linux/drivers/usb/gadget/f_phonet.c
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   1/*
   2 * f_phonet.c -- USB CDC Phonet function
   3 *
   4 * Copyright (C) 2007-2008 Nokia Corporation. All rights reserved.
   5 *
   6 * Author: RĂ©mi 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
  37struct phonet_port {
  38        struct f_phonet                 *usb;
  39        spinlock_t                      lock;
  40};
  41
  42struct 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
  55static int phonet_rxq_size = 17;
  56
  57static 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
  67static struct usb_interface_descriptor
  68pn_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
  77static const struct usb_cdc_header_desc
  78pn_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
  85static const struct usb_cdc_header_desc
  86pn_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
  93static struct usb_cdc_union_desc
  94pn_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
 103static struct usb_interface_descriptor
 104pn_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
 114static struct usb_interface_descriptor
 115pn_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
 125static struct usb_endpoint_descriptor
 126pn_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
 134static struct usb_endpoint_descriptor
 135pn_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
 144static struct usb_endpoint_descriptor
 145pn_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
 153static struct usb_endpoint_descriptor
 154pn_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
 163static 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
 175static 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
 189static int pn_net_open(struct net_device *dev)
 190{
 191        netif_wake_queue(dev);
 192        return 0;
 193}
 194
 195static int pn_net_close(struct net_device *dev)
 196{
 197        netif_stop_queue(dev);
 198        return 0;
 199}
 200
 201static 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
 224static 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
 252out_unlock:
 253        spin_unlock_irqrestore(&port->lock, flags);
 254out:
 255        if (unlikely(skb)) {
 256                dev_kfree_skb(skb);
 257                dev->stats.tx_dropped++;
 258        }
 259        return NETDEV_TX_OK;
 260}
 261
 262static 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
 270static 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
 277static 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 */
 298static int
 299pn_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 = __skb_alloc_page(gfp_flags | __GFP_NOMEMALLOC, NULL);
 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
 318static 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, PAGE_SIZE);
 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
 383static 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
 400static 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
 447static 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
 467static 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
 481static __init
 482int 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 = pn_fs_sink_desc.bEndpointAddress;
 519        pn_hs_source_desc.bEndpointAddress = pn_fs_source_desc.bEndpointAddress;
 520
 521        /* Do not try to bind Phonet twice... */
 522        status = usb_assign_descriptors(f, fs_pn_function, hs_pn_function,
 523                        NULL);
 524        if (status)
 525                goto err;
 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_req;
 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_req;
 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
 550err_req:
 551        for (i = 0; i < phonet_rxq_size && fp->out_reqv[i]; i++)
 552                usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);
 553err:
 554        usb_free_all_descriptors(f);
 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
 563static void
 564pn_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        usb_free_all_descriptors(f);
 577        kfree(fp);
 578}
 579
 580/*-------------------------------------------------------------------------*/
 581
 582static struct net_device *dev;
 583
 584int __init phonet_bind_config(struct usb_configuration *c)
 585{
 586        struct f_phonet *fp;
 587        int err, size;
 588
 589        size = sizeof(*fp) + (phonet_rxq_size * sizeof(struct usb_request *));
 590        fp = kzalloc(size, GFP_KERNEL);
 591        if (!fp)
 592                return -ENOMEM;
 593
 594        fp->dev = dev;
 595        fp->function.name = "phonet";
 596        fp->function.bind = pn_bind;
 597        fp->function.unbind = pn_unbind;
 598        fp->function.set_alt = pn_set_alt;
 599        fp->function.get_alt = pn_get_alt;
 600        fp->function.disable = pn_disconnect;
 601        spin_lock_init(&fp->rx.lock);
 602
 603        err = usb_add_function(c, &fp->function);
 604        if (err)
 605                kfree(fp);
 606        return err;
 607}
 608
 609int __init gphonet_setup(struct usb_gadget *gadget)
 610{
 611        struct phonet_port *port;
 612        int err;
 613
 614        /* Create net device */
 615        BUG_ON(dev);
 616        dev = alloc_netdev(sizeof(*port), "upnlink%d", pn_net_setup);
 617        if (!dev)
 618                return -ENOMEM;
 619
 620        port = netdev_priv(dev);
 621        spin_lock_init(&port->lock);
 622        netif_carrier_off(dev);
 623        SET_NETDEV_DEV(dev, &gadget->dev);
 624
 625        err = register_netdev(dev);
 626        if (err)
 627                free_netdev(dev);
 628        return err;
 629}
 630
 631void gphonet_cleanup(void)
 632{
 633        unregister_netdev(dev);
 634}
 635