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