drivers/usb/gadget/f_acm.c

   1 /*
   2  * f_acm.c -- USB CDC serial (ACM) function driver
   3  *
   4  * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
   5  * Copyright (C) 2008 by David Brownell
   6  * Copyright (C) 2008 by Nokia Corporation
   7  *
   8  * This software is distributed under the terms of the GNU General
   9  * Public License ("GPL") as published by the Free Software Foundation,
  10  * either version 2 of that License or (at your option) any later version.
  11  */
  12
  13 /* #define VERBOSE_DEBUG */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/device.h>
  17
  18 #include "u_serial.h"
  19 #include "gadget_chips.h"
  20
  21
  22 /*
  23  * This CDC ACM function support just wraps control functions and
  24  * notifications around the generic serial-over-usb code.
  25  *
  26  * Because CDC ACM is standardized by the USB-IF, many host operating
  27  * systems have drivers for it.  Accordingly, ACM is the preferred
  28  * interop solution for serial-port type connections.  The control
  29  * models are often not necessary, and in any case don't do much in
  30  * this bare-bones implementation.
  31  *
  32  * Note that even MS-Windows has some support for ACM.  However, that
  33  * support is somewhat broken because when you use ACM in a composite
  34  * device, having multiple interfaces confuses the poor OS.  It doesn't
  35  * seem to understand CDC Union descriptors.  The new "association"
  36  * descriptors (roughly equivalent to CDC Unions) may sometimes help.
  37  */
  38
  39 struct acm_ep_descs {
  40         struct usb_endpoint_descriptor  *in;
  41         struct usb_endpoint_descriptor  *out;
  42         struct usb_endpoint_descriptor  *notify;
  43 };
  44
  45 struct f_acm {
  46         struct gserial                  port;
  47         u8                              ctrl_id, data_id;
  48         u8                              port_num;
  49
  50         u8                              pending;
  51
  52         /* lock is mostly for pending and notify_req ... they get accessed
  53          * by callbacks both from tty (open/close/break) under its spinlock,
  54          * and notify_req.complete() which can't use that lock.
  55          */
  56         spinlock_t                      lock;
  57
  58         struct acm_ep_descs             fs;
  59         struct acm_ep_descs             hs;
  60
  61         struct usb_ep                   *notify;
  62         struct usb_endpoint_descriptor  *notify_desc;
  63         struct usb_request              *notify_req;
  64
  65         struct usb_cdc_line_coding      port_line_coding;       /* 8-N-1 etc */
  66
  67         /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
  68         u16                             port_handshake_bits;
  69 #define ACM_CTRL_RTS    (1 << 1)        /* unused with full duplex */
  70 #define ACM_CTRL_DTR    (1 << 0)        /* host is ready for data r/w */
  71
  72         /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
  73         u16                             serial_state;
  74 #define ACM_CTRL_OVERRUN        (1 << 6)
  75 #define ACM_CTRL_PARITY         (1 << 5)
  76 #define ACM_CTRL_FRAMING        (1 << 4)
  77 #define ACM_CTRL_RI             (1 << 3)
  78 #define ACM_CTRL_BRK            (1 << 2)
  79 #define ACM_CTRL_DSR            (1 << 1)
  80 #define ACM_CTRL_DCD            (1 << 0)
  81 };
  82
  83 static inline struct f_acm *func_to_acm(struct usb_function *f)
  84 {
  85         return container_of(f, struct f_acm, port.func);
  86 }
  87
  88 static inline struct f_acm *port_to_acm(struct gserial *p)
  89 {
  90         return container_of(p, struct f_acm, port);
  91 }
  92
  93 /*-------------------------------------------------------------------------*/
  94
  95 /* notification endpoint uses smallish and infrequent fixed-size messages */
  96
  97 #define GS_LOG2_NOTIFY_INTERVAL         5       /* 1 << 5 == 32 msec */
  98 #define GS_NOTIFY_MAXPACKET             10      /* notification + 2 bytes */
  99
 100 /* interface and class descriptors: */
 101
 102 static struct usb_interface_descriptor acm_control_interface_desc __initdata = {
 103         .bLength =              USB_DT_INTERFACE_SIZE,
 104         .bDescriptorType =      USB_DT_INTERFACE,
 105         /* .bInterfaceNumber = DYNAMIC */
 106         .bNumEndpoints =        1,
 107         .bInterfaceClass =      USB_CLASS_COMM,
 108         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
 109         .bInterfaceProtocol =   USB_CDC_ACM_PROTO_AT_V25TER,
 110         /* .iInterface = DYNAMIC */
 111 };
 112
 113 static struct usb_interface_descriptor acm_data_interface_desc __initdata = {
 114         .bLength =              USB_DT_INTERFACE_SIZE,
 115         .bDescriptorType =      USB_DT_INTERFACE,
 116         /* .bInterfaceNumber = DYNAMIC */
 117         .bNumEndpoints =        2,
 118         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 119         .bInterfaceSubClass =   0,
 120         .bInterfaceProtocol =   0,
 121         /* .iInterface = DYNAMIC */
 122 };
 123
 124 static struct usb_cdc_header_desc acm_header_desc __initdata = {
 125         .bLength =              sizeof(acm_header_desc),
 126         .bDescriptorType =      USB_DT_CS_INTERFACE,
 127         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 128         .bcdCDC =               cpu_to_le16(0x0110),
 129 };
 130
 131 static struct usb_cdc_call_mgmt_descriptor
 132 acm_call_mgmt_descriptor __initdata = {
 133         .bLength =              sizeof(acm_call_mgmt_descriptor),
 134         .bDescriptorType =      USB_DT_CS_INTERFACE,
 135         .bDescriptorSubType =   USB_CDC_CALL_MANAGEMENT_TYPE,
 136         .bmCapabilities =       0,
 137         /* .bDataInterface = DYNAMIC */
 138 };
 139
 140 static struct usb_cdc_acm_descriptor acm_descriptor __initdata = {
 141         .bLength =              sizeof(acm_descriptor),
 142         .bDescriptorType =      USB_DT_CS_INTERFACE,
 143         .bDescriptorSubType =   USB_CDC_ACM_TYPE,
 144         .bmCapabilities =       USB_CDC_CAP_LINE,
 145 };
 146
 147 static struct usb_cdc_union_desc acm_union_desc __initdata = {
 148         .bLength =              sizeof(acm_union_desc),
 149         .bDescriptorType =      USB_DT_CS_INTERFACE,
 150         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 151         /* .bMasterInterface0 = DYNAMIC */
 152         /* .bSlaveInterface0 =  DYNAMIC */
 153 };
 154
 155 /* full speed support: */
 156
 157 static struct usb_endpoint_descriptor acm_fs_notify_desc __initdata = {
 158         .bLength =              USB_DT_ENDPOINT_SIZE,
 159         .bDescriptorType =      USB_DT_ENDPOINT,
 160         .bEndpointAddress =     USB_DIR_IN,
 161         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 162         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 163         .bInterval =            1 << GS_LOG2_NOTIFY_INTERVAL,
 164 };
 165
 166 static struct usb_endpoint_descriptor acm_fs_in_desc __initdata = {
 167         .bLength =              USB_DT_ENDPOINT_SIZE,
 168         .bDescriptorType =      USB_DT_ENDPOINT,
 169         .bEndpointAddress =     USB_DIR_IN,
 170         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 171 };
 172
 173 static struct usb_endpoint_descriptor acm_fs_out_desc __initdata = {
 174         .bLength =              USB_DT_ENDPOINT_SIZE,
 175         .bDescriptorType =      USB_DT_ENDPOINT,
 176         .bEndpointAddress =     USB_DIR_OUT,
 177         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 178 };
 179
 180 static struct usb_descriptor_header *acm_fs_function[] __initdata = {
 181         (struct usb_descriptor_header *) &acm_control_interface_desc,
 182         (struct usb_descriptor_header *) &acm_header_desc,
 183         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 184         (struct usb_descriptor_header *) &acm_descriptor,
 185         (struct usb_descriptor_header *) &acm_union_desc,
 186         (struct usb_descriptor_header *) &acm_fs_notify_desc,
 187         (struct usb_descriptor_header *) &acm_data_interface_desc,
 188         (struct usb_descriptor_header *) &acm_fs_in_desc,
 189         (struct usb_descriptor_header *) &acm_fs_out_desc,
 190         NULL,
 191 };
 192
 193 /* high speed support: */
 194
 195 static struct usb_endpoint_descriptor acm_hs_notify_desc __initdata = {
 196         .bLength =              USB_DT_ENDPOINT_SIZE,
 197         .bDescriptorType =      USB_DT_ENDPOINT,
 198         .bEndpointAddress =     USB_DIR_IN,
 199         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 200         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 201         .bInterval =            GS_LOG2_NOTIFY_INTERVAL+4,
 202 };
 203
 204 static struct usb_endpoint_descriptor acm_hs_in_desc __initdata = {
 205         .bLength =              USB_DT_ENDPOINT_SIZE,
 206         .bDescriptorType =      USB_DT_ENDPOINT,
 207         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 208         .wMaxPacketSize =       cpu_to_le16(512),
 209 };
 210
 211 static struct usb_endpoint_descriptor acm_hs_out_desc __initdata = {
 212         .bLength =              USB_DT_ENDPOINT_SIZE,
 213         .bDescriptorType =      USB_DT_ENDPOINT,
 214         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 215         .wMaxPacketSize =       cpu_to_le16(512),
 216 };
 217
 218 static struct usb_descriptor_header *acm_hs_function[] __initdata = {
 219         (struct usb_descriptor_header *) &acm_control_interface_desc,
 220         (struct usb_descriptor_header *) &acm_header_desc,
 221         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 222         (struct usb_descriptor_header *) &acm_descriptor,
 223         (struct usb_descriptor_header *) &acm_union_desc,
 224         (struct usb_descriptor_header *) &acm_hs_notify_desc,
 225         (struct usb_descriptor_header *) &acm_data_interface_desc,
 226         (struct usb_descriptor_header *) &acm_hs_in_desc,
 227         (struct usb_descriptor_header *) &acm_hs_out_desc,
 228         NULL,
 229 };
 230
 231 /* string descriptors: */
 232
 233 #define ACM_CTRL_IDX    0
 234 #define ACM_DATA_IDX    1
 235
 236 /* static strings, in UTF-8 */
 237 static struct usb_string acm_string_defs[] = {
 238         [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
 239         [ACM_DATA_IDX].s = "CDC ACM Data",
 240         {  /* ZEROES END LIST */ },
 241 };
 242
 243 static struct usb_gadget_strings acm_string_table = {
 244         .language =             0x0409, /* en-us */
 245         .strings =              acm_string_defs,
 246 };
 247
 248 static struct usb_gadget_strings *acm_strings[] = {
 249         &acm_string_table,
 250         NULL,
 251 };
 252
 253 /*-------------------------------------------------------------------------*/
 254
 255 /* ACM control ... data handling is delegated to tty library code.
 256  * The main task of this function is to activate and deactivate
 257  * that code based on device state; track parameters like line
 258  * speed, handshake state, and so on; and issue notifications.
 259  */
 260
 261 static void acm_complete_set_line_coding(struct usb_ep *ep,
 262                 struct usb_request *req)
 263 {
 264         struct f_acm    *acm = ep->driver_data;
 265         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 266
 267         if (req->status != 0) {
 268                 DBG(cdev, "acm ttyGS%d completion, err %d\n",
 269                                 acm->port_num, req->status);
 270                 return;
 271         }
 272
 273         /* normal completion */
 274         if (req->actual != sizeof(acm->port_line_coding)) {
 275                 DBG(cdev, "acm ttyGS%d short resp, len %d\n",
 276                                 acm->port_num, req->actual);
 277                 usb_ep_set_halt(ep);
 278         } else {
 279                 struct usb_cdc_line_coding      *value = req->buf;
 280
 281                 /* REVISIT:  we currently just remember this data.
 282                  * If we change that, (a) validate it first, then
 283                  * (b) update whatever hardware needs updating,
 284                  * (c) worry about locking.  This is information on
 285                  * the order of 9600-8-N-1 ... most of which means
 286                  * nothing unless we control a real RS232 line.
 287                  */
 288                 acm->port_line_coding = *value;
 289         }
 290 }
 291
 292 static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 293 {
 294         struct f_acm            *acm = func_to_acm(f);
 295         struct usb_composite_dev *cdev = f->config->cdev;
 296         struct usb_request      *req = cdev->req;
 297         int                     value = -EOPNOTSUPP;
 298         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 299         u16                     w_value = le16_to_cpu(ctrl->wValue);
 300         u16                     w_length = le16_to_cpu(ctrl->wLength);
 301
 302         /* composite driver infrastructure handles everything except
 303          * CDC class messages; interface activation uses set_alt().
 304          *
 305          * Note CDC spec table 4 lists the ACM request profile.  It requires
 306          * encapsulated command support ... we don't handle any, and respond
 307          * to them by stalling.  Options include get/set/clear comm features
 308          * (not that useful) and SEND_BREAK.
 309          */
 310         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 311
 312         /* SET_LINE_CODING ... just read and save what the host sends */
 313         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 314                         | USB_CDC_REQ_SET_LINE_CODING:
 315                 if (w_length != sizeof(struct usb_cdc_line_coding)
 316                                 || w_index != acm->ctrl_id)
 317                         goto invalid;
 318
 319                 value = w_length;
 320                 cdev->gadget->ep0->driver_data = acm;
 321                 req->complete = acm_complete_set_line_coding;
 322                 break;
 323
 324         /* GET_LINE_CODING ... return what host sent, or initial value */
 325         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 326                         | USB_CDC_REQ_GET_LINE_CODING:
 327                 if (w_index != acm->ctrl_id)
 328                         goto invalid;
 329
 330                 value = min_t(unsigned, w_length,
 331                                 sizeof(struct usb_cdc_line_coding));
 332                 memcpy(req->buf, &acm->port_line_coding, value);
 333                 break;
 334
 335         /* SET_CONTROL_LINE_STATE ... save what the host sent */
 336         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 337                         | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
 338                 if (w_index != acm->ctrl_id)
 339                         goto invalid;
 340
 341                 value = 0;
 342
 343                 /* FIXME we should not allow data to flow until the
 344                  * host sets the ACM_CTRL_DTR bit; and when it clears
 345                  * that bit, we should return to that no-flow state.
 346                  */
 347                 acm->port_handshake_bits = w_value;
 348                 break;
 349
 350         default:
 351 invalid:
 352                 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 353                         ctrl->bRequestType, ctrl->bRequest,
 354                         w_value, w_index, w_length);
 355         }
 356
 357         /* respond with data transfer or status phase? */
 358         if (value >= 0) {
 359                 DBG(cdev, "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
 360                         acm->port_num, ctrl->bRequestType, ctrl->bRequest,
 361                         w_value, w_index, w_length);
 362                 req->zero = 0;
 363                 req->length = value;
 364                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 365                 if (value < 0)
 366                         ERROR(cdev, "acm response on ttyGS%d, err %d\n",
 367                                         acm->port_num, value);
 368         }
 369
 370         /* device either stalls (value < 0) or reports success */
 371         return value;
 372 }
 373
 374 static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 375 {
 376         struct f_acm            *acm = func_to_acm(f);
 377         struct usb_composite_dev *cdev = f->config->cdev;
 378
 379         /* we know alt == 0, so this is an activation or a reset */
 380
 381         if (intf == acm->ctrl_id) {
 382                 if (acm->notify->driver_data) {
 383                         VDBG(cdev, "reset acm control interface %d\n", intf);
 384                         usb_ep_disable(acm->notify);
 385                 } else {
 386                         VDBG(cdev, "init acm ctrl interface %d\n", intf);
 387                         acm->notify_desc = ep_choose(cdev->gadget,
 388                                         acm->hs.notify,
 389                                         acm->fs.notify);
 390                 }
 391                 usb_ep_enable(acm->notify, acm->notify_desc);
 392                 acm->notify->driver_data = acm;
 393
 394         } else if (intf == acm->data_id) {
 395                 if (acm->port.in->driver_data) {
 396                         DBG(cdev, "reset acm ttyGS%d\n", acm->port_num);
 397                         gserial_disconnect(&acm->port);
 398                 } else {
 399                         DBG(cdev, "activate acm ttyGS%d\n", acm->port_num);
 400                         acm->port.in_desc = ep_choose(cdev->gadget,
 401                                         acm->hs.in, acm->fs.in);
 402                         acm->port.out_desc = ep_choose(cdev->gadget,
 403                                         acm->hs.out, acm->fs.out);
 404                 }
 405                 gserial_connect(&acm->port, acm->port_num);
 406
 407         } else
 408                 return -EINVAL;
 409
 410         return 0;
 411 }
 412
 413 static void acm_disable(struct usb_function *f)
 414 {
 415         struct f_acm    *acm = func_to_acm(f);
 416         struct usb_composite_dev *cdev = f->config->cdev;
 417
 418         DBG(cdev, "acm ttyGS%d deactivated\n", acm->port_num);
 419         gserial_disconnect(&acm->port);
 420         usb_ep_disable(acm->notify);
 421         acm->notify->driver_data = NULL;
 422 }
 423
 424 /*-------------------------------------------------------------------------*/
 425
 426 /**
 427  * acm_cdc_notify - issue CDC notification to host
 428  * @acm: wraps host to be notified
 429  * @type: notification type
 430  * @value: Refer to cdc specs, wValue field.
 431  * @data: data to be sent
 432  * @length: size of data
 433  * Context: irqs blocked, acm->lock held, acm_notify_req non-null
 434  *
 435  * Returns zero on sucess or a negative errno.
 436  *
 437  * See section 6.3.5 of the CDC 1.1 specification for information
 438  * about the only notification we issue:  SerialState change.
 439  */
 440 static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
 441                 void *data, unsigned length)
 442 {
 443         struct usb_ep                   *ep = acm->notify;
 444         struct usb_request              *req;
 445         struct usb_cdc_notification     *notify;
 446         const unsigned                  len = sizeof(*notify) + length;
 447         void                            *buf;
 448         int                             status;
 449
 450         req = acm->notify_req;
 451         acm->notify_req = NULL;
 452         acm->pending = false;
 453
 454         req->length = len;
 455         notify = req->buf;
 456         buf = notify + 1;
 457
 458         notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
 459                         | USB_RECIP_INTERFACE;
 460         notify->bNotificationType = type;
 461         notify->wValue = cpu_to_le16(value);
 462         notify->wIndex = cpu_to_le16(acm->ctrl_id);
 463         notify->wLength = cpu_to_le16(length);
 464         memcpy(buf, data, length);
 465
 466         /* ep_queue() can complete immediately if it fills the fifo... */
 467         spin_unlock(&acm->lock);
 468         status = usb_ep_queue(ep, req, GFP_ATOMIC);
 469         spin_lock(&acm->lock);
 470
 471         if (status < 0) {
 472                 ERROR(acm->port.func.config->cdev,
 473                                 "acm ttyGS%d can't notify serial state, %d\n",
 474                                 acm->port_num, status);
 475                 acm->notify_req = req;
 476         }
 477
 478         return status;
 479 }
 480
 481 static int acm_notify_serial_state(struct f_acm *acm)
 482 {
 483         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 484         int                     status;
 485
 486         spin_lock(&acm->lock);
 487         if (acm->notify_req) {
 488                 DBG(cdev, "acm ttyGS%d serial state %04x\n",
 489                                 acm->port_num, acm->serial_state);
 490                 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
 491                                 0, &acm->serial_state, sizeof(acm->serial_state));
 492         } else {
 493                 acm->pending = true;
 494                 status = 0;
 495         }
 496         spin_unlock(&acm->lock);
 497         return status;
 498 }
 499
 500 static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
 501 {
 502         struct f_acm            *acm = req->context;
 503         u8                      doit = false;
 504
 505         /* on this call path we do NOT hold the port spinlock,
 506          * which is why ACM needs its own spinlock
 507          */
 508         spin_lock(&acm->lock);
 509         if (req->status != -ESHUTDOWN)
 510                 doit = acm->pending;
 511         acm->notify_req = req;
 512         spin_unlock(&acm->lock);
 513
 514         if (doit)
 515                 acm_notify_serial_state(acm);
 516 }
 517
 518 /* connect == the TTY link is open */
 519
 520 static void acm_connect(struct gserial *port)
 521 {
 522         struct f_acm            *acm = port_to_acm(port);
 523
 524         acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
 525         acm_notify_serial_state(acm);
 526 }
 527
 528 static void acm_disconnect(struct gserial *port)
 529 {
 530         struct f_acm            *acm = port_to_acm(port);
 531
 532         acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
 533         acm_notify_serial_state(acm);
 534 }
 535
 536 static int acm_send_break(struct gserial *port, int duration)
 537 {
 538         struct f_acm            *acm = port_to_acm(port);
 539         u16                     state;
 540
 541         state = acm->serial_state;
 542         state &= ~ACM_CTRL_BRK;
 543         if (duration)
 544                 state |= ACM_CTRL_BRK;
 545
 546         acm->serial_state = state;
 547         return acm_notify_serial_state(acm);
 548 }
 549
 550 /*-------------------------------------------------------------------------*/
 551
 552 /* ACM function driver setup/binding */
 553 static int __init
 554 acm_bind(struct usb_configuration *c, struct usb_function *f)
 555 {
 556         struct usb_composite_dev *cdev = c->cdev;
 557         struct f_acm            *acm = func_to_acm(f);
 558         int                     status;
 559         struct usb_ep           *ep;
 560
 561         /* allocate instance-specific interface IDs, and patch descriptors */
 562         status = usb_interface_id(c, f);
 563         if (status < 0)
 564                 goto fail;
 565         acm->ctrl_id = status;
 566
 567         acm_control_interface_desc.bInterfaceNumber = status;
 568         acm_union_desc .bMasterInterface0 = status;
 569
 570         status = usb_interface_id(c, f);
 571         if (status < 0)
 572                 goto fail;
 573         acm->data_id = status;
 574
 575         acm_data_interface_desc.bInterfaceNumber = status;
 576         acm_union_desc.bSlaveInterface0 = status;
 577         acm_call_mgmt_descriptor.bDataInterface = status;
 578
 579         status = -ENODEV;
 580
 581         /* allocate instance-specific endpoints */
 582         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
 583         if (!ep)
 584                 goto fail;
 585         acm->port.in = ep;
 586         ep->driver_data = cdev; /* claim */
 587
 588         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
 589         if (!ep)
 590                 goto fail;
 591         acm->port.out = ep;
 592         ep->driver_data = cdev; /* claim */
 593
 594         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
 595         if (!ep)
 596                 goto fail;
 597         acm->notify = ep;
 598         ep->driver_data = cdev; /* claim */
 599
 600         /* allocate notification */
 601         acm->notify_req = gs_alloc_req(ep,
 602                         sizeof(struct usb_cdc_notification) + 2,
 603                         GFP_KERNEL);
 604         if (!acm->notify_req)
 605                 goto fail;
 606
 607         acm->notify_req->complete = acm_cdc_notify_complete;
 608         acm->notify_req->context = acm;
 609
 610         /* copy descriptors, and track endpoint copies */
 611         f->descriptors = usb_copy_descriptors(acm_fs_function);
 612         if (!f->descriptors)
 613                 goto fail;
 614
 615         acm->fs.in = usb_find_endpoint(acm_fs_function,
 616                         f->descriptors, &acm_fs_in_desc);
 617         acm->fs.out = usb_find_endpoint(acm_fs_function,
 618                         f->descriptors, &acm_fs_out_desc);
 619         acm->fs.notify = usb_find_endpoint(acm_fs_function,
 620                         f->descriptors, &acm_fs_notify_desc);
 621
 622         /* support all relevant hardware speeds... we expect that when
 623          * hardware is dual speed, all bulk-capable endpoints work at
 624          * both speeds
 625          */
 626         if (gadget_is_dualspeed(c->cdev->gadget)) {
 627                 acm_hs_in_desc.bEndpointAddress =
 628                                 acm_fs_in_desc.bEndpointAddress;
 629                 acm_hs_out_desc.bEndpointAddress =
 630                                 acm_fs_out_desc.bEndpointAddress;
 631                 acm_hs_notify_desc.bEndpointAddress =
 632                                 acm_fs_notify_desc.bEndpointAddress;
 633
 634                 /* copy descriptors, and track endpoint copies */
 635                 f->hs_descriptors = usb_copy_descriptors(acm_hs_function);
 636
 637                 acm->hs.in = usb_find_endpoint(acm_hs_function,
 638                                 f->hs_descriptors, &acm_hs_in_desc);
 639                 acm->hs.out = usb_find_endpoint(acm_hs_function,
 640                                 f->hs_descriptors, &acm_hs_out_desc);
 641                 acm->hs.notify = usb_find_endpoint(acm_hs_function,
 642                                 f->hs_descriptors, &acm_hs_notify_desc);
 643         }
 644
 645         DBG(cdev, "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 646                         acm->port_num,
 647                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 648                         acm->port.in->name, acm->port.out->name,
 649                         acm->notify->name);
 650         return 0;
 651
 652 fail:
 653         if (acm->notify_req)
 654                 gs_free_req(acm->notify, acm->notify_req);
 655
 656         /* we might as well release our claims on endpoints */
 657         if (acm->notify)
 658                 acm->notify->driver_data = NULL;
 659         if (acm->port.out)
 660                 acm->port.out->driver_data = NULL;
 661         if (acm->port.in)
 662                 acm->port.in->driver_data = NULL;
 663
 664         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 665
 666         return status;
 667 }
 668
 669 static void
 670 acm_unbind(struct usb_configuration *c, struct usb_function *f)
 671 {
 672         struct f_acm            *acm = func_to_acm(f);
 673
 674         if (gadget_is_dualspeed(c->cdev->gadget))
 675                 usb_free_descriptors(f->hs_descriptors);
 676         usb_free_descriptors(f->descriptors);
 677         gs_free_req(acm->notify, acm->notify_req);
 678         kfree(acm);
 679 }
 680
 681 /* Some controllers can't support CDC ACM ... */
 682 static inline bool can_support_cdc(struct usb_configuration *c)
 683 {
 684         /* SH3 doesn't support multiple interfaces */
 685         if (gadget_is_sh(c->cdev->gadget))
 686                 return false;
 687
 688         /* sa1100 doesn't have a third interrupt endpoint */
 689         if (gadget_is_sa1100(c->cdev->gadget))
 690                 return false;
 691
 692         /* everything else is *probably* fine ... */
 693         return true;
 694 }
 695
 696 /**
 697  * acm_bind_config - add a CDC ACM function to a configuration
 698  * @c: the configuration to support the CDC ACM instance
 699  * @port_num: /dev/ttyGS* port this interface will use
 700  * Context: single threaded during gadget setup
 701  *
 702  * Returns zero on success, else negative errno.
 703  *
 704  * Caller must have called @gserial_setup() with enough ports to
 705  * handle all the ones it binds.  Caller is also responsible
 706  * for calling @gserial_cleanup() before module unload.
 707  */
 708 int __init acm_bind_config(struct usb_configuration *c, u8 port_num)
 709 {
 710         struct f_acm    *acm;
 711         int             status;
 712
 713         if (!can_support_cdc(c))
 714                 return -EINVAL;
 715
 716         /* REVISIT might want instance-specific strings to help
 717          * distinguish instances ...
 718          */
 719
 720         /* maybe allocate device-global string IDs, and patch descriptors */
 721         if (acm_string_defs[ACM_CTRL_IDX].id == 0) {
 722                 status = usb_string_id(c->cdev);
 723                 if (status < 0)
 724                         return status;
 725                 acm_string_defs[ACM_CTRL_IDX].id = status;
 726
 727                 acm_control_interface_desc.iInterface = status;
 728
 729                 status = usb_string_id(c->cdev);
 730                 if (status < 0)
 731                         return status;
 732                 acm_string_defs[ACM_DATA_IDX].id = status;
 733
 734                 acm_data_interface_desc.iInterface = status;
 735         }
 736
 737         /* allocate and initialize one new instance */
 738         acm = kzalloc(sizeof *acm, GFP_KERNEL);
 739         if (!acm)
 740                 return -ENOMEM;
 741
 742         spin_lock_init(&acm->lock);
 743
 744         acm->port_num = port_num;
 745
 746         acm->port.connect = acm_connect;
 747         acm->port.disconnect = acm_disconnect;
 748         acm->port.send_break = acm_send_break;
 749
 750         acm->port.func.name = "acm";
 751         acm->port.func.strings = acm_strings;
 752         /* descriptors are per-instance copies */
 753         acm->port.func.bind = acm_bind;
 754         acm->port.func.unbind = acm_unbind;
 755         acm->port.func.set_alt = acm_set_alt;
 756         acm->port.func.setup = acm_setup;
 757         acm->port.func.disable = acm_disable;
 758
 759         status = usb_add_function(c, &acm->port.func);
 760         if (status)
 761                 kfree(acm);
 762         return status;
 763 }