1 /*
2 * f_acm.c -- USB CDC serial (ACM) function driver
3 *
4 * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
5 * Copyright (C) 2008 by David Brownell
6 * Copyright (C) 2008 by Nokia Corporation
7 * Copyright (C) 2009 by Samsung Electronics
8 * Author: Michal Nazarewicz (mina86@mina86.com)
9 *
10 * This software is distributed under the terms of the GNU General
11 * Public License ("GPL") as published by the Free Software Foundation,
12 * either version 2 of that License or (at your option) any later version.
13 */
14
15 /* #define VERBOSE_DEBUG */
16
17 #include <linux/slab.h>
18 #include <linux/kernel.h>
19 #include <linux/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 static struct usb_endpoint_descriptor acm_ss_in_desc = {
241 .bLength = USB_DT_ENDPOINT_SIZE,
242 .bDescriptorType = USB_DT_ENDPOINT,
243 .bmAttributes = USB_ENDPOINT_XFER_BULK,
244 .wMaxPacketSize = cpu_to_le16(1024),
245 };
246
247 static struct usb_endpoint_descriptor acm_ss_out_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_ss_ep_comp_descriptor acm_ss_bulk_comp_desc = {
255 .bLength = sizeof acm_ss_bulk_comp_desc,
256 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
257 };
258
259 static struct usb_descriptor_header *acm_ss_function[] = {
260 (struct usb_descriptor_header *) &acm_iad_descriptor,
261 (struct usb_descriptor_header *) &acm_control_interface_desc,
262 (struct usb_descriptor_header *) &acm_header_desc,
263 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
264 (struct usb_descriptor_header *) &acm_descriptor,
265 (struct usb_descriptor_header *) &acm_union_desc,
266 (struct usb_descriptor_header *) &acm_hs_notify_desc,
267 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
268 (struct usb_descriptor_header *) &acm_data_interface_desc,
269 (struct usb_descriptor_header *) &acm_ss_in_desc,
270 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
271 (struct usb_descriptor_header *) &acm_ss_out_desc,
272 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
273 NULL,
274 };
275
276 /* string descriptors: */
277
278 #define ACM_CTRL_IDX 0
279 #define ACM_DATA_IDX 1
280 #define ACM_IAD_IDX 2
281
282 /* static strings, in UTF-8 */
283 static struct usb_string acm_string_defs[] = {
284 [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
285 [ACM_DATA_IDX].s = "CDC ACM Data",
286 [ACM_IAD_IDX ].s = "CDC Serial",
287 { /* ZEROES END LIST */ },
288 };
289
290 static struct usb_gadget_strings acm_string_table = {
291 .language = 0x0409, /* en-us */
292 .strings = acm_string_defs,
293 };
294
295 static struct usb_gadget_strings *acm_strings[] = {
296 &acm_string_table,
297 NULL,
298 };
299
300 /*-------------------------------------------------------------------------*/
301
302 /* ACM control ... data handling is delegated to tty library code.
303 * The main task of this function is to activate and deactivate
304 * that code based on device state; track parameters like line
305 * speed, handshake state, and so on; and issue notifications.
306 */
307
acm_complete_set_line_coding(struct usb_ep * ep,struct usb_request * req)308 static void acm_complete_set_line_coding(struct usb_ep *ep,
309 struct usb_request *req)
310 {
311 struct f_acm *acm = ep->driver_data;
312 struct usb_composite_dev *cdev = acm->port.func.config->cdev;
313
314 if (req->status != 0) {
315 DBG(cdev, "acm ttyGS%d completion, err %d\n",
316 acm->port_num, req->status);
317 return;
318 }
319
320 /* normal completion */
321 if (req->actual != sizeof(acm->port_line_coding)) {
322 DBG(cdev, "acm ttyGS%d short resp, len %d\n",
323 acm->port_num, req->actual);
324 usb_ep_set_halt(ep);
325 } else {
326 struct usb_cdc_line_coding *value = req->buf;
327
328 /* REVISIT: we currently just remember this data.
329 * If we change that, (a) validate it first, then
330 * (b) update whatever hardware needs updating,
331 * (c) worry about locking. This is information on
332 * the order of 9600-8-N-1 ... most of which means
333 * nothing unless we control a real RS232 line.
334 */
335 acm->port_line_coding = *value;
336 }
337 }
338
acm_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)339 static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
340 {
341 struct f_acm *acm = func_to_acm(f);
342 struct usb_composite_dev *cdev = f->config->cdev;
343 struct usb_request *req = cdev->req;
344 int value = -EOPNOTSUPP;
345 u16 w_index = le16_to_cpu(ctrl->wIndex);
346 u16 w_value = le16_to_cpu(ctrl->wValue);
347 u16 w_length = le16_to_cpu(ctrl->wLength);
348
349 /* composite driver infrastructure handles everything except
350 * CDC class messages; interface activation uses set_alt().
351 *
352 * Note CDC spec table 4 lists the ACM request profile. It requires
353 * encapsulated command support ... we don't handle any, and respond
354 * to them by stalling. Options include get/set/clear comm features
355 * (not that useful) and SEND_BREAK.
356 */
357 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
358
359 /* SET_LINE_CODING ... just read and save what the host sends */
360 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
361 | USB_CDC_REQ_SET_LINE_CODING:
362 if (w_length != sizeof(struct usb_cdc_line_coding)
363 || w_index != acm->ctrl_id)
364 goto invalid;
365
366 value = w_length;
367 cdev->gadget->ep0->driver_data = acm;
368 req->complete = acm_complete_set_line_coding;
369 break;
370
371 /* GET_LINE_CODING ... return what host sent, or initial value */
372 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
373 | USB_CDC_REQ_GET_LINE_CODING:
374 if (w_index != acm->ctrl_id)
375 goto invalid;
376
377 value = min_t(unsigned, w_length,
378 sizeof(struct usb_cdc_line_coding));
379 memcpy(req->buf, &acm->port_line_coding, value);
380 break;
381
382 /* SET_CONTROL_LINE_STATE ... save what the host sent */
383 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
384 | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
385 if (w_index != acm->ctrl_id)
386 goto invalid;
387
388 value = 0;
389
390 /* FIXME we should not allow data to flow until the
391 * host sets the ACM_CTRL_DTR bit; and when it clears
392 * that bit, we should return to that no-flow state.
393 */
394 acm->port_handshake_bits = w_value;
395 break;
396
397 default:
398 invalid:
399 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
400 ctrl->bRequestType, ctrl->bRequest,
401 w_value, w_index, w_length);
402 }
403
404 /* respond with data transfer or status phase? */
405 if (value >= 0) {
406 DBG(cdev, "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
407 acm->port_num, ctrl->bRequestType, ctrl->bRequest,
408 w_value, w_index, w_length);
409 req->zero = 0;
410 req->length = value;
411 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
412 if (value < 0)
413 ERROR(cdev, "acm response on ttyGS%d, err %d\n",
414 acm->port_num, value);
415 }
416
417 /* device either stalls (value < 0) or reports success */
418 return value;
419 }
420
acm_set_alt(struct usb_function * f,unsigned intf,unsigned alt)421 static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
422 {
423 struct f_acm *acm = func_to_acm(f);
424 struct usb_composite_dev *cdev = f->config->cdev;
425
426 /* we know alt == 0, so this is an activation or a reset */
427
428 if (intf == acm->ctrl_id) {
429 if (acm->notify->driver_data) {
430 VDBG(cdev, "reset acm control interface %d\n", intf);
431 usb_ep_disable(acm->notify);
432 } else {
433 VDBG(cdev, "init acm ctrl interface %d\n", intf);
434 if (config_ep_by_speed(cdev->gadget, f, acm->notify))
435 return -EINVAL;
436 }
437 usb_ep_enable(acm->notify);
438 acm->notify->driver_data = acm;
439
440 } else if (intf == acm->data_id) {
441 if (acm->port.in->driver_data) {
442 DBG(cdev, "reset acm ttyGS%d\n", acm->port_num);
443 gserial_disconnect(&acm->port);
444 }
445 if (!acm->port.in->desc || !acm->port.out->desc) {
446 DBG(cdev, "activate acm ttyGS%d\n", acm->port_num);
447 if (config_ep_by_speed(cdev->gadget, f,
448 acm->port.in) ||
449 config_ep_by_speed(cdev->gadget, f,
450 acm->port.out)) {
451 acm->port.in->desc = NULL;
452 acm->port.out->desc = NULL;
453 return -EINVAL;
454 }
455 }
456 gserial_connect(&acm->port, acm->port_num);
457
458 } else
459 return -EINVAL;
460
461 return 0;
462 }
463
acm_disable(struct usb_function * f)464 static void acm_disable(struct usb_function *f)
465 {
466 struct f_acm *acm = func_to_acm(f);
467 struct usb_composite_dev *cdev = f->config->cdev;
468
469 DBG(cdev, "acm ttyGS%d deactivated\n", acm->port_num);
470 gserial_disconnect(&acm->port);
471 usb_ep_disable(acm->notify);
472 acm->notify->driver_data = NULL;
473 }
474
475 /*-------------------------------------------------------------------------*/
476
477 /**
478 * acm_cdc_notify - issue CDC notification to host
479 * @acm: wraps host to be notified
480 * @type: notification type
481 * @value: Refer to cdc specs, wValue field.
482 * @data: data to be sent
483 * @length: size of data
484 * Context: irqs blocked, acm->lock held, acm_notify_req non-null
485 *
486 * Returns zero on success or a negative errno.
487 *
488 * See section 6.3.5 of the CDC 1.1 specification for information
489 * about the only notification we issue: SerialState change.
490 */
acm_cdc_notify(struct f_acm * acm,u8 type,u16 value,void * data,unsigned length)491 static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
492 void *data, unsigned length)
493 {
494 struct usb_ep *ep = acm->notify;
495 struct usb_request *req;
496 struct usb_cdc_notification *notify;
497 const unsigned len = sizeof(*notify) + length;
498 void *buf;
499 int status;
500
501 req = acm->notify_req;
502 acm->notify_req = NULL;
503 acm->pending = false;
504
505 req->length = len;
506 notify = req->buf;
507 buf = notify + 1;
508
509 notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
510 | USB_RECIP_INTERFACE;
511 notify->bNotificationType = type;
512 notify->wValue = cpu_to_le16(value);
513 notify->wIndex = cpu_to_le16(acm->ctrl_id);
514 notify->wLength = cpu_to_le16(length);
515 memcpy(buf, data, length);
516
517 /* ep_queue() can complete immediately if it fills the fifo... */
518 spin_unlock(&acm->lock);
519 status = usb_ep_queue(ep, req, GFP_ATOMIC);
520 spin_lock(&acm->lock);
521
522 if (status < 0) {
523 ERROR(acm->port.func.config->cdev,
524 "acm ttyGS%d can't notify serial state, %d\n",
525 acm->port_num, status);
526 acm->notify_req = req;
527 }
528
529 return status;
530 }
531
acm_notify_serial_state(struct f_acm * acm)532 static int acm_notify_serial_state(struct f_acm *acm)
533 {
534 struct usb_composite_dev *cdev = acm->port.func.config->cdev;
535 int status;
536
537 spin_lock(&acm->lock);
538 if (acm->notify_req) {
539 DBG(cdev, "acm ttyGS%d serial state %04x\n",
540 acm->port_num, acm->serial_state);
541 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
542 0, &acm->serial_state, sizeof(acm->serial_state));
543 } else {
544 acm->pending = true;
545 status = 0;
546 }
547 spin_unlock(&acm->lock);
548 return status;
549 }
550
acm_cdc_notify_complete(struct usb_ep * ep,struct usb_request * req)551 static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
552 {
553 struct f_acm *acm = req->context;
554 u8 doit = false;
555
556 /* on this call path we do NOT hold the port spinlock,
557 * which is why ACM needs its own spinlock
558 */
559 spin_lock(&acm->lock);
560 if (req->status != -ESHUTDOWN)
561 doit = acm->pending;
562 acm->notify_req = req;
563 spin_unlock(&acm->lock);
564
565 if (doit)
566 acm_notify_serial_state(acm);
567 }
568
569 /* connect == the TTY link is open */
570
acm_connect(struct gserial * port)571 static void acm_connect(struct gserial *port)
572 {
573 struct f_acm *acm = port_to_acm(port);
574
575 acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
576 acm_notify_serial_state(acm);
577 }
578
acm_disconnect(struct gserial * port)579 static void acm_disconnect(struct gserial *port)
580 {
581 struct f_acm *acm = port_to_acm(port);
582
583 acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
584 acm_notify_serial_state(acm);
585 }
586
acm_send_break(struct gserial * port,int duration)587 static int acm_send_break(struct gserial *port, int duration)
588 {
589 struct f_acm *acm = port_to_acm(port);
590 u16 state;
591
592 state = acm->serial_state;
593 state &= ~ACM_CTRL_BRK;
594 if (duration)
595 state |= ACM_CTRL_BRK;
596
597 acm->serial_state = state;
598 return acm_notify_serial_state(acm);
599 }
600
601 /*-------------------------------------------------------------------------*/
602
603 /* ACM function driver setup/binding */
604 static int
acm_bind(struct usb_configuration * c,struct usb_function * f)605 acm_bind(struct usb_configuration *c, struct usb_function *f)
606 {
607 struct usb_composite_dev *cdev = c->cdev;
608 struct f_acm *acm = func_to_acm(f);
609 int status;
610 struct usb_ep *ep;
611
612 /* allocate instance-specific interface IDs, and patch descriptors */
613 status = usb_interface_id(c, f);
614 if (status < 0)
615 goto fail;
616 acm->ctrl_id = status;
617 acm_iad_descriptor.bFirstInterface = status;
618
619 acm_control_interface_desc.bInterfaceNumber = status;
620 acm_union_desc .bMasterInterface0 = status;
621
622 status = usb_interface_id(c, f);
623 if (status < 0)
624 goto fail;
625 acm->data_id = status;
626
627 acm_data_interface_desc.bInterfaceNumber = status;
628 acm_union_desc.bSlaveInterface0 = status;
629 acm_call_mgmt_descriptor.bDataInterface = status;
630
631 status = -ENODEV;
632
633 /* allocate instance-specific endpoints */
634 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
635 if (!ep)
636 goto fail;
637 acm->port.in = ep;
638 ep->driver_data = cdev; /* claim */
639
640 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
641 if (!ep)
642 goto fail;
643 acm->port.out = ep;
644 ep->driver_data = cdev; /* claim */
645
646 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
647 if (!ep)
648 goto fail;
649 acm->notify = ep;
650 ep->driver_data = cdev; /* claim */
651
652 /* allocate notification */
653 acm->notify_req = gs_alloc_req(ep,
654 sizeof(struct usb_cdc_notification) + 2,
655 GFP_KERNEL);
656 if (!acm->notify_req)
657 goto fail;
658
659 acm->notify_req->complete = acm_cdc_notify_complete;
660 acm->notify_req->context = acm;
661
662 /* copy descriptors */
663 f->descriptors = usb_copy_descriptors(acm_fs_function);
664 if (!f->descriptors)
665 goto fail;
666
667 /* support all relevant hardware speeds... we expect that when
668 * hardware is dual speed, all bulk-capable endpoints work at
669 * both speeds
670 */
671 if (gadget_is_dualspeed(c->cdev->gadget)) {
672 acm_hs_in_desc.bEndpointAddress =
673 acm_fs_in_desc.bEndpointAddress;
674 acm_hs_out_desc.bEndpointAddress =
675 acm_fs_out_desc.bEndpointAddress;
676 acm_hs_notify_desc.bEndpointAddress =
677 acm_fs_notify_desc.bEndpointAddress;
678
679 /* copy descriptors */
680 f->hs_descriptors = usb_copy_descriptors(acm_hs_function);
681 }
682 if (gadget_is_superspeed(c->cdev->gadget)) {
683 acm_ss_in_desc.bEndpointAddress =
684 acm_fs_in_desc.bEndpointAddress;
685 acm_ss_out_desc.bEndpointAddress =
686 acm_fs_out_desc.bEndpointAddress;
687
688 /* copy descriptors, and track endpoint copies */
689 f->ss_descriptors = usb_copy_descriptors(acm_ss_function);
690 if (!f->ss_descriptors)
691 goto fail;
692 }
693
694 DBG(cdev, "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
695 acm->port_num,
696 gadget_is_superspeed(c->cdev->gadget) ? "super" :
697 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
698 acm->port.in->name, acm->port.out->name,
699 acm->notify->name);
700 return 0;
701
702 fail:
703 if (acm->notify_req)
704 gs_free_req(acm->notify, acm->notify_req);
705
706 /* we might as well release our claims on endpoints */
707 if (acm->notify)
708 acm->notify->driver_data = NULL;
709 if (acm->port.out)
710 acm->port.out->driver_data = NULL;
711 if (acm->port.in)
712 acm->port.in->driver_data = NULL;
713
714 ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
715
716 return status;
717 }
718
719 static void
acm_unbind(struct usb_configuration * c,struct usb_function * f)720 acm_unbind(struct usb_configuration *c, struct usb_function *f)
721 {
722 struct f_acm *acm = func_to_acm(f);
723
724 if (gadget_is_dualspeed(c->cdev->gadget))
725 usb_free_descriptors(f->hs_descriptors);
726 if (gadget_is_superspeed(c->cdev->gadget))
727 usb_free_descriptors(f->ss_descriptors);
728 usb_free_descriptors(f->descriptors);
729 gs_free_req(acm->notify, acm->notify_req);
730 kfree(acm);
731 }
732
733 /* Some controllers can't support CDC ACM ... */
can_support_cdc(struct usb_configuration * c)734 static inline bool can_support_cdc(struct usb_configuration *c)
735 {
736 /* everything else is *probably* fine ... */
737 return true;
738 }
739
740 /**
741 * acm_bind_config - add a CDC ACM function to a configuration
742 * @c: the configuration to support the CDC ACM instance
743 * @port_num: /dev/ttyGS* port this interface will use
744 * Context: single threaded during gadget setup
745 *
746 * Returns zero on success, else negative errno.
747 *
748 * Caller must have called @gserial_setup() with enough ports to
749 * handle all the ones it binds. Caller is also responsible
750 * for calling @gserial_cleanup() before module unload.
751 */
acm_bind_config(struct usb_configuration * c,u8 port_num)752 int acm_bind_config(struct usb_configuration *c, u8 port_num)
753 {
754 struct f_acm *acm;
755 int status;
756
757 if (!can_support_cdc(c))
758 return -EINVAL;
759
760 /* REVISIT might want instance-specific strings to help
761 * distinguish instances ...
762 */
763
764 /* maybe allocate device-global string IDs, and patch descriptors */
765 if (acm_string_defs[ACM_CTRL_IDX].id == 0) {
766 status = usb_string_id(c->cdev);
767 if (status < 0)
768 return status;
769 acm_string_defs[ACM_CTRL_IDX].id = status;
770
771 acm_control_interface_desc.iInterface = status;
772
773 status = usb_string_id(c->cdev);
774 if (status < 0)
775 return status;
776 acm_string_defs[ACM_DATA_IDX].id = status;
777
778 acm_data_interface_desc.iInterface = status;
779
780 status = usb_string_id(c->cdev);
781 if (status < 0)
782 return status;
783 acm_string_defs[ACM_IAD_IDX].id = status;
784
785 acm_iad_descriptor.iFunction = status;
786 }
787
788 /* allocate and initialize one new instance */
789 acm = kzalloc(sizeof *acm, GFP_KERNEL);
790 if (!acm)
791 return -ENOMEM;
792
793 spin_lock_init(&acm->lock);
794
795 acm->port_num = port_num;
796
797 acm->port.connect = acm_connect;
798 acm->port.disconnect = acm_disconnect;
799 acm->port.send_break = acm_send_break;
800
801 acm->port.func.name = "acm";
802 acm->port.func.strings = acm_strings;
803 /* descriptors are per-instance copies */
804 acm->port.func.bind = acm_bind;
805 acm->port.func.unbind = acm_unbind;
806 acm->port.func.set_alt = acm_set_alt;
807 acm->port.func.setup = acm_setup;
808 acm->port.func.disable = acm_disable;
809
810 status = usb_add_function(c, &acm->port.func);
811 if (status)
812 kfree(acm);
813 return status;
814 }
815