         int err;
 132
 133         page = alloc_page(gfp_flags);
 134         if (!page)
 135                 return -ENOMEM;
 136
 137         usb_fill_bulk_urb(req, pnd->usb, pnd->rx_pipe, page_address(page),
 138                                 PAGE_SIZE, rx_complete, dev);
 139         req->transfer_flags = 0;
 140         err = usb_submit_urb(req, gfp_flags);
 141         if (unlikely(err)) {
 142                 dev_dbg(&dev->dev, "RX submit error (%d)\n", err);
 143                 put_page(page);
 144         }
 145         return err;
 146 }
 147
 148 static void rx_complete(struct urb *req)
 149 {
 150         struct net_device *dev = req->context;
 151         struct usbpn_dev *pnd = netdev_priv(dev);
 152         struct page *page = virt_to_page(req->transfer_buffer);
 153         struct sk_buff *skb;
 154         unsigned long flags;
 155         int status = req->status;
 156
 157         switch (status) {
 158         case 0:
 159                 spin_lock_irqsave(&pnd->rx_lock, flags);
 160                 skb = pnd->rx_skb;
 161                 if (!skb) {
 162                         skb = pnd->rx_skb = netdev_alloc_skb(dev, 12);
 163                         if (likely(skb)) {
 164                                 /* Can't use pskb_pull() on page in IRQ */
 165                                 memcpy(skb_put(skb, 1), page_address(page), 1);
 166                                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
 167                                                 page, 1, req->actual_length,
 168                                                 req->actual_length);
 169                                 page = NULL;
 170                         }
 171                 } else {
 172                         skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
 173                                         page, 0, req->actual_length,
 174                                         req->actual_length);
 175                         page = NULL;
 176                 }
 177                 if (req->actual_length < PAGE_SIZE)
 178                         pnd->rx_skb = NULL; /* Last fragment */
 179                 else
 180                         skb = NULL;
 181                 spin_unlock_irqrestore(&pnd->rx_lock, flags);
 182                 if (skb) {
 183                         skb->protocol = htons(ETH_P_PHONET);
 184                         skb_reset_mac_header(skb);
 185                         __skb_pull(skb, 1);
 186                         skb->dev = dev;
 187                         dev->stats.rx_packets++;
 188                         dev->stats.rx_bytes += skb->len;
 189
 190                         netif_rx(skb);
 191                 }
 192                 goto resubmit;
 193
 194         case -ENOENT:
 195         case -ECONNRESET:
 196         case -ESHUTDOWN:
 197                 req = NULL;
 198                 break;
 199
 200         case -EOVERFLOW:
 201                 dev->stats.rx_over_errors++;
 202                 dev_dbg(&dev->dev, "RX overflow\n");
 203                 break;
 204
 205         case -EILSEQ:
 206                 dev->stats.rx_crc_errors++;
 207                 break;
 208         }
 209
 210         dev->stats.rx_errors++;
 211 resubmit:
 212         if (page)
 213                 put_page(page);
 214         if (req)
 215                 rx_submit(pnd, req, GFP_ATOMIC | __GFP_COLD);
 216 }
 217
 218 static int usbpn_close(struct net_device *dev);
 219
 220 static int usbpn_open(struct net_device *dev)
 221 {
 222         struct usbpn_dev *pnd = netdev_priv(dev);
 223         int err;
 224         unsigned i;
 225         unsigned num = pnd->data_intf->cur_altsetting->desc.bInterfaceNumber;
 226
 227         err = usb_set_interface(pnd->usb, num, pnd->active_setting);
 228         if (err)
 229                 return err;
 230
 231         for (i = 0; i < rxq_size; i++) {
 232                 struct urb *req = usb_alloc_urb(0, GFP_KERNEL);
 233
 234                 if (!req || rx_submit(pnd, req, GFP_KERNEL | __GFP_COLD)) {
 235                         usbpn_close(dev);
 236                         return -ENOMEM;
 237                 }
 238                 pnd->urbs[i] = req;
 239         }
 240
 241         netif_wake_queue(dev);
 242         return 0;
 243 }
 244
 245 static int usbpn_close(struct net_device *dev)
 246 {
 247         struct usbpn_dev *pnd = netdev_priv(dev);
 248         unsigned i;
 249         unsigned num = pnd->data_intf->cur_altsetting->desc.bInterfaceNumber;
 250
 251         netif_stop_queue(dev);
 252
 253         for (i = 0; i < rxq_size; i++) {
 254                 struct urb *req = pnd->urbs[i];
 255
 256                 if (!req)
 257                         continue;
 258                 usb_kill_urb(req);
 259                 usb_free_urb(req);
 260                 pnd->urbs[i] = NULL;
 261         }
 262
 263         return usb_set_interface(pnd->usb, num, !pnd->active_setting);
 264 }
 265
 266 static int usbpn_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 267 {
 268         struct if_phonet_req *req = (struct if_phonet_req *)ifr;
 269
 270         switch (cmd) {
 271         case SIOCPNGAUTOCONF:
 272                 req->ifr_phonet_autoconf.device = PN_DEV_PC;
 273                 return 0;
 274         }
 275         return -ENOIOCTLCMD;
 276 }
 277
 278 static int usbpn_set_mtu(struct net_device *dev, int new_mtu)
 279 {
 280         if ((new_mtu < PHONET_MIN_MTU) || (new_mtu > PHONET_MAX_MTU))
 281                 return -EINVAL;
 282
 283         dev->mtu = new_mtu;
 284         return 0;
 285 }
 286
 287 static const struct net_device_ops usbpn_ops = {
 288         .ndo_open       = usbpn_open,
 289         .ndo_stop       = usbpn_close,
 290         .ndo_start_xmit = usbpn_xmit,
 291         .ndo_do_ioctl   = usbpn_ioctl,
 292         .ndo_change_mtu = usbpn_set_mtu,
 293 };
 294
 295 static void usbpn_setup(struct net_device *dev)
 296 {
 297         dev->features           = 0;
 298         dev->netdev_ops         = &usbpn_ops,
 299         dev->header_ops         = &phonet_header_ops;
 300         dev->type               = ARPHRD_PHONET;
 301         dev->flags              = IFF_POINTOPOINT | IFF_NOARP;
 302         dev->mtu                = PHONET_MAX_MTU;
 303         dev->hard_header_len    = 1;
 304         dev->dev_addr[0]        = PN_MEDIA_USB;
 305         dev->addr_len           = 1;
 306         dev->tx_queue_len       = 3;
 307
 308         dev->destructor         = free_netdev;
 309 }
 310
 311 /*
 312  * USB driver callbacks
 313  */
 314 static struct usb_device_id usbpn_ids[] = {
 315         {
 316                 .match_flags = USB_DEVICE_ID_MATCH_VENDOR
 317                         | USB_DEVICE_ID_MATCH_INT_CLASS
 318                         | USB_DEVICE_ID_MATCH_INT_SUBCLASS,
 319                 .idVendor = 0x0421, /* Nokia */
 320                 .bInterfaceClass = USB_CLASS_COMM,
 321                 .bInterfaceSubClass = 0xFE,
 322         },
 323         { },
 324 };
 325
 326 MODULE_DEVICE_TABLE(usb, usbpn_ids);
 327
 328 static struct usb_driver usbpn_driver;
 329
 330 int usbpn_probe(struct usb_interface *intf, const struct usb_device_id *id)
 331 {
 332         static const char ifname[] = "usbpn%d";
 333         const struct usb_cdc_union_desc *union_header = NULL;
 334         const struct usb_host_interface *data_desc;
 335         struct usb_interface *data_intf;
 336         struct usb_device *usbdev = interface_to_usbdev(intf);
 337         struct net_device *dev;
 338         struct usbpn_dev *pnd;
 339         u8 *data;
 340         int phonet = 0;
 341         int len, err;
 342
 343         data = intf->altsetting->extra;
 344         len = intf->altsetting->extralen;
 345         while (len >= 3) {
 346                 u8 dlen = data[0];
 347                 if (dlen < 3)
 348                         return -EINVAL;
 349
 350                 /* bDescriptorType */
 351                 if (data[1] == USB_DT_CS_INTERFACE) {
 352                         /* bDescriptorSubType */
 353                         switch (data[2]) {
 354                         case USB_CDC_UNION_TYPE:
 355                                 if (union_header || dlen < 5)
 356                                         break;
 357                                 union_header =
 358                                         (struct usb_cdc_union_desc *)data;
 359                                 break;
 360                         case 0xAB:
 361                                 phonet = 1;
 362                                 break;
 363                         }
 364                 }
 365                 data += dlen;
 366                 len -= dlen;
 367         }
 368
 369         if (!union_header || !phonet)
 370                 return -EINVAL;
 371
 372         data_intf = usb_ifnum_to_if(usbdev, union_header->bSlaveInterface0);
 373         if (data_intf == NULL)
 374                 return -ENODEV;
 375         /* Data interface has one inactive and one active setting */
 376         if (data_intf->num_altsetting != 2)
 377                 return -EINVAL;
 378         if (data_intf->altsetting[0].desc.bNumEndpoints == 0 &&
 379             data_intf->altsetting[1].desc.bNumEndpoints == 2)
 380                 data_desc = data_intf->altsetting + 1;
 381         else
 382         if (data_intf->altsetting[0].desc.bNumEndpoints == 2 &&
 383             data_intf->altsetting[1].desc.bNumEndpoints == 0)
 384                 data_desc = data_intf->altsetting;
 385         else
 386                 return -EINVAL;
 387
 388         dev = alloc_netdev(sizeof(*pnd) + sizeof(pnd->urbs[0]) * rxq_size,
 389                                 ifname, usbpn_setup);
 390         if (!dev)
 391                 return -ENOMEM;
 392
 393         pnd = netdev_priv(dev);
 394         SET_NETDEV_DEV(dev, &intf->dev);
 395
 396         pnd->dev = dev;
 397         pnd->usb = usb_get_dev(usbdev);
 398         pnd->intf = intf;
 399         pnd->data_intf = data_intf;
 400         spin_lock_init(&pnd->tx_lock);
 401         spin_lock_init(&pnd->rx_lock);
 402         /* Endpoints */
 403         if (usb_pipein(data_desc->endpoint[0].desc.bEndpointAddress)) {
 404                 pnd->rx_pipe = usb_rcvbulkpipe(usbdev,
 405                         data_desc->endpoint[0].desc.bEndpointAddress);
 406                 pnd->tx_pipe = usb_sndbulkpipe(usbdev,
 407                         data_desc->endpoint[1].desc.bEndpointAddress);
 408         } else {
 409                 pnd->rx_pipe = usb_rcvbulkpipe(usbdev,
 410                         data_desc->endpoint[1].desc.bEndpointAddress);
 411                 pnd->tx_pipe = usb_sndbulkpipe(usbdev,
 412                         data_desc->endpoint[0].desc.bEndpointAddress);
 413         }
 414         pnd->active_setting = data_desc - data_intf->altsetting;
 415
 416         err = usb_driver_claim_interface(&usbpn_driver, data_intf, pnd);
 417         if (err)
 418                 goto out;
 419
 420         /* Force inactive mode until the network device is brought UP */
 421         usb_set_interface(usbdev, union_header->bSlaveInterface0,
 422                                 !pnd->active_setting);
 423         usb_set_intfdata(intf, pnd);
 424
 425         err = register_netdev(dev);
 426         if (err) {
 427                 usb_driver_release_interface(&usbpn_driver, data_intf);
 428                 goto out;
 429         }
 430
 431         dev_dbg(&dev->dev, "USB CDC Phonet device found\n");
 432         return 0;
 433
 434 out:
 435         usb_set_intfdata(intf, NULL);
 436         free_netdev(dev);
 437         return err;
 438 }
 439
 440 static void usbpn_disconnect(struct usb_interface *intf)
 441 {
 442         struct usbpn_dev *pnd = usb_get_intfdata(intf);
 443         struct usb_device *usb = pnd->usb;
 444
 445         if (pnd->disconnected)
 446                 return;
 447
 448         pnd->disconnected = 1;
 449         usb_driver_release_interface(&usbpn_driver,
 450                         (pnd->intf == intf) ? pnd->data_intf : pnd->intf);
 451         unregister_netdev(pnd->dev);
 452         usb_put_dev(usb);
 453 }
 454
 455 static struct usb_driver usbpn_driver = {
 456         .name =         "cdc_phonet",
 457         .probe =        usbpn_probe,
 458         .disconnect =   usbpn_disconnect,
 459         .id_table =     usbpn_ids,
 460 };
 461
 462 module_usb_driver(usbpn_driver);
 463
 464 MODULE_AUTHOR("Remi Denis-Courmont");
 465 MODULE_DESCRIPTION("USB CDC Phonet host interface");
 466 MODULE_LICENSE("GPL");