drivers/usb/gadget/function/f_acm.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * f_acm.c -- USB CDC serial (ACM) function driver
   4  *
   5  * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
   6  * Copyright (C) 2008 by David Brownell
   7  * Copyright (C) 2008 by Nokia Corporation
   8  * Copyright (C) 2009 by Samsung Electronics
   9  * Author: Michal Nazarewicz (mina86@mina86.com)
  10  */
  11
  12 /* #define VERBOSE_DEBUG */
  13
  14 #include <linux/slab.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/device.h>
  18 #include <linux/err.h>
  19
  20 #include "u_serial.h"
  21
  22
  23 /*
  24  * This CDC ACM function support just wraps control functions and
  25  * notifications around the generic serial-over-usb code.
  26  *
  27  * Because CDC ACM is standardized by the USB-IF, many host operating
  28  * systems have drivers for it.  Accordingly, ACM is the preferred
  29  * interop solution for serial-port type connections.  The control
  30  * models are often not necessary, and in any case don't do much in
  31  * this bare-bones implementation.
  32  *
  33  * Note that even MS-Windows has some support for ACM.  However, that
  34  * support is somewhat broken because when you use ACM in a composite
  35  * device, having multiple interfaces confuses the poor OS.  It doesn't
  36  * seem to understand CDC Union descriptors.  The new "association"
  37  * descriptors (roughly equivalent to CDC Unions) may sometimes help.
  38  */
  39
  40 struct f_acm {
  41         struct gserial                  port;
  42         u8                              ctrl_id, data_id;
  43         u8                              port_num;
  44
  45         u8                              pending;
  46
  47         /* lock is mostly for pending and notify_req ... they get accessed
  48          * by callbacks both from tty (open/close/break) under its spinlock,
  49          * and notify_req.complete() which can't use that lock.
  50          */
  51         spinlock_t                      lock;
  52
  53         struct usb_ep                   *notify;
  54         struct usb_request              *notify_req;
  55
  56         struct usb_cdc_line_coding      port_line_coding;       /* 8-N-1 etc */
  57
  58         /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
  59         u16                             port_handshake_bits;
  60         /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
  61         u16                             serial_state;
  62 };
  63
  64 static inline struct f_acm *func_to_acm(struct usb_function *f)
  65 {
  66         return container_of(f, struct f_acm, port.func);
  67 }
  68
  69 static inline struct f_acm *port_to_acm(struct gserial *p)
  70 {
  71         return container_of(p, struct f_acm, port);
  72 }
  73
  74 /*-------------------------------------------------------------------------*/
  75
  76 /* notification endpoint uses smallish and infrequent fixed-size messages */
  77
  78 #define GS_NOTIFY_INTERVAL_MS           32
  79 #define GS_NOTIFY_MAXPACKET             10      /* notification + 2 bytes */
  80
  81 /* interface and class descriptors: */
  82
  83 static struct usb_interface_assoc_descriptor
  84 acm_iad_descriptor = {
  85         .bLength =              sizeof acm_iad_descriptor,
  86         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
  87
  88         /* .bFirstInterface =   DYNAMIC, */
  89         .bInterfaceCount =      2,      // control + data
  90         .bFunctionClass =       USB_CLASS_COMM,
  91         .bFunctionSubClass =    USB_CDC_SUBCLASS_ACM,
  92         .bFunctionProtocol =    USB_CDC_ACM_PROTO_AT_V25TER,
  93         /* .iFunction =         DYNAMIC */
  94 };
  95
  96
  97 static struct usb_interface_descriptor acm_control_interface_desc = {
  98         .bLength =              USB_DT_INTERFACE_SIZE,
  99         .bDescriptorType =      USB_DT_INTERFACE,
 100         /* .bInterfaceNumber = DYNAMIC */
 101         .bNumEndpoints =        1,
 102         .bInterfaceClass =      USB_CLASS_COMM,
 103         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
 104         .bInterfaceProtocol =   USB_CDC_ACM_PROTO_AT_V25TER,
 105         /* .iInterface = DYNAMIC */
 106 };
 107
 108 static struct usb_interface_descriptor acm_data_interface_desc = {
 109         .bLength =              USB_DT_INTERFACE_SIZE,
 110         .bDescriptorType =      USB_DT_INTERFACE,
 111         /* .bInterfaceNumber = DYNAMIC */
 112         .bNumEndpoints =        2,
 113         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 114         .bInterfaceSubClass =   0,
 115         .bInterfaceProtocol =   0,
 116         /* .iInterface = DYNAMIC */
 117 };
 118
 119 static struct usb_cdc_header_desc acm_header_desc = {
 120         .bLength =              sizeof(acm_header_desc),
 121         .bDescriptorType =      USB_DT_CS_INTERFACE,
 122         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 123         .bcdCDC =               cpu_to_le16(0x0110),
 124 };
 125
 126 static struct usb_cdc_call_mgmt_descriptor
 127 acm_call_mgmt_descriptor = {
 128         .bLength =              sizeof(acm_call_mgmt_descriptor),
 129         .bDescriptorType =      USB_DT_CS_INTERFACE,
 130         .bDescriptorSubType =   USB_CDC_CALL_MANAGEMENT_TYPE,
 131         .bmCapabilities =       0,
 132         /* .bDataInterface = DYNAMIC */
 133 };
 134
 135 static struct usb_cdc_acm_descriptor acm_descriptor = {
 136         .bLength =              sizeof(acm_descriptor),
 137         .bDescriptorType =      USB_DT_CS_INTERFACE,
 138         .bDescriptorSubType =   USB_CDC_ACM_TYPE,
 139         .bmCapabilities =       USB_CDC_CAP_LINE,
 140 };
 141
 142 static struct usb_cdc_union_desc acm_union_desc = {
 143         .bLength =              sizeof(acm_union_desc),
 144         .bDescriptorType =      USB_DT_CS_INTERFACE,
 145         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 146         /* .bMasterInterface0 = DYNAMIC */
 147         /* .bSlaveInterface0 =  DYNAMIC */
 148 };
 149
 150 /* full speed support: */
 151
 152 static struct usb_endpoint_descriptor acm_fs_notify_desc = {
 153         .bLength =              USB_DT_ENDPOINT_SIZE,
 154         .bDescriptorType =      USB_DT_ENDPOINT,
 155         .bEndpointAddress =     USB_DIR_IN,
 156         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 157         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 158         .bInterval =            GS_NOTIFY_INTERVAL_MS,
 159 };
 160
 161 static struct usb_endpoint_descriptor acm_fs_in_desc = {
 162         .bLength =              USB_DT_ENDPOINT_SIZE,
 163         .bDescriptorType =      USB_DT_ENDPOINT,
 164         .bEndpointAddress =     USB_DIR_IN,
 165         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 166 };
 167
 168 static struct usb_endpoint_descriptor acm_fs_out_desc = {
 169         .bLength =              USB_DT_ENDPOINT_SIZE,
 170         .bDescriptorType =      USB_DT_ENDPOINT,
 171         .bEndpointAddress =     USB_DIR_OUT,
 172         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 173 };
 174
 175 static struct usb_descriptor_header *acm_fs_function[] = {
 176         (struct usb_descriptor_header *) &acm_iad_descriptor,
 177         (struct usb_descriptor_header *) &acm_control_interface_desc,
 178         (struct usb_descriptor_header *) &acm_header_desc,
 179         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 180         (struct usb_descriptor_header *) &acm_descriptor,
 181         (struct usb_descriptor_header *) &acm_union_desc,
 182         (struct usb_descriptor_header *) &acm_fs_notify_desc,
 183         (struct usb_descriptor_header *) &acm_data_interface_desc,
 184         (struct usb_descriptor_header *) &acm_fs_in_desc,
 185         (struct usb_descriptor_header *) &acm_fs_out_desc,
 186         NULL,
 187 };
 188
 189 /* high speed support: */
 190 static struct usb_endpoint_descriptor acm_hs_notify_desc = {
 191         .bLength =              USB_DT_ENDPOINT_SIZE,
 192         .bDescriptorType =      USB_DT_ENDPOINT,
 193         .bEndpointAddress =     USB_DIR_IN,
 194         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 195         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 196         .bInterval =            USB_MS_TO_HS_INTERVAL(GS_NOTIFY_INTERVAL_MS),
 197 };
 198
 199 static struct usb_endpoint_descriptor acm_hs_in_desc = {
 200         .bLength =              USB_DT_ENDPOINT_SIZE,
 201         .bDescriptorType =      USB_DT_ENDPOINT,
 202         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 203         .wMaxPacketSize =       cpu_to_le16(512),
 204 };
 205
 206 static struct usb_endpoint_descriptor acm_hs_out_desc = {
 207         .bLength =              USB_DT_ENDPOINT_SIZE,
 208         .bDescriptorType =      USB_DT_ENDPOINT,
 209         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 210         .wMaxPacketSize =       cpu_to_le16(512),
 211 };
 212
 213 static struct usb_descriptor_header *acm_hs_function[] = {
 214         (struct usb_descriptor_header *) &acm_iad_descriptor,
 215         (struct usb_descriptor_header *) &acm_control_interface_desc,
 216         (struct usb_descriptor_header *) &acm_header_desc,
 217         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 218         (struct usb_descriptor_header *) &acm_descriptor,
 219         (struct usb_descriptor_header *) &acm_union_desc,
 220         (struct usb_descriptor_header *) &acm_hs_notify_desc,
 221         (struct usb_descriptor_header *) &acm_data_interface_desc,
 222         (struct usb_descriptor_header *) &acm_hs_in_desc,
 223         (struct usb_descriptor_header *) &acm_hs_out_desc,
 224         NULL,
 225 };
 226
 227 static struct usb_endpoint_descriptor acm_ss_in_desc = {
 228         .bLength =              USB_DT_ENDPOINT_SIZE,
 229         .bDescriptorType =      USB_DT_ENDPOINT,
 230         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 231         .wMaxPacketSize =       cpu_to_le16(1024),
 232 };
 233
 234 static struct usb_endpoint_descriptor acm_ss_out_desc = {
 235         .bLength =              USB_DT_ENDPOINT_SIZE,
 236         .bDescriptorType =      USB_DT_ENDPOINT,
 237         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 238         .wMaxPacketSize =       cpu_to_le16(1024),
 239 };
 240
 241 static struct usb_ss_ep_comp_descriptor acm_ss_bulk_comp_desc = {
 242         .bLength =              sizeof acm_ss_bulk_comp_desc,
 243         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 244 };
 245
 246 static struct usb_descriptor_header *acm_ss_function[] = {
 247         (struct usb_descriptor_header *) &acm_iad_descriptor,
 248         (struct usb_descriptor_header *) &acm_control_interface_desc,
 249         (struct usb_descriptor_header *) &acm_header_desc,
 250         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 251         (struct usb_descriptor_header *) &acm_descriptor,
 252         (struct usb_descriptor_header *) &acm_union_desc,
 253         (struct usb_descriptor_header *) &acm_hs_notify_desc,
 254         (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
 255         (struct usb_descriptor_header *) &acm_data_interface_desc,
 256         (struct usb_descriptor_header *) &acm_ss_in_desc,
 257         (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
 258         (struct usb_descriptor_header *) &acm_ss_out_desc,
 259         (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
 260         NULL,
 261 };
 262
 263 /* string descriptors: */
 264
 265 #define ACM_CTRL_IDX    0
 266 #define ACM_DATA_IDX    1
 267 #define ACM_IAD_IDX     2
 268
 269 /* static strings, in UTF-8 */
 270 static struct usb_string acm_string_defs[] = {
 271         [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
 272         [ACM_DATA_IDX].s = "CDC ACM Data",
 273         [ACM_IAD_IDX ].s = "CDC Serial",
 274         {  } /* end of list */
 275 };
 276
 277 static struct usb_gadget_strings acm_string_table = {
 278         .language =             0x0409, /* en-us */
 279         .strings =              acm_string_defs,
 280 };
 281
 282 static struct usb_gadget_strings *acm_strings[] = {
 283         &acm_string_table,
 284         NULL,
 285 };
 286
 287 /*-------------------------------------------------------------------------*/
 288
 289 /* ACM control ... data handling is delegated to tty library code.
 290  * The main task of this function is to activate and deactivate
 291  * that code based on device state; track parameters like line
 292  * speed, handshake state, and so on; and issue notifications.
 293  */
 294
 295 static void acm_complete_set_line_coding(struct usb_ep *ep,
 296                 struct usb_request *req)
 297 {
 298         struct f_acm    *acm = ep->driver_data;
 299         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 300
 301         if (req->status != 0) {
 302                 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d completion, err %d\n",
 303                         acm->port_num, req->status);
 304                 return;
 305         }
 306
 307         /* normal completion */
 308         if (req->actual != sizeof(acm->port_line_coding)) {
 309                 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d short resp, len %d\n",
 310                         acm->port_num, req->actual);
 311                 usb_ep_set_halt(ep);
 312         } else {
 313                 struct usb_cdc_line_coding      *value = req->buf;
 314
 315                 /* REVISIT:  we currently just remember this data.
 316                  * If we change that, (a) validate it first, then
 317                  * (b) update whatever hardware needs updating,
 318                  * (c) worry about locking.  This is information on
 319                  * the order of 9600-8-N-1 ... most of which means
 320                  * nothing unless we control a real RS232 line.
 321                  */
 322                 acm->port_line_coding = *value;
 323         }
 324 }
 325
 326 static int acm_send_break(struct gserial *port, int duration);
 327
 328 static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 329 {
 330         struct f_acm            *acm = func_to_acm(f);
 331         struct usb_composite_dev *cdev = f->config->cdev;
 332         struct usb_request      *req = cdev->req;
 333         int                     value = -EOPNOTSUPP;
 334         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 335         u16                     w_value = le16_to_cpu(ctrl->wValue);
 336         u16                     w_length = le16_to_cpu(ctrl->wLength);
 337
 338         /* composite driver infrastructure handles everything except
 339          * CDC class messages; interface activation uses set_alt().
 340          *
 341          * Note CDC spec table 4 lists the ACM request profile.  It requires
 342          * encapsulated command support ... we don't handle any, and respond
 343          * to them by stalling.  Options include get/set/clear comm features
 344          * (not that useful) and SEND_BREAK.
 345          */
 346         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 347
 348         /* SET_LINE_CODING ... just read and save what the host sends */
 349         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 350                         | USB_CDC_REQ_SET_LINE_CODING:
 351                 if (w_length != sizeof(struct usb_cdc_line_coding)
 352                                 || w_index != acm->ctrl_id)
 353                         goto invalid;
 354
 355                 value = w_length;
 356                 cdev->gadget->ep0->driver_data = acm;
 357                 req->complete = acm_complete_set_line_coding;
 358                 break;
 359
 360         /* GET_LINE_CODING ... return what host sent, or initial value */
 361         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 362                         | USB_CDC_REQ_GET_LINE_CODING:
 363                 if (w_index != acm->ctrl_id)
 364                         goto invalid;
 365
 366                 value = min_t(unsigned, w_length,
 367                                 sizeof(struct usb_cdc_line_coding));
 368                 memcpy(req->buf, &acm->port_line_coding, value);
 369                 break;
 370
 371         /* SET_CONTROL_LINE_STATE ... save what the host sent */
 372         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 373                         | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
 374                 if (w_index != acm->ctrl_id)
 375                         goto invalid;
 376
 377                 value = 0;
 378
 379                 /* FIXME we should not allow data to flow until the
 380                  * host sets the USB_CDC_CTRL_DTR bit; and when it clears
 381                  * that bit, we should return to that no-flow state.
 382                  */
 383                 acm->port_handshake_bits = w_value;
 384                 break;
 385
 386         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 387                         | USB_CDC_REQ_SEND_BREAK:
 388                 if (w_index != acm->ctrl_id)
 389                         goto invalid;
 390
 391                 acm_send_break(&acm->port, w_value);
 392                 break;
 393
 394         default:
 395 invalid:
 396                 dev_vdbg(&cdev->gadget->dev,
 397                          "invalid control req%02x.%02x v%04x i%04x l%d\n",
 398                          ctrl->bRequestType, ctrl->bRequest,
 399                          w_value, w_index, w_length);
 400         }
 401
 402         /* respond with data transfer or status phase? */
 403         if (value >= 0) {
 404                 dev_dbg(&cdev->gadget->dev,
 405                         "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
 406                         acm->port_num, ctrl->bRequestType, ctrl->bRequest,
 407                         w_value, w_index, w_length);
 408                 req->zero = 0;
 409                 req->length = value;
 410                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 411                 if (value < 0)
 412                         ERROR(cdev, "acm response on ttyGS%d, err %d\n",
 413                                         acm->port_num, value);
 414         }
 415
 416         /* device either stalls (value < 0) or reports success */
 417         return value;
 418 }
 419
 420 static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 421 {
 422         struct f_acm            *acm = func_to_acm(f);
 423         struct usb_composite_dev *cdev = f->config->cdev;
 424
 425         /* we know alt == 0, so this is an activation or a reset */
 426
 427         if (intf == acm->ctrl_id) {
 428                 if (acm->notify->enabled) {
 429                         dev_vdbg(&cdev->gadget->dev,
 430                                         "reset acm control interface %d\n", intf);
 431                         usb_ep_disable(acm->notify);
 432                 }
 433
 434                 if (!acm->notify->desc)
 435                         if (config_ep_by_speed(cdev->gadget, f, acm->notify))
 436                                 return -EINVAL;
 437
 438                 usb_ep_enable(acm->notify);
 439
 440         } else if (intf == acm->data_id) {
 441                 if (acm->notify->enabled) {
 442                         dev_dbg(&cdev->gadget->dev,
 443                                 "reset acm ttyGS%d\n", acm->port_num);
 444                         gserial_disconnect(&acm->port);
 445                 }
 446                 if (!acm->port.in->desc || !acm->port.out->desc) {
 447                         dev_dbg(&cdev->gadget->dev,
 448                                 "activate acm ttyGS%d\n", acm->port_num);
 449                         if (config_ep_by_speed(cdev->gadget, f,
 450                                                acm->port.in) ||
 451                             config_ep_by_speed(cdev->gadget, f,
 452                                                acm->port.out)) {
 453                                 acm->port.in->desc = NULL;
 454                                 acm->port.out->desc = NULL;
 455                                 return -EINVAL;
 456                         }
 457                 }
 458                 gserial_connect(&acm->port, acm->port_num);
 459
 460         } else
 461                 return -EINVAL;
 462
 463         return 0;
 464 }
 465
 466 static void acm_disable(struct usb_function *f)
 467 {
 468         struct f_acm    *acm = func_to_acm(f);
 469         struct usb_composite_dev *cdev = f->config->cdev;
 470
 471         dev_dbg(&cdev->gadget->dev, "acm ttyGS%d deactivated\n", acm->port_num);
 472         gserial_disconnect(&acm->port);
 473         usb_ep_disable(acm->notify);
 474 }
 475
 476 /*-------------------------------------------------------------------------*/
 477
 478 /**
 479  * acm_cdc_notify - issue CDC notification to host
 480  * @acm: wraps host to be notified
 481  * @type: notification type
 482  * @value: Refer to cdc specs, wValue field.
 483  * @data: data to be sent
 484  * @length: size of data
 485  * Context: irqs blocked, acm->lock held, acm_notify_req non-null
 486  *
 487  * Returns zero on success or a negative errno.
 488  *
 489  * See section 6.3.5 of the CDC 1.1 specification for information
 490  * about the only notification we issue:  SerialState change.
 491  */
 492 static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
 493                 void *data, unsigned length)
 494 {
 495         struct usb_ep                   *ep = acm->notify;
 496         struct usb_request              *req;
 497         struct usb_cdc_notification     *notify;
 498         const unsigned                  len = sizeof(*notify) + length;
 499         void                            *buf;
 500         int                             status;
 501
 502         req = acm->notify_req;
 503         acm->notify_req = NULL;
 504         acm->pending = false;
 505
 506         req->length = len;
 507         notify = req->buf;
 508         buf = notify + 1;
 509
 510         notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
 511                         | USB_RECIP_INTERFACE;
 512         notify->bNotificationType = type;
 513         notify->wValue = cpu_to_le16(value);
 514         notify->wIndex = cpu_to_le16(acm->ctrl_id);
 515         notify->wLength = cpu_to_le16(length);
 516         memcpy(buf, data, length);
 517
 518         /* ep_queue() can complete immediately if it fills the fifo... */
 519         spin_unlock(&acm->lock);
 520         status = usb_ep_queue(ep, req, GFP_ATOMIC);
 521         spin_lock(&acm->lock);
 522
 523         if (status < 0) {
 524                 ERROR(acm->port.func.config->cdev,
 525                                 "acm ttyGS%d can't notify serial state, %d\n",
 526                                 acm->port_num, status);
 527                 acm->notify_req = req;
 528         }
 529
 530         return status;
 531 }
 532
 533 static int acm_notify_serial_state(struct f_acm *acm)
 534 {
 535         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 536         int                     status;
 537         __le16                  serial_state;
 538
 539         spin_lock(&acm->lock);
 540         if (acm->notify_req) {
 541                 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d serial state %04x\n",
 542                         acm->port_num, acm->serial_state);
 543                 serial_state = cpu_to_le16(acm->serial_state);
 544                 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
 545                                 0, &serial_state, sizeof(acm->serial_state));
 546         } else {
 547                 acm->pending = true;
 548                 status = 0;
 549         }
 550         spin_unlock(&acm->lock);
 551         return status;
 552 }
 553
 554 static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
 555 {
 556         struct f_acm            *acm = req->context;
 557         u8                      doit = false;
 558
 559         /* on this call path we do NOT hold the port spinlock,
 560          * which is why ACM needs its own spinlock
 561          */
 562         spin_lock(&acm->lock);
 563         if (req->status != -ESHUTDOWN)
 564                 doit = acm->pending;
 565         acm->notify_req = req;
 566         spin_unlock(&acm->lock);
 567
 568         if (doit)
 569                 acm_notify_serial_state(acm);
 570 }
 571
 572 /* connect == the TTY link is open */
 573
 574 static void acm_connect(struct gserial *port)
 575 {
 576         struct f_acm            *acm = port_to_acm(port);
 577
 578         acm->serial_state |= USB_CDC_SERIAL_STATE_DSR | USB_CDC_SERIAL_STATE_DCD;
 579         acm_notify_serial_state(acm);
 580 }
 581
 582 static void acm_disconnect(struct gserial *port)
 583 {
 584         struct f_acm            *acm = port_to_acm(port);
 585
 586         acm->serial_state &= ~(USB_CDC_SERIAL_STATE_DSR | USB_CDC_SERIAL_STATE_DCD);
 587         acm_notify_serial_state(acm);
 588 }
 589
 590 static int acm_send_break(struct gserial *port, int duration)
 591 {
 592         struct f_acm            *acm = port_to_acm(port);
 593         u16                     state;
 594
 595         state = acm->serial_state;
 596         state &= ~USB_CDC_SERIAL_STATE_BREAK;
 597         if (duration)
 598                 state |= USB_CDC_SERIAL_STATE_BREAK;
 599
 600         acm->serial_state = state;
 601         return acm_notify_serial_state(acm);
 602 }
 603
 604 /*-------------------------------------------------------------------------*/
 605
 606 /* ACM function driver setup/binding */
 607 static int
 608 acm_bind(struct usb_configuration *c, struct usb_function *f)
 609 {
 610         struct usb_composite_dev *cdev = c->cdev;
 611         struct f_acm            *acm = func_to_acm(f);
 612         struct usb_string       *us;
 613         int                     status;
 614         struct usb_ep           *ep;
 615
 616         /* REVISIT might want instance-specific strings to help
 617          * distinguish instances ...
 618          */
 619
 620         /* maybe allocate device-global string IDs, and patch descriptors */
 621         us = usb_gstrings_attach(cdev, acm_strings,
 622                         ARRAY_SIZE(acm_string_defs));
 623         if (IS_ERR(us))
 624                 return PTR_ERR(us);
 625         acm_control_interface_desc.iInterface = us[ACM_CTRL_IDX].id;
 626         acm_data_interface_desc.iInterface = us[ACM_DATA_IDX].id;
 627         acm_iad_descriptor.iFunction = us[ACM_IAD_IDX].id;
 628
 629         /* allocate instance-specific interface IDs, and patch descriptors */
 630         status = usb_interface_id(c, f);
 631         if (status < 0)
 632                 goto fail;
 633         acm->ctrl_id = status;
 634         acm_iad_descriptor.bFirstInterface = status;
 635
 636         acm_control_interface_desc.bInterfaceNumber = status;
 637         acm_union_desc .bMasterInterface0 = status;
 638
 639         status = usb_interface_id(c, f);
 640         if (status < 0)
 641                 goto fail;
 642         acm->data_id = status;
 643
 644         acm_data_interface_desc.bInterfaceNumber = status;
 645         acm_union_desc.bSlaveInterface0 = status;
 646         acm_call_mgmt_descriptor.bDataInterface = status;
 647
 648         status = -ENODEV;
 649
 650         /* allocate instance-specific endpoints */
 651         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
 652         if (!ep)
 653                 goto fail;
 654         acm->port.in = ep;
 655
 656         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
 657         if (!ep)
 658                 goto fail;
 659         acm->port.out = ep;
 660
 661         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
 662         if (!ep)
 663                 goto fail;
 664         acm->notify = ep;
 665
 666         /* allocate notification */
 667         acm->notify_req = gs_alloc_req(ep,
 668                         sizeof(struct usb_cdc_notification) + 2,
 669                         GFP_KERNEL);
 670         if (!acm->notify_req)
 671                 goto fail;
 672
 673         acm->notify_req->complete = acm_cdc_notify_complete;
 674         acm->notify_req->context = acm;
 675
 676         /* support all relevant hardware speeds... we expect that when
 677          * hardware is dual speed, all bulk-capable endpoints work at
 678          * both speeds
 679          */
 680         acm_hs_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
 681         acm_hs_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
 682         acm_hs_notify_desc.bEndpointAddress =
 683                 acm_fs_notify_desc.bEndpointAddress;
 684
 685         acm_ss_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
 686         acm_ss_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
 687
 688         status = usb_assign_descriptors(f, acm_fs_function, acm_hs_function,
 689                         acm_ss_function, acm_ss_function);
 690         if (status)
 691                 goto fail;
 692
 693         dev_dbg(&cdev->gadget->dev,
 694                 "acm ttyGS%d: IN/%s OUT/%s NOTIFY/%s\n",
 695                 acm->port_num,
 696                 acm->port.in->name, acm->port.out->name,
 697                 acm->notify->name);
 698         return 0;
 699
 700 fail:
 701         if (acm->notify_req)
 702                 gs_free_req(acm->notify, acm->notify_req);
 703
 704         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 705
 706         return status;
 707 }
 708
 709 static void acm_unbind(struct usb_configuration *c, struct usb_function *f)
 710 {
 711         struct f_acm            *acm = func_to_acm(f);
 712
 713         acm_string_defs[0].id = 0;
 714         usb_free_all_descriptors(f);
 715         if (acm->notify_req)
 716                 gs_free_req(acm->notify, acm->notify_req);
 717 }
 718
 719 static void acm_free_func(struct usb_function *f)
 720 {
 721         struct f_acm            *acm = func_to_acm(f);
 722
 723         kfree(acm);
 724 }
 725
 726 static void acm_resume(struct usb_function *f)
 727 {
 728         struct f_acm *acm = func_to_acm(f);
 729
 730         gserial_resume(&acm->port);
 731 }
 732
 733 static void acm_suspend(struct usb_function *f)
 734 {
 735         struct f_acm *acm = func_to_acm(f);
 736
 737         gserial_suspend(&acm->port);
 738 }
 739
 740 static struct usb_function *acm_alloc_func(struct usb_function_instance *fi)
 741 {
 742         struct f_serial_opts *opts;
 743         struct f_acm *acm;
 744
 745         acm = kzalloc(sizeof(*acm), GFP_KERNEL);
 746         if (!acm)
 747                 return ERR_PTR(-ENOMEM);
 748
 749         spin_lock_init(&acm->lock);
 750
 751         acm->port.connect = acm_connect;
 752         acm->port.disconnect = acm_disconnect;
 753         acm->port.send_break = acm_send_break;
 754
 755         acm->port.func.name = "acm";
 756         acm->port.func.strings = acm_strings;
 757         /* descriptors are per-instance copies */
 758         acm->port.func.bind = acm_bind;
 759         acm->port.func.set_alt = acm_set_alt;
 760         acm->port.func.setup = acm_setup;
 761         acm->port.func.disable = acm_disable;
 762
 763         opts = container_of(fi, struct f_serial_opts, func_inst);
 764         acm->port_num = opts->port_num;
 765         acm->port.func.unbind = acm_unbind;
 766         acm->port.func.free_func = acm_free_func;
 767         acm->port.func.resume = acm_resume;
 768         acm->port.func.suspend = acm_suspend;
 769
 770         return &acm->port.func;
 771 }
 772
 773 static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
 774 {
 775         return container_of(to_config_group(item), struct f_serial_opts,
 776                         func_inst.group);
 777 }
 778
 779 static void acm_attr_release(struct config_item *item)
 780 {
 781         struct f_serial_opts *opts = to_f_serial_opts(item);
 782
 783         usb_put_function_instance(&opts->func_inst);
 784 }
 785
 786 static struct configfs_item_operations acm_item_ops = {
 787         .release                = acm_attr_release,
 788 };
 789
 790 #ifdef CONFIG_U_SERIAL_CONSOLE
 791
 792 static ssize_t f_acm_console_store(struct config_item *item,
 793                 const char *page, size_t count)
 794 {
 795         return gserial_set_console(to_f_serial_opts(item)->port_num,
 796                                    page, count);
 797 }
 798
 799 static ssize_t f_acm_console_show(struct config_item *item, char *page)
 800 {
 801         return gserial_get_console(to_f_serial_opts(item)->port_num, page);
 802 }
 803
 804 CONFIGFS_ATTR(f_acm_, console);
 805
 806 #endif /* CONFIG_U_SERIAL_CONSOLE */
 807
 808 static ssize_t f_acm_port_num_show(struct config_item *item, char *page)
 809 {
 810         return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num);
 811 }
 812
 813 CONFIGFS_ATTR_RO(f_acm_, port_num);
 814
 815 static struct configfs_attribute *acm_attrs[] = {
 816 #ifdef CONFIG_U_SERIAL_CONSOLE
 817         &f_acm_attr_console,
 818 #endif
 819         &f_acm_attr_port_num,
 820         NULL,
 821 };
 822
 823 static const struct config_item_type acm_func_type = {
 824         .ct_item_ops    = &acm_item_ops,
 825         .ct_attrs       = acm_attrs,
 826         .ct_owner       = THIS_MODULE,
 827 };
 828
 829 static void acm_free_instance(struct usb_function_instance *fi)
 830 {
 831         struct f_serial_opts *opts;
 832
 833         opts = container_of(fi, struct f_serial_opts, func_inst);
 834         gserial_free_line(opts->port_num);
 835         kfree(opts);
 836 }
 837
 838 static struct usb_function_instance *acm_alloc_instance(void)
 839 {
 840         struct f_serial_opts *opts;
 841         int ret;
 842
 843         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 844         if (!opts)
 845                 return ERR_PTR(-ENOMEM);
 846         opts->func_inst.free_func_inst = acm_free_instance;
 847         ret = gserial_alloc_line(&opts->port_num);
 848         if (ret) {
 849                 kfree(opts);
 850                 return ERR_PTR(ret);
 851         }
 852         config_group_init_type_name(&opts->func_inst.group, "",
 853                         &acm_func_type);
 854         return &opts->func_inst;
 855 }
 856 DECLARE_USB_FUNCTION_INIT(acm, acm_alloc_instance, acm_alloc_func);
 857 MODULE_LICENSE("GPL");