drivers/usb/gadget/f_phonet.c

   1 /*
   2  * f_phonet.c -- USB CDC Phonet function
   3  *
   4  * Copyright (C) 2007-2008 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/mm.h>
  24 #include <linux/slab.h>
  25 #include <linux/kernel.h>
  26 #include <linux/device.h>
  27
  28 #include <linux/netdevice.h>
  29 #include <linux/if_ether.h>
  30 #include <linux/if_phonet.h>
  31 #include <linux/if_arp.h>
  32
  33 #include <linux/usb/ch9.h>
  34 #include <linux/usb/cdc.h>
  35 #include <linux/usb/composite.h>
  36
  37 #include "u_phonet.h"
  38
  39 #define PN_MEDIA_USB    0x1B
  40 #define MAXPACKET       512
  41 #if (PAGE_SIZE % MAXPACKET)
  42 #error MAXPACKET must divide PAGE_SIZE!
  43 #endif
  44
  45 /*-------------------------------------------------------------------------*/
  46
  47 struct phonet_port {
  48         struct f_phonet                 *usb;
  49         spinlock_t                      lock;
  50 };
  51
  52 struct f_phonet {
  53         struct usb_function             function;
  54         struct {
  55                 struct sk_buff          *skb;
  56                 spinlock_t              lock;
  57         } rx;
  58         struct net_device               *dev;
  59         struct usb_ep                   *in_ep, *out_ep;
  60
  61         struct usb_request              *in_req;
  62         struct usb_request              *out_reqv[0];
  63 };
  64
  65 static int phonet_rxq_size = 17;
  66
  67 static inline struct f_phonet *func_to_pn(struct usb_function *f)
  68 {
  69         return container_of(f, struct f_phonet, function);
  70 }
  71
  72 /*-------------------------------------------------------------------------*/
  73
  74 #define USB_CDC_SUBCLASS_PHONET 0xfe
  75 #define USB_CDC_PHONET_TYPE     0xab
  76
  77 static struct usb_interface_descriptor
  78 pn_control_intf_desc = {
  79         .bLength =              sizeof pn_control_intf_desc,
  80         .bDescriptorType =      USB_DT_INTERFACE,
  81
  82         /* .bInterfaceNumber =  DYNAMIC, */
  83         .bInterfaceClass =      USB_CLASS_COMM,
  84         .bInterfaceSubClass =   USB_CDC_SUBCLASS_PHONET,
  85 };
  86
  87 static const struct usb_cdc_header_desc
  88 pn_header_desc = {
  89         .bLength =              sizeof pn_header_desc,
  90         .bDescriptorType =      USB_DT_CS_INTERFACE,
  91         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
  92         .bcdCDC =               cpu_to_le16(0x0110),
  93 };
  94
  95 static const struct usb_cdc_header_desc
  96 pn_phonet_desc = {
  97         .bLength =              sizeof pn_phonet_desc,
  98         .bDescriptorType =      USB_DT_CS_INTERFACE,
  99         .bDescriptorSubType =   USB_CDC_PHONET_TYPE,
 100         .bcdCDC =               cpu_to_le16(0x1505), /* ??? */
 101 };
 102
 103 static struct usb_cdc_union_desc
 104 pn_union_desc = {
 105         .bLength =              sizeof pn_union_desc,
 106         .bDescriptorType =      USB_DT_CS_INTERFACE,
 107         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 108
 109         /* .bMasterInterface0 = DYNAMIC, */
 110         /* .bSlaveInterface0 =  DYNAMIC, */
 111 };
 112
 113 static struct usb_interface_descriptor
 114 pn_data_nop_intf_desc = {
 115         .bLength =              sizeof pn_data_nop_intf_desc,
 116         .bDescriptorType =      USB_DT_INTERFACE,
 117
 118         /* .bInterfaceNumber =  DYNAMIC, */
 119         .bAlternateSetting =    0,
 120         .bNumEndpoints =        0,
 121         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 122 };
 123
 124 static struct usb_interface_descriptor
 125 pn_data_intf_desc = {
 126         .bLength =              sizeof pn_data_intf_desc,
 127         .bDescriptorType =      USB_DT_INTERFACE,
 128
 129         /* .bInterfaceNumber =  DYNAMIC, */
 130         .bAlternateSetting =    1,
 131         .bNumEndpoints =        2,
 132         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 133 };
 134
 135 static struct usb_endpoint_descriptor
 136 pn_fs_sink_desc = {
 137         .bLength =              USB_DT_ENDPOINT_SIZE,
 138         .bDescriptorType =      USB_DT_ENDPOINT,
 139
 140         .bEndpointAddress =     USB_DIR_OUT,
 141         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 142 };
 143
 144 static struct usb_endpoint_descriptor
 145 pn_hs_sink_desc = {
 146         .bLength =              USB_DT_ENDPOINT_SIZE,
 147         .bDescriptorType =      USB_DT_ENDPOINT,
 148
 149         .bEndpointAddress =     USB_DIR_OUT,
 150         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 151         .wMaxPacketSize =       cpu_to_le16(MAXPACKET),
 152 };
 153
 154 static struct usb_endpoint_descriptor
 155 pn_fs_source_desc = {
 156         .bLength =              USB_DT_ENDPOINT_SIZE,
 157         .bDescriptorType =      USB_DT_ENDPOINT,
 158
 159         .bEndpointAddress =     USB_DIR_IN,
 160         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 161 };
 162
 163 static struct usb_endpoint_descriptor
 164 pn_hs_source_desc = {
 165         .bLength =              USB_DT_ENDPOINT_SIZE,
 166         .bDescriptorType =      USB_DT_ENDPOINT,
 167
 168         .bEndpointAddress =     USB_DIR_IN,
 169         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 170         .wMaxPacketSize =       cpu_to_le16(512),
 171 };
 172
 173 static struct usb_descriptor_header *fs_pn_function[] = {
 174         (struct usb_descriptor_header *) &pn_control_intf_desc,
 175         (struct usb_descriptor_header *) &pn_header_desc,
 176         (struct usb_descriptor_header *) &pn_phonet_desc,
 177         (struct usb_descriptor_header *) &pn_union_desc,
 178         (struct usb_descriptor_header *) &pn_data_nop_intf_desc,
 179         (struct usb_descriptor_header *) &pn_data_intf_desc,
 180         (struct usb_descriptor_header *) &pn_fs_sink_desc,
 181         (struct usb_descriptor_header *) &pn_fs_source_desc,
 182         NULL,
 183 };
 184
 185 static struct usb_descriptor_header *hs_pn_function[] = {
 186         (struct usb_descriptor_header *) &pn_control_intf_desc,
 187         (struct usb_descriptor_header *) &pn_header_desc,
 188         (struct usb_descriptor_header *) &pn_phonet_desc,
 189         (struct usb_descriptor_header *) &pn_union_desc,
 190         (struct usb_descriptor_header *) &pn_data_nop_intf_desc,
 191         (struct usb_descriptor_header *) &pn_data_intf_desc,
 192         (struct usb_descriptor_header *) &pn_hs_sink_desc,
 193         (struct usb_descriptor_header *) &pn_hs_source_desc,
 194         NULL,
 195 };
 196
 197 /*-------------------------------------------------------------------------*/
 198
 199 static int pn_net_open(struct net_device *dev)
 200 {
 201         netif_wake_queue(dev);
 202         return 0;
 203 }
 204
 205 static int pn_net_close(struct net_device *dev)
 206 {
 207         netif_stop_queue(dev);
 208         return 0;
 209 }
 210
 211 static void pn_tx_complete(struct usb_ep *ep, struct usb_request *req)
 212 {
 213         struct f_phonet *fp = ep->driver_data;
 214         struct net_device *dev = fp->dev;
 215         struct sk_buff *skb = req->context;
 216
 217         switch (req->status) {
 218         case 0:
 219                 dev->stats.tx_packets++;
 220                 dev->stats.tx_bytes += skb->len;
 221                 break;
 222
 223         case -ESHUTDOWN: /* disconnected */
 224         case -ECONNRESET: /* disabled */
 225                 dev->stats.tx_aborted_errors++;
 226         default:
 227                 dev->stats.tx_errors++;
 228         }
 229
 230         dev_kfree_skb_any(skb);
 231         netif_wake_queue(dev);
 232 }
 233
 234 static int pn_net_xmit(struct sk_buff *skb, struct net_device *dev)
 235 {
 236         struct phonet_port *port = netdev_priv(dev);
 237         struct f_phonet *fp;
 238         struct usb_request *req;
 239         unsigned long flags;
 240
 241         if (skb->protocol != htons(ETH_P_PHONET))
 242                 goto out;
 243
 244         spin_lock_irqsave(&port->lock, flags);
 245         fp = port->usb;
 246         if (unlikely(!fp)) /* race with carrier loss */
 247                 goto out_unlock;
 248
 249         req = fp->in_req;
 250         req->buf = skb->data;
 251         req->length = skb->len;
 252         req->complete = pn_tx_complete;
 253         req->zero = 1;
 254         req->context = skb;
 255
 256         if (unlikely(usb_ep_queue(fp->in_ep, req, GFP_ATOMIC)))
 257                 goto out_unlock;
 258
 259         netif_stop_queue(dev);
 260         skb = NULL;
 261
 262 out_unlock:
 263         spin_unlock_irqrestore(&port->lock, flags);
 264 out:
 265         if (unlikely(skb)) {
 266                 dev_kfree_skb(skb);
 267                 dev->stats.tx_dropped++;
 268         }
 269         return NETDEV_TX_OK;
 270 }
 271
 272 static int pn_net_mtu(struct net_device *dev, int new_mtu)
 273 {
 274         if ((new_mtu < PHONET_MIN_MTU) || (new_mtu > PHONET_MAX_MTU))
 275                 return -EINVAL;
 276         dev->mtu = new_mtu;
 277         return 0;
 278 }
 279
 280 static const struct net_device_ops pn_netdev_ops = {
 281         .ndo_open       = pn_net_open,
 282         .ndo_stop       = pn_net_close,
 283         .ndo_start_xmit = pn_net_xmit,
 284         .ndo_change_mtu = pn_net_mtu,
 285 };
 286
 287 static void pn_net_setup(struct net_device *dev)
 288 {
 289         dev->features           = 0;
 290         dev->type               = ARPHRD_PHONET;
 291         dev->flags              = IFF_POINTOPOINT | IFF_NOARP;
 292         dev->mtu                = PHONET_DEV_MTU;
 293         dev->hard_header_len    = 1;
 294         dev->dev_addr[0]        = PN_MEDIA_USB;
 295         dev->addr_len           = 1;
 296         dev->tx_queue_len       = 1;
 297
 298         dev->netdev_ops         = &pn_netdev_ops;
 299         dev->destructor         = free_netdev;
 300         dev->header_ops         = &phonet_header_ops;
 301 }
 302
 303 /*-------------------------------------------------------------------------*/
 304
 305 /*
 306  * Queue buffer for data from the host
 307  */
 308 static int
 309 pn_rx_submit(struct f_phonet *fp, struct usb_request *req, gfp_t gfp_flags)
 310 {
 311         struct net_device *dev = fp->dev;
 312         struct page *page;
 313         int err;
 314
 315         page = __netdev_alloc_page(dev, gfp_flags);
 316         if (!page)
 317                 return -ENOMEM;
 318
 319         req->buf = page_address(page);
 320         req->length = PAGE_SIZE;
 321         req->context = page;
 322
 323         err = usb_ep_queue(fp->out_ep, req, gfp_flags);
 324         if (unlikely(err))
 325                 netdev_free_page(dev, page);
 326         return err;
 327 }
 328
 329 static void pn_rx_complete(struct usb_ep *ep, struct usb_request *req)
 330 {
 331         struct f_phonet *fp = ep->driver_data;
 332         struct net_device *dev = fp->dev;
 333         struct page *page = req->context;
 334         struct sk_buff *skb;
 335         unsigned long flags;
 336         int status = req->status;
 337
 338         switch (status) {
 339         case 0:
 340                 spin_lock_irqsave(&fp->rx.lock, flags);
 341                 skb = fp->rx.skb;
 342                 if (!skb)
 343                         skb = fp->rx.skb = netdev_alloc_skb(dev, 12);
 344                 if (req->actual < req->length) /* Last fragment */
 345                         fp->rx.skb = NULL;
 346                 spin_unlock_irqrestore(&fp->rx.lock, flags);
 347
 348                 if (unlikely(!skb))
 349                         break;
 350
 351                 if (skb->len == 0) { /* First fragment */
 352                         skb->protocol = htons(ETH_P_PHONET);
 353                         skb_reset_mac_header(skb);
 354                         /* Can't use pskb_pull() on page in IRQ */
 355                         memcpy(skb_put(skb, 1), page_address(page), 1);
 356                 }
 357
 358                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
 359                                 skb->len == 0, req->actual);
 360                 page = NULL;
 361
 362                 if (req->actual < req->length) { /* Last fragment */
 363                         skb->dev = dev;
 364                         dev->stats.rx_packets++;
 365                         dev->stats.rx_bytes += skb->len;
 366
 367                         netif_rx(skb);
 368                 }
 369                 break;
 370
 371         /* Do not resubmit in these cases: */
 372         case -ESHUTDOWN: /* disconnect */
 373         case -ECONNABORTED: /* hw reset */
 374         case -ECONNRESET: /* dequeued (unlink or netif down) */
 375                 req = NULL;
 376                 break;
 377
 378         /* Do resubmit in these cases: */
 379         case -EOVERFLOW: /* request buffer overflow */
 380                 dev->stats.rx_over_errors++;
 381         default:
 382                 dev->stats.rx_errors++;
 383                 break;
 384         }
 385
 386         if (page)
 387                 netdev_free_page(dev, page);
 388         if (req)
 389                 pn_rx_submit(fp, req, GFP_ATOMIC);
 390 }
 391
 392 /*-------------------------------------------------------------------------*/
 393
 394 static void __pn_reset(struct usb_function *f)
 395 {
 396         struct f_phonet *fp = func_to_pn(f);
 397         struct net_device *dev = fp->dev;
 398         struct phonet_port *port = netdev_priv(dev);
 399
 400         netif_carrier_off(dev);
 401         port->usb = NULL;
 402
 403         usb_ep_disable(fp->out_ep);
 404         usb_ep_disable(fp->in_ep);
 405         if (fp->rx.skb) {
 406                 dev_kfree_skb_irq(fp->rx.skb);
 407                 fp->rx.skb = NULL;
 408         }
 409 }
 410
 411 static int pn_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 412 {
 413         struct f_phonet *fp = func_to_pn(f);
 414         struct usb_gadget *gadget = fp->function.config->cdev->gadget;
 415
 416         if (intf == pn_control_intf_desc.bInterfaceNumber)
 417                 /* control interface, no altsetting */
 418                 return (alt > 0) ? -EINVAL : 0;
 419
 420         if (intf == pn_data_intf_desc.bInterfaceNumber) {
 421                 struct net_device *dev = fp->dev;
 422                 struct phonet_port *port = netdev_priv(dev);
 423
 424                 /* data intf (0: inactive, 1: active) */
 425                 if (alt > 1)
 426                         return -EINVAL;
 427
 428                 spin_lock(&port->lock);
 429                 __pn_reset(f);
 430                 if (alt == 1) {
 431                         int i;
 432
 433                         if (config_ep_by_speed(gadget, f, fp->in_ep) ||
 434                             config_ep_by_speed(gadget, f, fp->out_ep)) {
 435                                 fp->in_ep->desc = NULL;
 436                                 fp->out_ep->desc = NULL;
 437                                 return -EINVAL;
 438                         }
 439                         usb_ep_enable(fp->out_ep);
 440                         usb_ep_enable(fp->in_ep);
 441
 442                         port->usb = fp;
 443                         fp->out_ep->driver_data = fp;
 444                         fp->in_ep->driver_data = fp;
 445
 446                         netif_carrier_on(dev);
 447                         for (i = 0; i < phonet_rxq_size; i++)
 448                                 pn_rx_submit(fp, fp->out_reqv[i], GFP_ATOMIC);
 449                 }
 450                 spin_unlock(&port->lock);
 451                 return 0;
 452         }
 453
 454         return -EINVAL;
 455 }
 456
 457 static int pn_get_alt(struct usb_function *f, unsigned intf)
 458 {
 459         struct f_phonet *fp = func_to_pn(f);
 460
 461         if (intf == pn_control_intf_desc.bInterfaceNumber)
 462                 return 0;
 463
 464         if (intf == pn_data_intf_desc.bInterfaceNumber) {
 465                 struct phonet_port *port = netdev_priv(fp->dev);
 466                 u8 alt;
 467
 468                 spin_lock(&port->lock);
 469                 alt = port->usb != NULL;
 470                 spin_unlock(&port->lock);
 471                 return alt;
 472         }
 473
 474         return -EINVAL;
 475 }
 476
 477 static void pn_disconnect(struct usb_function *f)
 478 {
 479         struct f_phonet *fp = func_to_pn(f);
 480         struct phonet_port *port = netdev_priv(fp->dev);
 481         unsigned long flags;
 482
 483         /* remain disabled until set_alt */
 484         spin_lock_irqsave(&port->lock, flags);
 485         __pn_reset(f);
 486         spin_unlock_irqrestore(&port->lock, flags);
 487 }
 488
 489 /*-------------------------------------------------------------------------*/
 490
 491 static __init
 492 int pn_bind(struct usb_configuration *c, struct usb_function *f)
 493 {
 494         struct usb_composite_dev *cdev = c->cdev;
 495         struct usb_gadget *gadget = cdev->gadget;
 496         struct f_phonet *fp = func_to_pn(f);
 497         struct usb_ep *ep;
 498         int status, i;
 499
 500         /* Reserve interface IDs */
 501         status = usb_interface_id(c, f);
 502         if (status < 0)
 503                 goto err;
 504         pn_control_intf_desc.bInterfaceNumber = status;
 505         pn_union_desc.bMasterInterface0 = status;
 506
 507         status = usb_interface_id(c, f);
 508         if (status < 0)
 509                 goto err;
 510         pn_data_nop_intf_desc.bInterfaceNumber = status;
 511         pn_data_intf_desc.bInterfaceNumber = status;
 512         pn_union_desc.bSlaveInterface0 = status;
 513
 514         /* Reserve endpoints */
 515         status = -ENODEV;
 516         ep = usb_ep_autoconfig(gadget, &pn_fs_sink_desc);
 517         if (!ep)
 518                 goto err;
 519         fp->out_ep = ep;
 520         ep->driver_data = fp; /* Claim */
 521
 522         ep = usb_ep_autoconfig(gadget, &pn_fs_source_desc);
 523         if (!ep)
 524                 goto err;
 525         fp->in_ep = ep;
 526         ep->driver_data = fp; /* Claim */
 527
 528         pn_hs_sink_desc.bEndpointAddress =
 529                 pn_fs_sink_desc.bEndpointAddress;
 530         pn_hs_source_desc.bEndpointAddress =
 531                 pn_fs_source_desc.bEndpointAddress;
 532
 533         /* Do not try to bind Phonet twice... */
 534         fp->function.descriptors = fs_pn_function;
 535         fp->function.hs_descriptors = hs_pn_function;
 536
 537         /* Incoming USB requests */
 538         status = -ENOMEM;
 539         for (i = 0; i < phonet_rxq_size; i++) {
 540                 struct usb_request *req;
 541
 542                 req = usb_ep_alloc_request(fp->out_ep, GFP_KERNEL);
 543                 if (!req)
 544                         goto err;
 545
 546                 req->complete = pn_rx_complete;
 547                 fp->out_reqv[i] = req;
 548         }
 549
 550         /* Outgoing USB requests */
 551         fp->in_req = usb_ep_alloc_request(fp->in_ep, GFP_KERNEL);
 552         if (!fp->in_req)
 553                 goto err;
 554
 555         INFO(cdev, "USB CDC Phonet function\n");
 556         INFO(cdev, "using %s, OUT %s, IN %s\n", cdev->gadget->name,
 557                 fp->out_ep->name, fp->in_ep->name);
 558         return 0;
 559
 560 err:
 561         if (fp->out_ep)
 562                 fp->out_ep->driver_data = NULL;
 563         if (fp->in_ep)
 564                 fp->in_ep->driver_data = NULL;
 565         ERROR(cdev, "USB CDC Phonet: cannot autoconfigure\n");
 566         return status;
 567 }
 568
 569 static void
 570 pn_unbind(struct usb_configuration *c, struct usb_function *f)
 571 {
 572         struct f_phonet *fp = func_to_pn(f);
 573         int i;
 574
 575         /* We are already disconnected */
 576         if (fp->in_req)
 577                 usb_ep_free_request(fp->in_ep, fp->in_req);
 578         for (i = 0; i < phonet_rxq_size; i++)
 579                 if (fp->out_reqv[i])
 580                         usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);
 581
 582         kfree(fp);
 583 }
 584
 585 /*-------------------------------------------------------------------------*/
 586
 587 static struct net_device *dev;
 588
 589 int __init phonet_bind_config(struct usb_configuration *c)
 590 {
 591         struct f_phonet *fp;
 592         int err, size;
 593
 594         size = sizeof(*fp) + (phonet_rxq_size * sizeof(struct usb_request *));
 595         fp = kzalloc(size, GFP_KERNEL);
 596         if (!fp)
 597                 return -ENOMEM;
 598
 599         fp->dev = dev;
 600         fp->function.name = "phonet";
 601         fp->function.bind = pn_bind;
 602         fp->function.unbind = pn_unbind;
 603         fp->function.set_alt = pn_set_alt;
 604         fp->function.get_alt = pn_get_alt;
 605         fp->function.disable = pn_disconnect;
 606         spin_lock_init(&fp->rx.lock);
 607
 608         err = usb_add_function(c, &fp->function);
 609         if (err)
 610                 kfree(fp);
 611         return err;
 612 }
 613
 614 int __init gphonet_setup(struct usb_gadget *gadget)
 615 {
 616         struct phonet_port *port;
 617         int err;
 618
 619         /* Create net device */
 620         BUG_ON(dev);
 621         dev = alloc_netdev(sizeof(*port), "upnlink%d", pn_net_setup);
 622         if (!dev)
 623                 return -ENOMEM;
 624
 625         port = netdev_priv(dev);
 626         spin_lock_init(&port->lock);
 627         netif_carrier_off(dev);
 628         SET_NETDEV_DEV(dev, &gadget->dev);
 629
 630         err = register_netdev(dev);
 631         if (err)
 632                 free_netdev(dev);
 633         return err;
 634 }
 635
 636 void gphonet_cleanup(void)
 637 {
 638         unregister_netdev(dev);
 639 }