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  * Copyright (C) 2009 by Samsung Electronics
   8  * Author: Michal Nazarewicz (m.nazarewicz@samsung.com)
   9  *
  10  * This software is distributed under the terms of the GNU General
  11  * Public License ("GPL") as published by the Free Software Foundation,
  12  * either version 2 of that License or (at your option) any later version.
  13  */
  14
  15 /* #define VERBOSE_DEBUG */
  16
  17 #include <linux/slab.h>
  18 #include <linux/kernel.h>
  19 #include <linux/device.h>
  20
  21 #include "u_serial.h"
  22 #include "gadget_chips.h"
  23
  24
  25 /*
  26  * This CDC ACM function support just wraps control functions and
  27  * notifications around the generic serial-over-usb code.
  28  *
  29  * Because CDC ACM is standardized by the USB-IF, many host operating
  30  * systems have drivers for it.  Accordingly, ACM is the preferred
  31  * interop solution for serial-port type connections.  The control
  32  * models are often not necessary, and in any case don't do much in
  33  * this bare-bones implementation.
  34  *
  35  * Note that even MS-Windows has some support for ACM.  However, that
  36  * support is somewhat broken because when you use ACM in a composite
  37  * device, having multiple interfaces confuses the poor OS.  It doesn't
  38  * seem to understand CDC Union descriptors.  The new "association"
  39  * descriptors (roughly equivalent to CDC Unions) may sometimes help.
  40  */
  41
  42 struct f_acm {
  43         struct gserial                  port;
  44         u8                              ctrl_id, data_id;
  45         u8                              port_num;
  46
  47         u8                              pending;
  48
  49         /* lock is mostly for pending and notify_req ... they get accessed
  50          * by callbacks both from tty (open/close/break) under its spinlock,
  51          * and notify_req.complete() which can't use that lock.
  52          */
  53         spinlock_t                      lock;
  54
  55         struct usb_ep                   *notify;
  56         struct usb_request              *notify_req;
  57
  58         struct usb_cdc_line_coding      port_line_coding;       /* 8-N-1 etc */
  59
  60         /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
  61         u16                             port_handshake_bits;
  62 #define ACM_CTRL_RTS    (1 << 1)        /* unused with full duplex */
  63 #define ACM_CTRL_DTR    (1 << 0)        /* host is ready for data r/w */
  64
  65         /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
  66         u16                             serial_state;
  67 #define ACM_CTRL_OVERRUN        (1 << 6)
  68 #define ACM_CTRL_PARITY         (1 << 5)
  69 #define ACM_CTRL_FRAMING        (1 << 4)
  70 #define ACM_CTRL_RI             (1 << 3)
  71 #define ACM_CTRL_BRK            (1 << 2)
  72 #define ACM_CTRL_DSR            (1 << 1)
  73 #define ACM_CTRL_DCD            (1 << 0)
  74 };
  75
  76 static inline struct f_acm *func_to_acm(struct usb_function *f)
  77 {
  78         return container_of(f, struct f_acm, port.func);
  79 }
  80
  81 static inline struct f_acm *port_to_acm(struct gserial *p)
  82 {
  83         return container_of(p, struct f_acm, port);
  84 }
  85
  86 /*-------------------------------------------------------------------------*/
  87
  88 /* notification endpoint uses smallish and infrequent fixed-size messages */
  89
  90 #define GS_LOG2_NOTIFY_INTERVAL         5       /* 1 << 5 == 32 msec */
  91 #define GS_NOTIFY_MAXPACKET             10      /* notification + 2 bytes */
  92
  93 /* interface and class descriptors: */
  94
  95 static struct usb_interface_assoc_descriptor
  96 acm_iad_descriptor = {
  97         .bLength =              sizeof acm_iad_descriptor,
  98         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
  99
 100         /* .bFirstInterface =   DYNAMIC, */
 101         .bInterfaceCount =      2,      // control + data
 102         .bFunctionClass =       USB_CLASS_COMM,
 103         .bFunctionSubClass =    USB_CDC_SUBCLASS_ACM,
 104         .bFunctionProtocol =    USB_CDC_ACM_PROTO_AT_V25TER,
 105         /* .iFunction =         DYNAMIC */
 106 };
 107
 108
 109 static struct usb_interface_descriptor acm_control_interface_desc = {
 110         .bLength =              USB_DT_INTERFACE_SIZE,
 111         .bDescriptorType =      USB_DT_INTERFACE,
 112         /* .bInterfaceNumber = DYNAMIC */
 113         .bNumEndpoints =        1,
 114         .bInterfaceClass =      USB_CLASS_COMM,
 115         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
 116         .bInterfaceProtocol =   USB_CDC_ACM_PROTO_AT_V25TER,
 117         /* .iInterface = DYNAMIC */
 118 };
 119
 120 static struct usb_interface_descriptor acm_data_interface_desc = {
 121         .bLength =              USB_DT_INTERFACE_SIZE,
 122         .bDescriptorType =      USB_DT_INTERFACE,
 123         /* .bInterfaceNumber = DYNAMIC */
 124         .bNumEndpoints =        2,
 125         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 126         .bInterfaceSubClass =   0,
 127         .bInterfaceProtocol =   0,
 128         /* .iInterface = DYNAMIC */
 129 };
 130
 131 static struct usb_cdc_header_desc acm_header_desc = {
 132         .bLength =              sizeof(acm_header_desc),
 133         .bDescriptorType =      USB_DT_CS_INTERFACE,
 134         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 135         .bcdCDC =               cpu_to_le16(0x0110),
 136 };
 137
 138 static struct usb_cdc_call_mgmt_descriptor
 139 acm_call_mgmt_descriptor = {
 140         .bLength =              sizeof(acm_call_mgmt_descriptor),
 141         .bDescriptorType =      USB_DT_CS_INTERFACE,
 142         .bDescriptorSubType =   USB_CDC_CALL_MANAGEMENT_TYPE,
 143         .bmCapabilities =       0,
 144         /* .bDataInterface = DYNAMIC */
 145 };
 146
 147 static struct usb_cdc_acm_descriptor acm_descriptor = {
 148         .bLength =              sizeof(acm_descriptor),
 149         .bDescriptorType =      USB_DT_CS_INTERFACE,
 150         .bDescriptorSubType =   USB_CDC_ACM_TYPE,
 151         .bmCapabilities =       USB_CDC_CAP_LINE,
 152 };
 153
 154 static struct usb_cdc_union_desc acm_union_desc = {
 155         .bLength =              sizeof(acm_union_desc),
 156         .bDescriptorType =      USB_DT_CS_INTERFACE,
 157         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 158         /* .bMasterInterface0 = DYNAMIC */
 159         /* .bSlaveInterface0 =  DYNAMIC */
 160 };
 161
 162 /* full speed support: */
 163
 164 static struct usb_endpoint_descriptor acm_fs_notify_desc = {
 165         .bLength =              USB_DT_ENDPOINT_SIZE,
 166         .bDescriptorType =      USB_DT_ENDPOINT,
 167         .bEndpointAddress =     USB_DIR_IN,
 168         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 169         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 170         .bInterval =            1 << GS_LOG2_NOTIFY_INTERVAL,
 171 };
 172
 173 static struct usb_endpoint_descriptor acm_fs_in_desc = {
 174         .bLength =              USB_DT_ENDPOINT_SIZE,
 175         .bDescriptorType =      USB_DT_ENDPOINT,
 176         .bEndpointAddress =     USB_DIR_IN,
 177         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 178 };
 179
 180 static struct usb_endpoint_descriptor acm_fs_out_desc = {
 181         .bLength =              USB_DT_ENDPOINT_SIZE,
 182         .bDescriptorType =      USB_DT_ENDPOINT,
 183         .bEndpointAddress =     USB_DIR_OUT,
 184         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 185 };
 186
 187 static struct usb_descriptor_header *acm_fs_function[] = {
 188         (struct usb_descriptor_header *) &acm_iad_descriptor,
 189         (struct usb_descriptor_header *) &acm_control_interface_desc,
 190         (struct usb_descriptor_header *) &acm_header_desc,
 191         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 192         (struct usb_descriptor_header *) &acm_descriptor,
 193         (struct usb_descriptor_header *) &acm_union_desc,
 194         (struct usb_descriptor_header *) &acm_fs_notify_desc,
 195         (struct usb_descriptor_header *) &acm_data_interface_desc,
 196         (struct usb_descriptor_header *) &acm_fs_in_desc,
 197         (struct usb_descriptor_header *) &acm_fs_out_desc,
 198         NULL,
 199 };
 200
 201 /* high speed support: */
 202
 203 static struct usb_endpoint_descriptor acm_hs_notify_desc = {
 204         .bLength =              USB_DT_ENDPOINT_SIZE,
 205         .bDescriptorType =      USB_DT_ENDPOINT,
 206         .bEndpointAddress =     USB_DIR_IN,
 207         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 208         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 209         .bInterval =            GS_LOG2_NOTIFY_INTERVAL+4,
 210 };
 211
 212 static struct usb_endpoint_descriptor acm_hs_in_desc = {
 213         .bLength =              USB_DT_ENDPOINT_SIZE,
 214         .bDescriptorType =      USB_DT_ENDPOINT,
 215         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 216         .wMaxPacketSize =       cpu_to_le16(512),
 217 };
 218
 219 static struct usb_endpoint_descriptor acm_hs_out_desc = {
 220         .bLength =              USB_DT_ENDPOINT_SIZE,
 221         .bDescriptorType =      USB_DT_ENDPOINT,
 222         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 223         .wMaxPacketSize =       cpu_to_le16(512),
 224 };
 225
 226 static struct usb_descriptor_header *acm_hs_function[] = {
 227         (struct usb_descriptor_header *) &acm_iad_descriptor,
 228         (struct usb_descriptor_header *) &acm_control_interface_desc,
 229         (struct usb_descriptor_header *) &acm_header_desc,
 230         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 231         (struct usb_descriptor_header *) &acm_descriptor,
 232         (struct usb_descriptor_header *) &acm_union_desc,
 233         (struct usb_descriptor_header *) &acm_hs_notify_desc,
 234         (struct usb_descriptor_header *) &acm_data_interface_desc,
 235         (struct usb_descriptor_header *) &acm_hs_in_desc,
 236         (struct usb_descriptor_header *) &acm_hs_out_desc,
 237         NULL,
 238 };
 239
 240 /* string descriptors: */
 241
 242 #define ACM_CTRL_IDX    0
 243 #define ACM_DATA_IDX    1
 244 #define ACM_IAD_IDX     2
 245
 246 /* static strings, in UTF-8 */
 247 static struct usb_string acm_string_defs[] = {
 248         [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
 249         [ACM_DATA_IDX].s = "CDC ACM Data",
 250         [ACM_IAD_IDX ].s = "CDC Serial",
 251         {  /* ZEROES END LIST */ },
 252 };
 253
 254 static struct usb_gadget_strings acm_string_table = {
 255         .language =             0x0409, /* en-us */
 256         .strings =              acm_string_defs,
 257 };
 258
 259 static struct usb_gadget_strings *acm_strings[] = {
 260         &acm_string_table,
 261         NULL,
 262 };
 263
 264 /*-------------------------------------------------------------------------*/
 265
 266 /* ACM control ... data handling is delegated to tty library code.
 267  * The main task of this function is to activate and deactivate
 268  * that code based on device state; track parameters like line
 269  * speed, handshake state, and so on; and issue notifications.
 270  */
 271
 272 static void acm_complete_set_line_coding(struct usb_ep *ep,
 273                 struct usb_request *req)
 274 {
 275         struct f_acm    *acm = ep->driver_data;
 276         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 277
 278         if (req->status != 0) {
 279                 DBG(cdev, "acm ttyGS%d completion, err %d\n",
 280                                 acm->port_num, req->status);
 281                 return;
 282         }
 283
 284         /* normal completion */
 285         if (req->actual != sizeof(acm->port_line_coding)) {
 286                 DBG(cdev, "acm ttyGS%d short resp, len %d\n",
 287                                 acm->port_num, req->actual);
 288                 usb_ep_set_halt(ep);
 289         } else {
 290                 struct usb_cdc_line_coding      *value = req->buf;
 291
 292                 /* REVISIT:  we currently just remember this data.
 293                  * If we change that, (a) validate it first, then
 294                  * (b) update whatever hardware needs updating,
 295                  * (c) worry about locking.  This is information on
 296                  * the order of 9600-8-N-1 ... most of which means
 297                  * nothing unless we control a real RS232 line.
 298                  */
 299                 acm->port_line_coding = *value;
 300         }
 301 }
 302
 303 static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 304 {
 305         struct f_acm            *acm = func_to_acm(f);
 306         struct usb_composite_dev *cdev = f->config->cdev;
 307         struct usb_request      *req = cdev->req;
 308         int                     value = -EOPNOTSUPP;
 309         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 310         u16                     w_value = le16_to_cpu(ctrl->wValue);
 311         u16                     w_length = le16_to_cpu(ctrl->wLength);
 312
 313         /* composite driver infrastructure handles everything except
 314          * CDC class messages; interface activation uses set_alt().
 315          *
 316          * Note CDC spec table 4 lists the ACM request profile.  It requires
 317          * encapsulated command support ... we don't handle any, and respond
 318          * to them by stalling.  Options include get/set/clear comm features
 319          * (not that useful) and SEND_BREAK.
 320          */
 321         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 322
 323         /* SET_LINE_CODING ... just read and save what the host sends */
 324         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 325                         | USB_CDC_REQ_SET_LINE_CODING:
 326                 if (w_length != sizeof(struct usb_cdc_line_coding)
 327                                 || w_index != acm->ctrl_id)
 328                         goto invalid;
 329
 330                 value = w_length;
 331                 cdev->gadget->ep0->driver_data = acm;
 332                 req->complete = acm_complete_set_line_coding;
 333                 break;
 334
 335         /* GET_LINE_CODING ... return what host sent, or initial value */
 336         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 337                         | USB_CDC_REQ_GET_LINE_CODING:
 338                 if (w_index != acm->ctrl_id)
 339                         goto invalid;
 340
 341                 value = min_t(unsigned, w_length,
 342                                 sizeof(struct usb_cdc_line_coding));
 343                 memcpy(req->buf, &acm->port_line_coding, value);
 344                 break;
 345
 346         /* SET_CONTROL_LINE_STATE ... save what the host sent */
 347         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 348                         | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
 349                 if (w_index != acm->ctrl_id)
 350                         goto invalid;
 351
 352                 value = 0;
 353
 354                 /* FIXME we should not allow data to flow until the
 355                  * host sets the ACM_CTRL_DTR bit; and when it clears
 356                  * that bit, we should return to that no-flow state.
 357                  */
 358                 acm->port_handshake_bits = w_value;
 359                 break;
 360
 361         default:
 362 invalid:
 363                 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 364                         ctrl->bRequestType, ctrl->bRequest,
 365                         w_value, w_index, w_length);
 366         }
 367
 368         /* respond with data transfer or status phase? */
 369         if (value >= 0) {
 370                 DBG(cdev, "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
 371                         acm->port_num, ctrl->bRequestType, ctrl->bRequest,
 372                         w_value, w_index, w_length);
 373                 req->zero = 0;
 374                 req->length = value;
 375                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 376                 if (value < 0)
 377                         ERROR(cdev, "acm response on ttyGS%d, err %d\n",
 378                                         acm->port_num, value);
 379         }
 380
 381         /* device either stalls (value < 0) or reports success */
 382         return value;
 383 }
 384
 385 static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 386 {
 387         struct f_acm            *acm = func_to_acm(f);
 388         struct usb_composite_dev *cdev = f->config->cdev;
 389
 390         /* we know alt == 0, so this is an activation or a reset */
 391
 392         if (intf == acm->ctrl_id) {
 393                 if (acm->notify->driver_data) {
 394                         VDBG(cdev, "reset acm control interface %d\n", intf);
 395                         usb_ep_disable(acm->notify);
 396                 } else {
 397                         VDBG(cdev, "init acm ctrl interface %d\n", intf);
 398                         if (config_ep_by_speed(cdev->gadget, f, acm->notify))
 399                                 return -EINVAL;
 400                 }
 401                 usb_ep_enable(acm->notify);
 402                 acm->notify->driver_data = acm;
 403
 404         } else if (intf == acm->data_id) {
 405                 if (acm->port.in->driver_data) {
 406                         DBG(cdev, "reset acm ttyGS%d\n", acm->port_num);
 407                         gserial_disconnect(&acm->port);
 408                 }
 409                 if (!acm->port.in->desc || !acm->port.out->desc) {
 410                         DBG(cdev, "activate acm ttyGS%d\n", acm->port_num);
 411                         if (config_ep_by_speed(cdev->gadget, f,
 412                                                acm->port.in) ||
 413                             config_ep_by_speed(cdev->gadget, f,
 414                                                acm->port.out)) {
 415                                 acm->port.in->desc = NULL;
 416                                 acm->port.out->desc = NULL;
 417                                 return -EINVAL;
 418                         }
 419                 }
 420                 gserial_connect(&acm->port, acm->port_num);
 421
 422         } else
 423                 return -EINVAL;
 424
 425         return 0;
 426 }
 427
 428 static void acm_disable(struct usb_function *f)
 429 {
 430         struct f_acm    *acm = func_to_acm(f);
 431         struct usb_composite_dev *cdev = f->config->cdev;
 432
 433         DBG(cdev, "acm ttyGS%d deactivated\n", acm->port_num);
 434         gserial_disconnect(&acm->port);
 435         usb_ep_disable(acm->notify);
 436         acm->notify->driver_data = NULL;
 437 }
 438
 439 /*-------------------------------------------------------------------------*/
 440
 441 /**
 442  * acm_cdc_notify - issue CDC notification to host
 443  * @acm: wraps host to be notified
 444  * @type: notification type
 445  * @value: Refer to cdc specs, wValue field.
 446  * @data: data to be sent
 447  * @length: size of data
 448  * Context: irqs blocked, acm->lock held, acm_notify_req non-null
 449  *
 450  * Returns zero on success or a negative errno.
 451  *
 452  * See section 6.3.5 of the CDC 1.1 specification for information
 453  * about the only notification we issue:  SerialState change.
 454  */
 455 static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
 456                 void *data, unsigned length)
 457 {
 458         struct usb_ep                   *ep = acm->notify;
 459         struct usb_request              *req;
 460         struct usb_cdc_notification     *notify;
 461         const unsigned                  len = sizeof(*notify) + length;
 462         void                            *buf;
 463         int                             status;
 464
 465         req = acm->notify_req;
 466         acm->notify_req = NULL;
 467         acm->pending = false;
 468
 469         req->length = len;
 470         notify = req->buf;
 471         buf = notify + 1;
 472
 473         notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
 474                         | USB_RECIP_INTERFACE;
 475         notify->bNotificationType = type;
 476         notify->wValue = cpu_to_le16(value);
 477         notify->wIndex = cpu_to_le16(acm->ctrl_id);
 478         notify->wLength = cpu_to_le16(length);
 479         memcpy(buf, data, length);
 480
 481         /* ep_queue() can complete immediately if it fills the fifo... */
 482         spin_unlock(&acm->lock);
 483         status = usb_ep_queue(ep, req, GFP_ATOMIC);
 484         spin_lock(&acm->lock);
 485
 486         if (status < 0) {
 487                 ERROR(acm->port.func.config->cdev,
 488                                 "acm ttyGS%d can't notify serial state, %d\n",
 489                                 acm->port_num, status);
 490                 acm->notify_req = req;
 491         }
 492
 493         return status;
 494 }
 495
 496 static int acm_notify_serial_state(struct f_acm *acm)
 497 {
 498         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 499         int                     status;
 500
 501         spin_lock(&acm->lock);
 502         if (acm->notify_req) {
 503                 DBG(cdev, "acm ttyGS%d serial state %04x\n",
 504                                 acm->port_num, acm->serial_state);
 505                 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
 506                                 0, &acm->serial_state, sizeof(acm->serial_state));
 507         } else {
 508                 acm->pending = true;
 509                 status = 0;
 510         }
 511         spin_unlock(&acm->lock);
 512         return status;
 513 }
 514
 515 static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
 516 {
 517         struct f_acm            *acm = req->context;
 518         u8                      doit = false;
 519
 520         /* on this call path we do NOT hold the port spinlock,
 521          * which is why ACM needs its own spinlock
 522          */
 523         spin_lock(&acm->lock);
 524         if (req->status != -ESHUTDOWN)
 525                 doit = acm->pending;
 526         acm->notify_req = req;
 527         spin_unlock(&acm->lock);
 528
 529         if (doit)
 530                 acm_notify_serial_state(acm);
 531 }
 532
 533 /* connect == the TTY link is open */
 534
 535 static void acm_connect(struct gserial *port)
 536 {
 537         struct f_acm            *acm = port_to_acm(port);
 538
 539         acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
 540         acm_notify_serial_state(acm);
 541 }
 542
 543 static void acm_disconnect(struct gserial *port)
 544 {
 545         struct f_acm            *acm = port_to_acm(port);
 546
 547         acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
 548         acm_notify_serial_state(acm);
 549 }
 550
 551 static int acm_send_break(struct gserial *port, int duration)
 552 {
 553         struct f_acm            *acm = port_to_acm(port);
 554         u16                     state;
 555
 556         state = acm->serial_state;
 557         state &= ~ACM_CTRL_BRK;
 558         if (duration)
 559                 state |= ACM_CTRL_BRK;
 560
 561         acm->serial_state = state;
 562         return acm_notify_serial_state(acm);
 563 }
 564
 565 /*-------------------------------------------------------------------------*/
 566
 567 /* ACM function driver setup/binding */
 568 static int
 569 acm_bind(struct usb_configuration *c, struct usb_function *f)
 570 {
 571         struct usb_composite_dev *cdev = c->cdev;
 572         struct f_acm            *acm = func_to_acm(f);
 573         int                     status;
 574         struct usb_ep           *ep;
 575
 576         /* allocate instance-specific interface IDs, and patch descriptors */
 577         status = usb_interface_id(c, f);
 578         if (status < 0)
 579                 goto fail;
 580         acm->ctrl_id = status;
 581         acm_iad_descriptor.bFirstInterface = status;
 582
 583         acm_control_interface_desc.bInterfaceNumber = status;
 584         acm_union_desc .bMasterInterface0 = status;
 585
 586         status = usb_interface_id(c, f);
 587         if (status < 0)
 588                 goto fail;
 589         acm->data_id = status;
 590
 591         acm_data_interface_desc.bInterfaceNumber = status;
 592         acm_union_desc.bSlaveInterface0 = status;
 593         acm_call_mgmt_descriptor.bDataInterface = status;
 594
 595         status = -ENODEV;
 596
 597         /* allocate instance-specific endpoints */
 598         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
 599         if (!ep)
 600                 goto fail;
 601         acm->port.in = ep;
 602         ep->driver_data = cdev; /* claim */
 603
 604         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
 605         if (!ep)
 606                 goto fail;
 607         acm->port.out = ep;
 608         ep->driver_data = cdev; /* claim */
 609
 610         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
 611         if (!ep)
 612                 goto fail;
 613         acm->notify = ep;
 614         ep->driver_data = cdev; /* claim */
 615
 616         /* allocate notification */
 617         acm->notify_req = gs_alloc_req(ep,
 618                         sizeof(struct usb_cdc_notification) + 2,
 619                         GFP_KERNEL);
 620         if (!acm->notify_req)
 621                 goto fail;
 622
 623         acm->notify_req->complete = acm_cdc_notify_complete;
 624         acm->notify_req->context = acm;
 625
 626         /* copy descriptors */
 627         f->descriptors = usb_copy_descriptors(acm_fs_function);
 628         if (!f->descriptors)
 629                 goto fail;
 630
 631         /* support all relevant hardware speeds... we expect that when
 632          * hardware is dual speed, all bulk-capable endpoints work at
 633          * both speeds
 634          */
 635         if (gadget_is_dualspeed(c->cdev->gadget)) {
 636                 acm_hs_in_desc.bEndpointAddress =
 637                                 acm_fs_in_desc.bEndpointAddress;
 638                 acm_hs_out_desc.bEndpointAddress =
 639                                 acm_fs_out_desc.bEndpointAddress;
 640                 acm_hs_notify_desc.bEndpointAddress =
 641                                 acm_fs_notify_desc.bEndpointAddress;
 642
 643                 /* copy descriptors */
 644                 f->hs_descriptors = usb_copy_descriptors(acm_hs_function);
 645         }
 646
 647         DBG(cdev, "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 648                         acm->port_num,
 649                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 650                         acm->port.in->name, acm->port.out->name,
 651                         acm->notify->name);
 652         return 0;
 653
 654 fail:
 655         if (acm->notify_req)
 656                 gs_free_req(acm->notify, acm->notify_req);
 657
 658         /* we might as well release our claims on endpoints */
 659         if (acm->notify)
 660                 acm->notify->driver_data = NULL;
 661         if (acm->port.out)
 662                 acm->port.out->driver_data = NULL;
 663         if (acm->port.in)
 664                 acm->port.in->driver_data = NULL;
 665
 666         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 667
 668         return status;
 669 }
 670
 671 static void
 672 acm_unbind(struct usb_configuration *c, struct usb_function *f)
 673 {
 674         struct f_acm            *acm = func_to_acm(f);
 675
 676         if (gadget_is_dualspeed(c->cdev->gadget))
 677                 usb_free_descriptors(f->hs_descriptors);
 678         usb_free_descriptors(f->descriptors);
 679         gs_free_req(acm->notify, acm->notify_req);
 680         kfree(acm);
 681 }
 682
 683 /* Some controllers can't support CDC ACM ... */
 684 static inline bool can_support_cdc(struct usb_configuration *c)
 685 {
 686         /* everything else is *probably* fine ... */
 687         return true;
 688 }
 689
 690 /**
 691  * acm_bind_config - add a CDC ACM function to a configuration
 692  * @c: the configuration to support the CDC ACM instance
 693  * @port_num: /dev/ttyGS* port this interface will use
 694  * Context: single threaded during gadget setup
 695  *
 696  * Returns zero on success, else negative errno.
 697  *
 698  * Caller must have called @gserial_setup() with enough ports to
 699  * handle all the ones it binds.  Caller is also responsible
 700  * for calling @gserial_cleanup() before module unload.
 701  */
 702 int acm_bind_config(struct usb_configuration *c, u8 port_num)
 703 {
 704         struct f_acm    *acm;
 705         int             status;
 706
 707         if (!can_support_cdc(c))
 708                 return -EINVAL;
 709
 710         /* REVISIT might want instance-specific strings to help
 711          * distinguish instances ...
 712          */
 713
 714         /* maybe allocate device-global string IDs, and patch descriptors */
 715         if (acm_string_defs[ACM_CTRL_IDX].id == 0) {
 716                 status = usb_string_id(c->cdev);
 717                 if (status < 0)
 718                         return status;
 719                 acm_string_defs[ACM_CTRL_IDX].id = status;
 720
 721                 acm_control_interface_desc.iInterface = status;
 722
 723                 status = usb_string_id(c->cdev);
 724                 if (status < 0)
 725                         return status;
 726                 acm_string_defs[ACM_DATA_IDX].id = status;
 727
 728                 acm_data_interface_desc.iInterface = status;
 729
 730                 status = usb_string_id(c->cdev);
 731                 if (status < 0)
 732                         return status;
 733                 acm_string_defs[ACM_IAD_IDX].id = status;
 734
 735                 acm_iad_descriptor.iFunction = status;
 736         }
 737
 738         /* allocate and initialize one new instance */
 739         acm = kzalloc(sizeof *acm, GFP_KERNEL);
 740         if (!acm)
 741                 return -ENOMEM;
 742
 743         spin_lock_init(&acm->lock);
 744
 745         acm->port_num = port_num;
 746
 747         acm->port.connect = acm_connect;
 748         acm->port.disconnect = acm_disconnect;
 749         acm->port.send_break = acm_send_break;
 750
 751         acm->port.func.name = "acm";
 752         acm->port.func.strings = acm_strings;
 753         /* descriptors are per-instance copies */
 754         acm->port.func.bind = acm_bind;
 755         acm->port.func.unbind = acm_unbind;
 756         acm->port.func.set_alt = acm_set_alt;
 757         acm->port.func.setup = acm_setup;
 758         acm->port.func.disable = acm_disable;
 759
 760         status = usb_add_function(c, &acm->port.func);
 761         if (status)
 762                 kfree(acm);
 763         return status;
 764 }