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         unsigned long flags;
 103
 104         switch (status) {
 105         case 0:
 106                 dev->stats.tx_bytes += skb->len;
 107                 break;
 108
 109         case -ENOENT:
 110         case -ECONNRESET:
 111         case -ESHUTDOWN:
 112                 dev->stats.tx_aborted_errors++;
 113                 /* fall through */
 114         default:
 115                 dev->stats.tx_errors++;
 116                 dev_dbg(&dev->dev, "TX error (%d)\n", status);
 117         }
 118         dev->stats.tx_packets++;
 119
 120         spin_lock_irqsave(&pnd->tx_lock, flags);
 121         pnd->tx_queue--;
 122         netif_wake_queue(dev);
 123         spin_unlock_irqrestore(&pnd->tx_lock, flags);
 124
 125         dev_kfree_skb_any(skb);
 126         usb_free_urb(req);
 127 }
 128
 129 static int rx_submit(struct usbpn_dev *pnd, struct urb *req, gfp_t gfp_flags)
 130 {
 131         struct net_device *dev = pnd->dev;
 132         struct page *page;
 133         int err;
 134
 135         page = __dev_alloc_page(gfp_flags | __GFP_NOMEMALLOC);
 136         if (!page)
 137                 return -ENOMEM;
 138
 139         usb_fill_bulk_urb(req, pnd->usb, pnd->rx_pipe, page_address(page),
 140                                 PAGE_SIZE, rx_complete, dev);
 141         req->transfer_flags = 0;
 142         err = usb_submit_urb(req, gfp_flags);
 143         if (unlikely(err)) {
 144                 dev_dbg(&dev->dev, "RX submit error (%d)\n", err);
 145                 put_page(page);
 146         }
 147         return err;
 148 }
 149
 150 static void rx_complete(struct urb *req)
 151 {
 152         struct net_device *dev = req->context;
 153         struct usbpn_dev *pnd = netdev_priv(dev);
 154         struct page *page = virt_to_page(req->transfer_buffer);
 155         struct sk_buff *skb;
 156         unsigned long flags;
 157         int status = req->status;
 158
 159         switch (status) {
 160         case 0:
 161                 spin_lock_irqsave(&pnd->rx_lock, flags);
 162                 skb = pnd->rx_skb;
 163                 if (!skb) {
 164                         skb = pnd->rx_skb = netdev_alloc_skb(dev, 12);
 165                         if (likely(skb)) {
 166                                 /* Can't use pskb_pull() on page in IRQ */
 167                                 skb_put_data(skb, page_address(page), 1);
 168                                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
 169                                                 page, 1, req->actual_length,
 170                                                 PAGE_SIZE);
 171                                 page = NULL;
 172                         }
 173                 } else {
 174                         skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
 175                                         page, 0, req->actual_length,
 176                                         PAGE_SIZE);
 177                         page = NULL;
 178                 }
 179                 if (req->actual_length < PAGE_SIZE)
 180                         pnd->rx_skb = NULL; /* Last fragment */
 181                 else
 182                         skb = NULL;
 183                 spin_unlock_irqrestore(&pnd->rx_lock, flags);
 184                 if (skb) {
 185                         skb->protocol = htons(ETH_P_PHONET);
 186                         skb_reset_mac_header(skb);
 187                         __skb_pull(skb, 1);
 188                         skb->dev = dev;
 189                         dev->stats.rx_packets++;
 190                         dev->stats.rx_bytes += skb->len;
 191
 192                         netif_rx(skb);
 193                 }
 194                 goto resubmit;
 195
 196         case -ENOENT:
 197         case -ECONNRESET:
 198         case -ESHUTDOWN:
 199                 req = NULL;
 200                 break;
 201
 202         case -EOVERFLOW:
 203                 dev->stats.rx_over_errors++;
 204                 dev_dbg(&dev->dev, "RX overflow\n");
 205                 break;
 206
 207         case -EILSEQ:
 208                 dev->stats.rx_crc_errors++;
 209                 break;
 210         }
 211
 212         dev->stats.rx_errors++;
 213 resubmit:
 214         if (page)
 215                 put_page(page);
 216         if (req)
 217                 rx_submit(pnd, req, GFP_ATOMIC);
 218 }
 219
 220 static int usbpn_close(struct net_device *dev);
 221
 222 static int usbpn_open(struct net_device *dev)
 223 {
 224         struct usbpn_dev *pnd = netdev_priv(dev);
 225         int err;
 226         unsigned i;
 227         unsigned num = pnd->data_intf->cur_altsetting->desc.bInterfaceNumber;
 228
 229         err = usb_set_interface(pnd->usb, num, pnd->active_setting);
 230         if (err)
 231                 return err;
 232
 233         for (i = 0; i < rxq_size; i++) {
 234                 struct urb *req = usb_alloc_urb(0, GFP_KERNEL);
 235
 236                 if (!req || rx_submit(pnd, req, GFP_KERNEL)) {
 237                         usb_free_urb(req);
 238                         usbpn_close(dev);
 239                         return -ENOMEM;
 240                 }
 241                 pnd->urbs[i] = req;
 242         }
 243
 244         netif_wake_queue(dev);
 245         return 0;
 246 }
 247
 248 static int usbpn_close(struct net_device *dev)
 249 {
 250         struct usbpn_dev *pnd = netdev_priv(dev);
 251         unsigned i;
 252         unsigned num = pnd->data_intf->cur_altsetting->desc.bInterfaceNumber;
 253
 254         netif_stop_queue(dev);
 255
 256         for (i = 0; i < rxq_size; i++) {
 257                 struct urb *req = pnd->urbs[i];
 258
 259                 if (!req)
 260                         continue;
 261                 usb_kill_urb(req);
 262                 usb_free_urb(req);
 263                 pnd->urbs[i] = NULL;
 264         }
 265
 266         return usb_set_interface(pnd->usb, num, !pnd->active_setting);
 267 }
 268
 269 static int usbpn_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 270 {
 271         struct if_phonet_req *req = (struct if_phonet_req *)ifr;
 272
 273         switch (cmd) {
 274         case SIOCPNGAUTOCONF:
 275                 req->ifr_phonet_autoconf.device = PN_DEV_PC;
 276                 return 0;
 277         }
 278         return -ENOIOCTLCMD;
 279 }
 280
 281 static const struct net_device_ops usbpn_ops = {
 282         .ndo_open       = usbpn_open,
 283         .ndo_stop       = usbpn_close,
 284         .ndo_start_xmit = usbpn_xmit,
 285         .ndo_do_ioctl   = usbpn_ioctl,
 286 };
 287
 288 static void usbpn_setup(struct net_device *dev)
 289 {
 290         dev->features           = 0;
 291         dev->netdev_ops         = &usbpn_ops,
 292         dev->header_ops         = &phonet_header_ops;
 293         dev->type               = ARPHRD_PHONET;
 294         dev->flags              = IFF_POINTOPOINT | IFF_NOARP;
 295         dev->mtu                = PHONET_MAX_MTU;
 296         dev->min_mtu            = PHONET_MIN_MTU;
 297         dev->max_mtu            = PHONET_MAX_MTU;
 298         dev->hard_header_len    = 1;
 299         dev->dev_addr[0]        = PN_MEDIA_USB;
 300         dev->addr_len           = 1;
 301         dev->tx_queue_len       = 3;
 302
 303         dev->needs_free_netdev  = true;
 304 }
 305
 306 /*
 307  * USB driver callbacks
 308  */
 309 static const struct usb_device_id usbpn_ids[] = {
 310         {
 311                 .match_flags = USB_DEVICE_ID_MATCH_VENDOR
 312                         | USB_DEVICE_ID_MATCH_INT_CLASS
 313                         | USB_DEVICE_ID_MATCH_INT_SUBCLASS,
 314                 .idVendor = 0x0421, /* Nokia */
 315                 .bInterfaceClass = USB_CLASS_COMM,
 316                 .bInterfaceSubClass = 0xFE,
 317         },
 318         { },
 319 };
 320
 321 MODULE_DEVICE_TABLE(usb, usbpn_ids);
 322
 323 static struct usb_driver usbpn_driver;
 324
 325 static int usbpn_probe(struct usb_interface *intf, const struct usb_device_id *id)
 326 {
 327         static const char ifname[] = "usbpn%d";
 328         const struct usb_cdc_union_desc *union_header = NULL;
 329         const struct usb_host_interface *data_desc;
 330         struct usb_interface *data_intf;
 331         struct usb_device *usbdev = interface_to_usbdev(intf);
 332         struct net_device *dev;
 333         struct usbpn_dev *pnd;
 334         u8 *data;
 335         int phonet = 0;
 336         int len, err;
 337         struct usb_cdc_parsed_header hdr;
 338
 339         data = intf->altsetting->extra;
 340         len = intf->altsetting->extralen;
 341         cdc_parse_cdc_header(&hdr, intf, data, len);
 342         union_header = hdr.usb_cdc_union_desc;
 343         phonet = hdr.phonet_magic_present;
 344
 345         if (!union_header || !phonet)
 346                 return -EINVAL;
 347
 348         data_intf = usb_ifnum_to_if(usbdev, union_header->bSlaveInterface0);
 349         if (data_intf == NULL)
 350                 return -ENODEV;
 351         /* Data interface has one inactive and one active setting */
 352         if (data_intf->num_altsetting != 2)
 353                 return -EINVAL;
 354         if (data_intf->altsetting[0].desc.bNumEndpoints == 0 &&
 355             data_intf->altsetting[1].desc.bNumEndpoints == 2)
 356                 data_desc = data_intf->altsetting + 1;
 357         else
 358         if (data_intf->altsetting[0].desc.bNumEndpoints == 2 &&
 359             data_intf->altsetting[1].desc.bNumEndpoints == 0)
 360                 data_desc = data_intf->altsetting;
 361         else
 362                 return -EINVAL;
 363
 364         dev = alloc_netdev(sizeof(*pnd) + sizeof(pnd->urbs[0]) * rxq_size,
 365                            ifname, NET_NAME_UNKNOWN, usbpn_setup);
 366         if (!dev)
 367                 return -ENOMEM;
 368
 369         pnd = netdev_priv(dev);
 370         SET_NETDEV_DEV(dev, &intf->dev);
 371
 372         pnd->dev = dev;
 373         pnd->usb = usbdev;
 374         pnd->intf = intf;
 375         pnd->data_intf = data_intf;
 376         spin_lock_init(&pnd->tx_lock);
 377         spin_lock_init(&pnd->rx_lock);
 378         /* Endpoints */
 379         if (usb_pipein(data_desc->endpoint[0].desc.bEndpointAddress)) {
 380                 pnd->rx_pipe = usb_rcvbulkpipe(usbdev,
 381                         data_desc->endpoint[0].desc.bEndpointAddress);
 382                 pnd->tx_pipe = usb_sndbulkpipe(usbdev,
 383                         data_desc->endpoint[1].desc.bEndpointAddress);
 384         } else {
 385                 pnd->rx_pipe = usb_rcvbulkpipe(usbdev,
 386                         data_desc->endpoint[1].desc.bEndpointAddress);
 387                 pnd->tx_pipe = usb_sndbulkpipe(usbdev,
 388                         data_desc->endpoint[0].desc.bEndpointAddress);
 389         }
 390         pnd->active_setting = data_desc - data_intf->altsetting;
 391
 392         err = usb_driver_claim_interface(&usbpn_driver, data_intf, pnd);
 393         if (err)
 394                 goto out;
 395
 396         /* Force inactive mode until the network device is brought UP */
 397         usb_set_interface(usbdev, union_header->bSlaveInterface0,
 398                                 !pnd->active_setting);
 399         usb_set_intfdata(intf, pnd);
 400
 401         err = register_netdev(dev);
 402         if (err) {
 403                 usb_driver_release_interface(&usbpn_driver, data_intf);
 404                 goto out;
 405         }
 406
 407         dev_dbg(&dev->dev, "USB CDC Phonet device found\n");
 408         return 0;
 409
 410 out:
 411         usb_set_intfdata(intf, NULL);
 412         free_netdev(dev);
 413         return err;
 414 }
 415
 416 static void usbpn_disconnect(struct usb_interface *intf)
 417 {
 418         struct usbpn_dev *pnd = usb_get_intfdata(intf);
 419
 420         if (pnd->disconnected)
 421                 return;
 422
 423         pnd->disconnected = 1;
 424         usb_driver_release_interface(&usbpn_driver,
 425                         (pnd->intf == intf) ? pnd->data_intf : pnd->intf);
 426         unregister_netdev(pnd->dev);
 427 }
 428
 429 static struct usb_driver usbpn_driver = {
 430         .name =         "cdc_phonet",
 431         .probe =        usbpn_probe,
 432         .disconnect =   usbpn_disconnect,
 433         .id_table =     usbpn_ids,
 434         .disable_hub_initiated_lpm = 1,
 435 };
 436
 437 module_usb_driver(usbpn_driver);
 438
 439 MODULE_AUTHOR("Remi Denis-Courmont");
 440 MODULE_DESCRIPTION("USB CDC Phonet host interface");
 441 MODULE_LICENSE("GPL");