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_endpoint_descriptor  *notify_desc;
  66         struct usb_request              *notify_req;
  67
  68         struct usb_cdc_line_coding      port_line_coding;       /* 8-N-1 etc */
  69
  70         /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
  71         u16                             port_handshake_bits;
  72 #define ACM_CTRL_RTS    (1 << 1)        /* unused with full duplex */
  73 #define ACM_CTRL_DTR    (1 << 0)        /* host is ready for data r/w */
  74
  75         /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
  76         u16                             serial_state;
  77 #define ACM_CTRL_OVERRUN        (1 << 6)
  78 #define ACM_CTRL_PARITY         (1 << 5)
  79 #define ACM_CTRL_FRAMING        (1 << 4)
  80 #define ACM_CTRL_RI             (1 << 3)
  81 #define ACM_CTRL_BRK            (1 << 2)
  82 #define ACM_CTRL_DSR            (1 << 1)
  83 #define ACM_CTRL_DCD            (1 << 0)
  84 };
  85
  86 static inline struct f_acm *func_to_acm(struct usb_function *f)
  87 {
  88         return container_of(f, struct f_acm, port.func);
  89 }
  90
  91 static inline struct f_acm *port_to_acm(struct gserial *p)
  92 {
  93         return container_of(p, struct f_acm, port);
  94 }
  95
  96 /*-------------------------------------------------------------------------*/
  97
  98 /* notification endpoint uses smallish and infrequent fixed-size messages */
  99
 100 #define GS_LOG2_NOTIFY_INTERVAL         5       /* 1 << 5 == 32 msec */
 101 #define GS_NOTIFY_MAXPACKET             10      /* notification + 2 bytes */
 102
 103 /* interface and class descriptors: */
 104
 105 static struct usb_interface_assoc_descriptor
 106 acm_iad_descriptor = {
 107         .bLength =              sizeof acm_iad_descriptor,
 108         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
 109
 110         /* .bFirstInterface =   DYNAMIC, */
 111         .bInterfaceCount =      2,      // control + data
 112         .bFunctionClass =       USB_CLASS_COMM,
 113         .bFunctionSubClass =    USB_CDC_SUBCLASS_ACM,
 114         .bFunctionProtocol =    USB_CDC_ACM_PROTO_AT_V25TER,
 115         /* .iFunction =         DYNAMIC */
 116 };
 117
 118
 119 static struct usb_interface_descriptor acm_control_interface_desc = {
 120         .bLength =              USB_DT_INTERFACE_SIZE,
 121         .bDescriptorType =      USB_DT_INTERFACE,
 122         /* .bInterfaceNumber = DYNAMIC */
 123         .bNumEndpoints =        1,
 124         .bInterfaceClass =      USB_CLASS_COMM,
 125         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
 126         .bInterfaceProtocol =   USB_CDC_ACM_PROTO_AT_V25TER,
 127         /* .iInterface = DYNAMIC */
 128 };
 129
 130 static struct usb_interface_descriptor acm_data_interface_desc = {
 131         .bLength =              USB_DT_INTERFACE_SIZE,
 132         .bDescriptorType =      USB_DT_INTERFACE,
 133         /* .bInterfaceNumber = DYNAMIC */
 134         .bNumEndpoints =        2,
 135         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 136         .bInterfaceSubClass =   0,
 137         .bInterfaceProtocol =   0,
 138         /* .iInterface = DYNAMIC */
 139 };
 140
 141 static struct usb_cdc_header_desc acm_header_desc = {
 142         .bLength =              sizeof(acm_header_desc),
 143         .bDescriptorType =      USB_DT_CS_INTERFACE,
 144         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 145         .bcdCDC =               cpu_to_le16(0x0110),
 146 };
 147
 148 static struct usb_cdc_call_mgmt_descriptor
 149 acm_call_mgmt_descriptor = {
 150         .bLength =              sizeof(acm_call_mgmt_descriptor),
 151         .bDescriptorType =      USB_DT_CS_INTERFACE,
 152         .bDescriptorSubType =   USB_CDC_CALL_MANAGEMENT_TYPE,
 153         .bmCapabilities =       0,
 154         /* .bDataInterface = DYNAMIC */
 155 };
 156
 157 static struct usb_cdc_acm_descriptor acm_descriptor = {
 158         .bLength =              sizeof(acm_descriptor),
 159         .bDescriptorType =      USB_DT_CS_INTERFACE,
 160         .bDescriptorSubType =   USB_CDC_ACM_TYPE,
 161         .bmCapabilities =       USB_CDC_CAP_LINE,
 162 };
 163
 164 static struct usb_cdc_union_desc acm_union_desc = {
 165         .bLength =              sizeof(acm_union_desc),
 166         .bDescriptorType =      USB_DT_CS_INTERFACE,
 167         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 168         /* .bMasterInterface0 = DYNAMIC */
 169         /* .bSlaveInterface0 =  DYNAMIC */
 170 };
 171
 172 /* full speed support: */
 173
 174 static struct usb_endpoint_descriptor acm_fs_notify_desc = {
 175         .bLength =              USB_DT_ENDPOINT_SIZE,
 176         .bDescriptorType =      USB_DT_ENDPOINT,
 177         .bEndpointAddress =     USB_DIR_IN,
 178         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 179         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 180         .bInterval =            1 << GS_LOG2_NOTIFY_INTERVAL,
 181 };
 182
 183 static struct usb_endpoint_descriptor acm_fs_in_desc = {
 184         .bLength =              USB_DT_ENDPOINT_SIZE,
 185         .bDescriptorType =      USB_DT_ENDPOINT,
 186         .bEndpointAddress =     USB_DIR_IN,
 187         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 188 };
 189
 190 static struct usb_endpoint_descriptor acm_fs_out_desc = {
 191         .bLength =              USB_DT_ENDPOINT_SIZE,
 192         .bDescriptorType =      USB_DT_ENDPOINT,
 193         .bEndpointAddress =     USB_DIR_OUT,
 194         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 195 };
 196
 197 static struct usb_descriptor_header *acm_fs_function[] = {
 198         (struct usb_descriptor_header *) &acm_iad_descriptor,
 199         (struct usb_descriptor_header *) &acm_control_interface_desc,
 200         (struct usb_descriptor_header *) &acm_header_desc,
 201         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 202         (struct usb_descriptor_header *) &acm_descriptor,
 203         (struct usb_descriptor_header *) &acm_union_desc,
 204         (struct usb_descriptor_header *) &acm_fs_notify_desc,
 205         (struct usb_descriptor_header *) &acm_data_interface_desc,
 206         (struct usb_descriptor_header *) &acm_fs_in_desc,
 207         (struct usb_descriptor_header *) &acm_fs_out_desc,
 208         NULL,
 209 };
 210
 211 /* high speed support: */
 212
 213 static struct usb_endpoint_descriptor acm_hs_notify_desc = {
 214         .bLength =              USB_DT_ENDPOINT_SIZE,
 215         .bDescriptorType =      USB_DT_ENDPOINT,
 216         .bEndpointAddress =     USB_DIR_IN,
 217         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 218         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 219         .bInterval =            GS_LOG2_NOTIFY_INTERVAL+4,
 220 };
 221
 222 static struct usb_endpoint_descriptor acm_hs_in_desc = {
 223         .bLength =              USB_DT_ENDPOINT_SIZE,
 224         .bDescriptorType =      USB_DT_ENDPOINT,
 225         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 226         .wMaxPacketSize =       cpu_to_le16(512),
 227 };
 228
 229 static struct usb_endpoint_descriptor acm_hs_out_desc = {
 230         .bLength =              USB_DT_ENDPOINT_SIZE,
 231         .bDescriptorType =      USB_DT_ENDPOINT,
 232         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 233         .wMaxPacketSize =       cpu_to_le16(512),
 234 };
 235
 236 static struct usb_descriptor_header *acm_hs_function[] = {
 237         (struct usb_descriptor_header *) &acm_iad_descriptor,
 238         (struct usb_descriptor_header *) &acm_control_interface_desc,
 239         (struct usb_descriptor_header *) &acm_header_desc,
 240         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 241         (struct usb_descriptor_header *) &acm_descriptor,
 242         (struct usb_descriptor_header *) &acm_union_desc,
 243         (struct usb_descriptor_header *) &acm_hs_notify_desc,
 244         (struct usb_descriptor_header *) &acm_data_interface_desc,
 245         (struct usb_descriptor_header *) &acm_hs_in_desc,
 246         (struct usb_descriptor_header *) &acm_hs_out_desc,
 247         NULL,
 248 };
 249
 250 /* string descriptors: */
 251
 252 #define ACM_CTRL_IDX    0
 253 #define ACM_DATA_IDX    1
 254 #define ACM_IAD_IDX     2
 255
 256 /* static strings, in UTF-8 */
 257 static struct usb_string acm_string_defs[] = {
 258         [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
 259         [ACM_DATA_IDX].s = "CDC ACM Data",
 260         [ACM_IAD_IDX ].s = "CDC Serial",
 261         {  /* ZEROES END LIST */ },
 262 };
 263
 264 static struct usb_gadget_strings acm_string_table = {
 265         .language =             0x0409, /* en-us */
 266         .strings =              acm_string_defs,
 267 };
 268
 269 static struct usb_gadget_strings *acm_strings[] = {
 270         &acm_string_table,
 271         NULL,
 272 };
 273
 274 /*-------------------------------------------------------------------------*/
 275
 276 /* ACM control ... data handling is delegated to tty library code.
 277  * The main task of this function is to activate and deactivate
 278  * that code based on device state; track parameters like line
 279  * speed, handshake state, and so on; and issue notifications.
 280  */
 281
 282 static void acm_complete_set_line_coding(struct usb_ep *ep,
 283                 struct usb_request *req)
 284 {
 285         struct f_acm    *acm = ep->driver_data;
 286         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 287
 288         if (req->status != 0) {
 289                 DBG(cdev, "acm ttyGS%d completion, err %d\n",
 290                                 acm->port_num, req->status);
 291                 return;
 292         }
 293
 294         /* normal completion */
 295         if (req->actual != sizeof(acm->port_line_coding)) {
 296                 DBG(cdev, "acm ttyGS%d short resp, len %d\n",
 297                                 acm->port_num, req->actual);
 298                 usb_ep_set_halt(ep);
 299         } else {
 300                 struct usb_cdc_line_coding      *value = req->buf;
 301
 302                 /* REVISIT:  we currently just remember this data.
 303                  * If we change that, (a) validate it first, then
 304                  * (b) update whatever hardware needs updating,
 305                  * (c) worry about locking.  This is information on
 306                  * the order of 9600-8-N-1 ... most of which means
 307                  * nothing unless we control a real RS232 line.
 308                  */
 309                 acm->port_line_coding = *value;
 310         }
 311 }
 312
 313 static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 314 {
 315         struct f_acm            *acm = func_to_acm(f);
 316         struct usb_composite_dev *cdev = f->config->cdev;
 317         struct usb_request      *req = cdev->req;
 318         int                     value = -EOPNOTSUPP;
 319         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 320         u16                     w_value = le16_to_cpu(ctrl->wValue);
 321         u16                     w_length = le16_to_cpu(ctrl->wLength);
 322
 323         /* composite driver infrastructure handles everything except
 324          * CDC class messages; interface activation uses set_alt().
 325          *
 326          * Note CDC spec table 4 lists the ACM request profile.  It requires
 327          * encapsulated command support ... we don't handle any, and respond
 328          * to them by stalling.  Options include get/set/clear comm features
 329          * (not that useful) and SEND_BREAK.
 330          */
 331         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 332
 333         /* SET_LINE_CODING ... just read and save what the host sends */
 334         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 335                         | USB_CDC_REQ_SET_LINE_CODING:
 336                 if (w_length != sizeof(struct usb_cdc_line_coding)
 337                                 || w_index != acm->ctrl_id)
 338                         goto invalid;
 339
 340                 value = w_length;
 341                 cdev->gadget->ep0->driver_data = acm;
 342                 req->complete = acm_complete_set_line_coding;
 343                 break;
 344
 345         /* GET_LINE_CODING ... return what host sent, or initial value */
 346         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 347                         | USB_CDC_REQ_GET_LINE_CODING:
 348                 if (w_index != acm->ctrl_id)
 349                         goto invalid;
 350
 351                 value = min_t(unsigned, w_length,
 352                                 sizeof(struct usb_cdc_line_coding));
 353                 memcpy(req->buf, &acm->port_line_coding, value);
 354                 break;
 355
 356         /* SET_CONTROL_LINE_STATE ... save what the host sent */
 357         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 358                         | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
 359                 if (w_index != acm->ctrl_id)
 360                         goto invalid;
 361
 362                 value = 0;
 363
 364                 /* FIXME we should not allow data to flow until the
 365                  * host sets the ACM_CTRL_DTR bit; and when it clears
 366                  * that bit, we should return to that no-flow state.
 367                  */
 368                 acm->port_handshake_bits = w_value;
 369                 break;
 370
 371         default:
 372 invalid:
 373                 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 374                         ctrl->bRequestType, ctrl->bRequest,
 375                         w_value, w_index, w_length);
 376         }
 377
 378         /* respond with data transfer or status phase? */
 379         if (value >= 0) {
 380                 DBG(cdev, "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
 381                         acm->port_num, ctrl->bRequestType, ctrl->bRequest,
 382                         w_value, w_index, w_length);
 383                 req->zero = 0;
 384                 req->length = value;
 385                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 386                 if (value < 0)
 387                         ERROR(cdev, "acm response on ttyGS%d, err %d\n",
 388                                         acm->port_num, value);
 389         }
 390
 391         /* device either stalls (value < 0) or reports success */
 392         return value;
 393 }
 394
 395 static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 396 {
 397         struct f_acm            *acm = func_to_acm(f);
 398         struct usb_composite_dev *cdev = f->config->cdev;
 399
 400         /* we know alt == 0, so this is an activation or a reset */
 401
 402         if (intf == acm->ctrl_id) {
 403                 if (acm->notify->driver_data) {
 404                         VDBG(cdev, "reset acm control interface %d\n", intf);
 405                         usb_ep_disable(acm->notify);
 406                 } else {
 407                         VDBG(cdev, "init acm ctrl interface %d\n", intf);
 408                         acm->notify_desc = ep_choose(cdev->gadget,
 409                                         acm->hs.notify,
 410                                         acm->fs.notify);
 411                 }
 412                 usb_ep_enable(acm->notify, acm->notify_desc);
 413                 acm->notify->driver_data = acm;
 414
 415         } else if (intf == acm->data_id) {
 416                 if (acm->port.in->driver_data) {
 417                         DBG(cdev, "reset acm ttyGS%d\n", acm->port_num);
 418                         gserial_disconnect(&acm->port);
 419                 } else {
 420                         DBG(cdev, "activate acm ttyGS%d\n", acm->port_num);
 421                         acm->port.in_desc = ep_choose(cdev->gadget,
 422                                         acm->hs.in, acm->fs.in);
 423                         acm->port.out_desc = ep_choose(cdev->gadget,
 424                                         acm->hs.out, acm->fs.out);
 425                 }
 426                 gserial_connect(&acm->port, acm->port_num);
 427
 428         } else
 429                 return -EINVAL;
 430
 431         return 0;
 432 }
 433
 434 static void acm_disable(struct usb_function *f)
 435 {
 436         struct f_acm    *acm = func_to_acm(f);
 437         struct usb_composite_dev *cdev = f->config->cdev;
 438
 439         DBG(cdev, "acm ttyGS%d deactivated\n", acm->port_num);
 440         gserial_disconnect(&acm->port);
 441         usb_ep_disable(acm->notify);
 442         acm->notify->driver_data = NULL;
 443 }
 444
 445 /*-------------------------------------------------------------------------*/
 446
 447 /**
 448  * acm_cdc_notify - issue CDC notification to host
 449  * @acm: wraps host to be notified
 450  * @type: notification type
 451  * @value: Refer to cdc specs, wValue field.
 452  * @data: data to be sent
 453  * @length: size of data
 454  * Context: irqs blocked, acm->lock held, acm_notify_req non-null
 455  *
 456  * Returns zero on success or a negative errno.
 457  *
 458  * See section 6.3.5 of the CDC 1.1 specification for information
 459  * about the only notification we issue:  SerialState change.
 460  */
 461 static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
 462                 void *data, unsigned length)
 463 {
 464         struct usb_ep                   *ep = acm->notify;
 465         struct usb_request              *req;
 466         struct usb_cdc_notification     *notify;
 467         const unsigned                  len = sizeof(*notify) + length;
 468         void                            *buf;
 469         int                             status;
 470
 471         req = acm->notify_req;
 472         acm->notify_req = NULL;
 473         acm->pending = false;
 474
 475         req->length = len;
 476         notify = req->buf;
 477         buf = notify + 1;
 478
 479         notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
 480                         | USB_RECIP_INTERFACE;
 481         notify->bNotificationType = type;
 482         notify->wValue = cpu_to_le16(value);
 483         notify->wIndex = cpu_to_le16(acm->ctrl_id);
 484         notify->wLength = cpu_to_le16(length);
 485         memcpy(buf, data, length);
 486
 487         /* ep_queue() can complete immediately if it fills the fifo... */
 488         spin_unlock(&acm->lock);
 489         status = usb_ep_queue(ep, req, GFP_ATOMIC);
 490         spin_lock(&acm->lock);
 491
 492         if (status < 0) {
 493                 ERROR(acm->port.func.config->cdev,
 494                                 "acm ttyGS%d can't notify serial state, %d\n",
 495                                 acm->port_num, status);
 496                 acm->notify_req = req;
 497         }
 498
 499         return status;
 500 }
 501
 502 static int acm_notify_serial_state(struct f_acm *acm)
 503 {
 504         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 505         int                     status;
 506
 507         spin_lock(&acm->lock);
 508         if (acm->notify_req) {
 509                 DBG(cdev, "acm ttyGS%d serial state %04x\n",
 510                                 acm->port_num, acm->serial_state);
 511                 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
 512                                 0, &acm->serial_state, sizeof(acm->serial_state));
 513         } else {
 514                 acm->pending = true;
 515                 status = 0;
 516         }
 517         spin_unlock(&acm->lock);
 518         return status;
 519 }
 520
 521 static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
 522 {
 523         struct f_acm            *acm = req->context;
 524         u8                      doit = false;
 525
 526         /* on this call path we do NOT hold the port spinlock,
 527          * which is why ACM needs its own spinlock
 528          */
 529         spin_lock(&acm->lock);
 530         if (req->status != -ESHUTDOWN)
 531                 doit = acm->pending;
 532         acm->notify_req = req;
 533         spin_unlock(&acm->lock);
 534
 535         if (doit)
 536                 acm_notify_serial_state(acm);
 537 }
 538
 539 /* connect == the TTY link is open */
 540
 541 static void acm_connect(struct gserial *port)
 542 {
 543         struct f_acm            *acm = port_to_acm(port);
 544
 545         acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
 546         acm_notify_serial_state(acm);
 547 }
 548
 549 static void acm_disconnect(struct gserial *port)
 550 {
 551         struct f_acm            *acm = port_to_acm(port);
 552
 553         acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
 554         acm_notify_serial_state(acm);
 555 }
 556
 557 static int acm_send_break(struct gserial *port, int duration)
 558 {
 559         struct f_acm            *acm = port_to_acm(port);
 560         u16                     state;
 561
 562         state = acm->serial_state;
 563         state &= ~ACM_CTRL_BRK;
 564         if (duration)
 565                 state |= ACM_CTRL_BRK;
 566
 567         acm->serial_state = state;
 568         return acm_notify_serial_state(acm);
 569 }
 570
 571 /*-------------------------------------------------------------------------*/
 572
 573 /* ACM function driver setup/binding */
 574 static int
 575 acm_bind(struct usb_configuration *c, struct usb_function *f)
 576 {
 577         struct usb_composite_dev *cdev = c->cdev;
 578         struct f_acm            *acm = func_to_acm(f);
 579         int                     status;
 580         struct usb_ep           *ep;
 581
 582         /* allocate instance-specific interface IDs, and patch descriptors */
 583         status = usb_interface_id(c, f);
 584         if (status < 0)
 585                 goto fail;
 586         acm->ctrl_id = status;
 587         acm_iad_descriptor.bFirstInterface = status;
 588
 589         acm_control_interface_desc.bInterfaceNumber = status;
 590         acm_union_desc .bMasterInterface0 = status;
 591
 592         status = usb_interface_id(c, f);
 593         if (status < 0)
 594                 goto fail;
 595         acm->data_id = status;
 596
 597         acm_data_interface_desc.bInterfaceNumber = status;
 598         acm_union_desc.bSlaveInterface0 = status;
 599         acm_call_mgmt_descriptor.bDataInterface = status;
 600
 601         status = -ENODEV;
 602
 603         /* allocate instance-specific endpoints */
 604         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
 605         if (!ep)
 606                 goto fail;
 607         acm->port.in = ep;
 608         ep->driver_data = cdev; /* claim */
 609
 610         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
 611         if (!ep)
 612                 goto fail;
 613         acm->port.out = ep;
 614         ep->driver_data = cdev; /* claim */
 615
 616         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
 617         if (!ep)
 618                 goto fail;
 619         acm->notify = ep;
 620         ep->driver_data = cdev; /* claim */
 621
 622         /* allocate notification */
 623         acm->notify_req = gs_alloc_req(ep,
 624                         sizeof(struct usb_cdc_notification) + 2,
 625                         GFP_KERNEL);
 626         if (!acm->notify_req)
 627                 goto fail;
 628
 629         acm->notify_req->complete = acm_cdc_notify_complete;
 630         acm->notify_req->context = acm;
 631
 632         /* copy descriptors, and track endpoint copies */
 633         f->descriptors = usb_copy_descriptors(acm_fs_function);
 634         if (!f->descriptors)
 635                 goto fail;
 636
 637         acm->fs.in = usb_find_endpoint(acm_fs_function,
 638                         f->descriptors, &acm_fs_in_desc);
 639         acm->fs.out = usb_find_endpoint(acm_fs_function,
 640                         f->descriptors, &acm_fs_out_desc);
 641         acm->fs.notify = usb_find_endpoint(acm_fs_function,
 642                         f->descriptors, &acm_fs_notify_desc);
 643
 644         /* support all relevant hardware speeds... we expect that when
 645          * hardware is dual speed, all bulk-capable endpoints work at
 646          * both speeds
 647          */
 648         if (gadget_is_dualspeed(c->cdev->gadget)) {
 649                 acm_hs_in_desc.bEndpointAddress =
 650                                 acm_fs_in_desc.bEndpointAddress;
 651                 acm_hs_out_desc.bEndpointAddress =
 652                                 acm_fs_out_desc.bEndpointAddress;
 653                 acm_hs_notify_desc.bEndpointAddress =
 654                                 acm_fs_notify_desc.bEndpointAddress;
 655
 656                 /* copy descriptors, and track endpoint copies */
 657                 f->hs_descriptors = usb_copy_descriptors(acm_hs_function);
 658
 659                 acm->hs.in = usb_find_endpoint(acm_hs_function,
 660                                 f->hs_descriptors, &acm_hs_in_desc);
 661                 acm->hs.out = usb_find_endpoint(acm_hs_function,
 662                                 f->hs_descriptors, &acm_hs_out_desc);
 663                 acm->hs.notify = usb_find_endpoint(acm_hs_function,
 664                                 f->hs_descriptors, &acm_hs_notify_desc);
 665         }
 666
 667         DBG(cdev, "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 668                         acm->port_num,
 669                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 670                         acm->port.in->name, acm->port.out->name,
 671                         acm->notify->name);
 672         return 0;
 673
 674 fail:
 675         if (acm->notify_req)
 676                 gs_free_req(acm->notify, acm->notify_req);
 677
 678         /* we might as well release our claims on endpoints */
 679         if (acm->notify)
 680                 acm->notify->driver_data = NULL;
 681         if (acm->port.out)
 682                 acm->port.out->driver_data = NULL;
 683         if (acm->port.in)
 684                 acm->port.in->driver_data = NULL;
 685
 686         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 687
 688         return status;
 689 }
 690
 691 static void
 692 acm_unbind(struct usb_configuration *c, struct usb_function *f)
 693 {
 694         struct f_acm            *acm = func_to_acm(f);
 695
 696         if (gadget_is_dualspeed(c->cdev->gadget))
 697                 usb_free_descriptors(f->hs_descriptors);
 698         usb_free_descriptors(f->descriptors);
 699         gs_free_req(acm->notify, acm->notify_req);
 700         kfree(acm);
 701 }
 702
 703 /* Some controllers can't support CDC ACM ... */
 704 static inline bool can_support_cdc(struct usb_configuration *c)
 705 {
 706         /* everything else is *probably* fine ... */
 707         return true;
 708 }
 709
 710 /**
 711  * acm_bind_config - add a CDC ACM function to a configuration
 712  * @c: the configuration to support the CDC ACM instance
 713  * @port_num: /dev/ttyGS* port this interface will use
 714  * Context: single threaded during gadget setup
 715  *
 716  * Returns zero on success, else negative errno.
 717  *
 718  * Caller must have called @gserial_setup() with enough ports to
 719  * handle all the ones it binds.  Caller is also responsible
 720  * for calling @gserial_cleanup() before module unload.
 721  */
 722 int acm_bind_config(struct usb_configuration *c, u8 port_num)
 723 {
 724         struct f_acm    *acm;
 725         int             status;
 726
 727         if (!can_support_cdc(c))
 728                 return -EINVAL;
 729
 730         /* REVISIT might want instance-specific strings to help
 731          * distinguish instances ...
 732          */
 733
 734         /* maybe allocate device-global string IDs, and patch descriptors */
 735         if (acm_string_defs[ACM_CTRL_IDX].id == 0) {
 736                 status = usb_string_id(c->cdev);
 737                 if (status < 0)
 738                         return status;
 739                 acm_string_defs[ACM_CTRL_IDX].id = status;
 740
 741                 acm_control_interface_desc.iInterface = status;
 742
 743                 status = usb_string_id(c->cdev);
 744                 if (status < 0)
 745                         return status;
 746                 acm_string_defs[ACM_DATA_IDX].id = status;
 747
 748                 acm_data_interface_desc.iInterface = status;
 749
 750                 status = usb_string_id(c->cdev);
 751                 if (status < 0)
 752                         return status;
 753                 acm_string_defs[ACM_IAD_IDX].id = status;
 754
 755                 acm_iad_descriptor.iFunction = status;
 756         }
 757
 758         /* allocate and initialize one new instance */
 759         acm = kzalloc(sizeof *acm, GFP_KERNEL);
 760         if (!acm)
 761                 return -ENOMEM;
 762
 763         spin_lock_init(&acm->lock);
 764
 765         acm->port_num = port_num;
 766
 767         acm->port.connect = acm_connect;
 768         acm->port.disconnect = acm_disconnect;
 769         acm->port.send_break = acm_send_break;
 770
 771         acm->port.func.name = "acm";
 772         acm->port.func.strings = acm_strings;
 773         /* descriptors are per-instance copies */
 774         acm->port.func.bind = acm_bind;
 775         acm->port.func.unbind = acm_unbind;
 776         acm->port.func.set_alt = acm_set_alt;
 777         acm->port.func.setup = acm_setup;
 778         acm->port.func.disable = acm_disable;
 779
 780         status = usb_add_function(c, &acm->port.func);
 781         if (status)
 782                 kfree(acm);
 783         return status;
 784 }