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