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