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 #include "gadget_chips.h"
  25
  26
  27 /*
  28  * This CDC ACM function support just wraps control functions and
  29  * notifications around the generic serial-over-usb code.
  30  *
  31  * Because CDC ACM is standardized by the USB-IF, many host operating
  32  * systems have drivers for it.  Accordingly, ACM is the preferred
  33  * interop solution for serial-port type connections.  The control
  34  * models are often not necessary, and in any case don't do much in
  35  * this bare-bones implementation.
  36  *
  37  * Note that even MS-Windows has some support for ACM.  However, that
  38  * support is somewhat broken because when you use ACM in a composite
  39  * device, having multiple interfaces confuses the poor OS.  It doesn't
  40  * seem to understand CDC Union descriptors.  The new "association"
  41  * descriptors (roughly equivalent to CDC Unions) may sometimes help.
  42  */
  43
  44 struct f_acm {
  45         struct gserial                  port;
  46         u8                              ctrl_id, data_id;
  47         u8                              port_num;
  48
  49         u8                              pending;
  50
  51         /* lock is mostly for pending and notify_req ... they get accessed
  52          * by callbacks both from tty (open/close/break) under its spinlock,
  53          * and notify_req.complete() which can't use that lock.
  54          */
  55         spinlock_t                      lock;
  56
  57         struct usb_ep                   *notify;
  58         struct usb_request              *notify_req;
  59
  60         struct usb_cdc_line_coding      port_line_coding;       /* 8-N-1 etc */
  61
  62         /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
  63         u16                             port_handshake_bits;
  64 #define ACM_CTRL_RTS    (1 << 1)        /* unused with full duplex */
  65 #define ACM_CTRL_DTR    (1 << 0)        /* host is ready for data r/w */
  66
  67         /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
  68         u16                             serial_state;
  69 #define ACM_CTRL_OVERRUN        (1 << 6)
  70 #define ACM_CTRL_PARITY         (1 << 5)
  71 #define ACM_CTRL_FRAMING        (1 << 4)
  72 #define ACM_CTRL_RI             (1 << 3)
  73 #define ACM_CTRL_BRK            (1 << 2)
  74 #define ACM_CTRL_DSR            (1 << 1)
  75 #define ACM_CTRL_DCD            (1 << 0)
  76 };
  77
  78 static inline struct f_acm *func_to_acm(struct usb_function *f)
  79 {
  80         return container_of(f, struct f_acm, port.func);
  81 }
  82
  83 static inline struct f_acm *port_to_acm(struct gserial *p)
  84 {
  85         return container_of(p, struct f_acm, port);
  86 }
  87
  88 /*-------------------------------------------------------------------------*/
  89
  90 /* notification endpoint uses smallish and infrequent fixed-size messages */
  91
  92 #define GS_NOTIFY_INTERVAL_MS           32
  93 #define GS_NOTIFY_MAXPACKET             10      /* notification + 2 bytes */
  94
  95 /* interface and class descriptors: */
  96
  97 static struct usb_interface_assoc_descriptor
  98 acm_iad_descriptor = {
  99         .bLength =              sizeof acm_iad_descriptor,
 100         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
 101
 102         /* .bFirstInterface =   DYNAMIC, */
 103         .bInterfaceCount =      2,      // control + data
 104         .bFunctionClass =       USB_CLASS_COMM,
 105         .bFunctionSubClass =    USB_CDC_SUBCLASS_ACM,
 106         .bFunctionProtocol =    USB_CDC_ACM_PROTO_AT_V25TER,
 107         /* .iFunction =         DYNAMIC */
 108 };
 109
 110
 111 static struct usb_interface_descriptor acm_control_interface_desc = {
 112         .bLength =              USB_DT_INTERFACE_SIZE,
 113         .bDescriptorType =      USB_DT_INTERFACE,
 114         /* .bInterfaceNumber = DYNAMIC */
 115         .bNumEndpoints =        1,
 116         .bInterfaceClass =      USB_CLASS_COMM,
 117         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
 118         .bInterfaceProtocol =   USB_CDC_ACM_PROTO_AT_V25TER,
 119         /* .iInterface = DYNAMIC */
 120 };
 121
 122 static struct usb_interface_descriptor acm_data_interface_desc = {
 123         .bLength =              USB_DT_INTERFACE_SIZE,
 124         .bDescriptorType =      USB_DT_INTERFACE,
 125         /* .bInterfaceNumber = DYNAMIC */
 126         .bNumEndpoints =        2,
 127         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 128         .bInterfaceSubClass =   0,
 129         .bInterfaceProtocol =   0,
 130         /* .iInterface = DYNAMIC */
 131 };
 132
 133 static struct usb_cdc_header_desc acm_header_desc = {
 134         .bLength =              sizeof(acm_header_desc),
 135         .bDescriptorType =      USB_DT_CS_INTERFACE,
 136         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 137         .bcdCDC =               cpu_to_le16(0x0110),
 138 };
 139
 140 static struct usb_cdc_call_mgmt_descriptor
 141 acm_call_mgmt_descriptor = {
 142         .bLength =              sizeof(acm_call_mgmt_descriptor),
 143         .bDescriptorType =      USB_DT_CS_INTERFACE,
 144         .bDescriptorSubType =   USB_CDC_CALL_MANAGEMENT_TYPE,
 145         .bmCapabilities =       0,
 146         /* .bDataInterface = DYNAMIC */
 147 };
 148
 149 static struct usb_cdc_acm_descriptor acm_descriptor = {
 150         .bLength =              sizeof(acm_descriptor),
 151         .bDescriptorType =      USB_DT_CS_INTERFACE,
 152         .bDescriptorSubType =   USB_CDC_ACM_TYPE,
 153         .bmCapabilities =       USB_CDC_CAP_LINE,
 154 };
 155
 156 static struct usb_cdc_union_desc acm_union_desc = {
 157         .bLength =              sizeof(acm_union_desc),
 158         .bDescriptorType =      USB_DT_CS_INTERFACE,
 159         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 160         /* .bMasterInterface0 = DYNAMIC */
 161         /* .bSlaveInterface0 =  DYNAMIC */
 162 };
 163
 164 /* full speed support: */
 165
 166 static struct usb_endpoint_descriptor acm_fs_notify_desc = {
 167         .bLength =              USB_DT_ENDPOINT_SIZE,
 168         .bDescriptorType =      USB_DT_ENDPOINT,
 169         .bEndpointAddress =     USB_DIR_IN,
 170         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 171         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 172         .bInterval =            GS_NOTIFY_INTERVAL_MS,
 173 };
 174
 175 static struct usb_endpoint_descriptor acm_fs_in_desc = {
 176         .bLength =              USB_DT_ENDPOINT_SIZE,
 177         .bDescriptorType =      USB_DT_ENDPOINT,
 178         .bEndpointAddress =     USB_DIR_IN,
 179         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 180 };
 181
 182 static struct usb_endpoint_descriptor acm_fs_out_desc = {
 183         .bLength =              USB_DT_ENDPOINT_SIZE,
 184         .bDescriptorType =      USB_DT_ENDPOINT,
 185         .bEndpointAddress =     USB_DIR_OUT,
 186         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 187 };
 188
 189 static struct usb_descriptor_header *acm_fs_function[] = {
 190         (struct usb_descriptor_header *) &acm_iad_descriptor,
 191         (struct usb_descriptor_header *) &acm_control_interface_desc,
 192         (struct usb_descriptor_header *) &acm_header_desc,
 193         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 194         (struct usb_descriptor_header *) &acm_descriptor,
 195         (struct usb_descriptor_header *) &acm_union_desc,
 196         (struct usb_descriptor_header *) &acm_fs_notify_desc,
 197         (struct usb_descriptor_header *) &acm_data_interface_desc,
 198         (struct usb_descriptor_header *) &acm_fs_in_desc,
 199         (struct usb_descriptor_header *) &acm_fs_out_desc,
 200         NULL,
 201 };
 202
 203 /* high speed support: */
 204 static struct usb_endpoint_descriptor acm_hs_notify_desc = {
 205         .bLength =              USB_DT_ENDPOINT_SIZE,
 206         .bDescriptorType =      USB_DT_ENDPOINT,
 207         .bEndpointAddress =     USB_DIR_IN,
 208         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 209         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 210         .bInterval =            USB_MS_TO_HS_INTERVAL(GS_NOTIFY_INTERVAL_MS),
 211 };
 212
 213 static struct usb_endpoint_descriptor acm_hs_in_desc = {
 214         .bLength =              USB_DT_ENDPOINT_SIZE,
 215         .bDescriptorType =      USB_DT_ENDPOINT,
 216         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 217         .wMaxPacketSize =       cpu_to_le16(512),
 218 };
 219
 220 static struct usb_endpoint_descriptor acm_hs_out_desc = {
 221         .bLength =              USB_DT_ENDPOINT_SIZE,
 222         .bDescriptorType =      USB_DT_ENDPOINT,
 223         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 224         .wMaxPacketSize =       cpu_to_le16(512),
 225 };
 226
 227 static struct usb_descriptor_header *acm_hs_function[] = {
 228         (struct usb_descriptor_header *) &acm_iad_descriptor,
 229         (struct usb_descriptor_header *) &acm_control_interface_desc,
 230         (struct usb_descriptor_header *) &acm_header_desc,
 231         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 232         (struct usb_descriptor_header *) &acm_descriptor,
 233         (struct usb_descriptor_header *) &acm_union_desc,
 234         (struct usb_descriptor_header *) &acm_hs_notify_desc,
 235         (struct usb_descriptor_header *) &acm_data_interface_desc,
 236         (struct usb_descriptor_header *) &acm_hs_in_desc,
 237         (struct usb_descriptor_header *) &acm_hs_out_desc,
 238         NULL,
 239 };
 240
 241 static struct usb_endpoint_descriptor acm_ss_in_desc = {
 242         .bLength =              USB_DT_ENDPOINT_SIZE,
 243         .bDescriptorType =      USB_DT_ENDPOINT,
 244         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 245         .wMaxPacketSize =       cpu_to_le16(1024),
 246 };
 247
 248 static struct usb_endpoint_descriptor acm_ss_out_desc = {
 249         .bLength =              USB_DT_ENDPOINT_SIZE,
 250         .bDescriptorType =      USB_DT_ENDPOINT,
 251         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 252         .wMaxPacketSize =       cpu_to_le16(1024),
 253 };
 254
 255 static struct usb_ss_ep_comp_descriptor acm_ss_bulk_comp_desc = {
 256         .bLength =              sizeof acm_ss_bulk_comp_desc,
 257         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 258 };
 259
 260 static struct usb_descriptor_header *acm_ss_function[] = {
 261         (struct usb_descriptor_header *) &acm_iad_descriptor,
 262         (struct usb_descriptor_header *) &acm_control_interface_desc,
 263         (struct usb_descriptor_header *) &acm_header_desc,
 264         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 265         (struct usb_descriptor_header *) &acm_descriptor,
 266         (struct usb_descriptor_header *) &acm_union_desc,
 267         (struct usb_descriptor_header *) &acm_hs_notify_desc,
 268         (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
 269         (struct usb_descriptor_header *) &acm_data_interface_desc,
 270         (struct usb_descriptor_header *) &acm_ss_in_desc,
 271         (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
 272         (struct usb_descriptor_header *) &acm_ss_out_desc,
 273         (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
 274         NULL,
 275 };
 276
 277 /* string descriptors: */
 278
 279 #define ACM_CTRL_IDX    0
 280 #define ACM_DATA_IDX    1
 281 #define ACM_IAD_IDX     2
 282
 283 /* static strings, in UTF-8 */
 284 static struct usb_string acm_string_defs[] = {
 285         [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
 286         [ACM_DATA_IDX].s = "CDC ACM Data",
 287         [ACM_IAD_IDX ].s = "CDC Serial",
 288         {  } /* end of list */
 289 };
 290
 291 static struct usb_gadget_strings acm_string_table = {
 292         .language =             0x0409, /* en-us */
 293         .strings =              acm_string_defs,
 294 };
 295
 296 static struct usb_gadget_strings *acm_strings[] = {
 297         &acm_string_table,
 298         NULL,
 299 };
 300
 301 /*-------------------------------------------------------------------------*/
 302
 303 /* ACM control ... data handling is delegated to tty library code.
 304  * The main task of this function is to activate and deactivate
 305  * that code based on device state; track parameters like line
 306  * speed, handshake state, and so on; and issue notifications.
 307  */
 308
 309 static void acm_complete_set_line_coding(struct usb_ep *ep,
 310                 struct usb_request *req)
 311 {
 312         struct f_acm    *acm = ep->driver_data;
 313         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 314
 315         if (req->status != 0) {
 316                 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d completion, err %d\n",
 317                         acm->port_num, req->status);
 318                 return;
 319         }
 320
 321         /* normal completion */
 322         if (req->actual != sizeof(acm->port_line_coding)) {
 323                 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d short resp, len %d\n",
 324                         acm->port_num, req->actual);
 325                 usb_ep_set_halt(ep);
 326         } else {
 327                 struct usb_cdc_line_coding      *value = req->buf;
 328
 329                 /* REVISIT:  we currently just remember this data.
 330                  * If we change that, (a) validate it first, then
 331                  * (b) update whatever hardware needs updating,
 332                  * (c) worry about locking.  This is information on
 333                  * the order of 9600-8-N-1 ... most of which means
 334                  * nothing unless we control a real RS232 line.
 335                  */
 336                 acm->port_line_coding = *value;
 337         }
 338 }
 339
 340 static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 341 {
 342         struct f_acm            *acm = func_to_acm(f);
 343         struct usb_composite_dev *cdev = f->config->cdev;
 344         struct usb_request      *req = cdev->req;
 345         int                     value = -EOPNOTSUPP;
 346         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 347         u16                     w_value = le16_to_cpu(ctrl->wValue);
 348         u16                     w_length = le16_to_cpu(ctrl->wLength);
 349
 350         /* composite driver infrastructure handles everything except
 351          * CDC class messages; interface activation uses set_alt().
 352          *
 353          * Note CDC spec table 4 lists the ACM request profile.  It requires
 354          * encapsulated command support ... we don't handle any, and respond
 355          * to them by stalling.  Options include get/set/clear comm features
 356          * (not that useful) and SEND_BREAK.
 357          */
 358         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 359
 360         /* SET_LINE_CODING ... just read and save what the host sends */
 361         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 362                         | USB_CDC_REQ_SET_LINE_CODING:
 363                 if (w_length != sizeof(struct usb_cdc_line_coding)
 364                                 || w_index != acm->ctrl_id)
 365                         goto invalid;
 366
 367                 value = w_length;
 368                 cdev->gadget->ep0->driver_data = acm;
 369                 req->complete = acm_complete_set_line_coding;
 370                 break;
 371
 372         /* GET_LINE_CODING ... return what host sent, or initial value */
 373         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 374                         | USB_CDC_REQ_GET_LINE_CODING:
 375                 if (w_index != acm->ctrl_id)
 376                         goto invalid;
 377
 378                 value = min_t(unsigned, w_length,
 379                                 sizeof(struct usb_cdc_line_coding));
 380                 memcpy(req->buf, &acm->port_line_coding, value);
 381                 break;
 382
 383         /* SET_CONTROL_LINE_STATE ... save what the host sent */
 384         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 385                         | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
 386                 if (w_index != acm->ctrl_id)
 387                         goto invalid;
 388
 389                 value = 0;
 390
 391                 /* FIXME we should not allow data to flow until the
 392                  * host sets the ACM_CTRL_DTR bit; and when it clears
 393                  * that bit, we should return to that no-flow state.
 394                  */
 395                 acm->port_handshake_bits = w_value;
 396                 break;
 397
 398         default:
 399 invalid:
 400                 dev_vdbg(&cdev->gadget->dev,
 401                          "invalid control req%02x.%02x v%04x i%04x l%d\n",
 402                          ctrl->bRequestType, ctrl->bRequest,
 403                          w_value, w_index, w_length);
 404         }
 405
 406         /* respond with data transfer or status phase? */
 407         if (value >= 0) {
 408                 dev_dbg(&cdev->gadget->dev,
 409                         "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
 410                         acm->port_num, ctrl->bRequestType, ctrl->bRequest,
 411                         w_value, w_index, w_length);
 412                 req->zero = 0;
 413                 req->length = value;
 414                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 415                 if (value < 0)
 416                         ERROR(cdev, "acm response on ttyGS%d, err %d\n",
 417                                         acm->port_num, value);
 418         }
 419
 420         /* device either stalls (value < 0) or reports success */
 421         return value;
 422 }
 423
 424 static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 425 {
 426         struct f_acm            *acm = func_to_acm(f);
 427         struct usb_composite_dev *cdev = f->config->cdev;
 428
 429         /* we know alt == 0, so this is an activation or a reset */
 430
 431         if (intf == acm->ctrl_id) {
 432                 if (acm->notify->driver_data) {
 433                         dev_vdbg(&cdev->gadget->dev,
 434                                  "reset acm control interface %d\n", intf);
 435                         usb_ep_disable(acm->notify);
 436                 }
 437
 438                 if (!acm->notify->desc)
 439                         if (config_ep_by_speed(cdev->gadget, f, acm->notify))
 440                                 return -EINVAL;
 441
 442                 usb_ep_enable(acm->notify);
 443                 acm->notify->driver_data = acm;
 444
 445         } else if (intf == acm->data_id) {
 446                 if (acm->port.in->driver_data) {
 447                         dev_dbg(&cdev->gadget->dev,
 448                                 "reset acm ttyGS%d\n", acm->port_num);
 449                         gserial_disconnect(&acm->port);
 450                 }
 451                 if (!acm->port.in->desc || !acm->port.out->desc) {
 452                         dev_dbg(&cdev->gadget->dev,
 453                                 "activate acm ttyGS%d\n", acm->port_num);
 454                         if (config_ep_by_speed(cdev->gadget, f,
 455                                                acm->port.in) ||
 456                             config_ep_by_speed(cdev->gadget, f,
 457                                                acm->port.out)) {
 458                                 acm->port.in->desc = NULL;
 459                                 acm->port.out->desc = NULL;
 460                                 return -EINVAL;
 461                         }
 462                 }
 463                 gserial_connect(&acm->port, acm->port_num);
 464
 465         } else
 466                 return -EINVAL;
 467
 468         return 0;
 469 }
 470
 471 static void acm_disable(struct usb_function *f)
 472 {
 473         struct f_acm    *acm = func_to_acm(f);
 474         struct usb_composite_dev *cdev = f->config->cdev;
 475
 476         dev_dbg(&cdev->gadget->dev, "acm ttyGS%d deactivated\n", acm->port_num);
 477         gserial_disconnect(&acm->port);
 478         usb_ep_disable(acm->notify);
 479         acm->notify->driver_data = NULL;
 480 }
 481
 482 /*-------------------------------------------------------------------------*/
 483
 484 /**
 485  * acm_cdc_notify - issue CDC notification to host
 486  * @acm: wraps host to be notified
 487  * @type: notification type
 488  * @value: Refer to cdc specs, wValue field.
 489  * @data: data to be sent
 490  * @length: size of data
 491  * Context: irqs blocked, acm->lock held, acm_notify_req non-null
 492  *
 493  * Returns zero on success or a negative errno.
 494  *
 495  * See section 6.3.5 of the CDC 1.1 specification for information
 496  * about the only notification we issue:  SerialState change.
 497  */
 498 static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
 499                 void *data, unsigned length)
 500 {
 501         struct usb_ep                   *ep = acm->notify;
 502         struct usb_request              *req;
 503         struct usb_cdc_notification     *notify;
 504         const unsigned                  len = sizeof(*notify) + length;
 505         void                            *buf;
 506         int                             status;
 507
 508         req = acm->notify_req;
 509         acm->notify_req = NULL;
 510         acm->pending = false;
 511
 512         req->length = len;
 513         notify = req->buf;
 514         buf = notify + 1;
 515
 516         notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
 517                         | USB_RECIP_INTERFACE;
 518         notify->bNotificationType = type;
 519         notify->wValue = cpu_to_le16(value);
 520         notify->wIndex = cpu_to_le16(acm->ctrl_id);
 521         notify->wLength = cpu_to_le16(length);
 522         memcpy(buf, data, length);
 523
 524         /* ep_queue() can complete immediately if it fills the fifo... */
 525         spin_unlock(&acm->lock);
 526         status = usb_ep_queue(ep, req, GFP_ATOMIC);
 527         spin_lock(&acm->lock);
 528
 529         if (status < 0) {
 530                 ERROR(acm->port.func.config->cdev,
 531                                 "acm ttyGS%d can't notify serial state, %d\n",
 532                                 acm->port_num, status);
 533                 acm->notify_req = req;
 534         }
 535
 536         return status;
 537 }
 538
 539 static int acm_notify_serial_state(struct f_acm *acm)
 540 {
 541         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 542         int                     status;
 543
 544         spin_lock(&acm->lock);
 545         if (acm->notify_req) {
 546                 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d serial state %04x\n",
 547                         acm->port_num, acm->serial_state);
 548                 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
 549                                 0, &acm->serial_state, sizeof(acm->serial_state));
 550         } else {
 551                 acm->pending = true;
 552                 status = 0;
 553         }
 554         spin_unlock(&acm->lock);
 555         return status;
 556 }
 557
 558 static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
 559 {
 560         struct f_acm            *acm = req->context;
 561         u8                      doit = false;
 562
 563         /* on this call path we do NOT hold the port spinlock,
 564          * which is why ACM needs its own spinlock
 565          */
 566         spin_lock(&acm->lock);
 567         if (req->status != -ESHUTDOWN)
 568                 doit = acm->pending;
 569         acm->notify_req = req;
 570         spin_unlock(&acm->lock);
 571
 572         if (doit)
 573                 acm_notify_serial_state(acm);
 574 }
 575
 576 /* connect == the TTY link is open */
 577
 578 static void acm_connect(struct gserial *port)
 579 {
 580         struct f_acm            *acm = port_to_acm(port);
 581
 582         acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
 583         acm_notify_serial_state(acm);
 584 }
 585
 586 static void acm_disconnect(struct gserial *port)
 587 {
 588         struct f_acm            *acm = port_to_acm(port);
 589
 590         acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
 591         acm_notify_serial_state(acm);
 592 }
 593
 594 static int acm_send_break(struct gserial *port, int duration)
 595 {
 596         struct f_acm            *acm = port_to_acm(port);
 597         u16                     state;
 598
 599         state = acm->serial_state;
 600         state &= ~ACM_CTRL_BRK;
 601         if (duration)
 602                 state |= ACM_CTRL_BRK;
 603
 604         acm->serial_state = state;
 605         return acm_notify_serial_state(acm);
 606 }
 607
 608 /*-------------------------------------------------------------------------*/
 609
 610 /* ACM function driver setup/binding */
 611 static int
 612 acm_bind(struct usb_configuration *c, struct usb_function *f)
 613 {
 614         struct usb_composite_dev *cdev = c->cdev;
 615         struct f_acm            *acm = func_to_acm(f);
 616         struct usb_string       *us;
 617         int                     status;
 618         struct usb_ep           *ep;
 619
 620         /* REVISIT might want instance-specific strings to help
 621          * distinguish instances ...
 622          */
 623
 624         /* maybe allocate device-global string IDs, and patch descriptors */
 625         us = usb_gstrings_attach(cdev, acm_strings,
 626                         ARRAY_SIZE(acm_string_defs));
 627         if (IS_ERR(us))
 628                 return PTR_ERR(us);
 629         acm_control_interface_desc.iInterface = us[ACM_CTRL_IDX].id;
 630         acm_data_interface_desc.iInterface = us[ACM_DATA_IDX].id;
 631         acm_iad_descriptor.iFunction = us[ACM_IAD_IDX].id;
 632
 633         /* allocate instance-specific interface IDs, and patch descriptors */
 634         status = usb_interface_id(c, f);
 635         if (status < 0)
 636                 goto fail;
 637         acm->ctrl_id = status;
 638         acm_iad_descriptor.bFirstInterface = status;
 639
 640         acm_control_interface_desc.bInterfaceNumber = status;
 641         acm_union_desc .bMasterInterface0 = status;
 642
 643         status = usb_interface_id(c, f);
 644         if (status < 0)
 645                 goto fail;
 646         acm->data_id = status;
 647
 648         acm_data_interface_desc.bInterfaceNumber = status;
 649         acm_union_desc.bSlaveInterface0 = status;
 650         acm_call_mgmt_descriptor.bDataInterface = status;
 651
 652         status = -ENODEV;
 653
 654         /* allocate instance-specific endpoints */
 655         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
 656         if (!ep)
 657                 goto fail;
 658         acm->port.in = ep;
 659         ep->driver_data = cdev; /* claim */
 660
 661         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
 662         if (!ep)
 663                 goto fail;
 664         acm->port.out = ep;
 665         ep->driver_data = cdev; /* claim */
 666
 667         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
 668         if (!ep)
 669                 goto fail;
 670         acm->notify = ep;
 671         ep->driver_data = cdev; /* claim */
 672
 673         /* allocate notification */
 674         acm->notify_req = gs_alloc_req(ep,
 675                         sizeof(struct usb_cdc_notification) + 2,
 676                         GFP_KERNEL);
 677         if (!acm->notify_req)
 678                 goto fail;
 679
 680         acm->notify_req->complete = acm_cdc_notify_complete;
 681         acm->notify_req->context = acm;
 682
 683         /* support all relevant hardware speeds... we expect that when
 684          * hardware is dual speed, all bulk-capable endpoints work at
 685          * both speeds
 686          */
 687         acm_hs_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
 688         acm_hs_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
 689         acm_hs_notify_desc.bEndpointAddress =
 690                 acm_fs_notify_desc.bEndpointAddress;
 691
 692         acm_ss_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
 693         acm_ss_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
 694
 695         status = usb_assign_descriptors(f, acm_fs_function, acm_hs_function,
 696                         acm_ss_function);
 697         if (status)
 698                 goto fail;
 699
 700         dev_dbg(&cdev->gadget->dev,
 701                 "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 702                 acm->port_num,
 703                 gadget_is_superspeed(c->cdev->gadget) ? "super" :
 704                 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 705                 acm->port.in->name, acm->port.out->name,
 706                 acm->notify->name);
 707         return 0;
 708
 709 fail:
 710         if (acm->notify_req)
 711                 gs_free_req(acm->notify, acm->notify_req);
 712
 713         /* we might as well release our claims on endpoints */
 714         if (acm->notify)
 715                 acm->notify->driver_data = NULL;
 716         if (acm->port.out)
 717                 acm->port.out->driver_data = NULL;
 718         if (acm->port.in)
 719                 acm->port.in->driver_data = NULL;
 720
 721         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 722
 723         return status;
 724 }
 725
 726 static void acm_unbind(struct usb_configuration *c, struct usb_function *f)
 727 {
 728         struct f_acm            *acm = func_to_acm(f);
 729
 730         acm_string_defs[0].id = 0;
 731         usb_free_all_descriptors(f);
 732         if (acm->notify_req)
 733                 gs_free_req(acm->notify, acm->notify_req);
 734 }
 735
 736 static void acm_free_func(struct usb_function *f)
 737 {
 738         struct f_acm            *acm = func_to_acm(f);
 739
 740         kfree(acm);
 741 }
 742
 743 static struct usb_function *acm_alloc_func(struct usb_function_instance *fi)
 744 {
 745         struct f_serial_opts *opts;
 746         struct f_acm *acm;
 747
 748         acm = kzalloc(sizeof(*acm), GFP_KERNEL);
 749         if (!acm)
 750                 return ERR_PTR(-ENOMEM);
 751
 752         spin_lock_init(&acm->lock);
 753
 754         acm->port.connect = acm_connect;
 755         acm->port.disconnect = acm_disconnect;
 756         acm->port.send_break = acm_send_break;
 757
 758         acm->port.func.name = "acm";
 759         acm->port.func.strings = acm_strings;
 760         /* descriptors are per-instance copies */
 761         acm->port.func.bind = acm_bind;
 762         acm->port.func.set_alt = acm_set_alt;
 763         acm->port.func.setup = acm_setup;
 764         acm->port.func.disable = acm_disable;
 765
 766         opts = container_of(fi, struct f_serial_opts, func_inst);
 767         acm->port_num = opts->port_num;
 768         acm->port.func.unbind = acm_unbind;
 769         acm->port.func.free_func = acm_free_func;
 770
 771         return &acm->port.func;
 772 }
 773
 774 static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
 775 {
 776         return container_of(to_config_group(item), struct f_serial_opts,
 777                         func_inst.group);
 778 }
 779
 780 CONFIGFS_ATTR_STRUCT(f_serial_opts);
 781 static ssize_t f_acm_attr_show(struct config_item *item,
 782                                  struct configfs_attribute *attr,
 783                                  char *page)
 784 {
 785         struct f_serial_opts *opts = to_f_serial_opts(item);
 786         struct f_serial_opts_attribute *f_serial_opts_attr =
 787                 container_of(attr, struct f_serial_opts_attribute, attr);
 788         ssize_t ret = 0;
 789
 790         if (f_serial_opts_attr->show)
 791                 ret = f_serial_opts_attr->show(opts, page);
 792         return ret;
 793 }
 794
 795 static void acm_attr_release(struct config_item *item)
 796 {
 797         struct f_serial_opts *opts = to_f_serial_opts(item);
 798
 799         usb_put_function_instance(&opts->func_inst);
 800 }
 801
 802 static struct configfs_item_operations acm_item_ops = {
 803         .release                = acm_attr_release,
 804         .show_attribute         = f_acm_attr_show,
 805 };
 806
 807 static ssize_t f_acm_port_num_show(struct f_serial_opts *opts, char *page)
 808 {
 809         return sprintf(page, "%u\n", opts->port_num);
 810 }
 811
 812 static struct f_serial_opts_attribute f_acm_port_num =
 813         __CONFIGFS_ATTR_RO(port_num, f_acm_port_num_show);
 814
 815
 816 static struct configfs_attribute *acm_attrs[] = {
 817         &f_acm_port_num.attr,
 818         NULL,
 819 };
 820
 821 static struct config_item_type acm_func_type = {
 822         .ct_item_ops    = &acm_item_ops,
 823         .ct_attrs       = acm_attrs,
 824         .ct_owner       = THIS_MODULE,
 825 };
 826
 827 static void acm_free_instance(struct usb_function_instance *fi)
 828 {
 829         struct f_serial_opts *opts;
 830
 831         opts = container_of(fi, struct f_serial_opts, func_inst);
 832         gserial_free_line(opts->port_num);
 833         kfree(opts);
 834 }
 835
 836 static struct usb_function_instance *acm_alloc_instance(void)
 837 {
 838         struct f_serial_opts *opts;
 839         int ret;
 840
 841         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 842         if (!opts)
 843                 return ERR_PTR(-ENOMEM);
 844         opts->func_inst.free_func_inst = acm_free_instance;
 845         ret = gserial_alloc_line(&opts->port_num);
 846         if (ret) {
 847                 kfree(opts);
 848                 return ERR_PTR(ret);
 849         }
 850         config_group_init_type_name(&opts->func_inst.group, "",
 851                         &acm_func_type);
 852         return &opts->func_inst;
 853 }
 854 DECLARE_USB_FUNCTION_INIT(acm, acm_alloc_instance, acm_alloc_func);
 855 MODULE_LICENSE("GPL");