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 acm_ep_descs {
  43         struct usb_endpoint_descriptor  *in;
  44         struct usb_endpoint_descriptor  *out;
  45         struct usb_endpoint_descriptor  *notify;
  46 };
  47
  48 struct f_acm {
  49         struct gserial                  port;
  50         u8                              ctrl_id, data_id;
  51         u8                              port_num;
  52
  53         u8                              pending;
  54
  55         /* lock is mostly for pending and notify_req ... they get accessed
  56          * by callbacks both from tty (open/close/break) under its spinlock,
  57          * and notify_req.complete() which can't use that lock.
  58          */
  59         spinlock_t                      lock;
  60
  61         struct acm_ep_descs             fs;
  62         struct acm_ep_descs             hs;
  63
  64         struct usb_ep                   *notify;
  65         struct usb_request              *notify_req;
  66
  67         struct usb_cdc_line_coding      port_line_coding;       /* 8-N-1 etc */
  68
  69         /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
  70         u16                             port_handshake_bits;
  71 #define ACM_CTRL_RTS    (1 << 1)        /* unused with full duplex */
  72 #define ACM_CTRL_DTR    (1 << 0)        /* host is ready for data r/w */
  73
  74         /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
  75         u16                             serial_state;
  76 #define ACM_CTRL_OVERRUN        (1 << 6)
  77 #define ACM_CTRL_PARITY         (1 << 5)
  78 #define ACM_CTRL_FRAMING        (1 << 4)
  79 #define ACM_CTRL_RI             (1 << 3)
  80 #define ACM_CTRL_BRK            (1 << 2)
  81 #define ACM_CTRL_DSR            (1 << 1)
  82 #define ACM_CTRL_DCD            (1 << 0)
  83 };
  84
  85 static inline struct f_acm *func_to_acm(struct usb_function *f)
  86 {
  87         return container_of(f, struct f_acm, port.func);
  88 }
  89
  90 static inline struct f_acm *port_to_acm(struct gserial *p)
  91 {
  92         return container_of(p, struct f_acm, port);
  93 }
  94
  95 /*-------------------------------------------------------------------------*/
  96
  97 /* notification endpoint uses smallish and infrequent fixed-size messages */
  98
  99 #define GS_LOG2_NOTIFY_INTERVAL         5       /* 1 << 5 == 32 msec */
 100 #define GS_NOTIFY_MAXPACKET             10      /* notification + 2 bytes */
 101
 102 /* interface and class descriptors: */
 103
 104 static struct usb_interface_assoc_descriptor
 105 acm_iad_descriptor = {
 106         .bLength =              sizeof acm_iad_descriptor,
 107         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
 108
 109         /* .bFirstInterface =   DYNAMIC, */
 110         .bInterfaceCount =      2,      // control + data
 111         .bFunctionClass =       USB_CLASS_COMM,
 112         .bFunctionSubClass =    USB_CDC_SUBCLASS_ACM,
 113         .bFunctionProtocol =    USB_CDC_ACM_PROTO_AT_V25TER,
 114         /* .iFunction =         DYNAMIC */
 115 };
 116
 117
 118 static struct usb_interface_descriptor acm_control_interface_desc = {
 119         .bLength =              USB_DT_INTERFACE_SIZE,
 120         .bDescriptorType =      USB_DT_INTERFACE,
 121         /* .bInterfaceNumber = DYNAMIC */
 122         .bNumEndpoints =        1,
 123         .bInterfaceClass =      USB_CLASS_COMM,
 124         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
 125         .bInterfaceProtocol =   USB_CDC_ACM_PROTO_AT_V25TER,
 126         /* .iInterface = DYNAMIC */
 127 };
 128
 129 static struct usb_interface_descriptor acm_data_interface_desc = {
 130         .bLength =              USB_DT_INTERFACE_SIZE,
 131         .bDescriptorType =      USB_DT_INTERFACE,
 132         /* .bInterfaceNumber = DYNAMIC */
 133         .bNumEndpoints =        2,
 134         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 135         .bInterfaceSubClass =   0,
 136         .bInterfaceProtocol =   0,
 137         /* .iInterface = DYNAMIC */
 138 };
 139
 140 static struct usb_cdc_header_desc acm_header_desc = {
 141         .bLength =              sizeof(acm_header_desc),
 142         .bDescriptorType =      USB_DT_CS_INTERFACE,
 143         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 144         .bcdCDC =               cpu_to_le16(0x0110),
 145 };
 146
 147 static struct usb_cdc_call_mgmt_descriptor
 148 acm_call_mgmt_descriptor = {
 149         .bLength =              sizeof(acm_call_mgmt_descriptor),
 150         .bDescriptorType =      USB_DT_CS_INTERFACE,
 151         .bDescriptorSubType =   USB_CDC_CALL_MANAGEMENT_TYPE,
 152         .bmCapabilities =       0,
 153         /* .bDataInterface = DYNAMIC */
 154 };
 155
 156 static struct usb_cdc_acm_descriptor acm_descriptor = {
 157         .bLength =              sizeof(acm_descriptor),
 158         .bDescriptorType =      USB_DT_CS_INTERFACE,
 159         .bDescriptorSubType =   USB_CDC_ACM_TYPE,
 160         .bmCapabilities =       USB_CDC_CAP_LINE,
 161 };
 162
 163 static struct usb_cdc_union_desc acm_union_desc = {
 164         .bLength =              sizeof(acm_union_desc),
 165         .bDescriptorType =      USB_DT_CS_INTERFACE,
 166         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 167         /* .bMasterInterface0 = DYNAMIC */
 168         /* .bSlaveInterface0 =  DYNAMIC */
 169 };
 170
 171 /* full speed support: */
 172
 173 static struct usb_endpoint_descriptor acm_fs_notify_desc = {
 174         .bLength =              USB_DT_ENDPOINT_SIZE,
 175         .bDescriptorType =      USB_DT_ENDPOINT,
 176         .bEndpointAddress =     USB_DIR_IN,
 177         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 178         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 179         .bInterval =            1 << GS_LOG2_NOTIFY_INTERVAL,
 180 };
 181
 182 static struct usb_endpoint_descriptor acm_fs_in_desc = {
 183         .bLength =              USB_DT_ENDPOINT_SIZE,
 184         .bDescriptorType =      USB_DT_ENDPOINT,
 185         .bEndpointAddress =     USB_DIR_IN,
 186         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 187 };
 188
 189 static struct usb_endpoint_descriptor acm_fs_out_desc = {
 190         .bLength =              USB_DT_ENDPOINT_SIZE,
 191         .bDescriptorType =      USB_DT_ENDPOINT,
 192         .bEndpointAddress =     USB_DIR_OUT,
 193         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 194 };
 195
 196 static struct usb_descriptor_header *acm_fs_function[] = {
 197         (struct usb_descriptor_header *) &acm_iad_descriptor,
 198         (struct usb_descriptor_header *) &acm_control_interface_desc,
 199         (struct usb_descriptor_header *) &acm_header_desc,
 200         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 201         (struct usb_descriptor_header *) &acm_descriptor,
 202         (struct usb_descriptor_header *) &acm_union_desc,
 203         (struct usb_descriptor_header *) &acm_fs_notify_desc,
 204         (struct usb_descriptor_header *) &acm_data_interface_desc,
 205         (struct usb_descriptor_header *) &acm_fs_in_desc,
 206         (struct usb_descriptor_header *) &acm_fs_out_desc,
 207         NULL,
 208 };
 209
 210 /* high speed support: */
 211
 212 static struct usb_endpoint_descriptor acm_hs_notify_desc = {
 213         .bLength =              USB_DT_ENDPOINT_SIZE,
 214         .bDescriptorType =      USB_DT_ENDPOINT,
 215         .bEndpointAddress =     USB_DIR_IN,
 216         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 217         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 218         .bInterval =            GS_LOG2_NOTIFY_INTERVAL+4,
 219 };
 220
 221 static struct usb_endpoint_descriptor acm_hs_in_desc = {
 222         .bLength =              USB_DT_ENDPOINT_SIZE,
 223         .bDescriptorType =      USB_DT_ENDPOINT,
 224         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 225         .wMaxPacketSize =       cpu_to_le16(512),
 226 };
 227
 228 static struct usb_endpoint_descriptor acm_hs_out_desc = {
 229         .bLength =              USB_DT_ENDPOINT_SIZE,
 230         .bDescriptorType =      USB_DT_ENDPOINT,
 231         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 232         .wMaxPacketSize =       cpu_to_le16(512),
 233 };
 234
 235 static struct usb_descriptor_header *acm_hs_function[] = {
 236         (struct usb_descriptor_header *) &acm_iad_descriptor,
 237         (struct usb_descriptor_header *) &acm_control_interface_desc,
 238         (struct usb_descriptor_header *) &acm_header_desc,
 239         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 240         (struct usb_descriptor_header *) &acm_descriptor,
 241         (struct usb_descriptor_header *) &acm_union_desc,
 242         (struct usb_descriptor_header *) &acm_hs_notify_desc,
 243         (struct usb_descriptor_header *) &acm_data_interface_desc,
 244         (struct usb_descriptor_header *) &acm_hs_in_desc,
 245         (struct usb_descriptor_header *) &acm_hs_out_desc,
 246         NULL,
 247 };
 248
 249 /* string descriptors: */
 250
 251 #define ACM_CTRL_IDX    0
 252 #define ACM_DATA_IDX    1
 253 #define ACM_IAD_IDX     2
 254
 255 /* static strings, in UTF-8 */
 256 static struct usb_string acm_string_defs[] = {
 257         [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
 258         [ACM_DATA_IDX].s = "CDC ACM Data",
 259         [ACM_IAD_IDX ].s = "CDC Serial",
 260         {  /* ZEROES END LIST */ },
 261 };
 262
 263 static struct usb_gadget_strings acm_string_table = {
 264         .language =             0x0409, /* en-us */
 265         .strings =              acm_string_defs,
 266 };
 267
 268 static struct usb_gadget_strings *acm_strings[] = {
 269         &acm_string_table,
 270         NULL,
 271 };
 272
 273 /*-------------------------------------------------------------------------*/
 274
 275 /* ACM control ... data handling is delegated to tty library code.
 276  * The main task of this function is to activate and deactivate
 277  * that code based on device state; track parameters like line
 278  * speed, handshake state, and so on; and issue notifications.
 279  */
 280
 281 static void acm_complete_set_line_coding(struct usb_ep *ep,
 282                 struct usb_request *req)
 283 {
 284         struct f_acm    *acm = ep->driver_data;
 285         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 286
 287         if (req->status != 0) {
 288                 DBG(cdev, "acm ttyGS%d completion, err %d\n",
 289                                 acm->port_num, req->status);
 290                 return;
 291         }
 292
 293         /* normal completion */
 294         if (req->actual != sizeof(acm->port_line_coding)) {
 295                 DBG(cdev, "acm ttyGS%d short resp, len %d\n",
 296                                 acm->port_num, req->actual);
 297                 usb_ep_set_halt(ep);
 298         } else {
 299                 struct usb_cdc_line_coding      *value = req->buf;
 300
 301                 /* REVISIT:  we currently just remember this data.
 302                  * If we change that, (a) validate it first, then
 303                  * (b) update whatever hardware needs updating,
 304                  * (c) worry about locking.  This is information on
 305                  * the order of 9600-8-N-1 ... most of which means
 306                  * nothing unless we control a real RS232 line.
 307                  */
 308                 acm->port_line_coding = *value;
 309         }
 310 }
 311
 312 static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 313 {
 314         struct f_acm            *acm = func_to_acm(f);
 315         struct usb_composite_dev *cdev = f->config->cdev;
 316         struct usb_request      *req = cdev->req;
 317         int                     value = -EOPNOTSUPP;
 318         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 319         u16                     w_value = le16_to_cpu(ctrl->wValue);
 320         u16                     w_length = le16_to_cpu(ctrl->wLength);
 321
 322         /* composite driver infrastructure handles everything except
 323          * CDC class messages; interface activation uses set_alt().
 324          *
 325          * Note CDC spec table 4 lists the ACM request profile.  It requires
 326          * encapsulated command support ... we don't handle any, and respond
 327          * to them by stalling.  Options include get/set/clear comm features
 328          * (not that useful) and SEND_BREAK.
 329          */
 330         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 331
 332         /* SET_LINE_CODING ... just read and save what the host sends */
 333         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 334                         | USB_CDC_REQ_SET_LINE_CODING:
 335                 if (w_length != sizeof(struct usb_cdc_line_coding)
 336                                 || w_index != acm->ctrl_id)
 337                         goto invalid;
 338
 339                 value = w_length;
 340                 cdev->gadget->ep0->driver_data = acm;
 341                 req->complete = acm_complete_set_line_coding;
 342                 break;
 343
 344         /* GET_LINE_CODING ... return what host sent, or initial value */
 345         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 346                         | USB_CDC_REQ_GET_LINE_CODING:
 347                 if (w_index != acm->ctrl_id)
 348                         goto invalid;
 349
 350                 value = min_t(unsigned, w_length,
 351                                 sizeof(struct usb_cdc_line_coding));
 352                 memcpy(req->buf, &acm->port_line_coding, value);
 353                 break;
 354
 355         /* SET_CONTROL_LINE_STATE ... save what the host sent */
 356         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 357                         | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
 358                 if (w_index != acm->ctrl_id)
 359                         goto invalid;
 360
 361                 value = 0;
 362
 363                 /* FIXME we should not allow data to flow until the
 364                  * host sets the ACM_CTRL_DTR bit; and when it clears
 365                  * that bit, we should return to that no-flow state.
 366                  */
 367                 acm->port_handshake_bits = w_value;
 368                 break;
 369
 370         default:
 371 invalid:
 372                 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 373                         ctrl->bRequestType, ctrl->bRequest,
 374                         w_value, w_index, w_length);
 375         }
 376
 377         /* respond with data transfer or status phase? */
 378         if (value >= 0) {
 379                 DBG(cdev, "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
 380                         acm->port_num, ctrl->bRequestType, ctrl->bRequest,
 381                         w_value, w_index, w_length);
 382                 req->zero = 0;
 383                 req->length = value;
 384                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 385                 if (value < 0)
 386                         ERROR(cdev, "acm response on ttyGS%d, err %d\n",
 387                                         acm->port_num, value);
 388         }
 389
 390         /* device either stalls (value < 0) or reports success */
 391         return value;
 392 }
 393
 394 static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 395 {
 396         struct f_acm            *acm = func_to_acm(f);
 397         struct usb_composite_dev *cdev = f->config->cdev;
 398
 399         /* we know alt == 0, so this is an activation or a reset */
 400
 401         if (intf == acm->ctrl_id) {
 402                 if (acm->notify->driver_data) {
 403                         VDBG(cdev, "reset acm control interface %d\n", intf);
 404                         usb_ep_disable(acm->notify);
 405                 } else {
 406                         VDBG(cdev, "init acm ctrl interface %d\n", intf);
 407                         acm->notify->desc = ep_choose(cdev->gadget,
 408                                         acm->hs.notify,
 409                                         acm->fs.notify);
 410                 }
 411                 usb_ep_enable(acm->notify);
 412                 acm->notify->driver_data = acm;
 413
 414         } else if (intf == acm->data_id) {
 415                 if (acm->port.in->driver_data) {
 416                         DBG(cdev, "reset acm ttyGS%d\n", acm->port_num);
 417                         gserial_disconnect(&acm->port);
 418                 } else {
 419                         DBG(cdev, "activate acm ttyGS%d\n", acm->port_num);
 420                         acm->port.in->desc = ep_choose(cdev->gadget,
 421                                         acm->hs.in, acm->fs.in);
 422                         acm->port.out->desc = ep_choose(cdev->gadget,
 423                                         acm->hs.out, acm->fs.out);
 424                 }
 425                 gserial_connect(&acm->port, acm->port_num);
 426
 427         } else
 428                 return -EINVAL;
 429
 430         return 0;
 431 }
 432
 433 static void acm_disable(struct usb_function *f)
 434 {
 435         struct f_acm    *acm = func_to_acm(f);
 436         struct usb_composite_dev *cdev = f->config->cdev;
 437
 438         DBG(cdev, "acm ttyGS%d deactivated\n", acm->port_num);
 439         gserial_disconnect(&acm->port);
 440         usb_ep_disable(acm->notify);
 441         acm->notify->driver_data = NULL;
 442 }
 443
 444 /*-------------------------------------------------------------------------*/
 445
 446 /**
 447  * acm_cdc_notify - issue CDC notification to host
 448  * @acm: wraps host to be notified
 449  * @type: notification type
 450  * @value: Refer to cdc specs, wValue field.
 451  * @data: data to be sent
 452  * @length: size of data
 453  * Context: irqs blocked, acm->lock held, acm_notify_req non-null
 454  *
 455  * Returns zero on success or a negative errno.
 456  *
 457  * See section 6.3.5 of the CDC 1.1 specification for information
 458  * about the only notification we issue:  SerialState change.
 459  */
 460 static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
 461                 void *data, unsigned length)
 462 {
 463         struct usb_ep                   *ep = acm->notify;
 464         struct usb_request              *req;
 465         struct usb_cdc_notification     *notify;
 466         const unsigned                  len = sizeof(*notify) + length;
 467         void                            *buf;
 468         int                             status;
 469
 470         req = acm->notify_req;
 471         acm->notify_req = NULL;
 472         acm->pending = false;
 473
 474         req->length = len;
 475         notify = req->buf;
 476         buf = notify + 1;
 477
 478         notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
 479                         | USB_RECIP_INTERFACE;
 480         notify->bNotificationType = type;
 481         notify->wValue = cpu_to_le16(value);
 482         notify->wIndex = cpu_to_le16(acm->ctrl_id);
 483         notify->wLength = cpu_to_le16(length);
 484         memcpy(buf, data, length);
 485
 486         /* ep_queue() can complete immediately if it fills the fifo... */
 487         spin_unlock(&acm->lock);
 488         status = usb_ep_queue(ep, req, GFP_ATOMIC);
 489         spin_lock(&acm->lock);
 490
 491         if (status < 0) {
 492                 ERROR(acm->port.func.config->cdev,
 493                                 "acm ttyGS%d can't notify serial state, %d\n",
 494                                 acm->port_num, status);
 495                 acm->notify_req = req;
 496         }
 497
 498         return status;
 499 }
 500
 501 static int acm_notify_serial_state(struct f_acm *acm)
 502 {
 503         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 504         int                     status;
 505
 506         spin_lock(&acm->lock);
 507         if (acm->notify_req) {
 508                 DBG(cdev, "acm ttyGS%d serial state %04x\n",
 509                                 acm->port_num, acm->serial_state);
 510                 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
 511                                 0, &acm->serial_state, sizeof(acm->serial_state));
 512         } else {
 513                 acm->pending = true;
 514                 status = 0;
 515         }
 516         spin_unlock(&acm->lock);
 517         return status;
 518 }
 519
 520 static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
 521 {
 522         struct f_acm            *acm = req->context;
 523         u8                      doit = false;
 524
 525         /* on this call path we do NOT hold the port spinlock,
 526          * which is why ACM needs its own spinlock
 527          */
 528         spin_lock(&acm->lock);
 529         if (req->status != -ESHUTDOWN)
 530                 doit = acm->pending;
 531         acm->notify_req = req;
 532         spin_unlock(&acm->lock);
 533
 534         if (doit)
 535                 acm_notify_serial_state(acm);
 536 }
 537
 538 /* connect == the TTY link is open */
 539
 540 static void acm_connect(struct gserial *port)
 541 {
 542         struct f_acm            *acm = port_to_acm(port);
 543
 544         acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
 545         acm_notify_serial_state(acm);
 546 }
 547
 548 static void acm_disconnect(struct gserial *port)
 549 {
 550         struct f_acm            *acm = port_to_acm(port);
 551
 552         acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
 553         acm_notify_serial_state(acm);
 554 }
 555
 556 static int acm_send_break(struct gserial *port, int duration)
 557 {
 558         struct f_acm            *acm = port_to_acm(port);
 559         u16                     state;
 560
 561         state = acm->serial_state;
 562         state &= ~ACM_CTRL_BRK;
 563         if (duration)
 564                 state |= ACM_CTRL_BRK;
 565
 566         acm->serial_state = state;
 567         return acm_notify_serial_state(acm);
 568 }
 569
 570 /*-------------------------------------------------------------------------*/
 571
 572 /* ACM function driver setup/binding */
 573 static int
 574 acm_bind(struct usb_configuration *c, struct usb_function *f)
 575 {
 576         struct usb_composite_dev *cdev = c->cdev;
 577         struct f_acm            *acm = func_to_acm(f);
 578         int                     status;
 579         struct usb_ep           *ep;
 580
 581         /* allocate instance-specific interface IDs, and patch descriptors */
 582         status = usb_interface_id(c, f);
 583         if (status < 0)
 584                 goto fail;
 585         acm->ctrl_id = status;
 586         acm_iad_descriptor.bFirstInterface = status;
 587
 588         acm_control_interface_desc.bInterfaceNumber = status;
 589         acm_union_desc .bMasterInterface0 = status;
 590
 591         status = usb_interface_id(c, f);
 592         if (status < 0)
 593                 goto fail;
 594         acm->data_id = status;
 595
 596         acm_data_interface_desc.bInterfaceNumber = status;
 597         acm_union_desc.bSlaveInterface0 = status;
 598         acm_call_mgmt_descriptor.bDataInterface = status;
 599
 600         status = -ENODEV;
 601
 602         /* allocate instance-specific endpoints */
 603         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
 604         if (!ep)
 605                 goto fail;
 606         acm->port.in = ep;
 607         ep->driver_data = cdev; /* claim */
 608
 609         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
 610         if (!ep)
 611                 goto fail;
 612         acm->port.out = ep;
 613         ep->driver_data = cdev; /* claim */
 614
 615         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
 616         if (!ep)
 617                 goto fail;
 618         acm->notify = ep;
 619         ep->driver_data = cdev; /* claim */
 620
 621         /* allocate notification */
 622         acm->notify_req = gs_alloc_req(ep,
 623                         sizeof(struct usb_cdc_notification) + 2,
 624                         GFP_KERNEL);
 625         if (!acm->notify_req)
 626                 goto fail;
 627
 628         acm->notify_req->complete = acm_cdc_notify_complete;
 629         acm->notify_req->context = acm;
 630
 631         /* copy descriptors, and track endpoint copies */
 632         f->descriptors = usb_copy_descriptors(acm_fs_function);
 633         if (!f->descriptors)
 634                 goto fail;
 635
 636         acm->fs.in = usb_find_endpoint(acm_fs_function,
 637                         f->descriptors, &acm_fs_in_desc);
 638         acm->fs.out = usb_find_endpoint(acm_fs_function,
 639                         f->descriptors, &acm_fs_out_desc);
 640         acm->fs.notify = usb_find_endpoint(acm_fs_function,
 641                         f->descriptors, &acm_fs_notify_desc);
 642
 643         /* support all relevant hardware speeds... we expect that when
 644          * hardware is dual speed, all bulk-capable endpoints work at
 645          * both speeds
 646          */
 647         if (gadget_is_dualspeed(c->cdev->gadget)) {
 648                 acm_hs_in_desc.bEndpointAddress =
 649                                 acm_fs_in_desc.bEndpointAddress;
 650                 acm_hs_out_desc.bEndpointAddress =
 651                                 acm_fs_out_desc.bEndpointAddress;
 652                 acm_hs_notify_desc.bEndpointAddress =
 653                                 acm_fs_notify_desc.bEndpointAddress;
 654
 655                 /* copy descriptors, and track endpoint copies */
 656                 f->hs_descriptors = usb_copy_descriptors(acm_hs_function);
 657
 658                 acm->hs.in = usb_find_endpoint(acm_hs_function,
 659                                 f->hs_descriptors, &acm_hs_in_desc);
 660                 acm->hs.out = usb_find_endpoint(acm_hs_function,
 661                                 f->hs_descriptors, &acm_hs_out_desc);
 662                 acm->hs.notify = usb_find_endpoint(acm_hs_function,
 663                                 f->hs_descriptors, &acm_hs_notify_desc);
 664         }
 665
 666         DBG(cdev, "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 667                         acm->port_num,
 668                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 669                         acm->port.in->name, acm->port.out->name,
 670                         acm->notify->name);
 671         return 0;
 672
 673 fail:
 674         if (acm->notify_req)
 675                 gs_free_req(acm->notify, acm->notify_req);
 676
 677         /* we might as well release our claims on endpoints */
 678         if (acm->notify)
 679                 acm->notify->driver_data = NULL;
 680         if (acm->port.out)
 681                 acm->port.out->driver_data = NULL;
 682         if (acm->port.in)
 683                 acm->port.in->driver_data = NULL;
 684
 685         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 686
 687         return status;
 688 }
 689
 690 static void
 691 acm_unbind(struct usb_configuration *c, struct usb_function *f)
 692 {
 693         struct f_acm            *acm = func_to_acm(f);
 694
 695         if (gadget_is_dualspeed(c->cdev->gadget))
 696                 usb_free_descriptors(f->hs_descriptors);
 697         usb_free_descriptors(f->descriptors);
 698         gs_free_req(acm->notify, acm->notify_req);
 699         kfree(acm);
 700 }
 701
 702 /* Some controllers can't support CDC ACM ... */
 703 static inline bool can_support_cdc(struct usb_configuration *c)
 704 {
 705         /* everything else is *probably* fine ... */
 706         return true;
 707 }
 708
 709 /**
 710  * acm_bind_config - add a CDC ACM function to a configuration
 711  * @c: the configuration to support the CDC ACM instance
 712  * @port_num: /dev/ttyGS* port this interface will use
 713  * Context: single threaded during gadget setup
 714  *
 715  * Returns zero on success, else negative errno.
 716  *
 717  * Caller must have called @gserial_setup() with enough ports to
 718  * handle all the ones it binds.  Caller is also responsible
 719  * for calling @gserial_cleanup() before module unload.
 720  */
 721 int acm_bind_config(struct usb_configuration *c, u8 port_num)
 722 {
 723         struct f_acm    *acm;
 724         int             status;
 725
 726         if (!can_support_cdc(c))
 727                 return -EINVAL;
 728
 729         /* REVISIT might want instance-specific strings to help
 730          * distinguish instances ...
 731          */
 732
 733         /* maybe allocate device-global string IDs, and patch descriptors */
 734         if (acm_string_defs[ACM_CTRL_IDX].id == 0) {
 735                 status = usb_string_id(c->cdev);
 736                 if (status < 0)
 737                         return status;
 738                 acm_string_defs[ACM_CTRL_IDX].id = status;
 739
 740                 acm_control_interface_desc.iInterface = status;
 741
 742                 status = usb_string_id(c->cdev);
 743                 if (status < 0)
 744                         return status;
 745                 acm_string_defs[ACM_DATA_IDX].id = status;
 746
 747                 acm_data_interface_desc.iInterface = status;
 748
 749                 status = usb_string_id(c->cdev);
 750                 if (status < 0)
 751                         return status;
 752                 acm_string_defs[ACM_IAD_IDX].id = status;
 753
 754                 acm_iad_descriptor.iFunction = status;
 755         }
 756
 757         /* allocate and initialize one new instance */
 758         acm = kzalloc(sizeof *acm, GFP_KERNEL);
 759         if (!acm)
 760                 return -ENOMEM;
 761
 762         spin_lock_init(&acm->lock);
 763
 764         acm->port_num = port_num;
 765
 766         acm->port.connect = acm_connect;
 767         acm->port.disconnect = acm_disconnect;
 768         acm->port.send_break = acm_send_break;
 769
 770         acm->port.func.name = "acm";
 771         acm->port.func.strings = acm_strings;
 772         /* descriptors are per-instance copies */
 773         acm->port.func.bind = acm_bind;
 774         acm->port.func.unbind = acm_unbind;
 775         acm->port.func.set_alt = acm_set_alt;
 776         acm->port.func.setup = acm_setup;
 777         acm->port.func.disable = acm_disable;
 778
 779         status = usb_add_function(c, &acm->port.func);
 780         if (status)
 781                 kfree(acm);
 782         return status;
 783 }