1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * f_acm.c -- USB CDC serial (ACM) function driver
4 *
5 * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
6 * Copyright (C) 2008 by David Brownell
7 * Copyright (C) 2008 by Nokia Corporation
8 * Copyright (C) 2009 by Samsung Electronics
9 * Author: Michal Nazarewicz (mina86@mina86.com)
10 */
11
12 /* #define VERBOSE_DEBUG */
13
14 #include <linux/slab.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/device.h>
18 #include <linux/err.h>
19
20 #include "u_serial.h"
21
22
23 /*
24 * This CDC ACM function support just wraps control functions and
25 * notifications around the generic serial-over-usb code.
26 *
27 * Because CDC ACM is standardized by the USB-IF, many host operating
28 * systems have drivers for it. Accordingly, ACM is the preferred
29 * interop solution for serial-port type connections. The control
30 * models are often not necessary, and in any case don't do much in
31 * this bare-bones implementation.
32 *
33 * Note that even MS-Windows has some support for ACM. However, that
34 * support is somewhat broken because when you use ACM in a composite
35 * device, having multiple interfaces confuses the poor OS. It doesn't
36 * seem to understand CDC Union descriptors. The new "association"
37 * descriptors (roughly equivalent to CDC Unions) may sometimes help.
38 */
39
40 struct f_acm {
41 struct gserial port;
42 u8 ctrl_id, data_id;
43 u8 port_num;
44 u8 bInterfaceProtocol;
45
46 u8 pending;
47
48 /* lock is mostly for pending and notify_req ... they get accessed
49 * by callbacks both from tty (open/close/break) under its spinlock,
50 * and notify_req.complete() which can't use that lock.
51 */
52 spinlock_t lock;
53
54 struct usb_ep *notify;
55 struct usb_request *notify_req;
56
57 struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */
58
59 /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
60 u16 port_handshake_bits;
61 /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
62 u16 serial_state;
63 };
64
func_to_acm(struct usb_function * f)65 static inline struct f_acm *func_to_acm(struct usb_function *f)
66 {
67 return container_of(f, struct f_acm, port.func);
68 }
69
port_to_acm(struct gserial * p)70 static inline struct f_acm *port_to_acm(struct gserial *p)
71 {
72 return container_of(p, struct f_acm, port);
73 }
74
75 /*-------------------------------------------------------------------------*/
76
77 /* notification endpoint uses smallish and infrequent fixed-size messages */
78
79 #define GS_NOTIFY_INTERVAL_MS 32
80 #define GS_NOTIFY_MAXPACKET 10 /* notification + 2 bytes */
81
82 /* interface and class descriptors: */
83
84 static struct usb_interface_assoc_descriptor
85 acm_iad_descriptor = {
86 .bLength = sizeof acm_iad_descriptor,
87 .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
88
89 /* .bFirstInterface = DYNAMIC, */
90 .bInterfaceCount = 2, // control + data
91 .bFunctionClass = USB_CLASS_COMM,
92 .bFunctionSubClass = USB_CDC_SUBCLASS_ACM,
93 /* .bFunctionProtocol = DYNAMIC */
94 /* .iFunction = DYNAMIC */
95 };
96
97
98 static struct usb_interface_descriptor acm_control_interface_desc = {
99 .bLength = USB_DT_INTERFACE_SIZE,
100 .bDescriptorType = USB_DT_INTERFACE,
101 /* .bInterfaceNumber = DYNAMIC */
102 .bNumEndpoints = 1,
103 .bInterfaceClass = USB_CLASS_COMM,
104 .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
105 /* .bInterfaceProtocol = DYNAMIC */
106 /* .iInterface = DYNAMIC */
107 };
108
109 static struct usb_interface_descriptor acm_data_interface_desc = {
110 .bLength = USB_DT_INTERFACE_SIZE,
111 .bDescriptorType = USB_DT_INTERFACE,
112 /* .bInterfaceNumber = DYNAMIC */
113 .bNumEndpoints = 2,
114 .bInterfaceClass = USB_CLASS_CDC_DATA,
115 .bInterfaceSubClass = 0,
116 .bInterfaceProtocol = 0,
117 /* .iInterface = DYNAMIC */
118 };
119
120 static struct usb_cdc_header_desc acm_header_desc = {
121 .bLength = sizeof(acm_header_desc),
122 .bDescriptorType = USB_DT_CS_INTERFACE,
123 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
124 .bcdCDC = cpu_to_le16(0x0110),
125 };
126
127 static struct usb_cdc_call_mgmt_descriptor
128 acm_call_mgmt_descriptor = {
129 .bLength = sizeof(acm_call_mgmt_descriptor),
130 .bDescriptorType = USB_DT_CS_INTERFACE,
131 .bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE,
132 .bmCapabilities = 0,
133 /* .bDataInterface = DYNAMIC */
134 };
135
136 static struct usb_cdc_acm_descriptor acm_descriptor = {
137 .bLength = sizeof(acm_descriptor),
138 .bDescriptorType = USB_DT_CS_INTERFACE,
139 .bDescriptorSubType = USB_CDC_ACM_TYPE,
140 .bmCapabilities = USB_CDC_CAP_LINE,
141 };
142
143 static struct usb_cdc_union_desc acm_union_desc = {
144 .bLength = sizeof(acm_union_desc),
145 .bDescriptorType = USB_DT_CS_INTERFACE,
146 .bDescriptorSubType = USB_CDC_UNION_TYPE,
147 /* .bMasterInterface0 = DYNAMIC */
148 /* .bSlaveInterface0 = DYNAMIC */
149 };
150
151 /* full speed support: */
152
153 static struct usb_endpoint_descriptor acm_fs_notify_desc = {
154 .bLength = USB_DT_ENDPOINT_SIZE,
155 .bDescriptorType = USB_DT_ENDPOINT,
156 .bEndpointAddress = USB_DIR_IN,
157 .bmAttributes = USB_ENDPOINT_XFER_INT,
158 .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET),
159 .bInterval = GS_NOTIFY_INTERVAL_MS,
160 };
161
162 static struct usb_endpoint_descriptor acm_fs_in_desc = {
163 .bLength = USB_DT_ENDPOINT_SIZE,
164 .bDescriptorType = USB_DT_ENDPOINT,
165 .bEndpointAddress = USB_DIR_IN,
166 .bmAttributes = USB_ENDPOINT_XFER_BULK,
167 };
168
169 static struct usb_endpoint_descriptor acm_fs_out_desc = {
170 .bLength = USB_DT_ENDPOINT_SIZE,
171 .bDescriptorType = USB_DT_ENDPOINT,
172 .bEndpointAddress = USB_DIR_OUT,
173 .bmAttributes = USB_ENDPOINT_XFER_BULK,
174 };
175
176 static struct usb_descriptor_header *acm_fs_function[] = {
177 (struct usb_descriptor_header *) &acm_iad_descriptor,
178 (struct usb_descriptor_header *) &acm_control_interface_desc,
179 (struct usb_descriptor_header *) &acm_header_desc,
180 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
181 (struct usb_descriptor_header *) &acm_descriptor,
182 (struct usb_descriptor_header *) &acm_union_desc,
183 (struct usb_descriptor_header *) &acm_fs_notify_desc,
184 (struct usb_descriptor_header *) &acm_data_interface_desc,
185 (struct usb_descriptor_header *) &acm_fs_in_desc,
186 (struct usb_descriptor_header *) &acm_fs_out_desc,
187 NULL,
188 };
189
190 /* high speed support: */
191 static struct usb_endpoint_descriptor acm_hs_notify_desc = {
192 .bLength = USB_DT_ENDPOINT_SIZE,
193 .bDescriptorType = USB_DT_ENDPOINT,
194 .bEndpointAddress = USB_DIR_IN,
195 .bmAttributes = USB_ENDPOINT_XFER_INT,
196 .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET),
197 .bInterval = USB_MS_TO_HS_INTERVAL(GS_NOTIFY_INTERVAL_MS),
198 };
199
200 static struct usb_endpoint_descriptor acm_hs_in_desc = {
201 .bLength = USB_DT_ENDPOINT_SIZE,
202 .bDescriptorType = USB_DT_ENDPOINT,
203 .bmAttributes = USB_ENDPOINT_XFER_BULK,
204 .wMaxPacketSize = cpu_to_le16(512),
205 };
206
207 static struct usb_endpoint_descriptor acm_hs_out_desc = {
208 .bLength = USB_DT_ENDPOINT_SIZE,
209 .bDescriptorType = USB_DT_ENDPOINT,
210 .bmAttributes = USB_ENDPOINT_XFER_BULK,
211 .wMaxPacketSize = cpu_to_le16(512),
212 };
213
214 static struct usb_descriptor_header *acm_hs_function[] = {
215 (struct usb_descriptor_header *) &acm_iad_descriptor,
216 (struct usb_descriptor_header *) &acm_control_interface_desc,
217 (struct usb_descriptor_header *) &acm_header_desc,
218 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
219 (struct usb_descriptor_header *) &acm_descriptor,
220 (struct usb_descriptor_header *) &acm_union_desc,
221 (struct usb_descriptor_header *) &acm_hs_notify_desc,
222 (struct usb_descriptor_header *) &acm_data_interface_desc,
223 (struct usb_descriptor_header *) &acm_hs_in_desc,
224 (struct usb_descriptor_header *) &acm_hs_out_desc,
225 NULL,
226 };
227
228 static struct usb_endpoint_descriptor acm_ss_in_desc = {
229 .bLength = USB_DT_ENDPOINT_SIZE,
230 .bDescriptorType = USB_DT_ENDPOINT,
231 .bmAttributes = USB_ENDPOINT_XFER_BULK,
232 .wMaxPacketSize = cpu_to_le16(1024),
233 };
234
235 static struct usb_endpoint_descriptor acm_ss_out_desc = {
236 .bLength = USB_DT_ENDPOINT_SIZE,
237 .bDescriptorType = USB_DT_ENDPOINT,
238 .bmAttributes = USB_ENDPOINT_XFER_BULK,
239 .wMaxPacketSize = cpu_to_le16(1024),
240 };
241
242 static struct usb_ss_ep_comp_descriptor acm_ss_bulk_comp_desc = {
243 .bLength = sizeof acm_ss_bulk_comp_desc,
244 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
245 };
246
247 static struct usb_descriptor_header *acm_ss_function[] = {
248 (struct usb_descriptor_header *) &acm_iad_descriptor,
249 (struct usb_descriptor_header *) &acm_control_interface_desc,
250 (struct usb_descriptor_header *) &acm_header_desc,
251 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
252 (struct usb_descriptor_header *) &acm_descriptor,
253 (struct usb_descriptor_header *) &acm_union_desc,
254 (struct usb_descriptor_header *) &acm_hs_notify_desc,
255 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
256 (struct usb_descriptor_header *) &acm_data_interface_desc,
257 (struct usb_descriptor_header *) &acm_ss_in_desc,
258 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
259 (struct usb_descriptor_header *) &acm_ss_out_desc,
260 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
261 NULL,
262 };
263
264 /* string descriptors: */
265
266 #define ACM_CTRL_IDX 0
267 #define ACM_DATA_IDX 1
268 #define ACM_IAD_IDX 2
269
270 /* static strings, in UTF-8 */
271 static struct usb_string acm_string_defs[] = {
272 [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
273 [ACM_DATA_IDX].s = "CDC ACM Data",
274 [ACM_IAD_IDX ].s = "CDC Serial",
275 { } /* end of list */
276 };
277
278 static struct usb_gadget_strings acm_string_table = {
279 .language = 0x0409, /* en-us */
280 .strings = acm_string_defs,
281 };
282
283 static struct usb_gadget_strings *acm_strings[] = {
284 &acm_string_table,
285 NULL,
286 };
287
288 /*-------------------------------------------------------------------------*/
289
290 /* ACM control ... data handling is delegated to tty library code.
291 * The main task of this function is to activate and deactivate
292 * that code based on device state; track parameters like line
293 * speed, handshake state, and so on; and issue notifications.
294 */
295
acm_complete_set_line_coding(struct usb_ep * ep,struct usb_request * req)296 static void acm_complete_set_line_coding(struct usb_ep *ep,
297 struct usb_request *req)
298 {
299 struct f_acm *acm = ep->driver_data;
300 struct usb_composite_dev *cdev = acm->port.func.config->cdev;
301
302 if (req->status != 0) {
303 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d completion, err %d\n",
304 acm->port_num, req->status);
305 return;
306 }
307
308 /* normal completion */
309 if (req->actual != sizeof(acm->port_line_coding)) {
310 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d short resp, len %d\n",
311 acm->port_num, req->actual);
312 usb_ep_set_halt(ep);
313 } else {
314 struct usb_cdc_line_coding *value = req->buf;
315
316 /* REVISIT: we currently just remember this data.
317 * If we change that, (a) validate it first, then
318 * (b) update whatever hardware needs updating,
319 * (c) worry about locking. This is information on
320 * the order of 9600-8-N-1 ... most of which means
321 * nothing unless we control a real RS232 line.
322 */
323 acm->port_line_coding = *value;
324 }
325 }
326
327 static int acm_send_break(struct gserial *port, int duration);
328
acm_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)329 static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
330 {
331 struct f_acm *acm = func_to_acm(f);
332 struct usb_composite_dev *cdev = f->config->cdev;
333 struct usb_request *req = cdev->req;
334 int value = -EOPNOTSUPP;
335 u16 w_index = le16_to_cpu(ctrl->wIndex);
336 u16 w_value = le16_to_cpu(ctrl->wValue);
337 u16 w_length = le16_to_cpu(ctrl->wLength);
338
339 /* composite driver infrastructure handles everything except
340 * CDC class messages; interface activation uses set_alt().
341 *
342 * Note CDC spec table 4 lists the ACM request profile. It requires
343 * encapsulated command support ... we don't handle any, and respond
344 * to them by stalling. Options include get/set/clear comm features
345 * (not that useful) and SEND_BREAK.
346 */
347 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
348
349 /* SET_LINE_CODING ... just read and save what the host sends */
350 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
351 | USB_CDC_REQ_SET_LINE_CODING:
352 if (w_length != sizeof(struct usb_cdc_line_coding)
353 || w_index != acm->ctrl_id)
354 goto invalid;
355
356 value = w_length;
357 cdev->gadget->ep0->driver_data = acm;
358 req->complete = acm_complete_set_line_coding;
359 break;
360
361 /* GET_LINE_CODING ... return what host sent, or initial value */
362 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
363 | USB_CDC_REQ_GET_LINE_CODING:
364 if (w_index != acm->ctrl_id)
365 goto invalid;
366
367 value = min_t(unsigned, w_length,
368 sizeof(struct usb_cdc_line_coding));
369 memcpy(req->buf, &acm->port_line_coding, value);
370 break;
371
372 /* SET_CONTROL_LINE_STATE ... save what the host sent */
373 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
374 | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
375 if (w_index != acm->ctrl_id)
376 goto invalid;
377
378 value = 0;
379
380 /* FIXME we should not allow data to flow until the
381 * host sets the USB_CDC_CTRL_DTR bit; and when it clears
382 * that bit, we should return to that no-flow state.
383 */
384 acm->port_handshake_bits = w_value;
385 break;
386
387 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
388 | USB_CDC_REQ_SEND_BREAK:
389 if (w_index != acm->ctrl_id)
390 goto invalid;
391
392 acm_send_break(&acm->port, w_value);
393 break;
394
395 default:
396 invalid:
397 dev_vdbg(&cdev->gadget->dev,
398 "invalid control req%02x.%02x v%04x i%04x l%d\n",
399 ctrl->bRequestType, ctrl->bRequest,
400 w_value, w_index, w_length);
401 }
402
403 /* respond with data transfer or status phase? */
404 if (value >= 0) {
405 dev_dbg(&cdev->gadget->dev,
406 "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->enabled) {
430 dev_vdbg(&cdev->gadget->dev,
431 "reset acm control interface %d\n", intf);
432 usb_ep_disable(acm->notify);
433 }
434
435 if (!acm->notify->desc)
436 if (config_ep_by_speed(cdev->gadget, f, acm->notify))
437 return -EINVAL;
438
439 usb_ep_enable(acm->notify);
440
441 } else if (intf == acm->data_id) {
442 if (acm->notify->enabled) {
443 dev_dbg(&cdev->gadget->dev,
444 "reset acm ttyGS%d\n", acm->port_num);
445 gserial_disconnect(&acm->port);
446 }
447 if (!acm->port.in->desc || !acm->port.out->desc) {
448 dev_dbg(&cdev->gadget->dev,
449 "activate acm ttyGS%d\n", acm->port_num);
450 if (config_ep_by_speed(cdev->gadget, f,
451 acm->port.in) ||
452 config_ep_by_speed(cdev->gadget, f,
453 acm->port.out)) {
454 acm->port.in->desc = NULL;
455 acm->port.out->desc = NULL;
456 return -EINVAL;
457 }
458 }
459 gserial_connect(&acm->port, acm->port_num);
460
461 } else
462 return -EINVAL;
463
464 return 0;
465 }
466
acm_disable(struct usb_function * f)467 static void acm_disable(struct usb_function *f)
468 {
469 struct f_acm *acm = func_to_acm(f);
470 struct usb_composite_dev *cdev = f->config->cdev;
471
472 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d deactivated\n", acm->port_num);
473 gserial_disconnect(&acm->port);
474 usb_ep_disable(acm->notify);
475 }
476
477 /*-------------------------------------------------------------------------*/
478
479 /**
480 * acm_cdc_notify - issue CDC notification to host
481 * @acm: wraps host to be notified
482 * @type: notification type
483 * @value: Refer to cdc specs, wValue field.
484 * @data: data to be sent
485 * @length: size of data
486 * Context: irqs blocked, acm->lock held, acm_notify_req non-null
487 *
488 * Returns zero on success or a negative errno.
489 *
490 * See section 6.3.5 of the CDC 1.1 specification for information
491 * about the only notification we issue: SerialState change.
492 */
acm_cdc_notify(struct f_acm * acm,u8 type,u16 value,void * data,unsigned length)493 static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
494 void *data, unsigned length)
495 {
496 struct usb_ep *ep = acm->notify;
497 struct usb_request *req;
498 struct usb_cdc_notification *notify;
499 const unsigned len = sizeof(*notify) + length;
500 void *buf;
501 int status;
502
503 req = acm->notify_req;
504 acm->notify_req = NULL;
505 acm->pending = false;
506
507 req->length = len;
508 notify = req->buf;
509 buf = notify + 1;
510
511 notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
512 | USB_RECIP_INTERFACE;
513 notify->bNotificationType = type;
514 notify->wValue = cpu_to_le16(value);
515 notify->wIndex = cpu_to_le16(acm->ctrl_id);
516 notify->wLength = cpu_to_le16(length);
517 memcpy(buf, data, length);
518
519 /* ep_queue() can complete immediately if it fills the fifo... */
520 spin_unlock(&acm->lock);
521 status = usb_ep_queue(ep, req, GFP_ATOMIC);
522 spin_lock(&acm->lock);
523
524 if (status < 0) {
525 ERROR(acm->port.func.config->cdev,
526 "acm ttyGS%d can't notify serial state, %d\n",
527 acm->port_num, status);
528 acm->notify_req = req;
529 }
530
531 return status;
532 }
533
acm_notify_serial_state(struct f_acm * acm)534 static int acm_notify_serial_state(struct f_acm *acm)
535 {
536 struct usb_composite_dev *cdev = acm->port.func.config->cdev;
537 int status;
538 __le16 serial_state;
539
540 spin_lock(&acm->lock);
541 if (acm->notify_req) {
542 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d serial state %04x\n",
543 acm->port_num, acm->serial_state);
544 serial_state = cpu_to_le16(acm->serial_state);
545 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
546 0, &serial_state, sizeof(acm->serial_state));
547 } else {
548 acm->pending = true;
549 status = 0;
550 }
551 spin_unlock(&acm->lock);
552 return status;
553 }
554
acm_cdc_notify_complete(struct usb_ep * ep,struct usb_request * req)555 static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
556 {
557 struct f_acm *acm = req->context;
558 u8 doit = false;
559
560 /* on this call path we do NOT hold the port spinlock,
561 * which is why ACM needs its own spinlock
562 */
563 spin_lock(&acm->lock);
564 if (req->status != -ESHUTDOWN)
565 doit = acm->pending;
566 acm->notify_req = req;
567 spin_unlock(&acm->lock);
568
569 if (doit)
570 acm_notify_serial_state(acm);
571 }
572
573 /* connect == the TTY link is open */
574
acm_connect(struct gserial * port)575 static void acm_connect(struct gserial *port)
576 {
577 struct f_acm *acm = port_to_acm(port);
578
579 acm->serial_state |= USB_CDC_SERIAL_STATE_DSR | USB_CDC_SERIAL_STATE_DCD;
580 acm_notify_serial_state(acm);
581 }
582
acm_disconnect(struct gserial * port)583 static void acm_disconnect(struct gserial *port)
584 {
585 struct f_acm *acm = port_to_acm(port);
586
587 acm->serial_state &= ~(USB_CDC_SERIAL_STATE_DSR | USB_CDC_SERIAL_STATE_DCD);
588 acm_notify_serial_state(acm);
589 }
590
acm_send_break(struct gserial * port,int duration)591 static int acm_send_break(struct gserial *port, int duration)
592 {
593 struct f_acm *acm = port_to_acm(port);
594 u16 state;
595
596 state = acm->serial_state;
597 state &= ~USB_CDC_SERIAL_STATE_BREAK;
598 if (duration)
599 state |= USB_CDC_SERIAL_STATE_BREAK;
600
601 acm->serial_state = state;
602 return acm_notify_serial_state(acm);
603 }
604
605 /*-------------------------------------------------------------------------*/
606
607 /* ACM function driver setup/binding */
608 static int
acm_bind(struct usb_configuration * c,struct usb_function * f)609 acm_bind(struct usb_configuration *c, struct usb_function *f)
610 {
611 struct usb_composite_dev *cdev = c->cdev;
612 struct f_acm *acm = func_to_acm(f);
613 struct usb_string *us;
614 int status;
615 struct usb_ep *ep;
616
617 /* REVISIT might want instance-specific strings to help
618 * distinguish instances ...
619 */
620
621 /* maybe allocate device-global string IDs, and patch descriptors */
622 us = usb_gstrings_attach(cdev, acm_strings,
623 ARRAY_SIZE(acm_string_defs));
624 if (IS_ERR(us))
625 return PTR_ERR(us);
626 acm_control_interface_desc.iInterface = us[ACM_CTRL_IDX].id;
627 acm_data_interface_desc.iInterface = us[ACM_DATA_IDX].id;
628 acm_iad_descriptor.iFunction = us[ACM_IAD_IDX].id;
629
630 /* allocate instance-specific interface IDs, and patch descriptors */
631 status = usb_interface_id(c, f);
632 if (status < 0)
633 goto fail;
634 acm->ctrl_id = status;
635 acm_iad_descriptor.bFirstInterface = status;
636
637 acm_control_interface_desc.bInterfaceNumber = status;
638 acm_union_desc .bMasterInterface0 = status;
639
640 status = usb_interface_id(c, f);
641 if (status < 0)
642 goto fail;
643 acm->data_id = status;
644
645 acm_data_interface_desc.bInterfaceNumber = status;
646 acm_union_desc.bSlaveInterface0 = status;
647 acm_call_mgmt_descriptor.bDataInterface = status;
648
649 status = -ENODEV;
650
651 /* allocate instance-specific endpoints */
652 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
653 if (!ep)
654 goto fail;
655 acm->port.in = ep;
656
657 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
658 if (!ep)
659 goto fail;
660 acm->port.out = ep;
661
662 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
663 if (!ep)
664 goto fail;
665 acm->notify = ep;
666
667 acm_iad_descriptor.bFunctionProtocol = acm->bInterfaceProtocol;
668 acm_control_interface_desc.bInterfaceProtocol = acm->bInterfaceProtocol;
669
670 /* allocate notification */
671 acm->notify_req = gs_alloc_req(ep,
672 sizeof(struct usb_cdc_notification) + 2,
673 GFP_KERNEL);
674 if (!acm->notify_req)
675 goto fail;
676
677 acm->notify_req->complete = acm_cdc_notify_complete;
678 acm->notify_req->context = acm;
679
680 /* support all relevant hardware speeds... we expect that when
681 * hardware is dual speed, all bulk-capable endpoints work at
682 * both speeds
683 */
684 acm_hs_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
685 acm_hs_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
686 acm_hs_notify_desc.bEndpointAddress =
687 acm_fs_notify_desc.bEndpointAddress;
688
689 acm_ss_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
690 acm_ss_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
691
692 status = usb_assign_descriptors(f, acm_fs_function, acm_hs_function,
693 acm_ss_function, acm_ss_function);
694 if (status)
695 goto fail;
696
697 dev_dbg(&cdev->gadget->dev,
698 "acm ttyGS%d: IN/%s OUT/%s NOTIFY/%s\n",
699 acm->port_num,
700 acm->port.in->name, acm->port.out->name,
701 acm->notify->name);
702 return 0;
703
704 fail:
705 if (acm->notify_req)
706 gs_free_req(acm->notify, acm->notify_req);
707
708 ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
709
710 return status;
711 }
712
acm_unbind(struct usb_configuration * c,struct usb_function * f)713 static void acm_unbind(struct usb_configuration *c, struct usb_function *f)
714 {
715 struct f_acm *acm = func_to_acm(f);
716
717 acm_string_defs[0].id = 0;
718 usb_free_all_descriptors(f);
719 if (acm->notify_req)
720 gs_free_req(acm->notify, acm->notify_req);
721 }
722
acm_free_func(struct usb_function * f)723 static void acm_free_func(struct usb_function *f)
724 {
725 struct f_acm *acm = func_to_acm(f);
726 struct f_serial_opts *opts;
727
728 opts = container_of(f->fi, struct f_serial_opts, func_inst);
729
730 kfree(acm);
731 mutex_lock(&opts->lock);
732 opts->instances--;
733 mutex_unlock(&opts->lock);
734 }
735
acm_resume(struct usb_function * f)736 static void acm_resume(struct usb_function *f)
737 {
738 struct f_acm *acm = func_to_acm(f);
739
740 gserial_resume(&acm->port);
741 }
742
acm_suspend(struct usb_function * f)743 static void acm_suspend(struct usb_function *f)
744 {
745 struct f_acm *acm = func_to_acm(f);
746
747 gserial_suspend(&acm->port);
748 }
749
acm_alloc_func(struct usb_function_instance * fi)750 static struct usb_function *acm_alloc_func(struct usb_function_instance *fi)
751 {
752 struct f_serial_opts *opts;
753 struct f_acm *acm;
754
755 acm = kzalloc(sizeof(*acm), GFP_KERNEL);
756 if (!acm)
757 return ERR_PTR(-ENOMEM);
758
759 spin_lock_init(&acm->lock);
760
761 acm->port.connect = acm_connect;
762 acm->port.disconnect = acm_disconnect;
763 acm->port.send_break = acm_send_break;
764
765 acm->port.func.name = "acm";
766 acm->port.func.strings = acm_strings;
767 /* descriptors are per-instance copies */
768 acm->port.func.bind = acm_bind;
769 acm->port.func.set_alt = acm_set_alt;
770 acm->port.func.setup = acm_setup;
771 acm->port.func.disable = acm_disable;
772
773 opts = container_of(fi, struct f_serial_opts, func_inst);
774 mutex_lock(&opts->lock);
775 acm->port_num = opts->port_num;
776 acm->bInterfaceProtocol = opts->protocol;
777 opts->instances++;
778 mutex_unlock(&opts->lock);
779 acm->port.func.unbind = acm_unbind;
780 acm->port.func.free_func = acm_free_func;
781 acm->port.func.resume = acm_resume;
782 acm->port.func.suspend = acm_suspend;
783
784 return &acm->port.func;
785 }
786
to_f_serial_opts(struct config_item * item)787 static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
788 {
789 return container_of(to_config_group(item), struct f_serial_opts,
790 func_inst.group);
791 }
792
acm_attr_release(struct config_item * item)793 static void acm_attr_release(struct config_item *item)
794 {
795 struct f_serial_opts *opts = to_f_serial_opts(item);
796
797 usb_put_function_instance(&opts->func_inst);
798 }
799
800 static struct configfs_item_operations acm_item_ops = {
801 .release = acm_attr_release,
802 };
803
804 #ifdef CONFIG_U_SERIAL_CONSOLE
805
f_acm_console_store(struct config_item * item,const char * page,size_t count)806 static ssize_t f_acm_console_store(struct config_item *item,
807 const char *page, size_t count)
808 {
809 return gserial_set_console(to_f_serial_opts(item)->port_num,
810 page, count);
811 }
812
f_acm_console_show(struct config_item * item,char * page)813 static ssize_t f_acm_console_show(struct config_item *item, char *page)
814 {
815 return gserial_get_console(to_f_serial_opts(item)->port_num, page);
816 }
817
818 CONFIGFS_ATTR(f_acm_, console);
819
820 #endif /* CONFIG_U_SERIAL_CONSOLE */
821
f_acm_port_num_show(struct config_item * item,char * page)822 static ssize_t f_acm_port_num_show(struct config_item *item, char *page)
823 {
824 return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num);
825 }
826
827 CONFIGFS_ATTR_RO(f_acm_, port_num);
828
f_acm_protocol_show(struct config_item * item,char * page)829 static ssize_t f_acm_protocol_show(struct config_item *item, char *page)
830 {
831 return sprintf(page, "%u\n", to_f_serial_opts(item)->protocol);
832 }
833
f_acm_protocol_store(struct config_item * item,const char * page,size_t count)834 static ssize_t f_acm_protocol_store(struct config_item *item,
835 const char *page, size_t count)
836 {
837 struct f_serial_opts *opts = to_f_serial_opts(item);
838 int ret;
839
840 mutex_lock(&opts->lock);
841
842 if (opts->instances) {
843 ret = -EBUSY;
844 goto out;
845 }
846
847 ret = kstrtou8(page, 0, &opts->protocol);
848 if (ret)
849 goto out;
850 ret = count;
851
852 out:
853 mutex_unlock(&opts->lock);
854 return ret;
855 }
856
857 CONFIGFS_ATTR(f_acm_, protocol);
858
859 static struct configfs_attribute *acm_attrs[] = {
860 #ifdef CONFIG_U_SERIAL_CONSOLE
861 &f_acm_attr_console,
862 #endif
863 &f_acm_attr_port_num,
864 &f_acm_attr_protocol,
865 NULL,
866 };
867
868 static const struct config_item_type acm_func_type = {
869 .ct_item_ops = &acm_item_ops,
870 .ct_attrs = acm_attrs,
871 .ct_owner = THIS_MODULE,
872 };
873
acm_free_instance(struct usb_function_instance * fi)874 static void acm_free_instance(struct usb_function_instance *fi)
875 {
876 struct f_serial_opts *opts;
877
878 opts = container_of(fi, struct f_serial_opts, func_inst);
879 gserial_free_line(opts->port_num);
880 mutex_destroy(&opts->lock);
881 kfree(opts);
882 }
883
acm_alloc_instance(void)884 static struct usb_function_instance *acm_alloc_instance(void)
885 {
886 struct f_serial_opts *opts;
887 int ret;
888
889 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
890 if (!opts)
891 return ERR_PTR(-ENOMEM);
892 opts->protocol = USB_CDC_ACM_PROTO_AT_V25TER;
893 opts->func_inst.free_func_inst = acm_free_instance;
894 mutex_init(&opts->lock);
895 ret = gserial_alloc_line(&opts->port_num);
896 if (ret) {
897 kfree(opts);
898 return ERR_PTR(ret);
899 }
900 config_group_init_type_name(&opts->func_inst.group, "",
901 &acm_func_type);
902 return &opts->func_inst;
903 }
904 DECLARE_USB_FUNCTION_INIT(acm, acm_alloc_instance, acm_alloc_func);
905 MODULE_DESCRIPTION("USB CDC serial (ACM) function driver");
906 MODULE_LICENSE("GPL");
907