drivers/usb/gadget/f_acm.c

   1 /*
   2  * f_acm.c -- USB CDC serial (ACM) function driver
   3  *
   4  * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
   5  * Copyright (C) 2008 by David Brownell
   6  * Copyright (C) 2008 by Nokia Corporation
   7  * Copyright (C) 2009 by Samsung Electronics
   8  * Author: Michal Nazarewicz (mina86@mina86.com)
   9  *
  10  * This software is distributed under the terms of the GNU General
  11  * Public License ("GPL") as published by the Free Software Foundation,
  12  * either version 2 of that License or (at your option) any later version.
  13  */
  14
  15 /* #define VERBOSE_DEBUG */
  16 #ifdef pr_fmt
  17 #undef pr_fmt
  18 #endif
  19 #define pr_fmt(fmt) "["KBUILD_MODNAME"]" fmt
  20
  21 #include <linux/slab.h>
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/device.h>
  25 #include <linux/err.h>
  26 #include <linux/printk.h>
  27 #include "u_serial.h"
  28 #include "gadget_chips.h"
  29
  30
  31 #define ACM_LOG "USB_ACM"
  32
  33 /*
  34  * This CDC ACM function support just wraps control functions and
  35  * notifications around the generic serial-over-usb code.
  36  *
  37  * Because CDC ACM is standardized by the USB-IF, many host operating
  38  * systems have drivers for it.  Accordingly, ACM is the preferred
  39  * interop solution for serial-port type connections.  The control
  40  * models are often not necessary, and in any case don't do much in
  41  * this bare-bones implementation.
  42  *
  43  * Note that even MS-Windows has some support for ACM.  However, that
  44  * support is somewhat broken because when you use ACM in a composite
  45  * device, having multiple interfaces confuses the poor OS.  It doesn't
  46  * seem to understand CDC Union descriptors.  The new "association"
  47  * descriptors (roughly equivalent to CDC Unions) may sometimes help.
  48  */
  49
  50 struct f_acm {
  51         struct gserial                  port;
  52         u8                              ctrl_id, data_id;
  53         u8                              port_num;
  54
  55         u8                              pending;
  56
  57         /* lock is mostly for pending and notify_req ... they get accessed
  58          * by callbacks both from tty (open/close/break) under its spinlock,
  59          * and notify_req.complete() which can't use that lock.
  60          */
  61         spinlock_t                      lock;
  62
  63         struct usb_ep                   *notify;
  64         struct usb_request              *notify_req;
  65
  66         struct usb_cdc_line_coding      port_line_coding;       /* 8-N-1 etc */
  67
  68         /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
  69         u16                             port_handshake_bits;
  70 #define ACM_CTRL_RTS    (1 << 1)        /* unused with full duplex */
  71 #define ACM_CTRL_DTR    (1 << 0)        /* host is ready for data r/w */
  72
  73         /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
  74         u16                             serial_state;
  75 #define ACM_CTRL_OVERRUN        (1 << 6)
  76 #define ACM_CTRL_PARITY         (1 << 5)
  77 #define ACM_CTRL_FRAMING        (1 << 4)
  78 #define ACM_CTRL_RI             (1 << 3)
  79 #define ACM_CTRL_BRK            (1 << 2)
  80 #define ACM_CTRL_DSR            (1 << 1)
  81 #define ACM_CTRL_DCD            (1 << 0)
  82 };
  83
  84 static inline struct f_acm *func_to_acm(struct usb_function *f)
  85 {
  86         return container_of(f, struct f_acm, port.func);
  87 }
  88
  89 static inline struct f_acm *port_to_acm(struct gserial *p)
  90 {
  91         return container_of(p, struct f_acm, port);
  92 }
  93
  94 /*-------------------------------------------------------------------------*/
  95
  96 /* notification endpoint uses smallish and infrequent fixed-size messages */
  97
  98 #define GS_NOTIFY_INTERVAL_MS           32
  99 #define GS_NOTIFY_MAXPACKET             10      /* notification + 2 bytes */
 100
 101 /* interface and class descriptors: */
 102
 103 static struct usb_interface_assoc_descriptor
 104 acm_iad_descriptor = {
 105         .bLength =              sizeof acm_iad_descriptor,
 106         .bDescriptorType =      USB_DT_INTERFACE_ASSOCIATION,
 107
 108         /* .bFirstInterface =   DYNAMIC, */
 109         .bInterfaceCount =      2,      // control + data
 110         .bFunctionClass =       USB_CLASS_COMM,
 111         .bFunctionSubClass =    USB_CDC_SUBCLASS_ACM,
 112         .bFunctionProtocol =    USB_CDC_ACM_PROTO_AT_V25TER,
 113         /* .iFunction =         DYNAMIC */
 114 };
 115
 116
 117 static struct usb_interface_descriptor acm_control_interface_desc = {
 118         .bLength =              USB_DT_INTERFACE_SIZE,
 119         .bDescriptorType =      USB_DT_INTERFACE,
 120         /* .bInterfaceNumber = DYNAMIC */
 121         .bNumEndpoints =        1,
 122         .bInterfaceClass =      USB_CLASS_COMM,
 123         .bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
 124         .bInterfaceProtocol =   USB_CDC_ACM_PROTO_AT_V25TER,
 125         /* .iInterface = DYNAMIC */
 126 };
 127
 128 static struct usb_interface_descriptor acm_data_interface_desc = {
 129         .bLength =              USB_DT_INTERFACE_SIZE,
 130         .bDescriptorType =      USB_DT_INTERFACE,
 131         /* .bInterfaceNumber = DYNAMIC */
 132         .bNumEndpoints =        2,
 133         .bInterfaceClass =      USB_CLASS_CDC_DATA,
 134         .bInterfaceSubClass =   0,
 135         .bInterfaceProtocol =   0,
 136         /* .iInterface = DYNAMIC */
 137 };
 138
 139 static struct usb_cdc_header_desc acm_header_desc = {
 140         .bLength =              sizeof(acm_header_desc),
 141         .bDescriptorType =      USB_DT_CS_INTERFACE,
 142         .bDescriptorSubType =   USB_CDC_HEADER_TYPE,
 143         .bcdCDC =               cpu_to_le16(0x0110),
 144 };
 145
 146 static struct usb_cdc_call_mgmt_descriptor
 147 acm_call_mgmt_descriptor = {
 148         .bLength =              sizeof(acm_call_mgmt_descriptor),
 149         .bDescriptorType =      USB_DT_CS_INTERFACE,
 150         .bDescriptorSubType =   USB_CDC_CALL_MANAGEMENT_TYPE,
 151         .bmCapabilities =       0,
 152         /* .bDataInterface = DYNAMIC */
 153 };
 154
 155 static struct usb_cdc_acm_descriptor acm_descriptor = {
 156         .bLength =              sizeof(acm_descriptor),
 157         .bDescriptorType =      USB_DT_CS_INTERFACE,
 158         .bDescriptorSubType =   USB_CDC_ACM_TYPE,
 159         .bmCapabilities =       USB_CDC_CAP_LINE,
 160 };
 161
 162 static struct usb_cdc_union_desc acm_union_desc = {
 163         .bLength =              sizeof(acm_union_desc),
 164         .bDescriptorType =      USB_DT_CS_INTERFACE,
 165         .bDescriptorSubType =   USB_CDC_UNION_TYPE,
 166         /* .bMasterInterface0 = DYNAMIC */
 167         /* .bSlaveInterface0 =  DYNAMIC */
 168 };
 169
 170 /* full speed support: */
 171
 172 static struct usb_endpoint_descriptor acm_fs_notify_desc = {
 173         .bLength =              USB_DT_ENDPOINT_SIZE,
 174         .bDescriptorType =      USB_DT_ENDPOINT,
 175         .bEndpointAddress =     USB_DIR_IN,
 176         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 177         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 178         .bInterval =            GS_NOTIFY_INTERVAL_MS,
 179 };
 180
 181 static struct usb_endpoint_descriptor acm_fs_in_desc = {
 182         .bLength =              USB_DT_ENDPOINT_SIZE,
 183         .bDescriptorType =      USB_DT_ENDPOINT,
 184         .bEndpointAddress =     USB_DIR_IN,
 185         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 186 };
 187
 188 static struct usb_endpoint_descriptor acm_fs_out_desc = {
 189         .bLength =              USB_DT_ENDPOINT_SIZE,
 190         .bDescriptorType =      USB_DT_ENDPOINT,
 191         .bEndpointAddress =     USB_DIR_OUT,
 192         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 193 };
 194
 195 static struct usb_descriptor_header *acm_fs_function[] = {
 196         (struct usb_descriptor_header *) &acm_iad_descriptor,
 197         (struct usb_descriptor_header *) &acm_control_interface_desc,
 198         (struct usb_descriptor_header *) &acm_header_desc,
 199         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 200         (struct usb_descriptor_header *) &acm_descriptor,
 201         (struct usb_descriptor_header *) &acm_union_desc,
 202         (struct usb_descriptor_header *) &acm_fs_notify_desc,
 203         (struct usb_descriptor_header *) &acm_data_interface_desc,
 204         (struct usb_descriptor_header *) &acm_fs_in_desc,
 205         (struct usb_descriptor_header *) &acm_fs_out_desc,
 206         NULL,
 207 };
 208
 209 /* high speed support: */
 210 static struct usb_endpoint_descriptor acm_hs_notify_desc = {
 211         .bLength =              USB_DT_ENDPOINT_SIZE,
 212         .bDescriptorType =      USB_DT_ENDPOINT,
 213         .bEndpointAddress =     USB_DIR_IN,
 214         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 215         .wMaxPacketSize =       cpu_to_le16(GS_NOTIFY_MAXPACKET),
 216         .bInterval =            USB_MS_TO_HS_INTERVAL(GS_NOTIFY_INTERVAL_MS),
 217 };
 218
 219 static struct usb_endpoint_descriptor acm_hs_in_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_endpoint_descriptor acm_hs_out_desc = {
 227         .bLength =              USB_DT_ENDPOINT_SIZE,
 228         .bDescriptorType =      USB_DT_ENDPOINT,
 229         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 230         .wMaxPacketSize =       cpu_to_le16(512),
 231 };
 232
 233 static struct usb_descriptor_header *acm_hs_function[] = {
 234         (struct usb_descriptor_header *) &acm_iad_descriptor,
 235         (struct usb_descriptor_header *) &acm_control_interface_desc,
 236         (struct usb_descriptor_header *) &acm_header_desc,
 237         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 238         (struct usb_descriptor_header *) &acm_descriptor,
 239         (struct usb_descriptor_header *) &acm_union_desc,
 240         (struct usb_descriptor_header *) &acm_hs_notify_desc,
 241         (struct usb_descriptor_header *) &acm_data_interface_desc,
 242         (struct usb_descriptor_header *) &acm_hs_in_desc,
 243         (struct usb_descriptor_header *) &acm_hs_out_desc,
 244         NULL,
 245 };
 246
 247 static struct usb_endpoint_descriptor acm_ss_in_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_endpoint_descriptor acm_ss_out_desc = {
 255         .bLength =              USB_DT_ENDPOINT_SIZE,
 256         .bDescriptorType =      USB_DT_ENDPOINT,
 257         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 258         .wMaxPacketSize =       cpu_to_le16(1024),
 259 };
 260
 261 static struct usb_ss_ep_comp_descriptor acm_ss_bulk_comp_desc = {
 262         .bLength =              sizeof acm_ss_bulk_comp_desc,
 263         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 264 };
 265
 266 static struct usb_descriptor_header *acm_ss_function[] = {
 267         (struct usb_descriptor_header *) &acm_iad_descriptor,
 268         (struct usb_descriptor_header *) &acm_control_interface_desc,
 269         (struct usb_descriptor_header *) &acm_header_desc,
 270         (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
 271         (struct usb_descriptor_header *) &acm_descriptor,
 272         (struct usb_descriptor_header *) &acm_union_desc,
 273         (struct usb_descriptor_header *) &acm_hs_notify_desc,
 274         (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
 275         (struct usb_descriptor_header *) &acm_data_interface_desc,
 276         (struct usb_descriptor_header *) &acm_ss_in_desc,
 277         (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
 278         (struct usb_descriptor_header *) &acm_ss_out_desc,
 279         (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
 280         NULL,
 281 };
 282
 283 /* string descriptors: */
 284
 285 #define ACM_CTRL_IDX    0
 286 #define ACM_DATA_IDX    1
 287 #define ACM_IAD_IDX     2
 288
 289 /* static strings, in UTF-8 */
 290 static struct usb_string acm_string_defs[] = {
 291         [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
 292         [ACM_DATA_IDX].s = "CDC ACM Data",
 293         [ACM_IAD_IDX ].s = "CDC Serial",
 294         {  } /* end of list */
 295 };
 296
 297 static struct usb_gadget_strings acm_string_table = {
 298         .language =             0x0409, /* en-us */
 299         .strings =              acm_string_defs,
 300 };
 301
 302 static struct usb_gadget_strings *acm_strings[] = {
 303         &acm_string_table,
 304         NULL,
 305 };
 306
 307 /*-------------------------------------------------------------------------*/
 308
 309 /* ACM control ... data handling is delegated to tty library code.
 310  * The main task of this function is to activate and deactivate
 311  * that code based on device state; track parameters like line
 312  * speed, handshake state, and so on; and issue notifications.
 313  */
 314
 315 static void acm_complete_set_line_coding(struct usb_ep *ep,
 316                 struct usb_request *req)
 317 {
 318         struct f_acm    *acm = ep->driver_data;
 319         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 320
 321         if (req->status != 0) {
 322                 DBG(cdev, "acm ttyGS%d completion, err %d\n",
 323                                 acm->port_num, req->status);
 324                 return;
 325         }
 326
 327         /* normal completion */
 328         if (req->actual != sizeof(acm->port_line_coding)) {
 329                 DBG(cdev, "acm ttyGS%d short resp, len %d\n",
 330                                 acm->port_num, req->actual);
 331                 usb_ep_set_halt(ep);
 332         } else {
 333                 struct usb_cdc_line_coding      *value = req->buf;
 334
 335                 /* REVISIT:  we currently just remember this data.
 336                  * If we change that, (a) validate it first, then
 337                  * (b) update whatever hardware needs updating,
 338                  * (c) worry about locking.  This is information on
 339                  * the order of 9600-8-N-1 ... most of which means
 340                  * nothing unless we control a real RS232 line.
 341                  */
 342                 acm->port_line_coding = *value;
 343
 344                 pr_debug("[XLOG_INFO][USB_ACM] %s: rate=%d, stop=%d, parity=%d, data=%d\n", __func__, \
 345                         acm->port_line_coding.dwDTERate, acm->port_line_coding.bCharFormat, \
 346                         acm->port_line_coding.bParityType, acm->port_line_coding.bDataBits);
 347         }
 348 }
 349
 350 static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 351 {
 352         struct f_acm            *acm = func_to_acm(f);
 353         struct usb_composite_dev *cdev = f->config->cdev;
 354         struct usb_request      *req = cdev->req;
 355         int                     value = -EOPNOTSUPP;
 356         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 357         u16                     w_value = le16_to_cpu(ctrl->wValue);
 358         u16                     w_length = le16_to_cpu(ctrl->wLength);
 359
 360         /* composite driver infrastructure handles everything except
 361          * CDC class messages; interface activation uses set_alt().
 362          *
 363          * Note CDC spec table 4 lists the ACM request profile.  It requires
 364          * encapsulated command support ... we don't handle any, and respond
 365          * to them by stalling.  Options include get/set/clear comm features
 366          * (not that useful) and SEND_BREAK.
 367          */
 368
 369         pr_debug("[XLOG_INFO][USB_ACM]%s: ttyGS%d req%02x.%02x v%04x i%04x len=%d\n", __func__, \
 370                 acm->port_num, ctrl->bRequestType, ctrl->bRequest, w_value, w_index, w_length);
 371
 372         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 373
 374         /* SET_LINE_CODING ... just read and save what the host sends */
 375         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 376                         | USB_CDC_REQ_SET_LINE_CODING:
 377                 if (w_length != sizeof(struct usb_cdc_line_coding)
 378                                 || w_index != acm->ctrl_id)
 379                         goto invalid;
 380
 381                 value = w_length;
 382                 cdev->gadget->ep0->driver_data = acm;
 383                 req->complete = acm_complete_set_line_coding;
 384                 break;
 385
 386         /* GET_LINE_CODING ... return what host sent, or initial value */
 387         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 388                         | USB_CDC_REQ_GET_LINE_CODING:
 389                 if (w_index != acm->ctrl_id)
 390                         goto invalid;
 391
 392                 value = min_t(unsigned, w_length,
 393                                 sizeof(struct usb_cdc_line_coding));
 394                 memcpy(req->buf, &acm->port_line_coding, value);
 395
 396                 pr_debug("[XLOG_INFO][USB_ACM]%s: rate=%d,stop=%d,parity=%d,data=%d\n", __func__, \
 397                         acm->port_line_coding.dwDTERate, acm->port_line_coding.bCharFormat, \
 398                         acm->port_line_coding.bParityType, acm->port_line_coding.bDataBits);
 399
 400                 break;
 401
 402         /* SET_CONTROL_LINE_STATE ... save what the host sent */
 403         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 404                         | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
 405                 if (w_index != acm->ctrl_id)
 406                         goto invalid;
 407
 408                 value = 0;
 409
 410                 /* FIXME we should not allow data to flow until the
 411                  * host sets the ACM_CTRL_DTR bit; and when it clears
 412                  * that bit, we should return to that no-flow state.
 413                  */
 414                 acm->port_handshake_bits = w_value;
 415                 break;
 416
 417         default:
 418 invalid:
 419                 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 420                         ctrl->bRequestType, ctrl->bRequest,
 421                         w_value, w_index, w_length);
 422         }
 423
 424         /* respond with data transfer or status phase? */
 425         if (value >= 0) {
 426                 DBG(cdev, "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
 427                         acm->port_num, ctrl->bRequestType, ctrl->bRequest,
 428                         w_value, w_index, w_length);
 429                 req->zero = 0;
 430                 req->length = value;
 431                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 432                 if (value < 0)
 433                         ERROR(cdev, "acm response on ttyGS%d, err %d\n",
 434                                         acm->port_num, value);
 435         }
 436
 437         /* device either stalls (value < 0) or reports success */
 438         return value;
 439 }
 440
 441 static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 442 {
 443         struct f_acm            *acm = func_to_acm(f);
 444         struct usb_composite_dev *cdev = f->config->cdev;
 445
 446         /* we know alt == 0, so this is an activation or a reset */
 447
 448         if (intf == acm->ctrl_id) {
 449                 if (acm->notify->driver_data) {
 450                         VDBG(cdev, "reset acm control interface %d\n", intf);
 451                         usb_ep_disable(acm->notify);
 452                 }
 453
 454                 if (!acm->notify->desc)
 455                         if (config_ep_by_speed(cdev->gadget, f, acm->notify))
 456                                 return -EINVAL;
 457
 458                 usb_ep_enable(acm->notify);
 459                 acm->notify->driver_data = acm;
 460
 461         } else if (intf == acm->data_id) {
 462                 if (acm->port.in->driver_data) {
 463                         DBG(cdev, "reset acm ttyGS%d\n", acm->port_num);
 464                         gserial_disconnect(&acm->port);
 465                 }
 466                 if (!acm->port.in->desc || !acm->port.out->desc) {
 467                         DBG(cdev, "activate acm ttyGS%d\n", acm->port_num);
 468                         if (config_ep_by_speed(cdev->gadget, f,
 469                                                acm->port.in) ||
 470                             config_ep_by_speed(cdev->gadget, f,
 471                                                acm->port.out)) {
 472                                 acm->port.in->desc = NULL;
 473                                 acm->port.out->desc = NULL;
 474                                 return -EINVAL;
 475                         }
 476                 }
 477                 gserial_connect(&acm->port, acm->port_num);
 478
 479         } else
 480                 return -EINVAL;
 481
 482         return 0;
 483 }
 484
 485 static void acm_disable(struct usb_function *f)
 486 {
 487         struct f_acm    *acm = func_to_acm(f);
 488         struct usb_composite_dev *cdev = f->config->cdev;
 489
 490         INFO(cdev, "acm ttyGS%d deactivated\n", acm->port_num);
 491         gserial_disconnect(&acm->port);
 492         usb_ep_disable(acm->notify);
 493         acm->notify->driver_data = NULL;
 494 }
 495
 496 /*-------------------------------------------------------------------------*/
 497
 498 /**
 499  * acm_cdc_notify - issue CDC notification to host
 500  * @acm: wraps host to be notified
 501  * @type: notification type
 502  * @value: Refer to cdc specs, wValue field.
 503  * @data: data to be sent
 504  * @length: size of data
 505  * Context: irqs blocked, acm->lock held, acm_notify_req non-null
 506  *
 507  * Returns zero on success or a negative errno.
 508  *
 509  * See section 6.3.5 of the CDC 1.1 specification for information
 510  * about the only notification we issue:  SerialState change.
 511  */
 512 static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
 513                 void *data, unsigned length)
 514 {
 515         struct usb_ep                   *ep = acm->notify;
 516         struct usb_request              *req;
 517         struct usb_cdc_notification     *notify;
 518         const unsigned                  len = sizeof(*notify) + length;
 519         void                            *buf;
 520         int                             status;
 521
 522         req = acm->notify_req;
 523         acm->notify_req = NULL;
 524         acm->pending = false;
 525
 526         req->length = len;
 527         notify = req->buf;
 528         buf = notify + 1;
 529
 530         notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
 531                         | USB_RECIP_INTERFACE;
 532         notify->bNotificationType = type;
 533         notify->wValue = cpu_to_le16(value);
 534         notify->wIndex = cpu_to_le16(acm->ctrl_id);
 535         notify->wLength = cpu_to_le16(length);
 536         memcpy(buf, data, length);
 537
 538         /* ep_queue() can complete immediately if it fills the fifo... */
 539         spin_unlock(&acm->lock);
 540         status = usb_ep_queue(ep, req, GFP_ATOMIC);
 541         spin_lock(&acm->lock);
 542
 543         if (status < 0) {
 544                 ERROR(acm->port.func.config->cdev,
 545                                 "acm ttyGS%d can't notify serial state, %d\n",
 546                                 acm->port_num, status);
 547                 acm->notify_req = req;
 548         }
 549
 550         return status;
 551 }
 552
 553 static int acm_notify_serial_state(struct f_acm *acm)
 554 {
 555         struct usb_composite_dev *cdev = acm->port.func.config->cdev;
 556         int                     status;
 557         __le16                  serial_state;
 558
 559         spin_lock(&acm->lock);
 560         if (acm->notify_req) {
 561                 DBG(cdev, "acm ttyGS%d serial state %04x\n",
 562                                 acm->port_num, acm->serial_state);
 563                 serial_state = cpu_to_le16(acm->serial_state);
 564                 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
 565                                 0, &serial_state, sizeof(acm->serial_state));
 566         } else {
 567                 acm->pending = true;
 568                 status = 0;
 569         }
 570         spin_unlock(&acm->lock);
 571         return status;
 572 }
 573
 574 static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
 575 {
 576         struct f_acm            *acm = req->context;
 577         u8                      doit = false;
 578
 579         /* on this call path we do NOT hold the port spinlock,
 580          * which is why ACM needs its own spinlock
 581          */
 582         spin_lock(&acm->lock);
 583         if (req->status != -ESHUTDOWN)
 584                 doit = acm->pending;
 585         acm->notify_req = req;
 586         spin_unlock(&acm->lock);
 587
 588         if (doit)
 589                 acm_notify_serial_state(acm);
 590 }
 591
 592 /* connect == the TTY link is open */
 593
 594 static void acm_connect(struct gserial *port)
 595 {
 596         struct f_acm            *acm = port_to_acm(port);
 597
 598         acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
 599         acm_notify_serial_state(acm);
 600 }
 601
 602 static void acm_disconnect(struct gserial *port)
 603 {
 604         struct f_acm            *acm = port_to_acm(port);
 605
 606         acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
 607         acm_notify_serial_state(acm);
 608 }
 609
 610 static int acm_send_break(struct gserial *port, int duration)
 611 {
 612         struct f_acm            *acm = port_to_acm(port);
 613         u16                     state;
 614
 615         state = acm->serial_state;
 616         state &= ~ACM_CTRL_BRK;
 617         if (duration)
 618                 state |= ACM_CTRL_BRK;
 619
 620         acm->serial_state = state;
 621         return acm_notify_serial_state(acm);
 622 }
 623
 624 /*-------------------------------------------------------------------------*/
 625
 626 /* ACM function driver setup/binding */
 627 static int
 628 acm_bind(struct usb_configuration *c, struct usb_function *f)
 629 {
 630         struct usb_composite_dev *cdev = c->cdev;
 631         struct f_acm            *acm = func_to_acm(f);
 632         struct usb_string       *us;
 633         int                     status;
 634         struct usb_ep           *ep;
 635
 636         /* REVISIT might want instance-specific strings to help
 637          * distinguish instances ...
 638          */
 639
 640         /* maybe allocate device-global string IDs, and patch descriptors */
 641         us = usb_gstrings_attach(cdev, acm_strings,
 642                         ARRAY_SIZE(acm_string_defs));
 643         if (IS_ERR(us))
 644                 return PTR_ERR(us);
 645         acm_control_interface_desc.iInterface = us[ACM_CTRL_IDX].id;
 646         acm_data_interface_desc.iInterface = us[ACM_DATA_IDX].id;
 647         acm_iad_descriptor.iFunction = us[ACM_IAD_IDX].id;
 648
 649         /* allocate instance-specific interface IDs, and patch descriptors */
 650         status = usb_interface_id(c, f);
 651         if (status < 0)
 652                 goto fail;
 653         acm->ctrl_id = status;
 654         acm_iad_descriptor.bFirstInterface = status;
 655
 656         acm_control_interface_desc.bInterfaceNumber = status;
 657         acm_union_desc .bMasterInterface0 = status;
 658
 659         status = usb_interface_id(c, f);
 660         if (status < 0)
 661                 goto fail;
 662         acm->data_id = status;
 663
 664         acm_data_interface_desc.bInterfaceNumber = status;
 665         acm_union_desc.bSlaveInterface0 = status;
 666         acm_call_mgmt_descriptor.bDataInterface = status;
 667
 668         status = -ENODEV;
 669
 670         /* allocate instance-specific endpoints */
 671         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
 672         if (!ep)
 673                 goto fail;
 674         acm->port.in = ep;
 675         ep->driver_data = cdev; /* claim */
 676
 677         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
 678         if (!ep)
 679                 goto fail;
 680         acm->port.out = ep;
 681         ep->driver_data = cdev; /* claim */
 682
 683         ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
 684         if (!ep)
 685                 goto fail;
 686         acm->notify = ep;
 687         ep->driver_data = cdev; /* claim */
 688
 689         /* allocate notification */
 690         acm->notify_req = gs_alloc_req(ep,
 691                         sizeof(struct usb_cdc_notification) + 2,
 692                         GFP_KERNEL);
 693         if (!acm->notify_req)
 694                 goto fail;
 695
 696         acm->notify_req->complete = acm_cdc_notify_complete;
 697         acm->notify_req->context = acm;
 698
 699         /* support all relevant hardware speeds... we expect that when
 700          * hardware is dual speed, all bulk-capable endpoints work at
 701          * both speeds
 702          */
 703         acm_hs_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
 704         acm_hs_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
 705         acm_hs_notify_desc.bEndpointAddress =
 706                 acm_fs_notify_desc.bEndpointAddress;
 707
 708         acm_ss_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
 709         acm_ss_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
 710
 711         status = usb_assign_descriptors(f, acm_fs_function, acm_hs_function,
 712                         acm_ss_function);
 713         if (status)
 714                 goto fail;
 715
 716         pr_debug("[XLOG_INFO][USB_ACM]%s: ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n", \
 717                         __func__, acm->port_num, \
 718                         gadget_is_superspeed(c->cdev->gadget) ? "super" : \
 719                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full", \
 720                         acm->port.in->name, acm->port.out->name, acm->notify->name);
 721
 722         DBG(cdev, "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 723                         acm->port_num,
 724                         gadget_is_superspeed(c->cdev->gadget) ? "super" :
 725                         gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 726                         acm->port.in->name, acm->port.out->name,
 727                         acm->notify->name);
 728         return 0;
 729
 730 fail:
 731         if (acm->notify_req)
 732                 gs_free_req(acm->notify, acm->notify_req);
 733
 734         /* we might as well release our claims on endpoints */
 735         if (acm->notify)
 736                 acm->notify->driver_data = NULL;
 737         if (acm->port.out)
 738                 acm->port.out->driver_data = NULL;
 739         if (acm->port.in)
 740                 acm->port.in->driver_data = NULL;
 741
 742         ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
 743
 744         return status;
 745 }
 746
 747 static void acm_unbind(struct usb_configuration *c, struct usb_function *f)
 748 {
 749         struct f_acm            *acm = func_to_acm(f);
 750
 751         acm_string_defs[0].id = 0;
 752         usb_free_all_descriptors(f);
 753         if (acm->notify_req)
 754                 gs_free_req(acm->notify, acm->notify_req);
 755 }
 756
 757 static void acm_free_func(struct usb_function *f)
 758 {
 759         struct f_acm            *acm = func_to_acm(f);
 760
 761         kfree(acm);
 762 }
 763
 764 static struct usb_function *acm_alloc_func(struct usb_function_instance *fi)
 765 {
 766         struct f_serial_opts *opts;
 767         struct f_acm *acm;
 768
 769         acm = kzalloc(sizeof(*acm), GFP_KERNEL);
 770         if (!acm)
 771                 return ERR_PTR(-ENOMEM);
 772
 773         spin_lock_init(&acm->lock);
 774
 775         acm->port.connect = acm_connect;
 776         acm->port.disconnect = acm_disconnect;
 777         acm->port.send_break = acm_send_break;
 778
 779         acm->port.func.name = "acm";
 780         acm->port.func.strings = acm_strings;
 781         /* descriptors are per-instance copies */
 782         acm->port.func.bind = acm_bind;
 783         acm->port.func.set_alt = acm_set_alt;
 784         acm->port.func.setup = acm_setup;
 785         acm->port.func.disable = acm_disable;
 786
 787         opts = container_of(fi, struct f_serial_opts, func_inst);
 788         acm->port_num = opts->port_num;
 789         acm->port.func.unbind = acm_unbind;
 790         acm->port.func.free_func = acm_free_func;
 791
 792         return &acm->port.func;
 793 }
 794
 795 static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
 796 {
 797         return container_of(to_config_group(item), struct f_serial_opts,
 798                         func_inst.group);
 799 }
 800
 801 CONFIGFS_ATTR_STRUCT(f_serial_opts);
 802 static ssize_t f_acm_attr_show(struct config_item *item,
 803                                  struct configfs_attribute *attr,
 804                                  char *page)
 805 {
 806         struct f_serial_opts *opts = to_f_serial_opts(item);
 807         struct f_serial_opts_attribute *f_serial_opts_attr =
 808                 container_of(attr, struct f_serial_opts_attribute, attr);
 809         ssize_t ret = 0;
 810
 811         if (f_serial_opts_attr->show)
 812                 ret = f_serial_opts_attr->show(opts, page);
 813         return ret;
 814 }
 815
 816 static void acm_attr_release(struct config_item *item)
 817 {
 818         struct f_serial_opts *opts = to_f_serial_opts(item);
 819
 820         usb_put_function_instance(&opts->func_inst);
 821 }
 822
 823 static struct configfs_item_operations acm_item_ops = {
 824         .release                = acm_attr_release,
 825         .show_attribute         = f_acm_attr_show,
 826 };
 827
 828 static ssize_t f_acm_port_num_show(struct f_serial_opts *opts, char *page)
 829 {
 830         return sprintf(page, "%u\n", opts->port_num);
 831 }
 832
 833 static struct f_serial_opts_attribute f_acm_port_num =
 834         __CONFIGFS_ATTR_RO(port_num, f_acm_port_num_show);
 835
 836
 837 static struct configfs_attribute *acm_attrs[] = {
 838         &f_acm_port_num.attr,
 839         NULL,
 840 };
 841
 842 static struct config_item_type acm_func_type = {
 843         .ct_item_ops    = &acm_item_ops,
 844         .ct_attrs       = acm_attrs,
 845         .ct_owner       = THIS_MODULE,
 846 };
 847
 848 static void acm_free_instance(struct usb_function_instance *fi)
 849 {
 850         struct f_serial_opts *opts;
 851
 852         opts = container_of(fi, struct f_serial_opts, func_inst);
 853         gserial_free_line(opts->port_num);
 854         kfree(opts);
 855 }
 856
 857 static struct usb_function_instance *acm_alloc_instance(void)
 858 {
 859         struct f_serial_opts *opts;
 860         int ret;
 861
 862         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 863         if (!opts)
 864                 return ERR_PTR(-ENOMEM);
 865         opts->func_inst.free_func_inst = acm_free_instance;
 866         ret = gserial_alloc_line(&opts->port_num);
 867         if (ret) {
 868                 kfree(opts);
 869                 return ERR_PTR(ret);
 870         }
 871         config_group_init_type_name(&opts->func_inst.group, "",
 872                         &acm_func_type);
 873         return &opts->func_inst;
 874 }
 875 DECLARE_USB_FUNCTION_INIT(acm, acm_alloc_instance, acm_alloc_func);
 876 MODULE_LICENSE("GPL");