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 (m.nazarewicz@samsung.com)
9 *
10 * This software is distributed under the terms of the GNU General
11 * Public License ("GPL") as published by the Free Software Foundation,
12 * either version 2 of that License or (at your option) any later version.
13 */
14
15 /* #define VERBOSE_DEBUG */
16
17 #include <linux/slab.h>
18 #include <linux/kernel.h>
19 #include <linux/device.h>
20
21 #include "u_serial.h"
22 #include "gadget_chips.h"
23
24
25 /*
26 * This CDC ACM function support just wraps control functions and
27 * notifications around the generic serial-over-usb code.
28 *
29 * Because CDC ACM is standardized by the USB-IF, many host operating
30 * systems have drivers for it. Accordingly, ACM is the preferred
31 * interop solution for serial-port type connections. The control
32 * models are often not necessary, and in any case don't do much in
33 * this bare-bones implementation.
34 *
35 * Note that even MS-Windows has some support for ACM. However, that
36 * support is somewhat broken because when you use ACM in a composite
37 * device, having multiple interfaces confuses the poor OS. It doesn't
38 * seem to understand CDC Union descriptors. The new "association"
39 * descriptors (roughly equivalent to CDC Unions) may sometimes help.
40 */
41
42 struct f_acm {
43 struct gserial port;
44 u8 ctrl_id, data_id;
45 u8 port_num;
46
47 u8 pending;
48
49 /* lock is mostly for pending and notify_req ... they get accessed
50 * by callbacks both from tty (open/close/break) under its spinlock,
51 * and notify_req.complete() which can't use that lock.
52 */
53 spinlock_t lock;
54
55 struct usb_ep *notify;
56 struct usb_request *notify_req;
57
58 struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */
59
60 /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
61 u16 port_handshake_bits;
62 #define ACM_CTRL_RTS (1 << 1) /* unused with full duplex */
63 #define ACM_CTRL_DTR (1 << 0) /* host is ready for data r/w */
64
65 /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
66 u16 serial_state;
67 #define ACM_CTRL_OVERRUN (1 << 6)
68 #define ACM_CTRL_PARITY (1 << 5)
69 #define ACM_CTRL_FRAMING (1 << 4)
70 #define ACM_CTRL_RI (1 << 3)
71 #define ACM_CTRL_BRK (1 << 2)
72 #define ACM_CTRL_DSR (1 << 1)
73 #define ACM_CTRL_DCD (1 << 0)
74 };
75
func_to_acm(struct usb_function * f)76 static inline struct f_acm *func_to_acm(struct usb_function *f)
77 {
78 return container_of(f, struct f_acm, port.func);
79 }
80
port_to_acm(struct gserial * p)81 static inline struct f_acm *port_to_acm(struct gserial *p)
82 {
83 return container_of(p, struct f_acm, port);
84 }
85
86 /*-------------------------------------------------------------------------*/
87
88 /* notification endpoint uses smallish and infrequent fixed-size messages */
89
90 #define GS_LOG2_NOTIFY_INTERVAL 5 /* 1 << 5 == 32 msec */
91 #define GS_NOTIFY_MAXPACKET 10 /* notification + 2 bytes */
92
93 /* interface and class descriptors: */
94
95 static struct usb_interface_assoc_descriptor
96 acm_iad_descriptor = {
97 .bLength = sizeof acm_iad_descriptor,
98 .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
99
100 /* .bFirstInterface = DYNAMIC, */
101 .bInterfaceCount = 2, // control + data
102 .bFunctionClass = USB_CLASS_COMM,
103 .bFunctionSubClass = USB_CDC_SUBCLASS_ACM,
104 .bFunctionProtocol = USB_CDC_ACM_PROTO_AT_V25TER,
105 /* .iFunction = DYNAMIC */
106 };
107
108
109 static struct usb_interface_descriptor acm_control_interface_desc = {
110 .bLength = USB_DT_INTERFACE_SIZE,
111 .bDescriptorType = USB_DT_INTERFACE,
112 /* .bInterfaceNumber = DYNAMIC */
113 .bNumEndpoints = 1,
114 .bInterfaceClass = USB_CLASS_COMM,
115 .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
116 .bInterfaceProtocol = USB_CDC_ACM_PROTO_AT_V25TER,
117 /* .iInterface = DYNAMIC */
118 };
119
120 static struct usb_interface_descriptor acm_data_interface_desc = {
121 .bLength = USB_DT_INTERFACE_SIZE,
122 .bDescriptorType = USB_DT_INTERFACE,
123 /* .bInterfaceNumber = DYNAMIC */
124 .bNumEndpoints = 2,
125 .bInterfaceClass = USB_CLASS_CDC_DATA,
126 .bInterfaceSubClass = 0,
127 .bInterfaceProtocol = 0,
128 /* .iInterface = DYNAMIC */
129 };
130
131 static struct usb_cdc_header_desc acm_header_desc = {
132 .bLength = sizeof(acm_header_desc),
133 .bDescriptorType = USB_DT_CS_INTERFACE,
134 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
135 .bcdCDC = cpu_to_le16(0x0110),
136 };
137
138 static struct usb_cdc_call_mgmt_descriptor
139 acm_call_mgmt_descriptor = {
140 .bLength = sizeof(acm_call_mgmt_descriptor),
141 .bDescriptorType = USB_DT_CS_INTERFACE,
142 .bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE,
143 .bmCapabilities = 0,
144 /* .bDataInterface = DYNAMIC */
145 };
146
147 static struct usb_cdc_acm_descriptor acm_descriptor = {
148 .bLength = sizeof(acm_descriptor),
149 .bDescriptorType = USB_DT_CS_INTERFACE,
150 .bDescriptorSubType = USB_CDC_ACM_TYPE,
151 .bmCapabilities = USB_CDC_CAP_LINE,
152 };
153
154 static struct usb_cdc_union_desc acm_union_desc = {
155 .bLength = sizeof(acm_union_desc),
156 .bDescriptorType = USB_DT_CS_INTERFACE,
157 .bDescriptorSubType = USB_CDC_UNION_TYPE,
158 /* .bMasterInterface0 = DYNAMIC */
159 /* .bSlaveInterface0 = DYNAMIC */
160 };
161
162 /* full speed support: */
163
164 static struct usb_endpoint_descriptor acm_fs_notify_desc = {
165 .bLength = USB_DT_ENDPOINT_SIZE,
166 .bDescriptorType = USB_DT_ENDPOINT,
167 .bEndpointAddress = USB_DIR_IN,
168 .bmAttributes = USB_ENDPOINT_XFER_INT,
169 .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET),
170 .bInterval = 1 << GS_LOG2_NOTIFY_INTERVAL,
171 };
172
173 static struct usb_endpoint_descriptor acm_fs_in_desc = {
174 .bLength = USB_DT_ENDPOINT_SIZE,
175 .bDescriptorType = USB_DT_ENDPOINT,
176 .bEndpointAddress = USB_DIR_IN,
177 .bmAttributes = USB_ENDPOINT_XFER_BULK,
178 };
179
180 static struct usb_endpoint_descriptor acm_fs_out_desc = {
181 .bLength = USB_DT_ENDPOINT_SIZE,
182 .bDescriptorType = USB_DT_ENDPOINT,
183 .bEndpointAddress = USB_DIR_OUT,
184 .bmAttributes = USB_ENDPOINT_XFER_BULK,
185 };
186
187 static struct usb_descriptor_header *acm_fs_function[] = {
188 (struct usb_descriptor_header *) &acm_iad_descriptor,
189 (struct usb_descriptor_header *) &acm_control_interface_desc,
190 (struct usb_descriptor_header *) &acm_header_desc,
191 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
192 (struct usb_descriptor_header *) &acm_descriptor,
193 (struct usb_descriptor_header *) &acm_union_desc,
194 (struct usb_descriptor_header *) &acm_fs_notify_desc,
195 (struct usb_descriptor_header *) &acm_data_interface_desc,
196 (struct usb_descriptor_header *) &acm_fs_in_desc,
197 (struct usb_descriptor_header *) &acm_fs_out_desc,
198 NULL,
199 };
200
201 /* high speed support: */
202
203 static struct usb_endpoint_descriptor acm_hs_notify_desc = {
204 .bLength = USB_DT_ENDPOINT_SIZE,
205 .bDescriptorType = USB_DT_ENDPOINT,
206 .bEndpointAddress = USB_DIR_IN,
207 .bmAttributes = USB_ENDPOINT_XFER_INT,
208 .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET),
209 .bInterval = GS_LOG2_NOTIFY_INTERVAL+4,
210 };
211
212 static struct usb_endpoint_descriptor acm_hs_in_desc = {
213 .bLength = USB_DT_ENDPOINT_SIZE,
214 .bDescriptorType = USB_DT_ENDPOINT,
215 .bmAttributes = USB_ENDPOINT_XFER_BULK,
216 .wMaxPacketSize = cpu_to_le16(512),
217 };
218
219 static struct usb_endpoint_descriptor acm_hs_out_desc = {
220 .bLength = USB_DT_ENDPOINT_SIZE,
221 .bDescriptorType = USB_DT_ENDPOINT,
222 .bmAttributes = USB_ENDPOINT_XFER_BULK,
223 .wMaxPacketSize = cpu_to_le16(512),
224 };
225
226 static struct usb_descriptor_header *acm_hs_function[] = {
227 (struct usb_descriptor_header *) &acm_iad_descriptor,
228 (struct usb_descriptor_header *) &acm_control_interface_desc,
229 (struct usb_descriptor_header *) &acm_header_desc,
230 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
231 (struct usb_descriptor_header *) &acm_descriptor,
232 (struct usb_descriptor_header *) &acm_union_desc,
233 (struct usb_descriptor_header *) &acm_hs_notify_desc,
234 (struct usb_descriptor_header *) &acm_data_interface_desc,
235 (struct usb_descriptor_header *) &acm_hs_in_desc,
236 (struct usb_descriptor_header *) &acm_hs_out_desc,
237 NULL,
238 };
239
240 /* string descriptors: */
241
242 #define ACM_CTRL_IDX 0
243 #define ACM_DATA_IDX 1
244 #define ACM_IAD_IDX 2
245
246 /* static strings, in UTF-8 */
247 static struct usb_string acm_string_defs[] = {
248 [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
249 [ACM_DATA_IDX].s = "CDC ACM Data",
250 [ACM_IAD_IDX ].s = "CDC Serial",
251 { /* ZEROES END LIST */ },
252 };
253
254 static struct usb_gadget_strings acm_string_table = {
255 .language = 0x0409, /* en-us */
256 .strings = acm_string_defs,
257 };
258
259 static struct usb_gadget_strings *acm_strings[] = {
260 &acm_string_table,
261 NULL,
262 };
263
264 /*-------------------------------------------------------------------------*/
265
266 /* ACM control ... data handling is delegated to tty library code.
267 * The main task of this function is to activate and deactivate
268 * that code based on device state; track parameters like line
269 * speed, handshake state, and so on; and issue notifications.
270 */
271
acm_complete_set_line_coding(struct usb_ep * ep,struct usb_request * req)272 static void acm_complete_set_line_coding(struct usb_ep *ep,
273 struct usb_request *req)
274 {
275 struct f_acm *acm = ep->driver_data;
276 struct usb_composite_dev *cdev = acm->port.func.config->cdev;
277
278 if (req->status != 0) {
279 DBG(cdev, "acm ttyGS%d completion, err %d\n",
280 acm->port_num, req->status);
281 return;
282 }
283
284 /* normal completion */
285 if (req->actual != sizeof(acm->port_line_coding)) {
286 DBG(cdev, "acm ttyGS%d short resp, len %d\n",
287 acm->port_num, req->actual);
288 usb_ep_set_halt(ep);
289 } else {
290 struct usb_cdc_line_coding *value = req->buf;
291
292 /* REVISIT: we currently just remember this data.
293 * If we change that, (a) validate it first, then
294 * (b) update whatever hardware needs updating,
295 * (c) worry about locking. This is information on
296 * the order of 9600-8-N-1 ... most of which means
297 * nothing unless we control a real RS232 line.
298 */
299 acm->port_line_coding = *value;
300 }
301 }
302
acm_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)303 static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
304 {
305 struct f_acm *acm = func_to_acm(f);
306 struct usb_composite_dev *cdev = f->config->cdev;
307 struct usb_request *req = cdev->req;
308 int value = -EOPNOTSUPP;
309 u16 w_index = le16_to_cpu(ctrl->wIndex);
310 u16 w_value = le16_to_cpu(ctrl->wValue);
311 u16 w_length = le16_to_cpu(ctrl->wLength);
312
313 /* composite driver infrastructure handles everything except
314 * CDC class messages; interface activation uses set_alt().
315 *
316 * Note CDC spec table 4 lists the ACM request profile. It requires
317 * encapsulated command support ... we don't handle any, and respond
318 * to them by stalling. Options include get/set/clear comm features
319 * (not that useful) and SEND_BREAK.
320 */
321 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
322
323 /* SET_LINE_CODING ... just read and save what the host sends */
324 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
325 | USB_CDC_REQ_SET_LINE_CODING:
326 if (w_length != sizeof(struct usb_cdc_line_coding)
327 || w_index != acm->ctrl_id)
328 goto invalid;
329
330 value = w_length;
331 cdev->gadget->ep0->driver_data = acm;
332 req->complete = acm_complete_set_line_coding;
333 break;
334
335 /* GET_LINE_CODING ... return what host sent, or initial value */
336 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
337 | USB_CDC_REQ_GET_LINE_CODING:
338 if (w_index != acm->ctrl_id)
339 goto invalid;
340
341 value = min_t(unsigned, w_length,
342 sizeof(struct usb_cdc_line_coding));
343 memcpy(req->buf, &acm->port_line_coding, value);
344 break;
345
346 /* SET_CONTROL_LINE_STATE ... save what the host sent */
347 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
348 | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
349 if (w_index != acm->ctrl_id)
350 goto invalid;
351
352 value = 0;
353
354 /* FIXME we should not allow data to flow until the
355 * host sets the ACM_CTRL_DTR bit; and when it clears
356 * that bit, we should return to that no-flow state.
357 */
358 acm->port_handshake_bits = w_value;
359 break;
360
361 default:
362 invalid:
363 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
364 ctrl->bRequestType, ctrl->bRequest,
365 w_value, w_index, w_length);
366 }
367
368 /* respond with data transfer or status phase? */
369 if (value >= 0) {
370 DBG(cdev, "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
371 acm->port_num, ctrl->bRequestType, ctrl->bRequest,
372 w_value, w_index, w_length);
373 req->zero = 0;
374 req->length = value;
375 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
376 if (value < 0)
377 ERROR(cdev, "acm response on ttyGS%d, err %d\n",
378 acm->port_num, value);
379 }
380
381 /* device either stalls (value < 0) or reports success */
382 return value;
383 }
384
acm_set_alt(struct usb_function * f,unsigned intf,unsigned alt)385 static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
386 {
387 struct f_acm *acm = func_to_acm(f);
388 struct usb_composite_dev *cdev = f->config->cdev;
389
390 /* we know alt == 0, so this is an activation or a reset */
391
392 if (intf == acm->ctrl_id) {
393 if (acm->notify->driver_data) {
394 VDBG(cdev, "reset acm control interface %d\n", intf);
395 usb_ep_disable(acm->notify);
396 } else {
397 VDBG(cdev, "init acm ctrl interface %d\n", intf);
398 if (config_ep_by_speed(cdev->gadget, f, acm->notify))
399 return -EINVAL;
400 }
401 usb_ep_enable(acm->notify);
402 acm->notify->driver_data = acm;
403
404 } else if (intf == acm->data_id) {
405 if (acm->port.in->driver_data) {
406 DBG(cdev, "reset acm ttyGS%d\n", acm->port_num);
407 gserial_disconnect(&acm->port);
408 }
409 if (!acm->port.in->desc || !acm->port.out->desc) {
410 DBG(cdev, "activate acm ttyGS%d\n", acm->port_num);
411 if (config_ep_by_speed(cdev->gadget, f,
412 acm->port.in) ||
413 config_ep_by_speed(cdev->gadget, f,
414 acm->port.out)) {
415 acm->port.in->desc = NULL;
416 acm->port.out->desc = NULL;
417 return -EINVAL;
418 }
419 }
420 gserial_connect(&acm->port, acm->port_num);
421
422 } else
423 return -EINVAL;
424
425 return 0;
426 }
427
acm_disable(struct usb_function * f)428 static void acm_disable(struct usb_function *f)
429 {
430 struct f_acm *acm = func_to_acm(f);
431 struct usb_composite_dev *cdev = f->config->cdev;
432
433 DBG(cdev, "acm ttyGS%d deactivated\n", acm->port_num);
434 gserial_disconnect(&acm->port);
435 usb_ep_disable(acm->notify);
436 acm->notify->driver_data = NULL;
437 }
438
439 /*-------------------------------------------------------------------------*/
440
441 /**
442 * acm_cdc_notify - issue CDC notification to host
443 * @acm: wraps host to be notified
444 * @type: notification type
445 * @value: Refer to cdc specs, wValue field.
446 * @data: data to be sent
447 * @length: size of data
448 * Context: irqs blocked, acm->lock held, acm_notify_req non-null
449 *
450 * Returns zero on success or a negative errno.
451 *
452 * See section 6.3.5 of the CDC 1.1 specification for information
453 * about the only notification we issue: SerialState change.
454 */
acm_cdc_notify(struct f_acm * acm,u8 type,u16 value,void * data,unsigned length)455 static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
456 void *data, unsigned length)
457 {
458 struct usb_ep *ep = acm->notify;
459 struct usb_request *req;
460 struct usb_cdc_notification *notify;
461 const unsigned len = sizeof(*notify) + length;
462 void *buf;
463 int status;
464
465 req = acm->notify_req;
466 acm->notify_req = NULL;
467 acm->pending = false;
468
469 req->length = len;
470 notify = req->buf;
471 buf = notify + 1;
472
473 notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
474 | USB_RECIP_INTERFACE;
475 notify->bNotificationType = type;
476 notify->wValue = cpu_to_le16(value);
477 notify->wIndex = cpu_to_le16(acm->ctrl_id);
478 notify->wLength = cpu_to_le16(length);
479 memcpy(buf, data, length);
480
481 /* ep_queue() can complete immediately if it fills the fifo... */
482 spin_unlock(&acm->lock);
483 status = usb_ep_queue(ep, req, GFP_ATOMIC);
484 spin_lock(&acm->lock);
485
486 if (status < 0) {
487 ERROR(acm->port.func.config->cdev,
488 "acm ttyGS%d can't notify serial state, %d\n",
489 acm->port_num, status);
490 acm->notify_req = req;
491 }
492
493 return status;
494 }
495
acm_notify_serial_state(struct f_acm * acm)496 static int acm_notify_serial_state(struct f_acm *acm)
497 {
498 struct usb_composite_dev *cdev = acm->port.func.config->cdev;
499 int status;
500
501 spin_lock(&acm->lock);
502 if (acm->notify_req) {
503 DBG(cdev, "acm ttyGS%d serial state %04x\n",
504 acm->port_num, acm->serial_state);
505 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
506 0, &acm->serial_state, sizeof(acm->serial_state));
507 } else {
508 acm->pending = true;
509 status = 0;
510 }
511 spin_unlock(&acm->lock);
512 return status;
513 }
514
acm_cdc_notify_complete(struct usb_ep * ep,struct usb_request * req)515 static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
516 {
517 struct f_acm *acm = req->context;
518 u8 doit = false;
519
520 /* on this call path we do NOT hold the port spinlock,
521 * which is why ACM needs its own spinlock
522 */
523 spin_lock(&acm->lock);
524 if (req->status != -ESHUTDOWN)
525 doit = acm->pending;
526 acm->notify_req = req;
527 spin_unlock(&acm->lock);
528
529 if (doit)
530 acm_notify_serial_state(acm);
531 }
532
533 /* connect == the TTY link is open */
534
acm_connect(struct gserial * port)535 static void acm_connect(struct gserial *port)
536 {
537 struct f_acm *acm = port_to_acm(port);
538
539 acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
540 acm_notify_serial_state(acm);
541 }
542
acm_disconnect(struct gserial * port)543 static void acm_disconnect(struct gserial *port)
544 {
545 struct f_acm *acm = port_to_acm(port);
546
547 acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
548 acm_notify_serial_state(acm);
549 }
550
acm_send_break(struct gserial * port,int duration)551 static int acm_send_break(struct gserial *port, int duration)
552 {
553 struct f_acm *acm = port_to_acm(port);
554 u16 state;
555
556 state = acm->serial_state;
557 state &= ~ACM_CTRL_BRK;
558 if (duration)
559 state |= ACM_CTRL_BRK;
560
561 acm->serial_state = state;
562 return acm_notify_serial_state(acm);
563 }
564
565 /*-------------------------------------------------------------------------*/
566
567 /* ACM function driver setup/binding */
568 static int
acm_bind(struct usb_configuration * c,struct usb_function * f)569 acm_bind(struct usb_configuration *c, struct usb_function *f)
570 {
571 struct usb_composite_dev *cdev = c->cdev;
572 struct f_acm *acm = func_to_acm(f);
573 int status;
574 struct usb_ep *ep;
575
576 /* allocate instance-specific interface IDs, and patch descriptors */
577 status = usb_interface_id(c, f);
578 if (status < 0)
579 goto fail;
580 acm->ctrl_id = status;
581 acm_iad_descriptor.bFirstInterface = status;
582
583 acm_control_interface_desc.bInterfaceNumber = status;
584 acm_union_desc .bMasterInterface0 = status;
585
586 status = usb_interface_id(c, f);
587 if (status < 0)
588 goto fail;
589 acm->data_id = status;
590
591 acm_data_interface_desc.bInterfaceNumber = status;
592 acm_union_desc.bSlaveInterface0 = status;
593 acm_call_mgmt_descriptor.bDataInterface = status;
594
595 status = -ENODEV;
596
597 /* allocate instance-specific endpoints */
598 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
599 if (!ep)
600 goto fail;
601 acm->port.in = ep;
602 ep->driver_data = cdev; /* claim */
603
604 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
605 if (!ep)
606 goto fail;
607 acm->port.out = ep;
608 ep->driver_data = cdev; /* claim */
609
610 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
611 if (!ep)
612 goto fail;
613 acm->notify = ep;
614 ep->driver_data = cdev; /* claim */
615
616 /* allocate notification */
617 acm->notify_req = gs_alloc_req(ep,
618 sizeof(struct usb_cdc_notification) + 2,
619 GFP_KERNEL);
620 if (!acm->notify_req)
621 goto fail;
622
623 acm->notify_req->complete = acm_cdc_notify_complete;
624 acm->notify_req->context = acm;
625
626 /* copy descriptors */
627 f->descriptors = usb_copy_descriptors(acm_fs_function);
628 if (!f->descriptors)
629 goto fail;
630
631 /* support all relevant hardware speeds... we expect that when
632 * hardware is dual speed, all bulk-capable endpoints work at
633 * both speeds
634 */
635 if (gadget_is_dualspeed(c->cdev->gadget)) {
636 acm_hs_in_desc.bEndpointAddress =
637 acm_fs_in_desc.bEndpointAddress;
638 acm_hs_out_desc.bEndpointAddress =
639 acm_fs_out_desc.bEndpointAddress;
640 acm_hs_notify_desc.bEndpointAddress =
641 acm_fs_notify_desc.bEndpointAddress;
642
643 /* copy descriptors */
644 f->hs_descriptors = usb_copy_descriptors(acm_hs_function);
645 }
646
647 DBG(cdev, "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
648 acm->port_num,
649 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
650 acm->port.in->name, acm->port.out->name,
651 acm->notify->name);
652 return 0;
653
654 fail:
655 if (acm->notify_req)
656 gs_free_req(acm->notify, acm->notify_req);
657
658 /* we might as well release our claims on endpoints */
659 if (acm->notify)
660 acm->notify->driver_data = NULL;
661 if (acm->port.out)
662 acm->port.out->driver_data = NULL;
663 if (acm->port.in)
664 acm->port.in->driver_data = NULL;
665
666 ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
667
668 return status;
669 }
670
671 static void
acm_unbind(struct usb_configuration * c,struct usb_function * f)672 acm_unbind(struct usb_configuration *c, struct usb_function *f)
673 {
674 struct f_acm *acm = func_to_acm(f);
675
676 if (gadget_is_dualspeed(c->cdev->gadget))
677 usb_free_descriptors(f->hs_descriptors);
678 usb_free_descriptors(f->descriptors);
679 gs_free_req(acm->notify, acm->notify_req);
680 kfree(acm);
681 }
682
683 /* Some controllers can't support CDC ACM ... */
can_support_cdc(struct usb_configuration * c)684 static inline bool can_support_cdc(struct usb_configuration *c)
685 {
686 /* everything else is *probably* fine ... */
687 return true;
688 }
689
690 /**
691 * acm_bind_config - add a CDC ACM function to a configuration
692 * @c: the configuration to support the CDC ACM instance
693 * @port_num: /dev/ttyGS* port this interface will use
694 * Context: single threaded during gadget setup
695 *
696 * Returns zero on success, else negative errno.
697 *
698 * Caller must have called @gserial_setup() with enough ports to
699 * handle all the ones it binds. Caller is also responsible
700 * for calling @gserial_cleanup() before module unload.
701 */
acm_bind_config(struct usb_configuration * c,u8 port_num)702 int acm_bind_config(struct usb_configuration *c, u8 port_num)
703 {
704 struct f_acm *acm;
705 int status;
706
707 if (!can_support_cdc(c))
708 return -EINVAL;
709
710 /* REVISIT might want instance-specific strings to help
711 * distinguish instances ...
712 */
713
714 /* maybe allocate device-global string IDs, and patch descriptors */
715 if (acm_string_defs[ACM_CTRL_IDX].id == 0) {
716 status = usb_string_id(c->cdev);
717 if (status < 0)
718 return status;
719 acm_string_defs[ACM_CTRL_IDX].id = status;
720
721 acm_control_interface_desc.iInterface = status;
722
723 status = usb_string_id(c->cdev);
724 if (status < 0)
725 return status;
726 acm_string_defs[ACM_DATA_IDX].id = status;
727
728 acm_data_interface_desc.iInterface = status;
729
730 status = usb_string_id(c->cdev);
731 if (status < 0)
732 return status;
733 acm_string_defs[ACM_IAD_IDX].id = status;
734
735 acm_iad_descriptor.iFunction = status;
736 }
737
738 /* allocate and initialize one new instance */
739 acm = kzalloc(sizeof *acm, GFP_KERNEL);
740 if (!acm)
741 return -ENOMEM;
742
743 spin_lock_init(&acm->lock);
744
745 acm->port_num = port_num;
746
747 acm->port.connect = acm_connect;
748 acm->port.disconnect = acm_disconnect;
749 acm->port.send_break = acm_send_break;
750
751 acm->port.func.name = "acm";
752 acm->port.func.strings = acm_strings;
753 /* descriptors are per-instance copies */
754 acm->port.func.bind = acm_bind;
755 acm->port.func.unbind = acm_unbind;
756 acm->port.func.set_alt = acm_set_alt;
757 acm->port.func.setup = acm_setup;
758 acm->port.func.disable = acm_disable;
759
760 status = usb_add_function(c, &acm->port.func);
761 if (status)
762 kfree(acm);
763 return status;
764 }
765