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
  39 /*-------------------------------------------------------------------------*/
  40
  41 struct phonet_port {
  42         struct f_phonet                 *usb;
  43         spinlock_t                      lock;
  44 };
  45
  46 struct f_phonet {
  47         struct usb_function             function;
  48         struct net_device               *dev;
  49         struct usb_ep                   *in_ep, *out_ep;
  50
  51         struct usb_request              *in_req;
  52         struct usb_request              *out_reqv[0];
  53 };
  54
  55 static int phonet_rxq_size = 2;
  56
  57 static inline struct f_phonet *func_to_pn(struct usb_function *f)
  58 {
  59         return container_of(f, struct f_phonet, function);
  60 }
  61
  62 /*-------------------------------------------------------------------------*/
  63
  64 #define USB_CDC_SUBCLASS_PHONET 0xfe
  65 #define USB_CDC_PHONET_TYPE     0xab
  66
  67 static struct usb_interface_descriptor
  68 pn_control_intf_desc = {
  69         .bLength =              sizeof pn_control_intf_desc,
  70         .bDescriptorType =      USB_DT_INTERFACE,
  71
  72         /* .bInterfaceNumber =  DYNAMIC, */
  73         .bInterfaceClass =      USB_CLASS_COMM,
  74         .bInterfaceSubClass =   USB_CDC_SUBCLASS_PHONET,
  75 };
  76
  77 static const struct usb_cdc_header_desc
  78 pn_header_desc = {
  79         .bLength =              sizeof pn_header_desc,
  80         .bDescriptorType =      USB_DT_CS_INTERFACE,
  81         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
  82         .bcdCDC =               __constant_cpu_to_le16(0x0110),
  83 };
  84
  85 static const struct usb_cdc_header_desc
  86 pn_phonet_desc = {
  87         .bLength =              sizeof pn_phonet_desc,
  88         .bDescriptorType =      USB_DT_CS_INTERFACE,
  89         .bDescriptorSubType =   USB_CDC_PHONET_TYPE,
  90         .bcdCDC =               __constant_cpu_to_le16(0x1505), /* ??? */
  91 };
  92
  93 static struct usb_cdc_union_desc
  94 pn_union_desc = {
  95         .bLength =              sizeof pn_union_desc,
  96         .bDescriptorType =      USB_DT_CS_INTERFACE,
  97         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
  98
  99         /* .bMasterInterface0 = DYNAMIC, */
 100         /* .bSlaveInterface0 =  DYNAMIC, */
 101 };
 102
 103 static struct usb_interface_descriptor
 104 pn_data_nop_intf_desc = {
 105         .bLength =              sizeof pn_data_nop_intf_desc,
 106         .bDescriptorType =      USB_DT_INTERFACE,
 107
 108         /* .bInterfaceNumber =  DYNAMIC, */
 109         .bAlternateSetting =    0,
 110         .bNumEndpoints =        0,
 111         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 112 };
 113
 114 static struct usb_interface_descriptor
 115 pn_data_intf_desc = {
 116         .bLength =              sizeof pn_data_intf_desc,
 117         .bDescriptorType =      USB_DT_INTERFACE,
 118
 119         /* .bInterfaceNumber =  DYNAMIC, */
 120         .bAlternateSetting =    1,
 121         .bNumEndpoints =        2,
 122         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 123 };
 124
 125 static struct usb_endpoint_descriptor
 126 pn_fs_sink_desc = {
 127         .bLength =              USB_DT_ENDPOINT_SIZE,
 128         .bDescriptorType =      USB_DT_ENDPOINT,
 129
 130         .bEndpointAddress =     USB_DIR_OUT,
 131         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 132 };
 133
 134 static struct usb_endpoint_descriptor
 135 pn_hs_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         .wMaxPacketSize =       __constant_cpu_to_le16(512),
 142 };
 143
 144 static struct usb_endpoint_descriptor
 145 pn_fs_source_desc = {
 146         .bLength =              USB_DT_ENDPOINT_SIZE,
 147         .bDescriptorType =      USB_DT_ENDPOINT,
 148
 149         .bEndpointAddress =     USB_DIR_IN,
 150         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 151 };
 152
 153 static struct usb_endpoint_descriptor
 154 pn_hs_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         .wMaxPacketSize =       __constant_cpu_to_le16(512),
 161 };
 162
 163 static struct usb_descriptor_header *fs_pn_function[] = {
 164         (struct usb_descriptor_header *) &pn_control_intf_desc,
 165         (struct usb_descriptor_header *) &pn_header_desc,
 166         (struct usb_descriptor_header *) &pn_phonet_desc,
 167         (struct usb_descriptor_header *) &pn_union_desc,
 168         (struct usb_descriptor_header *) &pn_data_nop_intf_desc,
 169         (struct usb_descriptor_header *) &pn_data_intf_desc,
 170         (struct usb_descriptor_header *) &pn_fs_sink_desc,
 171         (struct usb_descriptor_header *) &pn_fs_source_desc,
 172         NULL,
 173 };
 174
 175 static struct usb_descriptor_header *hs_pn_function[] = {
 176         (struct usb_descriptor_header *) &pn_control_intf_desc,
 177         (struct usb_descriptor_header *) &pn_header_desc,
 178         (struct usb_descriptor_header *) &pn_phonet_desc,
 179         (struct usb_descriptor_header *) &pn_union_desc,
 180         (struct usb_descriptor_header *) &pn_data_nop_intf_desc,
 181         (struct usb_descriptor_header *) &pn_data_intf_desc,
 182         (struct usb_descriptor_header *) &pn_hs_sink_desc,
 183         (struct usb_descriptor_header *) &pn_hs_source_desc,
 184         NULL,
 185 };
 186
 187 /*-------------------------------------------------------------------------*/
 188
 189 static int pn_net_open(struct net_device *dev)
 190 {
 191         if (netif_carrier_ok(dev))
 192                 netif_wake_queue(dev);
 193         return 0;
 194 }
 195
 196 static int pn_net_close(struct net_device *dev)
 197 {
 198         netif_stop_queue(dev);
 199         return 0;
 200 }
 201
 202 static void pn_tx_complete(struct usb_ep *ep, struct usb_request *req)
 203 {
 204         struct f_phonet *fp = ep->driver_data;
 205         struct net_device *dev = fp->dev;
 206         struct sk_buff *skb = req->context;
 207
 208         switch (req->status) {
 209         case 0:
 210                 dev->stats.tx_packets++;
 211                 dev->stats.tx_bytes += skb->len;
 212                 break;
 213
 214         case -ESHUTDOWN: /* disconnected */
 215         case -ECONNRESET: /* disabled */
 216                 dev->stats.tx_aborted_errors++;
 217         default:
 218                 dev->stats.tx_errors++;
 219         }
 220
 221         dev_kfree_skb_any(skb);
 222         if (netif_carrier_ok(dev))
 223                 netif_wake_queue(dev);
 224 }
 225
 226 static int pn_net_xmit(struct sk_buff *skb, struct net_device *dev)
 227 {
 228         struct phonet_port *port = netdev_priv(dev);
 229         struct f_phonet *fp;
 230         struct usb_request *req;
 231         unsigned long flags;
 232
 233         if (skb->protocol != htons(ETH_P_PHONET))
 234                 goto out;
 235
 236         spin_lock_irqsave(&port->lock, flags);
 237         fp = port->usb;
 238         if (unlikely(!fp)) /* race with carrier loss */
 239                 goto out_unlock;
 240
 241         req = fp->in_req;
 242         req->buf = skb->data;
 243         req->length = skb->len;
 244         req->complete = pn_tx_complete;
 245         req->zero = 1;
 246         req->context = skb;
 247
 248         if (unlikely(usb_ep_queue(fp->in_ep, req, GFP_ATOMIC)))
 249                 goto out_unlock;
 250
 251         netif_stop_queue(dev);
 252         skb = NULL;
 253
 254 out_unlock:
 255         spin_unlock_irqrestore(&port->lock, flags);
 256 out:
 257         if (unlikely(skb)) {
 258                 dev_kfree_skb_any(skb);
 259                 dev->stats.tx_dropped++;
 260         }
 261         return 0;
 262 }
 263
 264 static int pn_net_mtu(struct net_device *dev, int new_mtu)
 265 {
 266         struct phonet_port *port = netdev_priv(dev);
 267         unsigned long flags;
 268         int err = -EBUSY;
 269
 270         if ((new_mtu < PHONET_MIN_MTU) || (new_mtu > PHONET_MAX_MTU))
 271                 return -EINVAL;
 272
 273         spin_lock_irqsave(&port->lock, flags);
 274         if (!netif_carrier_ok(dev)) {
 275                 dev->mtu = new_mtu;
 276                 err = 0;
 277         }
 278         spin_unlock_irqrestore(&port->lock, flags);
 279         return err;
 280 }
 281
 282 static void pn_net_setup(struct net_device *dev)
 283 {
 284         dev->features           = 0;
 285         dev->type               = ARPHRD_PHONET;
 286         dev->flags              = IFF_POINTOPOINT | IFF_NOARP;
 287         dev->mtu                = PHONET_DEV_MTU;
 288         dev->hard_header_len    = 1;
 289         dev->dev_addr[0]        = PN_MEDIA_USB;
 290         dev->addr_len           = 1;
 291         dev->tx_queue_len       = 1;
 292
 293         dev->destructor         = free_netdev;
 294         dev->header_ops         = &phonet_header_ops;
 295         dev->open               = pn_net_open;
 296         dev->stop               = pn_net_close;
 297         dev->hard_start_xmit    = pn_net_xmit; /* mandatory */
 298         dev->change_mtu         = pn_net_mtu;
 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 sk_buff *skb;
 310         const size_t size = fp->dev->mtu;
 311         int err;
 312
 313         skb = alloc_skb(size, gfp_flags);
 314         if (!skb)
 315                 return -ENOMEM;
 316
 317         req->buf = skb->data;
 318         req->length = size;
 319         req->context = skb;
 320
 321         err = usb_ep_queue(fp->out_ep, req, gfp_flags);
 322         if (unlikely(err))
 323                 dev_kfree_skb_any(skb);
 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 sk_buff *skb = req->context;
 332         int status = req->status;
 333
 334         switch (status) {
 335         case 0:
 336                 if (unlikely(!netif_running(dev)))
 337                         break;
 338                 if (unlikely(req->actual < 1))
 339                         break;
 340                 skb_put(skb, req->actual);
 341                 skb->protocol = htons(ETH_P_PHONET);
 342                 skb_reset_mac_header(skb);
 343                 __skb_pull(skb, 1);
 344                 skb->dev = dev;
 345                 dev->stats.rx_packets++;
 346                 dev->stats.rx_bytes += skb->len;
 347
 348                 netif_rx(skb);
 349                 skb = NULL;
 350                 break;
 351
 352         /* Do not resubmit in these cases: */
 353         case -ESHUTDOWN: /* disconnect */
 354         case -ECONNABORTED: /* hw reset */
 355         case -ECONNRESET: /* dequeued (unlink or netif down) */
 356                 req = NULL;
 357                 break;
 358
 359         /* Do resubmit in these cases: */
 360         case -EOVERFLOW: /* request buffer overflow */
 361                 dev->stats.rx_over_errors++;
 362         default:
 363                 dev->stats.rx_errors++;
 364                 break;
 365         }
 366
 367         if (skb)
 368                 dev_kfree_skb_any(skb);
 369         if (req)
 370                 pn_rx_submit(fp, req, GFP_ATOMIC);
 371 }
 372
 373 /*-------------------------------------------------------------------------*/
 374
 375 static void __pn_reset(struct usb_function *f)
 376 {
 377         struct f_phonet *fp = func_to_pn(f);
 378         struct net_device *dev = fp->dev;
 379         struct phonet_port *port = netdev_priv(dev);
 380
 381         netif_carrier_off(dev);
 382         netif_stop_queue(dev);
 383         port->usb = NULL;
 384
 385         usb_ep_disable(fp->out_ep);
 386         usb_ep_disable(fp->in_ep);
 387 }
 388
 389 static int pn_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 390 {
 391         struct f_phonet *fp = func_to_pn(f);
 392         struct usb_gadget *gadget = fp->function.config->cdev->gadget;
 393
 394         if (intf == pn_control_intf_desc.bInterfaceNumber)
 395                 /* control interface, no altsetting */
 396                 return (alt > 0) ? -EINVAL : 0;
 397
 398         if (intf == pn_data_intf_desc.bInterfaceNumber) {
 399                 struct net_device *dev = fp->dev;
 400                 struct phonet_port *port = netdev_priv(dev);
 401
 402                 /* data intf (0: inactive, 1: active) */
 403                 if (alt > 1)
 404                         return -EINVAL;
 405
 406                 spin_lock(&port->lock);
 407                 __pn_reset(f);
 408                 if (alt == 1) {
 409                         struct usb_endpoint_descriptor *out, *in;
 410                         int i;
 411
 412                         out = ep_choose(gadget,
 413                                         &pn_hs_sink_desc,
 414                                         &pn_fs_sink_desc);
 415                         in = ep_choose(gadget,
 416                                         &pn_hs_source_desc,
 417                                         &pn_fs_source_desc);
 418                         usb_ep_enable(fp->out_ep, out);
 419                         usb_ep_enable(fp->in_ep, in);
 420
 421                         port->usb = fp;
 422                         fp->out_ep->driver_data = fp;
 423                         fp->in_ep->driver_data = fp;
 424
 425                         netif_carrier_on(dev);
 426                         if (netif_running(dev))
 427                                 netif_wake_queue(dev);
 428                         for (i = 0; i < phonet_rxq_size; i++)
 429                                 pn_rx_submit(fp, fp->out_reqv[i], GFP_ATOMIC);
 430                 }
 431                 spin_unlock(&port->lock);
 432                 return 0;
 433         }
 434
 435         return -EINVAL;
 436 }
 437
 438 static int pn_get_alt(struct usb_function *f, unsigned intf)
 439 {
 440         struct f_phonet *fp = func_to_pn(f);
 441
 442         if (intf == pn_control_intf_desc.bInterfaceNumber)
 443                 return 0;
 444
 445         if (intf == pn_data_intf_desc.bInterfaceNumber) {
 446                 struct phonet_port *port = netdev_priv(fp->dev);
 447                 u8 alt;
 448
 449                 spin_lock(&port->lock);
 450                 alt = port->usb != NULL;
 451                 spin_unlock(&port->lock);
 452                 return alt;
 453         }
 454
 455         return -EINVAL;
 456 }
 457
 458 static void pn_disconnect(struct usb_function *f)
 459 {
 460         struct f_phonet *fp = func_to_pn(f);
 461         struct phonet_port *port = netdev_priv(fp->dev);
 462         unsigned long flags;
 463
 464         /* remain disabled until set_alt */
 465         spin_lock_irqsave(&port->lock, flags);
 466         __pn_reset(f);
 467         spin_unlock_irqrestore(&port->lock, flags);
 468 }
 469
 470 /*-------------------------------------------------------------------------*/
 471
 472 static __init
 473 int pn_bind(struct usb_configuration *c, struct usb_function *f)
 474 {
 475         struct usb_composite_dev *cdev = c->cdev;
 476         struct usb_gadget *gadget = cdev->gadget;
 477         struct f_phonet *fp = func_to_pn(f);
 478         struct usb_ep *ep;
 479         int status, i;
 480
 481         /* Reserve interface IDs */
 482         status = usb_interface_id(c, f);
 483         if (status < 0)
 484                 goto err;
 485         pn_control_intf_desc.bInterfaceNumber = status;
 486         pn_union_desc.bMasterInterface0 = status;
 487
 488         status = usb_interface_id(c, f);
 489         if (status < 0)
 490                 goto err;
 491         pn_data_nop_intf_desc.bInterfaceNumber = status;
 492         pn_data_intf_desc.bInterfaceNumber = status;
 493         pn_union_desc.bSlaveInterface0 = status;
 494
 495         /* Reserve endpoints */
 496         status = -ENODEV;
 497         ep = usb_ep_autoconfig(gadget, &pn_fs_sink_desc);
 498         if (!ep)
 499                 goto err;
 500         fp->out_ep = ep;
 501         ep->driver_data = fp; /* Claim */
 502
 503         ep = usb_ep_autoconfig(gadget, &pn_fs_source_desc);
 504         if (!ep)
 505                 goto err;
 506         fp->in_ep = ep;
 507         ep->driver_data = fp; /* Claim */
 508
 509         pn_hs_sink_desc.bEndpointAddress =
 510                 pn_fs_sink_desc.bEndpointAddress;
 511         pn_hs_source_desc.bEndpointAddress =
 512                 pn_fs_source_desc.bEndpointAddress;
 513
 514         /* Do not try to bind Phonet twice... */
 515         fp->function.descriptors = fs_pn_function;
 516         fp->function.hs_descriptors = hs_pn_function;
 517
 518         /* Incoming USB requests */
 519         status = -ENOMEM;
 520         for (i = 0; i < phonet_rxq_size; i++) {
 521                 struct usb_request *req;
 522
 523                 req = usb_ep_alloc_request(fp->out_ep, GFP_KERNEL);
 524                 if (!req)
 525                         goto err;
 526
 527                 req->complete = pn_rx_complete;
 528                 fp->out_reqv[i] = req;
 529         }
 530
 531         /* Outgoing USB requests */
 532         fp->in_req = usb_ep_alloc_request(fp->in_ep, GFP_KERNEL);
 533         if (!fp->in_req)
 534                 goto err;
 535
 536         INFO(cdev, "USB CDC Phonet function\n");
 537         INFO(cdev, "using %s, OUT %s, IN %s\n", cdev->gadget->name,
 538                 fp->out_ep->name, fp->in_ep->name);
 539         return 0;
 540
 541 err:
 542         if (fp->out_ep)
 543                 fp->out_ep->driver_data = NULL;
 544         if (fp->in_ep)
 545                 fp->in_ep->driver_data = NULL;
 546         ERROR(cdev, "USB CDC Phonet: cannot autoconfigure\n");
 547         return status;
 548 }
 549
 550 static void
 551 pn_unbind(struct usb_configuration *c, struct usb_function *f)
 552 {
 553         struct f_phonet *fp = func_to_pn(f);
 554         int i;
 555
 556         /* We are already disconnected */
 557         if (fp->in_req)
 558                 usb_ep_free_request(fp->in_ep, fp->in_req);
 559         for (i = 0; i < phonet_rxq_size; i++)
 560                 if (fp->out_reqv[i])
 561                         usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);
 562
 563         kfree(fp);
 564 }
 565
 566 /*-------------------------------------------------------------------------*/
 567
 568 static struct net_device *dev;
 569
 570 int __init phonet_bind_config(struct usb_configuration *c)
 571 {
 572         struct f_phonet *fp;
 573         int err;
 574
 575         fp = kzalloc(sizeof(*fp), GFP_KERNEL);
 576         if (!fp)
 577                 return -ENOMEM;
 578
 579         fp->dev = dev;
 580         fp->function.name = "phonet";
 581         fp->function.bind = pn_bind;
 582         fp->function.unbind = pn_unbind;
 583         fp->function.set_alt = pn_set_alt;
 584         fp->function.get_alt = pn_get_alt;
 585         fp->function.disable = pn_disconnect;
 586
 587         err = usb_add_function(c, &fp->function);
 588         if (err)
 589                 kfree(fp);
 590         return err;
 591 }
 592
 593 int __init gphonet_setup(struct usb_gadget *gadget)
 594 {
 595         struct phonet_port *port;
 596         int err;
 597
 598         /* Create net device */
 599         BUG_ON(dev);
 600         dev = alloc_netdev(sizeof(*port)
 601                 + (phonet_rxq_size * sizeof(struct usb_request *)),
 602                                 "upnlink%d", pn_net_setup);
 603         if (!dev)
 604                 return -ENOMEM;
 605
 606         port = netdev_priv(dev);
 607         spin_lock_init(&port->lock);
 608         netif_carrier_off(dev);
 609         netif_stop_queue(dev);
 610         SET_NETDEV_DEV(dev, &gadget->dev);
 611
 612         err = register_netdev(dev);
 613         if (err)
 614                 free_netdev(dev);
 615         return err;
 616 }
 617
 618 void gphonet_cleanup(void)
 619 {
 620         unregister_netdev(dev);
 621 }