drivers/usb/gadget/function/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/module.h>
  20 #include <linux/device.h>
  21 #include <linux/err.h>
  22
  23 #include "u_serial.h"
  24
  25
  26 /*
  27  * This CDC ACM function support just wraps control functions and
  28  * notifications around the generic serial-over-usb code.
  29  *
  30  * Because CDC ACM is standardized by the USB-IF, many host operating
  31  * systems have drivers for it.  Accordingly, ACM is the preferred
  32  * interop solution for serial-port type connections.  The control
  33  * models are often not necessary, and in any case don't do much in
  34  * this bare-bones implementation.
  35  *
  36  * Note that even MS-Windows has some support for ACM.  However, that
  37  * support is somewhat broken because when you use ACM in a composite
  38  * device, having multiple interfaces confuses the poor OS.  It doesn't
  39  * seem to understand CDC Union descriptors.  The new "association"
  40  * descriptors (roughly equivalent to CDC Unions) may sometimes help.
  41  */
  42
  43 struct f_acm {
  44         struct gserial                  port;
  45         u8                              ctrl_id, data_id;
  46         u8                              port_num;
  47
  48         u8                              pending;
  49
  50         /* lock is mostly for pending and notify_req ... they get accessed
  51          * by callbacks both from tty (open/close/break) under its spinlock,
  52          * and notify_req.complete() which can't use that lock.
  53          */
  54         spinlock_t                      lock;
  55
  56         struct usb_ep                   *notify;
  57         struct usb_request              *notify_req;
  58
  59         struct usb_cdc_line_coding      port_line_coding;       /* 8-N-1 etc */
  60
  61         /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
  62         u16                             port_handshake_bits;
  63 #define ACM_CTRL_RTS    (1 << 1)        /* unused with full duplex */
  64 #define ACM_CTRL_DTR    (1 << 0)        /* host is ready for data r/w */
  65
  66         /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
  67         u16                             serial_state;
  68 #define ACM_CTRL_OVERRUN        (1 << 6)
  69 #define ACM_CTRL_PARITY         (1 << 5)
  70 #define ACM_CTRL_FRAMING        (1 << 4)
  71 #define ACM_CTRL_RI             (1 << 3)
  72 #define ACM_CTRL_BRK            (1 << 2)
  73 #define ACM_CTRL_DSR            (1 << 1)
  74 #define ACM_CTRL_DCD            (1 << 0)
  75 };
  76
  77 static inline struct f_acm *func_to_acm(struct usb_function *f)
  78 {
  79         return container_of(f, struct f_acm, port.func);
  80 }
  81
  82 static inline struct f_acm *port_to_acm(struct gserial *p)
  83 {
  84         return container_of(p, struct f_acm, port);
  85 }
  86
  87 /*-------------------------------------------------------------------------*/
  88
  89 /* notification endpoint uses smallish and infrequent fixed-size messages */
  90
  91 #define GS_NOTIFY_INTERVAL_MS           32
  92 #define GS_NOTIFY_MAXPACKET             10      /* notification + 2 bytes */
  93
  94 /* interface and class descriptors: */
  95
  96 static struct usb_interface_assoc_descriptor
  97 acm_iad_descriptor = {
  98         .bLength =              sizeof acm_iad_descriptor,
  99         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
 100
 101         /* .bFirstInterface =   DYNAMIC, */
 102         .bInterfaceCount =      2,      // control + data
 103         .bFunctionClass =       USB_CLASS_COMM,
 104         .bFunctionSubClass =    USB_CDC_SUBCLASS_ACM,
 105         .bFunctionProtocol =    USB_CDC_ACM_PROTO_AT_V25TER,
 106         /* .iFunction =         DYNAMIC */
 107 };
 108
 109
 110 static struct usb_interface_descriptor acm_control_interface_desc = {
 111         .bLength =              USB_DT_INTERFACE_SIZE,
 112         .bDescriptorType =      USB_DT_INTERFACE,
 113         /* .bInterfaceNumber = DYNAMIC */
 114         .bNumEndpoints =        1,
 115         .bInterfaceClass =      USB_CLASS_COMM,
 116         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
 117         .bInterfaceProtocol =   USB_CDC_ACM_PROTO_AT_V25TER,
 118         /* .iInterface = DYNAMIC */
 119 };
 120
 121 static struct usb_interface_descriptor acm_data_interface_desc = {
 122         .bLength =              USB_DT_INTERFACE_SIZE,
 123         .bDescriptorType =      USB_DT_INTERFACE,
 124         /* .bInterfaceNumber = DYNAMIC */
 125         .bNumEndpoints =        2,
 126         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 127         .bInterfaceSubClass =   0,
 128         .bInterfaceProtocol =   0,
 129         /* .iInterface = DYNAMIC */
 130 };
 131
 132 static struct usb_cdc_header_desc acm_header_desc = {
 133         .bLength =              sizeof(acm_header_desc),
 134         .bDescriptorType =      USB_DT_CS_INTERFACE,
 135         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 136         .bcdCDC =               cpu_to_le16(0x0110),
 137 };
 138
 139 static struct usb_cdc_call_mgmt_descriptor
 140 acm_call_mgmt_descriptor = {
 141         .bLength =              sizeof(acm_call_mgmt_descriptor),
 142         .bDescriptorType =      USB_DT_CS_INTERFACE,
 143         .bDescriptorSubType =   USB_CDC_CALL_MANAGEMENT_TYPE,
 144         .bmCapabilities =       0,
 145         /* .bDataInterface = DYNAMIC */
 146 };
 147
 148 static struct usb_cdc_acm_descriptor acm_descriptor = {
 149         .bLength =              sizeof(acm_descriptor),
 150         .bDescriptorType =      USB_DT_CS_INTERFACE,
 151         .bDescriptorSubType =   USB_CDC_ACM_TYPE,
 152         .bmCapabilities =       USB_CDC_CAP_LINE,
 153 };
 154
 155 static struct usb_cdc_union_desc acm_union_desc = {
 156         .bLength =              sizeof(acm_union_desc),
 157         .bDescriptorType =      USB_DT_CS_INTERFACE,
 158         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 159         /* .bMasterInterface0 = DYNAMIC */
 160         /* .bSlaveInterface0 =  DYNAMIC */
 161 };
 162
 163 /* full speed support: */
 164
 165 static struct usb_endpoint_descriptor acm_fs_notify_desc = {
 166         .bLength =              USB_DT_ENDPOINT_SIZE,
 167         .bDescriptorType =      USB_DT_ENDPOINT,
 168         .bEndpointAddress =     USB_DIR_IN,
 169         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 170         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 171         .bInterval =            GS_NOTIFY_INTERVAL_MS,
 172 };
 173
 174 static struct usb_endpoint_descriptor acm_fs_in_desc = {
 175         .bLength =              USB_DT_ENDPOINT_SIZE,
 176         .bDescriptorType =      USB_DT_ENDPOINT,
 177         .bEndpointAddress =     USB_DIR_IN,
 178         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 179 };
 180
 181 static struct usb_endpoint_descriptor acm_fs_out_desc = {
 182         .bLength =              USB_DT_ENDPOINT_SIZE,
 183         .bDescriptorType =      USB_DT_ENDPOINT,
 184         .bEndpointAddress =     USB_DIR_OUT,
 185         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 186 };
 187
 188 static struct usb_descriptor_header *acm_fs_function[] = {
 189         (struct usb_descriptor_header *) &acm_iad_descriptor,
 190         (struct usb_descriptor_header *) &acm_control_interface_desc,
 191         (struct usb_descriptor_header *) &acm_header_desc,
 192         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 193         (struct usb_descriptor_header *) &acm_descriptor,
 194         (struct usb_descriptor_header *) &acm_union_desc,
 195         (struct usb_descriptor_header *) &acm_fs_notify_desc,
 196         (struct usb_descriptor_header *) &acm_data_interface_desc,
 197         (struct usb_descriptor_header *) &acm_fs_in_desc,
 198         (struct usb_descriptor_header *) &acm_fs_out_desc,
 199         NULL,
 200 };
 201
 202 /* high speed support: */
 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 =            USB_MS_TO_HS_INTERVAL(GS_NOTIFY_INTERVAL_MS),
 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         {  } /* end of 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                 dev_dbg(&cdev->gadget->dev, "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                 dev_dbg(&cdev->gadget->dev, "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                 dev_vdbg(&cdev->gadget->dev,
 400                          "invalid control req%02x.%02x v%04x i%04x l%d\n",
 401                          ctrl->bRequestType, ctrl->bRequest,
 402                          w_value, w_index, w_length);
 403         }
 404
 405         /* respond with data transfer or status phase? */
 406         if (value >= 0) {
 407                 dev_dbg(&cdev->gadget->dev,
 408                         "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
 409                         acm->port_num, ctrl->bRequestType, ctrl->bRequest,
 410                         w_value, w_index, w_length);
 411                 req->zero = 0;
 412                 req->length = value;
 413                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 414                 if (value < 0)
 415                         ERROR(cdev, "acm response on ttyGS%d, err %d\n",
 416                                         acm->port_num, value);
 417         }
 418
 419         /* device either stalls (value < 0) or reports success */
 420         return value;
 421 }
 422
 423 static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 424 {
 425         struct f_acm            *acm = func_to_acm(f);
 426         struct usb_composite_dev *cdev = f->config->cdev;
 427
 428         /* we know alt == 0, so this is an activation or a reset */
 429
 430         if (intf == acm->ctrl_id) {
 431                 dev_vdbg(&cdev->gadget->dev,
 432                                 "reset acm control interface %d\n", intf);
 433                 usb_ep_disable(acm->notify);
 434
 435                 if (!acm->notify->desc)
 436                         if (config_ep_by_speed(cdev->gadget, f, acm->notify))
 437                                 return -EINVAL;
 438
 439                 usb_ep_enable(acm->notify);
 440
 441         } else if (intf == acm->data_id) {
 442                 if (acm->notify->enabled) {
 443                         dev_dbg(&cdev->gadget->dev,
 444                                 "reset acm ttyGS%d\n", acm->port_num);
 445                         gserial_disconnect(&acm->port);
 446                 }
 447                 if (!acm->port.in->desc || !acm->port.out->desc) {
 448                         dev_dbg(&cdev->gadget->dev,
 449                                 "activate acm ttyGS%d\n", acm->port_num);
 450                         if (config_ep_by_speed(cdev->gadget, f,
 451                                                acm->port.in) ||
 452                             config_ep_by_speed(cdev->gadget, f,
 453                                                acm->port.out)) {
 454                                 acm->port.in->desc = NULL;
 455                                 acm->port.out->desc = NULL;
 456                                 return -EINVAL;
 457                         }
 458                 }
 459                 gserial_connect(&acm->port, acm->port_num);
 460
 461         } else
 462                 return -EINVAL;
 463
 464         return 0;
 465 }
 466
 467 static void acm_disable(struct usb_function *f)
 468 {
 469         struct f_acm    *acm = func_to_acm(f);
 470         struct usb_composite_dev *cdev = f->config->cdev;
 471
 472         dev_dbg(&cdev->gadget->dev, "acm ttyGS%d deactivated\n", acm->port_num);
 473         gserial_disconnect(&acm->port);
 474         usb_ep_disable(acm->notify);
 475 }
 476
 477 /*-------------------------------------------------------------------------*/
 478
 479 /**
 480  * acm_cdc_notify - issue CDC notification to host
 481  * @acm: wraps host to be notified
 482  * @type: notification type
 483  * @value: Refer to cdc specs, wValue field.
 484  * @data: data to be sent
 485  * @length: size of data
 486  * Context: irqs blocked, acm->lock held, acm_notify_req non-null
 487  *
 488  * Returns zero on success or a negative errno.
 489  *
 490  * See section 6.3.5 of the CDC 1.1 specification for information
 491  * about the only notification we issue:  SerialState change.
 492  */
 493 static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
 494                 void *data, unsigned length)
 495 {
 496         struct usb_ep                   *ep = acm->notify;
 497         struct usb_request              *req;
 498         struct usb_cdc_notification     *notify;
 499         const unsigned                  len = sizeof(*notify) + length;
 500         void                            *buf;
 501         int                             status;
 502
 503         req = acm->notify_req;
 504         acm->notify_req = NULL;
 505         acm->pending = false;
 506
 507         req->length = len;
 508         notify = req->buf;
 509         buf = notify + 1;
 510
 511         notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
 512                         | USB_RECIP_INTERFACE;
 513         notify->bNotificationType = type;
 514         notify->wValue = cpu_to_le16(value);
 515         notify->wIndex = cpu_to_le16(acm->ctrl_id);
 516         notify->wLength = cpu_to_le16(length);
 517         memcpy(buf, data, length);
 518
 519         /* ep_queue() can complete immediately if it fills the fifo... */
 520         spin_unlock(&acm->lock);
 521         status = usb_ep_queue(ep, req, GFP_ATOMIC);
 522         spin_lock(&acm->lock);
 523
 524         if (status < 0) {
 525                 ERROR(acm->port.func.config->cdev,
 526                                 "acm ttyGS%d can't notify serial state, %d\n",
 527                                 acm->port_num, status);
 528                 acm->notify_req = req;
 529         }
 530
 531         return status;
 532 }
 533
 534 static int acm_notify_serial_state(struct f_acm *acm)
 535 {
 536         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 537         int                     status;
 538         __le16                  serial_state;
 539
 540         spin_lock(&acm->lock);
 541         if (acm->notify_req) {
 542                 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d serial state %04x\n",
 543                         acm->port_num, acm->serial_state);
 544                 serial_state = cpu_to_le16(acm->serial_state);
 545                 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
 546                                 0, &serial_state, sizeof(acm->serial_state));
 547         } else {
 548                 acm->pending = true;
 549                 status = 0;
 550         }
 551         spin_unlock(&acm->lock);
 552         return status;
 553 }
 554
 555 static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
 556 {
 557         struct f_acm            *acm = req->context;
 558         u8                      doit = false;
 559
 560         /* on this call path we do NOT hold the port spinlock,
 561          * which is why ACM needs its own spinlock
 562          */
 563         spin_lock(&acm->lock);
 564         if (req->status != -ESHUTDOWN)
 565                 doit = acm->pending;
 566         acm->notify_req = req;
 567         spin_unlock(&acm->lock);
 568
 569         if (doit)
 570                 acm_notify_serial_state(acm);
 571 }
 572
 573 /* connect == the TTY link is open */
 574
 575 static void acm_connect(struct gserial *port)
 576 {
 577         struct f_acm            *acm = port_to_acm(port);
 578
 579         acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
 580         acm_notify_serial_state(acm);
 581 }
 582
 583 static void acm_disconnect(struct gserial *port)
 584 {
 585         struct f_acm            *acm = port_to_acm(port);
 586
 587         acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
 588         acm_notify_serial_state(acm);
 589 }
 590
 591 static int acm_send_break(struct gserial *port, int duration)
 592 {
 593         struct f_acm            *acm = port_to_acm(port);
 594         u16                     state;
 595
 596         state = acm->serial_state;
 597         state &= ~ACM_CTRL_BRK;
 598         if (duration)
 599                 state |= ACM_CTRL_BRK;
 600
 601         acm->serial_state = state;
 602         return acm_notify_serial_state(acm);
 603 }
 604
 605 /*-------------------------------------------------------------------------*/
 606
 607 /* ACM function driver setup/binding */
 608 static int
 609 acm_bind(struct usb_configuration *c, struct usb_function *f)
 610 {
 611         struct usb_composite_dev *cdev = c->cdev;
 612         struct f_acm            *acm = func_to_acm(f);
 613         struct usb_string       *us;
 614         int                     status;
 615         struct usb_ep           *ep;
 616
 617         /* REVISIT might want instance-specific strings to help
 618          * distinguish instances ...
 619          */
 620
 621         /* maybe allocate device-global string IDs, and patch descriptors */
 622         us = usb_gstrings_attach(cdev, acm_strings,
 623                         ARRAY_SIZE(acm_string_defs));
 624         if (IS_ERR(us))
 625                 return PTR_ERR(us);
 626         acm_control_interface_desc.iInterface = us[ACM_CTRL_IDX].id;
 627         acm_data_interface_desc.iInterface = us[ACM_DATA_IDX].id;
 628         acm_iad_descriptor.iFunction = us[ACM_IAD_IDX].id;
 629
 630         /* allocate instance-specific interface IDs, and patch descriptors */
 631         status = usb_interface_id(c, f);
 632         if (status < 0)
 633                 goto fail;
 634         acm->ctrl_id = status;
 635         acm_iad_descriptor.bFirstInterface = status;
 636
 637         acm_control_interface_desc.bInterfaceNumber = status;
 638         acm_union_desc .bMasterInterface0 = status;
 639
 640         status = usb_interface_id(c, f);
 641         if (status < 0)
 642                 goto fail;
 643         acm->data_id = status;
 644
 645         acm_data_interface_desc.bInterfaceNumber = status;
 646         acm_union_desc.bSlaveInterface0 = status;
 647         acm_call_mgmt_descriptor.bDataInterface = status;
 648
 649         status = -ENODEV;
 650
 651         /* allocate instance-specific endpoints */
 652         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
 653         if (!ep)
 654                 goto fail;
 655         acm->port.in = ep;
 656
 657         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
 658         if (!ep)
 659                 goto fail;
 660         acm->port.out = ep;
 661
 662         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
 663         if (!ep)
 664                 goto fail;
 665         acm->notify = ep;
 666
 667         /* allocate notification */
 668         acm->notify_req = gs_alloc_req(ep,
 669                         sizeof(struct usb_cdc_notification) + 2,
 670                         GFP_KERNEL);
 671         if (!acm->notify_req)
 672                 goto fail;
 673
 674         acm->notify_req->complete = acm_cdc_notify_complete;
 675         acm->notify_req->context = acm;
 676
 677         /* support all relevant hardware speeds... we expect that when
 678          * hardware is dual speed, all bulk-capable endpoints work at
 679          * both speeds
 680          */
 681         acm_hs_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
 682         acm_hs_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
 683         acm_hs_notify_desc.bEndpointAddress =
 684                 acm_fs_notify_desc.bEndpointAddress;
 685
 686         acm_ss_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
 687         acm_ss_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
 688
 689         status = usb_assign_descriptors(f, acm_fs_function, acm_hs_function,
 690                         acm_ss_function, NULL);
 691         if (status)
 692                 goto fail;
 693
 694         dev_dbg(&cdev->gadget->dev,
 695                 "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 696                 acm->port_num,
 697                 gadget_is_superspeed(c->cdev->gadget) ? "super" :
 698                 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 699                 acm->port.in->name, acm->port.out->name,
 700                 acm->notify->name);
 701         return 0;
 702
 703 fail:
 704         if (acm->notify_req)
 705                 gs_free_req(acm->notify, acm->notify_req);
 706
 707         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 708
 709         return status;
 710 }
 711
 712 static void acm_unbind(struct usb_configuration *c, struct usb_function *f)
 713 {
 714         struct f_acm            *acm = func_to_acm(f);
 715
 716         acm_string_defs[0].id = 0;
 717         usb_free_all_descriptors(f);
 718         if (acm->notify_req)
 719                 gs_free_req(acm->notify, acm->notify_req);
 720 }
 721
 722 static void acm_free_func(struct usb_function *f)
 723 {
 724         struct f_acm            *acm = func_to_acm(f);
 725
 726         kfree(acm);
 727 }
 728
 729 static struct usb_function *acm_alloc_func(struct usb_function_instance *fi)
 730 {
 731         struct f_serial_opts *opts;
 732         struct f_acm *acm;
 733
 734         acm = kzalloc(sizeof(*acm), GFP_KERNEL);
 735         if (!acm)
 736                 return ERR_PTR(-ENOMEM);
 737
 738         spin_lock_init(&acm->lock);
 739
 740         acm->port.connect = acm_connect;
 741         acm->port.disconnect = acm_disconnect;
 742         acm->port.send_break = acm_send_break;
 743
 744         acm->port.func.name = "acm";
 745         acm->port.func.strings = acm_strings;
 746         /* descriptors are per-instance copies */
 747         acm->port.func.bind = acm_bind;
 748         acm->port.func.set_alt = acm_set_alt;
 749         acm->port.func.setup = acm_setup;
 750         acm->port.func.disable = acm_disable;
 751
 752         opts = container_of(fi, struct f_serial_opts, func_inst);
 753         acm->port_num = opts->port_num;
 754         acm->port.func.unbind = acm_unbind;
 755         acm->port.func.free_func = acm_free_func;
 756
 757         return &acm->port.func;
 758 }
 759
 760 static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
 761 {
 762         return container_of(to_config_group(item), struct f_serial_opts,
 763                         func_inst.group);
 764 }
 765
 766 static void acm_attr_release(struct config_item *item)
 767 {
 768         struct f_serial_opts *opts = to_f_serial_opts(item);
 769
 770         usb_put_function_instance(&opts->func_inst);
 771 }
 772
 773 static struct configfs_item_operations acm_item_ops = {
 774         .release                = acm_attr_release,
 775 };
 776
 777 static ssize_t f_acm_port_num_show(struct config_item *item, char *page)
 778 {
 779         return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num);
 780 }
 781
 782 CONFIGFS_ATTR_RO(f_acm_, port_num);
 783
 784 static struct configfs_attribute *acm_attrs[] = {
 785         &f_acm_attr_port_num,
 786         NULL,
 787 };
 788
 789 static struct config_item_type acm_func_type = {
 790         .ct_item_ops    = &acm_item_ops,
 791         .ct_attrs       = acm_attrs,
 792         .ct_owner       = THIS_MODULE,
 793 };
 794
 795 static void acm_free_instance(struct usb_function_instance *fi)
 796 {
 797         struct f_serial_opts *opts;
 798
 799         opts = container_of(fi, struct f_serial_opts, func_inst);
 800         gserial_free_line(opts->port_num);
 801         kfree(opts);
 802 }
 803
 804 static struct usb_function_instance *acm_alloc_instance(void)
 805 {
 806         struct f_serial_opts *opts;
 807         int ret;
 808
 809         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 810         if (!opts)
 811                 return ERR_PTR(-ENOMEM);
 812         opts->func_inst.free_func_inst = acm_free_instance;
 813         ret = gserial_alloc_line(&opts->port_num);
 814         if (ret) {
 815                 kfree(opts);
 816                 return ERR_PTR(ret);
 817         }
 818         config_group_init_type_name(&opts->func_inst.group, "",
 819                         &acm_func_type);
 820         return &opts->func_inst;
 821 }
 822 DECLARE_USB_FUNCTION_INIT(acm, acm_alloc_instance, acm_alloc_func);
 823 MODULE_LICENSE("GPL");