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
  13 #include <linux/mm.h>
  14 #include <linux/slab.h>
  15 #include <linux/kernel.h>
  16 #include <linux/device.h>
  17
  18 #include <linux/netdevice.h>
  19 #include <linux/if_ether.h>
  20 #include <linux/if_phonet.h>
  21 #include <linux/if_arp.h>
  22
  23 #include <linux/usb/ch9.h>
  24 #include <linux/usb/cdc.h>
  25 #include <linux/usb/composite.h>
  26
  27 #include "u_phonet.h"
  28
  29 #define PN_MEDIA_USB    0x1B
  30 #define MAXPACKET       512
  31 #if (PAGE_SIZE % MAXPACKET)
  32 #error MAXPACKET must divide PAGE_SIZE!
  33 #endif
  34
  35 /*-------------------------------------------------------------------------*/
  36
  37 struct phonet_port {
  38         struct f_phonet                 *usb;
  39         spinlock_t                      lock;
  40 };
  41
  42 struct f_phonet {
  43         struct usb_function             function;
  44         struct {
  45                 struct sk_buff          *skb;
  46                 spinlock_t              lock;
  47         } rx;
  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 = 17;
  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 =               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 =               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 =       cpu_to_le16(MAXPACKET),
 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 =       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         netif_wake_queue(dev);
 192         return 0;
 193 }
 194
 195 static int pn_net_close(struct net_device *dev)
 196 {
 197         netif_stop_queue(dev);
 198         return 0;
 199 }
 200
 201 static void pn_tx_complete(struct usb_ep *ep, struct usb_request *req)
 202 {
 203         struct f_phonet *fp = ep->driver_data;
 204         struct net_device *dev = fp->dev;
 205         struct sk_buff *skb = req->context;
 206
 207         switch (req->status) {
 208         case 0:
 209                 dev->stats.tx_packets++;
 210                 dev->stats.tx_bytes += skb->len;
 211                 break;
 212
 213         case -ESHUTDOWN: /* disconnected */
 214         case -ECONNRESET: /* disabled */
 215                 dev->stats.tx_aborted_errors++;
 216         default:
 217                 dev->stats.tx_errors++;
 218         }
 219
 220         dev_kfree_skb_any(skb);
 221         netif_wake_queue(dev);
 222 }
 223
 224 static int pn_net_xmit(struct sk_buff *skb, struct net_device *dev)
 225 {
 226         struct phonet_port *port = netdev_priv(dev);
 227         struct f_phonet *fp;
 228         struct usb_request *req;
 229         unsigned long flags;
 230
 231         if (skb->protocol != htons(ETH_P_PHONET))
 232                 goto out;
 233
 234         spin_lock_irqsave(&port->lock, flags);
 235         fp = port->usb;
 236         if (unlikely(!fp)) /* race with carrier loss */
 237                 goto out_unlock;
 238
 239         req = fp->in_req;
 240         req->buf = skb->data;
 241         req->length = skb->len;
 242         req->complete = pn_tx_complete;
 243         req->zero = 1;
 244         req->context = skb;
 245
 246         if (unlikely(usb_ep_queue(fp->in_ep, req, GFP_ATOMIC)))
 247                 goto out_unlock;
 248
 249         netif_stop_queue(dev);
 250         skb = NULL;
 251
 252 out_unlock:
 253         spin_unlock_irqrestore(&port->lock, flags);
 254 out:
 255         if (unlikely(skb)) {
 256                 dev_kfree_skb(skb);
 257                 dev->stats.tx_dropped++;
 258         }
 259         return NETDEV_TX_OK;
 260 }
 261
 262 static int pn_net_mtu(struct net_device *dev, int new_mtu)
 263 {
 264         if ((new_mtu < PHONET_MIN_MTU) || (new_mtu > PHONET_MAX_MTU))
 265                 return -EINVAL;
 266         dev->mtu = new_mtu;
 267         return 0;
 268 }
 269
 270 static const struct net_device_ops pn_netdev_ops = {
 271         .ndo_open       = pn_net_open,
 272         .ndo_stop       = pn_net_close,
 273         .ndo_start_xmit = pn_net_xmit,
 274         .ndo_change_mtu = pn_net_mtu,
 275 };
 276
 277 static void pn_net_setup(struct net_device *dev)
 278 {
 279         dev->features           = 0;
 280         dev->type               = ARPHRD_PHONET;
 281         dev->flags              = IFF_POINTOPOINT | IFF_NOARP;
 282         dev->mtu                = PHONET_DEV_MTU;
 283         dev->hard_header_len    = 1;
 284         dev->dev_addr[0]        = PN_MEDIA_USB;
 285         dev->addr_len           = 1;
 286         dev->tx_queue_len       = 1;
 287
 288         dev->netdev_ops         = &pn_netdev_ops;
 289         dev->destructor         = free_netdev;
 290         dev->header_ops         = &phonet_header_ops;
 291 }
 292
 293 /*-------------------------------------------------------------------------*/
 294
 295 /*
 296  * Queue buffer for data from the host
 297  */
 298 static int
 299 pn_rx_submit(struct f_phonet *fp, struct usb_request *req, gfp_t gfp_flags)
 300 {
 301         struct page *page;
 302         int err;
 303
 304         page = alloc_page(gfp_flags);
 305         if (!page)
 306                 return -ENOMEM;
 307
 308         req->buf = page_address(page);
 309         req->length = PAGE_SIZE;
 310         req->context = page;
 311
 312         err = usb_ep_queue(fp->out_ep, req, gfp_flags);
 313         if (unlikely(err))
 314                 put_page(page);
 315         return err;
 316 }
 317
 318 static void pn_rx_complete(struct usb_ep *ep, struct usb_request *req)
 319 {
 320         struct f_phonet *fp = ep->driver_data;
 321         struct net_device *dev = fp->dev;
 322         struct page *page = req->context;
 323         struct sk_buff *skb;
 324         unsigned long flags;
 325         int status = req->status;
 326
 327         switch (status) {
 328         case 0:
 329                 spin_lock_irqsave(&fp->rx.lock, flags);
 330                 skb = fp->rx.skb;
 331                 if (!skb)
 332                         skb = fp->rx.skb = netdev_alloc_skb(dev, 12);
 333                 if (req->actual < req->length) /* Last fragment */
 334                         fp->rx.skb = NULL;
 335                 spin_unlock_irqrestore(&fp->rx.lock, flags);
 336
 337                 if (unlikely(!skb))
 338                         break;
 339
 340                 if (skb->len == 0) { /* First fragment */
 341                         skb->protocol = htons(ETH_P_PHONET);
 342                         skb_reset_mac_header(skb);
 343                         /* Can't use pskb_pull() on page in IRQ */
 344                         memcpy(skb_put(skb, 1), page_address(page), 1);
 345                 }
 346
 347                 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
 348                                 skb->len <= 1, req->actual, req->actual);
 349                 page = NULL;
 350
 351                 if (req->actual < req->length) { /* Last fragment */
 352                         skb->dev = dev;
 353                         dev->stats.rx_packets++;
 354                         dev->stats.rx_bytes += skb->len;
 355
 356                         netif_rx(skb);
 357                 }
 358                 break;
 359
 360         /* Do not resubmit in these cases: */
 361         case -ESHUTDOWN: /* disconnect */
 362         case -ECONNABORTED: /* hw reset */
 363         case -ECONNRESET: /* dequeued (unlink or netif down) */
 364                 req = NULL;
 365                 break;
 366
 367         /* Do resubmit in these cases: */
 368         case -EOVERFLOW: /* request buffer overflow */
 369                 dev->stats.rx_over_errors++;
 370         default:
 371                 dev->stats.rx_errors++;
 372                 break;
 373         }
 374
 375         if (page)
 376                 put_page(page);
 377         if (req)
 378                 pn_rx_submit(fp, req, GFP_ATOMIC | __GFP_COLD);
 379 }
 380
 381 /*-------------------------------------------------------------------------*/
 382
 383 static void __pn_reset(struct usb_function *f)
 384 {
 385         struct f_phonet *fp = func_to_pn(f);
 386         struct net_device *dev = fp->dev;
 387         struct phonet_port *port = netdev_priv(dev);
 388
 389         netif_carrier_off(dev);
 390         port->usb = NULL;
 391
 392         usb_ep_disable(fp->out_ep);
 393         usb_ep_disable(fp->in_ep);
 394         if (fp->rx.skb) {
 395                 dev_kfree_skb_irq(fp->rx.skb);
 396                 fp->rx.skb = NULL;
 397         }
 398 }
 399
 400 static int pn_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 401 {
 402         struct f_phonet *fp = func_to_pn(f);
 403         struct usb_gadget *gadget = fp->function.config->cdev->gadget;
 404
 405         if (intf == pn_control_intf_desc.bInterfaceNumber)
 406                 /* control interface, no altsetting */
 407                 return (alt > 0) ? -EINVAL : 0;
 408
 409         if (intf == pn_data_intf_desc.bInterfaceNumber) {
 410                 struct net_device *dev = fp->dev;
 411                 struct phonet_port *port = netdev_priv(dev);
 412
 413                 /* data intf (0: inactive, 1: active) */
 414                 if (alt > 1)
 415                         return -EINVAL;
 416
 417                 spin_lock(&port->lock);
 418                 __pn_reset(f);
 419                 if (alt == 1) {
 420                         int i;
 421
 422                         if (config_ep_by_speed(gadget, f, fp->in_ep) ||
 423                             config_ep_by_speed(gadget, f, fp->out_ep)) {
 424                                 fp->in_ep->desc = NULL;
 425                                 fp->out_ep->desc = NULL;
 426                                 spin_unlock(&port->lock);
 427                                 return -EINVAL;
 428                         }
 429                         usb_ep_enable(fp->out_ep);
 430                         usb_ep_enable(fp->in_ep);
 431
 432                         port->usb = fp;
 433                         fp->out_ep->driver_data = fp;
 434                         fp->in_ep->driver_data = fp;
 435
 436                         netif_carrier_on(dev);
 437                         for (i = 0; i < phonet_rxq_size; i++)
 438                                 pn_rx_submit(fp, fp->out_reqv[i], GFP_ATOMIC | __GFP_COLD);
 439                 }
 440                 spin_unlock(&port->lock);
 441                 return 0;
 442         }
 443
 444         return -EINVAL;
 445 }
 446
 447 static int pn_get_alt(struct usb_function *f, unsigned intf)
 448 {
 449         struct f_phonet *fp = func_to_pn(f);
 450
 451         if (intf == pn_control_intf_desc.bInterfaceNumber)
 452                 return 0;
 453
 454         if (intf == pn_data_intf_desc.bInterfaceNumber) {
 455                 struct phonet_port *port = netdev_priv(fp->dev);
 456                 u8 alt;
 457
 458                 spin_lock(&port->lock);
 459                 alt = port->usb != NULL;
 460                 spin_unlock(&port->lock);
 461                 return alt;
 462         }
 463
 464         return -EINVAL;
 465 }
 466
 467 static void pn_disconnect(struct usb_function *f)
 468 {
 469         struct f_phonet *fp = func_to_pn(f);
 470         struct phonet_port *port = netdev_priv(fp->dev);
 471         unsigned long flags;
 472
 473         /* remain disabled until set_alt */
 474         spin_lock_irqsave(&port->lock, flags);
 475         __pn_reset(f);
 476         spin_unlock_irqrestore(&port->lock, flags);
 477 }
 478
 479 /*-------------------------------------------------------------------------*/
 480
 481 static __init
 482 int pn_bind(struct usb_configuration *c, struct usb_function *f)
 483 {
 484         struct usb_composite_dev *cdev = c->cdev;
 485         struct usb_gadget *gadget = cdev->gadget;
 486         struct f_phonet *fp = func_to_pn(f);
 487         struct usb_ep *ep;
 488         int status, i;
 489
 490         /* Reserve interface IDs */
 491         status = usb_interface_id(c, f);
 492         if (status < 0)
 493                 goto err;
 494         pn_control_intf_desc.bInterfaceNumber = status;
 495         pn_union_desc.bMasterInterface0 = status;
 496
 497         status = usb_interface_id(c, f);
 498         if (status < 0)
 499                 goto err;
 500         pn_data_nop_intf_desc.bInterfaceNumber = status;
 501         pn_data_intf_desc.bInterfaceNumber = status;
 502         pn_union_desc.bSlaveInterface0 = status;
 503
 504         /* Reserve endpoints */
 505         status = -ENODEV;
 506         ep = usb_ep_autoconfig(gadget, &pn_fs_sink_desc);
 507         if (!ep)
 508                 goto err;
 509         fp->out_ep = ep;
 510         ep->driver_data = fp; /* Claim */
 511
 512         ep = usb_ep_autoconfig(gadget, &pn_fs_source_desc);
 513         if (!ep)
 514                 goto err;
 515         fp->in_ep = ep;
 516         ep->driver_data = fp; /* Claim */
 517
 518         pn_hs_sink_desc.bEndpointAddress =
 519                 pn_fs_sink_desc.bEndpointAddress;
 520         pn_hs_source_desc.bEndpointAddress =
 521                 pn_fs_source_desc.bEndpointAddress;
 522
 523         /* Do not try to bind Phonet twice... */
 524         fp->function.descriptors = fs_pn_function;
 525         fp->function.hs_descriptors = hs_pn_function;
 526
 527         /* Incoming USB requests */
 528         status = -ENOMEM;
 529         for (i = 0; i < phonet_rxq_size; i++) {
 530                 struct usb_request *req;
 531
 532                 req = usb_ep_alloc_request(fp->out_ep, GFP_KERNEL);
 533                 if (!req)
 534                         goto err;
 535
 536                 req->complete = pn_rx_complete;
 537                 fp->out_reqv[i] = req;
 538         }
 539
 540         /* Outgoing USB requests */
 541         fp->in_req = usb_ep_alloc_request(fp->in_ep, GFP_KERNEL);
 542         if (!fp->in_req)
 543                 goto err;
 544
 545         INFO(cdev, "USB CDC Phonet function\n");
 546         INFO(cdev, "using %s, OUT %s, IN %s\n", cdev->gadget->name,
 547                 fp->out_ep->name, fp->in_ep->name);
 548         return 0;
 549
 550 err:
 551         if (fp->out_ep)
 552                 fp->out_ep->driver_data = NULL;
 553         if (fp->in_ep)
 554                 fp->in_ep->driver_data = NULL;
 555         ERROR(cdev, "USB CDC Phonet: cannot autoconfigure\n");
 556         return status;
 557 }
 558
 559 static void
 560 pn_unbind(struct usb_configuration *c, struct usb_function *f)
 561 {
 562         struct f_phonet *fp = func_to_pn(f);
 563         int i;
 564
 565         /* We are already disconnected */
 566         if (fp->in_req)
 567                 usb_ep_free_request(fp->in_ep, fp->in_req);
 568         for (i = 0; i < phonet_rxq_size; i++)
 569                 if (fp->out_reqv[i])
 570                         usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);
 571
 572         kfree(fp);
 573 }
 574
 575 /*-------------------------------------------------------------------------*/
 576
 577 static struct net_device *dev;
 578
 579 int __init phonet_bind_config(struct usb_configuration *c)
 580 {
 581         struct f_phonet *fp;
 582         int err, size;
 583
 584         size = sizeof(*fp) + (phonet_rxq_size * sizeof(struct usb_request *));
 585         fp = kzalloc(size, GFP_KERNEL);
 586         if (!fp)
 587                 return -ENOMEM;
 588
 589         fp->dev = dev;
 590         fp->function.name = "phonet";
 591         fp->function.bind = pn_bind;
 592         fp->function.unbind = pn_unbind;
 593         fp->function.set_alt = pn_set_alt;
 594         fp->function.get_alt = pn_get_alt;
 595         fp->function.disable = pn_disconnect;
 596         spin_lock_init(&fp->rx.lock);
 597
 598         err = usb_add_function(c, &fp->function);
 599         if (err)
 600                 kfree(fp);
 601         return err;
 602 }
 603
 604 int __init gphonet_setup(struct usb_gadget *gadget)
 605 {
 606         struct phonet_port *port;
 607         int err;
 608
 609         /* Create net device */
 610         BUG_ON(dev);
 611         dev = alloc_netdev(sizeof(*port), "upnlink%d", pn_net_setup);
 612         if (!dev)
 613                 return -ENOMEM;
 614
 615         port = netdev_priv(dev);
 616         spin_lock_init(&port->lock);
 617         netif_carrier_off(dev);
 618         SET_NETDEV_DEV(dev, &gadget->dev);
 619
 620         err = register_netdev(dev);
 621         if (err)
 622                 free_netdev(dev);
 623         return err;
 624 }
 625
 626 void gphonet_cleanup(void)
 627 {
 628         unregister_netdev(dev);
 629 }