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 (mina86@mina86.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 static struct usb_endpoint_descriptor acm_ss_in_desc = {
 241         .bLength =              USB_DT_ENDPOINT_SIZE,
 242         .bDescriptorType =      USB_DT_ENDPOINT,
 243         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 244         .wMaxPacketSize =       cpu_to_le16(1024),
 245 };
 246
 247 static struct usb_endpoint_descriptor acm_ss_out_desc = {
 248         .bLength =              USB_DT_ENDPOINT_SIZE,
 249         .bDescriptorType =      USB_DT_ENDPOINT,
 250         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 251         .wMaxPacketSize =       cpu_to_le16(1024),
 252 };
 253
 254 static struct usb_ss_ep_comp_descriptor acm_ss_bulk_comp_desc = {
 255         .bLength =              sizeof acm_ss_bulk_comp_desc,
 256         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 257 };
 258
 259 static struct usb_descriptor_header *acm_ss_function[] = {
 260         (struct usb_descriptor_header *) &acm_iad_descriptor,
 261         (struct usb_descriptor_header *) &acm_control_interface_desc,
 262         (struct usb_descriptor_header *) &acm_header_desc,
 263         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 264         (struct usb_descriptor_header *) &acm_descriptor,
 265         (struct usb_descriptor_header *) &acm_union_desc,
 266         (struct usb_descriptor_header *) &acm_hs_notify_desc,
 267         (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
 268         (struct usb_descriptor_header *) &acm_data_interface_desc,
 269         (struct usb_descriptor_header *) &acm_ss_in_desc,
 270         (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
 271         (struct usb_descriptor_header *) &acm_ss_out_desc,
 272         (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
 273         NULL,
 274 };
 275
 276 /* string descriptors: */
 277
 278 #define ACM_CTRL_IDX    0
 279 #define ACM_DATA_IDX    1
 280 #define ACM_IAD_IDX     2
 281
 282 /* static strings, in UTF-8 */
 283 static struct usb_string acm_string_defs[] = {
 284         [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
 285         [ACM_DATA_IDX].s = "CDC ACM Data",
 286         [ACM_IAD_IDX ].s = "CDC Serial",
 287         {  /* ZEROES END LIST */ },
 288 };
 289
 290 static struct usb_gadget_strings acm_string_table = {
 291         .language =             0x0409, /* en-us */
 292         .strings =              acm_string_defs,
 293 };
 294
 295 static struct usb_gadget_strings *acm_strings[] = {
 296         &acm_string_table,
 297         NULL,
 298 };
 299
 300 /*-------------------------------------------------------------------------*/
 301
 302 /* ACM control ... data handling is delegated to tty library code.
 303  * The main task of this function is to activate and deactivate
 304  * that code based on device state; track parameters like line
 305  * speed, handshake state, and so on; and issue notifications.
 306  */
 307
 308 static void acm_complete_set_line_coding(struct usb_ep *ep,
 309                 struct usb_request *req)
 310 {
 311         struct f_acm    *acm = ep->driver_data;
 312         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 313
 314         if (req->status != 0) {
 315                 DBG(cdev, "acm ttyGS%d completion, err %d\n",
 316                                 acm->port_num, req->status);
 317                 return;
 318         }
 319
 320         /* normal completion */
 321         if (req->actual != sizeof(acm->port_line_coding)) {
 322                 DBG(cdev, "acm ttyGS%d short resp, len %d\n",
 323                                 acm->port_num, req->actual);
 324                 usb_ep_set_halt(ep);
 325         } else {
 326                 struct usb_cdc_line_coding      *value = req->buf;
 327
 328                 /* REVISIT:  we currently just remember this data.
 329                  * If we change that, (a) validate it first, then
 330                  * (b) update whatever hardware needs updating,
 331                  * (c) worry about locking.  This is information on
 332                  * the order of 9600-8-N-1 ... most of which means
 333                  * nothing unless we control a real RS232 line.
 334                  */
 335                 acm->port_line_coding = *value;
 336         }
 337 }
 338
 339 static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 340 {
 341         struct f_acm            *acm = func_to_acm(f);
 342         struct usb_composite_dev *cdev = f->config->cdev;
 343         struct usb_request      *req = cdev->req;
 344         int                     value = -EOPNOTSUPP;
 345         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 346         u16                     w_value = le16_to_cpu(ctrl->wValue);
 347         u16                     w_length = le16_to_cpu(ctrl->wLength);
 348
 349         /* composite driver infrastructure handles everything except
 350          * CDC class messages; interface activation uses set_alt().
 351          *
 352          * Note CDC spec table 4 lists the ACM request profile.  It requires
 353          * encapsulated command support ... we don't handle any, and respond
 354          * to them by stalling.  Options include get/set/clear comm features
 355          * (not that useful) and SEND_BREAK.
 356          */
 357         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 358
 359         /* SET_LINE_CODING ... just read and save what the host sends */
 360         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 361                         | USB_CDC_REQ_SET_LINE_CODING:
 362                 if (w_length != sizeof(struct usb_cdc_line_coding)
 363                                 || w_index != acm->ctrl_id)
 364                         goto invalid;
 365
 366                 value = w_length;
 367                 cdev->gadget->ep0->driver_data = acm;
 368                 req->complete = acm_complete_set_line_coding;
 369                 break;
 370
 371         /* GET_LINE_CODING ... return what host sent, or initial value */
 372         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 373                         | USB_CDC_REQ_GET_LINE_CODING:
 374                 if (w_index != acm->ctrl_id)
 375                         goto invalid;
 376
 377                 value = min_t(unsigned, w_length,
 378                                 sizeof(struct usb_cdc_line_coding));
 379                 memcpy(req->buf, &acm->port_line_coding, value);
 380                 break;
 381
 382         /* SET_CONTROL_LINE_STATE ... save what the host sent */
 383         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 384                         | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
 385                 if (w_index != acm->ctrl_id)
 386                         goto invalid;
 387
 388                 value = 0;
 389
 390                 /* FIXME we should not allow data to flow until the
 391                  * host sets the ACM_CTRL_DTR bit; and when it clears
 392                  * that bit, we should return to that no-flow state.
 393                  */
 394                 acm->port_handshake_bits = w_value;
 395                 break;
 396
 397         default:
 398 invalid:
 399                 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 400                         ctrl->bRequestType, ctrl->bRequest,
 401                         w_value, w_index, w_length);
 402         }
 403
 404         /* respond with data transfer or status phase? */
 405         if (value >= 0) {
 406                 DBG(cdev, "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
 407                         acm->port_num, ctrl->bRequestType, ctrl->bRequest,
 408                         w_value, w_index, w_length);
 409                 req->zero = 0;
 410                 req->length = value;
 411                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 412                 if (value < 0)
 413                         ERROR(cdev, "acm response on ttyGS%d, err %d\n",
 414                                         acm->port_num, value);
 415         }
 416
 417         /* device either stalls (value < 0) or reports success */
 418         return value;
 419 }
 420
 421 static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 422 {
 423         struct f_acm            *acm = func_to_acm(f);
 424         struct usb_composite_dev *cdev = f->config->cdev;
 425
 426         /* we know alt == 0, so this is an activation or a reset */
 427
 428         if (intf == acm->ctrl_id) {
 429                 if (acm->notify->driver_data) {
 430                         VDBG(cdev, "reset acm control interface %d\n", intf);
 431                         usb_ep_disable(acm->notify);
 432                 } else {
 433                         VDBG(cdev, "init acm ctrl interface %d\n", intf);
 434                         if (config_ep_by_speed(cdev->gadget, f, acm->notify))
 435                                 return -EINVAL;
 436                 }
 437                 usb_ep_enable(acm->notify);
 438                 acm->notify->driver_data = acm;
 439
 440         } else if (intf == acm->data_id) {
 441                 if (acm->port.in->driver_data) {
 442                         DBG(cdev, "reset acm ttyGS%d\n", acm->port_num);
 443                         gserial_disconnect(&acm->port);
 444                 }
 445                 if (!acm->port.in->desc || !acm->port.out->desc) {
 446                         DBG(cdev, "activate acm ttyGS%d\n", acm->port_num);
 447                         if (config_ep_by_speed(cdev->gadget, f,
 448                                                acm->port.in) ||
 449                             config_ep_by_speed(cdev->gadget, f,
 450                                                acm->port.out)) {
 451                                 acm->port.in->desc = NULL;
 452                                 acm->port.out->desc = NULL;
 453                                 return -EINVAL;
 454                         }
 455                 }
 456                 gserial_connect(&acm->port, acm->port_num);
 457
 458         } else
 459                 return -EINVAL;
 460
 461         return 0;
 462 }
 463
 464 static void acm_disable(struct usb_function *f)
 465 {
 466         struct f_acm    *acm = func_to_acm(f);
 467         struct usb_composite_dev *cdev = f->config->cdev;
 468
 469         DBG(cdev, "acm ttyGS%d deactivated\n", acm->port_num);
 470         gserial_disconnect(&acm->port);
 471         usb_ep_disable(acm->notify);
 472         acm->notify->driver_data = NULL;
 473 }
 474
 475 /*-------------------------------------------------------------------------*/
 476
 477 /**
 478  * acm_cdc_notify - issue CDC notification to host
 479  * @acm: wraps host to be notified
 480  * @type: notification type
 481  * @value: Refer to cdc specs, wValue field.
 482  * @data: data to be sent
 483  * @length: size of data
 484  * Context: irqs blocked, acm->lock held, acm_notify_req non-null
 485  *
 486  * Returns zero on success or a negative errno.
 487  *
 488  * See section 6.3.5 of the CDC 1.1 specification for information
 489  * about the only notification we issue:  SerialState change.
 490  */
 491 static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
 492                 void *data, unsigned length)
 493 {
 494         struct usb_ep                   *ep = acm->notify;
 495         struct usb_request              *req;
 496         struct usb_cdc_notification     *notify;
 497         const unsigned                  len = sizeof(*notify) + length;
 498         void                            *buf;
 499         int                             status;
 500
 501         req = acm->notify_req;
 502         acm->notify_req = NULL;
 503         acm->pending = false;
 504
 505         req->length = len;
 506         notify = req->buf;
 507         buf = notify + 1;
 508
 509         notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
 510                         | USB_RECIP_INTERFACE;
 511         notify->bNotificationType = type;
 512         notify->wValue = cpu_to_le16(value);
 513         notify->wIndex = cpu_to_le16(acm->ctrl_id);
 514         notify->wLength = cpu_to_le16(length);
 515         memcpy(buf, data, length);
 516
 517         /* ep_queue() can complete immediately if it fills the fifo... */
 518         spin_unlock(&acm->lock);
 519         status = usb_ep_queue(ep, req, GFP_ATOMIC);
 520         spin_lock(&acm->lock);
 521
 522         if (status < 0) {
 523                 ERROR(acm->port.func.config->cdev,
 524                                 "acm ttyGS%d can't notify serial state, %d\n",
 525                                 acm->port_num, status);
 526                 acm->notify_req = req;
 527         }
 528
 529         return status;
 530 }
 531
 532 static int acm_notify_serial_state(struct f_acm *acm)
 533 {
 534         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 535         int                     status;
 536
 537         spin_lock(&acm->lock);
 538         if (acm->notify_req) {
 539                 DBG(cdev, "acm ttyGS%d serial state %04x\n",
 540                                 acm->port_num, acm->serial_state);
 541                 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
 542                                 0, &acm->serial_state, sizeof(acm->serial_state));
 543         } else {
 544                 acm->pending = true;
 545                 status = 0;
 546         }
 547         spin_unlock(&acm->lock);
 548         return status;
 549 }
 550
 551 static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
 552 {
 553         struct f_acm            *acm = req->context;
 554         u8                      doit = false;
 555
 556         /* on this call path we do NOT hold the port spinlock,
 557          * which is why ACM needs its own spinlock
 558          */
 559         spin_lock(&acm->lock);
 560         if (req->status != -ESHUTDOWN)
 561                 doit = acm->pending;
 562         acm->notify_req = req;
 563         spin_unlock(&acm->lock);
 564
 565         if (doit)
 566                 acm_notify_serial_state(acm);
 567 }
 568
 569 /* connect == the TTY link is open */
 570
 571 static void acm_connect(struct gserial *port)
 572 {
 573         struct f_acm            *acm = port_to_acm(port);
 574
 575         acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
 576         acm_notify_serial_state(acm);
 577 }
 578
 579 static void acm_disconnect(struct gserial *port)
 580 {
 581         struct f_acm            *acm = port_to_acm(port);
 582
 583         acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
 584         acm_notify_serial_state(acm);
 585 }
 586
 587 static int acm_send_break(struct gserial *port, int duration)
 588 {
 589         struct f_acm            *acm = port_to_acm(port);
 590         u16                     state;
 591
 592         state = acm->serial_state;
 593         state &= ~ACM_CTRL_BRK;
 594         if (duration)
 595                 state |= ACM_CTRL_BRK;
 596
 597         acm->serial_state = state;
 598         return acm_notify_serial_state(acm);
 599 }
 600
 601 /*-------------------------------------------------------------------------*/
 602
 603 /* ACM function driver setup/binding */
 604 static int
 605 acm_bind(struct usb_configuration *c, struct usb_function *f)
 606 {
 607         struct usb_composite_dev *cdev = c->cdev;
 608         struct f_acm            *acm = func_to_acm(f);
 609         int                     status;
 610         struct usb_ep           *ep;
 611
 612         /* allocate instance-specific interface IDs, and patch descriptors */
 613         status = usb_interface_id(c, f);
 614         if (status < 0)
 615                 goto fail;
 616         acm->ctrl_id = status;
 617         acm_iad_descriptor.bFirstInterface = status;
 618
 619         acm_control_interface_desc.bInterfaceNumber = status;
 620         acm_union_desc .bMasterInterface0 = status;
 621
 622         status = usb_interface_id(c, f);
 623         if (status < 0)
 624                 goto fail;
 625         acm->data_id = status;
 626
 627         acm_data_interface_desc.bInterfaceNumber = status;
 628         acm_union_desc.bSlaveInterface0 = status;
 629         acm_call_mgmt_descriptor.bDataInterface = status;
 630
 631         status = -ENODEV;
 632
 633         /* allocate instance-specific endpoints */
 634         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
 635         if (!ep)
 636                 goto fail;
 637         acm->port.in = ep;
 638         ep->driver_data = cdev; /* claim */
 639
 640         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
 641         if (!ep)
 642                 goto fail;
 643         acm->port.out = ep;
 644         ep->driver_data = cdev; /* claim */
 645
 646         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
 647         if (!ep)
 648                 goto fail;
 649         acm->notify = ep;
 650         ep->driver_data = cdev; /* claim */
 651
 652         /* allocate notification */
 653         acm->notify_req = gs_alloc_req(ep,
 654                         sizeof(struct usb_cdc_notification) + 2,
 655                         GFP_KERNEL);
 656         if (!acm->notify_req)
 657                 goto fail;
 658
 659         acm->notify_req->complete = acm_cdc_notify_complete;
 660         acm->notify_req->context = acm;
 661
 662         /* copy descriptors */
 663         f->descriptors = usb_copy_descriptors(acm_fs_function);
 664         if (!f->descriptors)
 665                 goto fail;
 666
 667         /* support all relevant hardware speeds... we expect that when
 668          * hardware is dual speed, all bulk-capable endpoints work at
 669          * both speeds
 670          */
 671         if (gadget_is_dualspeed(c->cdev->gadget)) {
 672                 acm_hs_in_desc.bEndpointAddress =
 673                                 acm_fs_in_desc.bEndpointAddress;
 674                 acm_hs_out_desc.bEndpointAddress =
 675                                 acm_fs_out_desc.bEndpointAddress;
 676                 acm_hs_notify_desc.bEndpointAddress =
 677                                 acm_fs_notify_desc.bEndpointAddress;
 678
 679                 /* copy descriptors */
 680                 f->hs_descriptors = usb_copy_descriptors(acm_hs_function);
 681         }
 682         if (gadget_is_superspeed(c->cdev->gadget)) {
 683                 acm_ss_in_desc.bEndpointAddress =
 684                         acm_fs_in_desc.bEndpointAddress;
 685                 acm_ss_out_desc.bEndpointAddress =
 686                         acm_fs_out_desc.bEndpointAddress;
 687
 688                 /* copy descriptors, and track endpoint copies */
 689                 f->ss_descriptors = usb_copy_descriptors(acm_ss_function);
 690                 if (!f->ss_descriptors)
 691                         goto fail;
 692         }
 693
 694         DBG(cdev, "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 695                         acm->port_num,
 696                         gadget_is_superspeed(c->cdev->gadget) ? "super" :
 697                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 698                         acm->port.in->name, acm->port.out->name,
 699                         acm->notify->name);
 700         return 0;
 701
 702 fail:
 703         if (acm->notify_req)
 704                 gs_free_req(acm->notify, acm->notify_req);
 705
 706         /* we might as well release our claims on endpoints */
 707         if (acm->notify)
 708                 acm->notify->driver_data = NULL;
 709         if (acm->port.out)
 710                 acm->port.out->driver_data = NULL;
 711         if (acm->port.in)
 712                 acm->port.in->driver_data = NULL;
 713
 714         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 715
 716         return status;
 717 }
 718
 719 static void
 720 acm_unbind(struct usb_configuration *c, struct usb_function *f)
 721 {
 722         struct f_acm            *acm = func_to_acm(f);
 723
 724         if (gadget_is_dualspeed(c->cdev->gadget))
 725                 usb_free_descriptors(f->hs_descriptors);
 726         if (gadget_is_superspeed(c->cdev->gadget))
 727                 usb_free_descriptors(f->ss_descriptors);
 728         usb_free_descriptors(f->descriptors);
 729         gs_free_req(acm->notify, acm->notify_req);
 730         kfree(acm);
 731 }
 732
 733 /* Some controllers can't support CDC ACM ... */
 734 static inline bool can_support_cdc(struct usb_configuration *c)
 735 {
 736         /* everything else is *probably* fine ... */
 737         return true;
 738 }
 739
 740 /**
 741  * acm_bind_config - add a CDC ACM function to a configuration
 742  * @c: the configuration to support the CDC ACM instance
 743  * @port_num: /dev/ttyGS* port this interface will use
 744  * Context: single threaded during gadget setup
 745  *
 746  * Returns zero on success, else negative errno.
 747  *
 748  * Caller must have called @gserial_setup() with enough ports to
 749  * handle all the ones it binds.  Caller is also responsible
 750  * for calling @gserial_cleanup() before module unload.
 751  */
 752 int acm_bind_config(struct usb_configuration *c, u8 port_num)
 753 {
 754         struct f_acm    *acm;
 755         int             status;
 756
 757         if (!can_support_cdc(c))
 758                 return -EINVAL;
 759
 760         /* REVISIT might want instance-specific strings to help
 761          * distinguish instances ...
 762          */
 763
 764         /* maybe allocate device-global string IDs, and patch descriptors */
 765         if (acm_string_defs[ACM_CTRL_IDX].id == 0) {
 766                 status = usb_string_id(c->cdev);
 767                 if (status < 0)
 768                         return status;
 769                 acm_string_defs[ACM_CTRL_IDX].id = status;
 770
 771                 acm_control_interface_desc.iInterface = status;
 772
 773                 status = usb_string_id(c->cdev);
 774                 if (status < 0)
 775                         return status;
 776                 acm_string_defs[ACM_DATA_IDX].id = status;
 777
 778                 acm_data_interface_desc.iInterface = status;
 779
 780                 status = usb_string_id(c->cdev);
 781                 if (status < 0)
 782                         return status;
 783                 acm_string_defs[ACM_IAD_IDX].id = status;
 784
 785                 acm_iad_descriptor.iFunction = status;
 786         }
 787
 788         /* allocate and initialize one new instance */
 789         acm = kzalloc(sizeof *acm, GFP_KERNEL);
 790         if (!acm)
 791                 return -ENOMEM;
 792
 793         spin_lock_init(&acm->lock);
 794
 795         acm->port_num = port_num;
 796
 797         acm->port.connect = acm_connect;
 798         acm->port.disconnect = acm_disconnect;
 799         acm->port.send_break = acm_send_break;
 800
 801         acm->port.func.name = "acm";
 802         acm->port.func.strings = acm_strings;
 803         /* descriptors are per-instance copies */
 804         acm->port.func.bind = acm_bind;
 805         acm->port.func.unbind = acm_unbind;
 806         acm->port.func.set_alt = acm_set_alt;
 807         acm->port.func.setup = acm_setup;
 808         acm->port.func.disable = acm_disable;
 809
 810         status = usb_add_function(c, &acm->port.func);
 811         if (status)
 812                 kfree(acm);
 813         return status;
 814 }