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f_acm.c
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linux-6.19.14/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/cleanup.h> 15#include <linux/slab.h> 16#include <linux/kernel.h> 17#include <linux/module.h> 18#include <linux/device.h> 19#include <linux/err.h> 20 21#include <linux/usb/gadget.h> 22 23#include "u_serial.h" 24 25 26/* 27 * This CDC ACM function support just wraps control functions and 28 * notifications around the generic serial-over-usb code. 29 * 30 * Because CDC ACM is standardized by the USB-IF, many host operating 31 * systems have drivers for it. Accordingly, ACM is the preferred 32 * interop solution for serial-port type connections. The control 33 * models are often not necessary, and in any case don't do much in 34 * this bare-bones implementation. 35 * 36 * Note that even MS-Windows has some support for ACM. However, that 37 * support is somewhat broken because when you use ACM in a composite 38 * device, having multiple interfaces confuses the poor OS. It doesn't 39 * seem to understand CDC Union descriptors. The new "association" 40 * descriptors (roughly equivalent to CDC Unions) may sometimes help. 41 */ 42 43struct f_acm { 44 struct gserial port; 45 u8 ctrl_id, data_id; 46 u8 port_num; 47 u8 bInterfaceProtocol; 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 /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */ 65 u16 serial_state; 66}; 67 68static inline struct f_acm *func_to_acm(struct usb_function *f) 69{ 70 return container_of(f, struct f_acm, port.func); 71} 72 73static inline struct f_acm *port_to_acm(struct gserial *p) 74{ 75 return container_of(p, struct f_acm, port); 76} 77 78/*-------------------------------------------------------------------------*/ 79 80/* notification endpoint uses smallish and infrequent fixed-size messages */ 81 82#define GS_NOTIFY_INTERVAL_MS 32 83#define GS_NOTIFY_MAXPACKET 10 /* notification + 2 bytes */ 84 85/* interface and class descriptors: */ 86 87static struct usb_interface_assoc_descriptor 88acm_iad_descriptor = { 89 .bLength = sizeof acm_iad_descriptor, 90 .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION, 91 92 /* .bFirstInterface = DYNAMIC, */ 93 .bInterfaceCount = 2, // control + data 94 .bFunctionClass = USB_CLASS_COMM, 95 .bFunctionSubClass = USB_CDC_SUBCLASS_ACM, 96 /* .bFunctionProtocol = DYNAMIC */ 97 /* .iFunction = DYNAMIC */ 98}; 99 100 101static struct usb_interface_descriptor acm_control_interface_desc = { 102 .bLength = USB_DT_INTERFACE_SIZE, 103 .bDescriptorType = USB_DT_INTERFACE, 104 /* .bInterfaceNumber = DYNAMIC */ 105 .bNumEndpoints = 1, 106 .bInterfaceClass = USB_CLASS_COMM, 107 .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM, 108 /* .bInterfaceProtocol = DYNAMIC */ 109 /* .iInterface = DYNAMIC */ 110}; 111 112static struct usb_interface_descriptor acm_data_interface_desc = { 113 .bLength = USB_DT_INTERFACE_SIZE, 114 .bDescriptorType = USB_DT_INTERFACE, 115 /* .bInterfaceNumber = DYNAMIC */ 116 .bNumEndpoints = 2, 117 .bInterfaceClass = USB_CLASS_CDC_DATA, 118 .bInterfaceSubClass = 0, 119 .bInterfaceProtocol = 0, 120 /* .iInterface = DYNAMIC */ 121}; 122 123static struct usb_cdc_header_desc acm_header_desc = { 124 .bLength = sizeof(acm_header_desc), 125 .bDescriptorType = USB_DT_CS_INTERFACE, 126 .bDescriptorSubType = USB_CDC_HEADER_TYPE, 127 .bcdCDC = cpu_to_le16(0x0110), 128}; 129 130static struct usb_cdc_call_mgmt_descriptor 131acm_call_mgmt_descriptor = { 132 .bLength = sizeof(acm_call_mgmt_descriptor), 133 .bDescriptorType = USB_DT_CS_INTERFACE, 134 .bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE, 135 .bmCapabilities = 0, 136 /* .bDataInterface = DYNAMIC */ 137}; 138 139static struct usb_cdc_acm_descriptor acm_descriptor = { 140 .bLength = sizeof(acm_descriptor), 141 .bDescriptorType = USB_DT_CS_INTERFACE, 142 .bDescriptorSubType = USB_CDC_ACM_TYPE, 143 .bmCapabilities = USB_CDC_CAP_LINE, 144}; 145 146static struct usb_cdc_union_desc acm_union_desc = { 147 .bLength = sizeof(acm_union_desc), 148 .bDescriptorType = USB_DT_CS_INTERFACE, 149 .bDescriptorSubType = USB_CDC_UNION_TYPE, 150 /* .bMasterInterface0 = DYNAMIC */ 151 /* .bSlaveInterface0 = DYNAMIC */ 152}; 153 154/* full speed support: */ 155 156static struct usb_endpoint_descriptor acm_fs_notify_desc = { 157 .bLength = USB_DT_ENDPOINT_SIZE, 158 .bDescriptorType = USB_DT_ENDPOINT, 159 .bEndpointAddress = USB_DIR_IN, 160 .bmAttributes = USB_ENDPOINT_XFER_INT, 161 .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET), 162 .bInterval = GS_NOTIFY_INTERVAL_MS, 163}; 164 165static struct usb_endpoint_descriptor acm_fs_in_desc = { 166 .bLength = USB_DT_ENDPOINT_SIZE, 167 .bDescriptorType = USB_DT_ENDPOINT, 168 .bEndpointAddress = USB_DIR_IN, 169 .bmAttributes = USB_ENDPOINT_XFER_BULK, 170}; 171 172static struct usb_endpoint_descriptor acm_fs_out_desc = { 173 .bLength = USB_DT_ENDPOINT_SIZE, 174 .bDescriptorType = USB_DT_ENDPOINT, 175 .bEndpointAddress = USB_DIR_OUT, 176 .bmAttributes = USB_ENDPOINT_XFER_BULK, 177}; 178 179static struct usb_descriptor_header *acm_fs_function[] = { 180 (struct usb_descriptor_header *) &acm_iad_descriptor, 181 (struct usb_descriptor_header *) &acm_control_interface_desc, 182 (struct usb_descriptor_header *) &acm_header_desc, 183 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor, 184 (struct usb_descriptor_header *) &acm_descriptor, 185 (struct usb_descriptor_header *) &acm_union_desc, 186 (struct usb_descriptor_header *) &acm_fs_notify_desc, 187 (struct usb_descriptor_header *) &acm_data_interface_desc, 188 (struct usb_descriptor_header *) &acm_fs_in_desc, 189 (struct usb_descriptor_header *) &acm_fs_out_desc, 190 NULL, 191}; 192 193/* high speed support: */ 194static struct usb_endpoint_descriptor acm_hs_notify_desc = { 195 .bLength = USB_DT_ENDPOINT_SIZE, 196 .bDescriptorType = USB_DT_ENDPOINT, 197 .bEndpointAddress = USB_DIR_IN, 198 .bmAttributes = USB_ENDPOINT_XFER_INT, 199 .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET), 200 .bInterval = USB_MS_TO_HS_INTERVAL(GS_NOTIFY_INTERVAL_MS), 201}; 202 203static struct usb_endpoint_descriptor acm_hs_in_desc = { 204 .bLength = USB_DT_ENDPOINT_SIZE, 205 .bDescriptorType = USB_DT_ENDPOINT, 206 .bmAttributes = USB_ENDPOINT_XFER_BULK, 207 .wMaxPacketSize = cpu_to_le16(512), 208}; 209 210static struct usb_endpoint_descriptor acm_hs_out_desc = { 211 .bLength = USB_DT_ENDPOINT_SIZE, 212 .bDescriptorType = USB_DT_ENDPOINT, 213 .bmAttributes = USB_ENDPOINT_XFER_BULK, 214 .wMaxPacketSize = cpu_to_le16(512), 215}; 216 217static struct usb_descriptor_header *acm_hs_function[] = { 218 (struct usb_descriptor_header *) &acm_iad_descriptor, 219 (struct usb_descriptor_header *) &acm_control_interface_desc, 220 (struct usb_descriptor_header *) &acm_header_desc, 221 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor, 222 (struct usb_descriptor_header *) &acm_descriptor, 223 (struct usb_descriptor_header *) &acm_union_desc, 224 (struct usb_descriptor_header *) &acm_hs_notify_desc, 225 (struct usb_descriptor_header *) &acm_data_interface_desc, 226 (struct usb_descriptor_header *) &acm_hs_in_desc, 227 (struct usb_descriptor_header *) &acm_hs_out_desc, 228 NULL, 229}; 230 231static struct usb_endpoint_descriptor acm_ss_in_desc = { 232 .bLength = USB_DT_ENDPOINT_SIZE, 233 .bDescriptorType = USB_DT_ENDPOINT, 234 .bmAttributes = USB_ENDPOINT_XFER_BULK, 235 .wMaxPacketSize = cpu_to_le16(1024), 236}; 237 238static struct usb_endpoint_descriptor acm_ss_out_desc = { 239 .bLength = USB_DT_ENDPOINT_SIZE, 240 .bDescriptorType = USB_DT_ENDPOINT, 241 .bmAttributes = USB_ENDPOINT_XFER_BULK, 242 .wMaxPacketSize = cpu_to_le16(1024), 243}; 244 245static struct usb_ss_ep_comp_descriptor acm_ss_bulk_comp_desc = { 246 .bLength = sizeof acm_ss_bulk_comp_desc, 247 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, 248}; 249 250static struct usb_descriptor_header *acm_ss_function[] = { 251 (struct usb_descriptor_header *) &acm_iad_descriptor, 252 (struct usb_descriptor_header *) &acm_control_interface_desc, 253 (struct usb_descriptor_header *) &acm_header_desc, 254 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor, 255 (struct usb_descriptor_header *) &acm_descriptor, 256 (struct usb_descriptor_header *) &acm_union_desc, 257 (struct usb_descriptor_header *) &acm_hs_notify_desc, 258 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc, 259 (struct usb_descriptor_header *) &acm_data_interface_desc, 260 (struct usb_descriptor_header *) &acm_ss_in_desc, 261 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc, 262 (struct usb_descriptor_header *) &acm_ss_out_desc, 263 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc, 264 NULL, 265}; 266 267/* string descriptors: */ 268 269#define ACM_CTRL_IDX 0 270#define ACM_DATA_IDX 1 271#define ACM_IAD_IDX 2 272 273/* static strings, in UTF-8 */ 274static struct usb_string acm_string_defs[] = { 275 [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)", 276 [ACM_DATA_IDX].s = "CDC ACM Data", 277 [ACM_IAD_IDX ].s = "CDC Serial", 278 { } /* end of list */ 279}; 280 281static struct usb_gadget_strings acm_string_table = { 282 .language = 0x0409, /* en-us */ 283 .strings = acm_string_defs, 284}; 285 286static struct usb_gadget_strings *acm_strings[] = { 287 &acm_string_table, 288 NULL, 289}; 290 291/*-------------------------------------------------------------------------*/ 292 293/* ACM control ... data handling is delegated to tty library code. 294 * The main task of this function is to activate and deactivate 295 * that code based on device state; track parameters like line 296 * speed, handshake state, and so on; and issue notifications. 297 */ 298 299static void acm_complete_set_line_coding(struct usb_ep *ep, 300 struct usb_request *req) 301{ 302 struct f_acm *acm = ep->driver_data; 303 struct usb_composite_dev *cdev = acm->port.func.config->cdev; 304 305 if (req->status != 0) { 306 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d completion, err %d\n", 307 acm->port_num, req->status); 308 return; 309 } 310 311 /* normal completion */ 312 if (req->actual != sizeof(acm->port_line_coding)) { 313 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d short resp, len %d\n", 314 acm->port_num, req->actual); 315 usb_ep_set_halt(ep); 316 } else { 317 struct usb_cdc_line_coding *value = req->buf; 318 319 /* REVISIT: we currently just remember this data. 320 * If we change that, (a) validate it first, then 321 * (b) update whatever hardware needs updating, 322 * (c) worry about locking. This is information on 323 * the order of 9600-8-N-1 ... most of which means 324 * nothing unless we control a real RS232 line. 325 */ 326 acm->port_line_coding = *value; 327 } 328} 329 330static int acm_send_break(struct gserial *port, int duration); 331 332static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl) 333{ 334 struct f_acm *acm = func_to_acm(f); 335 struct usb_composite_dev *cdev = f->config->cdev; 336 struct usb_request *req = cdev->req; 337 int value = -EOPNOTSUPP; 338 u16 w_index = le16_to_cpu(ctrl->wIndex); 339 u16 w_value = le16_to_cpu(ctrl->wValue); 340 u16 w_length = le16_to_cpu(ctrl->wLength); 341 342 /* composite driver infrastructure handles everything except 343 * CDC class messages; interface activation uses set_alt(). 344 * 345 * Note CDC spec table 4 lists the ACM request profile. It requires 346 * encapsulated command support ... we don't handle any, and respond 347 * to them by stalling. Options include get/set/clear comm features 348 * (not that useful) and SEND_BREAK. 349 */ 350 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) { 351 352 /* SET_LINE_CODING ... just read and save what the host sends */ 353 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8) 354 | USB_CDC_REQ_SET_LINE_CODING: 355 if (w_length != sizeof(struct usb_cdc_line_coding) 356 || w_index != acm->ctrl_id) 357 goto invalid; 358 359 value = w_length; 360 cdev->gadget->ep0->driver_data = acm; 361 req->complete = acm_complete_set_line_coding; 362 break; 363 364 /* GET_LINE_CODING ... return what host sent, or initial value */ 365 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8) 366 | USB_CDC_REQ_GET_LINE_CODING: 367 if (w_index != acm->ctrl_id) 368 goto invalid; 369 370 value = min_t(unsigned, w_length, 371 sizeof(struct usb_cdc_line_coding)); 372 memcpy(req->buf, &acm->port_line_coding, value); 373 break; 374 375 /* SET_CONTROL_LINE_STATE ... save what the host sent */ 376 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8) 377 | USB_CDC_REQ_SET_CONTROL_LINE_STATE: 378 if (w_index != acm->ctrl_id) 379 goto invalid; 380 381 value = 0; 382 383 /* FIXME we should not allow data to flow until the 384 * host sets the USB_CDC_CTRL_DTR bit; and when it clears 385 * that bit, we should return to that no-flow state. 386 */ 387 acm->port_handshake_bits = w_value; 388 break; 389 390 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8) 391 | USB_CDC_REQ_SEND_BREAK: 392 if (w_index != acm->ctrl_id) 393 goto invalid; 394 395 acm_send_break(&acm->port, w_value); 396 break; 397 398 default: 399invalid: 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 424static 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->enabled) { 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); 443 444 } else if (intf == acm->data_id) { 445 if (acm->notify->enabled) { 446 dev_dbg(&cdev->gadget->dev, 447 "reset acm ttyGS%d\n", acm->port_num); 448 gserial_disconnect(&acm->port); 449 } 450 if (!acm->port.in->desc || !acm->port.out->desc) { 451 dev_dbg(&cdev->gadget->dev, 452 "activate acm ttyGS%d\n", acm->port_num); 453 if (config_ep_by_speed(cdev->gadget, f, 454 acm->port.in) || 455 config_ep_by_speed(cdev->gadget, f, 456 acm->port.out)) { 457 acm->port.in->desc = NULL; 458 acm->port.out->desc = NULL; 459 return -EINVAL; 460 } 461 } 462 gserial_connect(&acm->port, acm->port_num); 463 464 } else 465 return -EINVAL; 466 467 return 0; 468} 469 470static void acm_disable(struct usb_function *f) 471{ 472 struct f_acm *acm = func_to_acm(f); 473 struct usb_composite_dev *cdev = f->config->cdev; 474 475 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d deactivated\n", acm->port_num); 476 gserial_disconnect(&acm->port); 477 usb_ep_disable(acm->notify); 478} 479 480/*-------------------------------------------------------------------------*/ 481 482/** 483 * acm_cdc_notify - issue CDC notification to host 484 * @acm: wraps host to be notified 485 * @type: notification type 486 * @value: Refer to cdc specs, wValue field. 487 * @data: data to be sent 488 * @length: size of data 489 * Context: irqs blocked, acm->lock held, acm_notify_req non-null 490 * 491 * Returns zero on success or a negative errno. 492 * 493 * See section 6.3.5 of the CDC 1.1 specification for information 494 * about the only notification we issue: SerialState change. 495 */ 496static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value, 497 void *data, unsigned length) 498{ 499 struct usb_ep *ep = acm->notify; 500 struct usb_request *req; 501 struct usb_cdc_notification *notify; 502 const unsigned len = sizeof(*notify) + length; 503 void *buf; 504 int status; 505 506 req = acm->notify_req; 507 acm->notify_req = NULL; 508 acm->pending = false; 509 510 req->length = len; 511 notify = req->buf; 512 buf = notify + 1; 513 514 notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS 515 | USB_RECIP_INTERFACE; 516 notify->bNotificationType = type; 517 notify->wValue = cpu_to_le16(value); 518 notify->wIndex = cpu_to_le16(acm->ctrl_id); 519 notify->wLength = cpu_to_le16(length); 520 memcpy(buf, data, length); 521 522 /* ep_queue() can complete immediately if it fills the fifo... */ 523 spin_unlock(&acm->lock); 524 status = usb_ep_queue(ep, req, GFP_ATOMIC); 525 spin_lock(&acm->lock); 526 527 if (status < 0) { 528 ERROR(acm->port.func.config->cdev, 529 "acm ttyGS%d can't notify serial state, %d\n", 530 acm->port_num, status); 531 acm->notify_req = req; 532 } 533 534 return status; 535} 536 537static int acm_notify_serial_state(struct f_acm *acm) 538{ 539 struct usb_composite_dev *cdev = acm->port.func.config->cdev; 540 int status; 541 __le16 serial_state; 542 543 spin_lock(&acm->lock); 544 if (acm->notify_req) { 545 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d serial state %04x\n", 546 acm->port_num, acm->serial_state); 547 serial_state = cpu_to_le16(acm->serial_state); 548 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE, 549 0, &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 558static 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 578static void acm_connect(struct gserial *port) 579{ 580 struct f_acm *acm = port_to_acm(port); 581 582 acm->serial_state |= USB_CDC_SERIAL_STATE_DSR | USB_CDC_SERIAL_STATE_DCD; 583 acm_notify_serial_state(acm); 584} 585 586static void acm_disconnect(struct gserial *port) 587{ 588 struct f_acm *acm = port_to_acm(port); 589 590 acm->serial_state &= ~(USB_CDC_SERIAL_STATE_DSR | USB_CDC_SERIAL_STATE_DCD); 591 acm_notify_serial_state(acm); 592} 593 594static 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 &= ~USB_CDC_SERIAL_STATE_BREAK; 601 if (duration) 602 state |= USB_CDC_SERIAL_STATE_BREAK; 603 604 acm->serial_state = state; 605 return acm_notify_serial_state(acm); 606} 607 608/*-------------------------------------------------------------------------*/ 609 610/* ACM function driver setup/binding */ 611static int 612acm_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 struct usb_request *request __free(free_usb_request) = NULL; 620 621 /* REVISIT might want instance-specific strings to help 622 * distinguish instances ... 623 */ 624 625 /* maybe allocate device-global string IDs, and patch descriptors */ 626 us = usb_gstrings_attach(cdev, acm_strings, 627 ARRAY_SIZE(acm_string_defs)); 628 if (IS_ERR(us)) 629 return PTR_ERR(us); 630 acm_control_interface_desc.iInterface = us[ACM_CTRL_IDX].id; 631 acm_data_interface_desc.iInterface = us[ACM_DATA_IDX].id; 632 acm_iad_descriptor.iFunction = us[ACM_IAD_IDX].id; 633 634 /* allocate instance-specific interface IDs, and patch descriptors */ 635 status = usb_interface_id(c, f); 636 if (status < 0) 637 return status; 638 acm->ctrl_id = status; 639 acm_iad_descriptor.bFirstInterface = status; 640 641 acm_control_interface_desc.bInterfaceNumber = status; 642 acm_union_desc .bMasterInterface0 = status; 643 644 status = usb_interface_id(c, f); 645 if (status < 0) 646 return status; 647 acm->data_id = status; 648 649 acm_data_interface_desc.bInterfaceNumber = status; 650 acm_union_desc.bSlaveInterface0 = status; 651 acm_call_mgmt_descriptor.bDataInterface = status; 652 653 /* allocate instance-specific endpoints */ 654 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc); 655 if (!ep) 656 return -ENODEV; 657 acm->port.in = ep; 658 659 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc); 660 if (!ep) 661 return -ENODEV; 662 acm->port.out = ep; 663 664 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc); 665 if (!ep) 666 return -ENODEV; 667 acm->notify = ep; 668 669 acm_iad_descriptor.bFunctionProtocol = acm->bInterfaceProtocol; 670 acm_control_interface_desc.bInterfaceProtocol = acm->bInterfaceProtocol; 671 672 /* allocate notification */ 673 request = gs_alloc_req(ep, 674 sizeof(struct usb_cdc_notification) + 2, 675 GFP_KERNEL); 676 if (!request) 677 return -ENODEV; 678 679 request->complete = acm_cdc_notify_complete; 680 request->context = acm; 681 682 /* support all relevant hardware speeds... we expect that when 683 * hardware is dual speed, all bulk-capable endpoints work at 684 * both speeds 685 */ 686 acm_hs_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress; 687 acm_hs_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress; 688 acm_hs_notify_desc.bEndpointAddress = 689 acm_fs_notify_desc.bEndpointAddress; 690 691 acm_ss_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress; 692 acm_ss_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress; 693 694 status = usb_assign_descriptors(f, acm_fs_function, acm_hs_function, 695 acm_ss_function, acm_ss_function); 696 if (status) 697 return status; 698 699 acm->notify_req = no_free_ptr(request); 700 701 dev_dbg(&cdev->gadget->dev, 702 "acm ttyGS%d: IN/%s OUT/%s NOTIFY/%s\n", 703 acm->port_num, 704 acm->port.in->name, acm->port.out->name, 705 acm->notify->name); 706 return 0; 707} 708 709static 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 719static void acm_free_func(struct usb_function *f) 720{ 721 struct f_acm *acm = func_to_acm(f); 722 struct f_serial_opts *opts; 723 724 opts = container_of(f->fi, struct f_serial_opts, func_inst); 725 726 kfree(acm); 727 mutex_lock(&opts->lock); 728 opts->instances--; 729 mutex_unlock(&opts->lock); 730} 731 732static void acm_resume(struct usb_function *f) 733{ 734 struct f_acm *acm = func_to_acm(f); 735 736 gserial_resume(&acm->port); 737} 738 739static void acm_suspend(struct usb_function *f) 740{ 741 struct f_acm *acm = func_to_acm(f); 742 743 gserial_suspend(&acm->port); 744} 745 746static struct usb_function *acm_alloc_func(struct usb_function_instance *fi) 747{ 748 struct f_serial_opts *opts; 749 struct f_acm *acm; 750 751 acm = kzalloc(sizeof(*acm), GFP_KERNEL); 752 if (!acm) 753 return ERR_PTR(-ENOMEM); 754 755 spin_lock_init(&acm->lock); 756 757 acm->port.connect = acm_connect; 758 acm->port.disconnect = acm_disconnect; 759 acm->port.send_break = acm_send_break; 760 761 acm->port.func.name = "acm"; 762 acm->port.func.strings = acm_strings; 763 /* descriptors are per-instance copies */ 764 acm->port.func.bind = acm_bind; 765 acm->port.func.set_alt = acm_set_alt; 766 acm->port.func.setup = acm_setup; 767 acm->port.func.disable = acm_disable; 768 769 opts = container_of(fi, struct f_serial_opts, func_inst); 770 mutex_lock(&opts->lock); 771 acm->port_num = opts->port_num; 772 acm->bInterfaceProtocol = opts->protocol; 773 opts->instances++; 774 mutex_unlock(&opts->lock); 775 acm->port.func.unbind = acm_unbind; 776 acm->port.func.free_func = acm_free_func; 777 acm->port.func.resume = acm_resume; 778 acm->port.func.suspend = acm_suspend; 779 780 return &acm->port.func; 781} 782 783static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item) 784{ 785 return container_of(to_config_group(item), struct f_serial_opts, 786 func_inst.group); 787} 788 789static void acm_attr_release(struct config_item *item) 790{ 791 struct f_serial_opts *opts = to_f_serial_opts(item); 792 793 usb_put_function_instance(&opts->func_inst); 794} 795 796static struct configfs_item_operations acm_item_ops = { 797 .release = acm_attr_release, 798}; 799 800#ifdef CONFIG_U_SERIAL_CONSOLE 801 802static ssize_t f_acm_console_store(struct config_item *item, 803 const char *page, size_t count) 804{ 805 return gserial_set_console(to_f_serial_opts(item)->port_num, 806 page, count); 807} 808 809static ssize_t f_acm_console_show(struct config_item *item, char *page) 810{ 811 return gserial_get_console(to_f_serial_opts(item)->port_num, page); 812} 813 814CONFIGFS_ATTR(f_acm_, console); 815 816#endif /* CONFIG_U_SERIAL_CONSOLE */ 817 818static ssize_t f_acm_port_num_show(struct config_item *item, char *page) 819{ 820 return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num); 821} 822 823CONFIGFS_ATTR_RO(f_acm_, port_num); 824 825static ssize_t f_acm_protocol_show(struct config_item *item, char *page) 826{ 827 return sprintf(page, "%u\n", to_f_serial_opts(item)->protocol); 828} 829 830static ssize_t f_acm_protocol_store(struct config_item *item, 831 const char *page, size_t count) 832{ 833 struct f_serial_opts *opts = to_f_serial_opts(item); 834 int ret; 835 836 mutex_lock(&opts->lock); 837 838 if (opts->instances) { 839 ret = -EBUSY; 840 goto out; 841 } 842 843 ret = kstrtou8(page, 0, &opts->protocol); 844 if (ret) 845 goto out; 846 ret = count; 847 848out: 849 mutex_unlock(&opts->lock); 850 return ret; 851} 852 853CONFIGFS_ATTR(f_acm_, protocol); 854 855static struct configfs_attribute *acm_attrs[] = { 856#ifdef CONFIG_U_SERIAL_CONSOLE 857 &f_acm_attr_console, 858#endif 859 &f_acm_attr_port_num, 860 &f_acm_attr_protocol, 861 NULL, 862}; 863 864static const struct config_item_type acm_func_type = { 865 .ct_item_ops = &acm_item_ops, 866 .ct_attrs = acm_attrs, 867 .ct_owner = THIS_MODULE, 868}; 869 870static void acm_free_instance(struct usb_function_instance *fi) 871{ 872 struct f_serial_opts *opts; 873 874 opts = container_of(fi, struct f_serial_opts, func_inst); 875 gserial_free_line(opts->port_num); 876 mutex_destroy(&opts->lock); 877 kfree(opts); 878} 879 880static struct usb_function_instance *acm_alloc_instance(void) 881{ 882 struct f_serial_opts *opts; 883 int ret; 884 885 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 886 if (!opts) 887 return ERR_PTR(-ENOMEM); 888 opts->protocol = USB_CDC_ACM_PROTO_AT_V25TER; 889 opts->func_inst.free_func_inst = acm_free_instance; 890 mutex_init(&opts->lock); 891 ret = gserial_alloc_line(&opts->port_num); 892 if (ret) { 893 kfree(opts); 894 return ERR_PTR(ret); 895 } 896 config_group_init_type_name(&opts->func_inst.group, "", 897 &acm_func_type); 898 return &opts->func_inst; 899} 900DECLARE_USB_FUNCTION_INIT(acm, acm_alloc_instance, acm_alloc_func); 901MODULE_DESCRIPTION("USB CDC serial (ACM) function driver"); 902MODULE_LICENSE("GPL");
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