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
45 u8 pending;
46
47 /* lock is mostly for pending and notify_req ... they get accessed
48 * by callbacks both from tty (open/close/break) under its spinlock,
49 * and notify_req.complete() which can't use that lock.
50 */
51 spinlock_t lock;
52
53 struct usb_ep *notify;
54 struct usb_request *notify_req;
55
56 struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */
57
58 /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
59 u16 port_handshake_bits;
60 #define ACM_CTRL_RTS (1 << 1) /* unused with full duplex */
61 #define ACM_CTRL_DTR (1 << 0) /* host is ready for data r/w */
62
63 /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
64 u16 serial_state;
65 #define ACM_CTRL_OVERRUN (1 << 6)
66 #define ACM_CTRL_PARITY (1 << 5)
67 #define ACM_CTRL_FRAMING (1 << 4)
68 #define ACM_CTRL_RI (1 << 3)
69 #define ACM_CTRL_BRK (1 << 2)
70 #define ACM_CTRL_DSR (1 << 1)
71 #define ACM_CTRL_DCD (1 << 0)
72 };
73
func_to_acm(struct usb_function * f)74 static inline struct f_acm *func_to_acm(struct usb_function *f)
75 {
76 return container_of(f, struct f_acm, port.func);
77 }
78
port_to_acm(struct gserial * p)79 static inline struct f_acm *port_to_acm(struct gserial *p)
80 {
81 return container_of(p, struct f_acm, port);
82 }
83
84 /*-------------------------------------------------------------------------*/
85
86 /* notification endpoint uses smallish and infrequent fixed-size messages */
87
88 #define GS_NOTIFY_INTERVAL_MS 32
89 #define GS_NOTIFY_MAXPACKET 10 /* notification + 2 bytes */
90
91 /* interface and class descriptors: */
92
93 static struct usb_interface_assoc_descriptor
94 acm_iad_descriptor = {
95 .bLength = sizeof acm_iad_descriptor,
96 .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
97
98 /* .bFirstInterface = DYNAMIC, */
99 .bInterfaceCount = 2, // control + data
100 .bFunctionClass = USB_CLASS_COMM,
101 .bFunctionSubClass = USB_CDC_SUBCLASS_ACM,
102 .bFunctionProtocol = USB_CDC_ACM_PROTO_AT_V25TER,
103 /* .iFunction = DYNAMIC */
104 };
105
106
107 static struct usb_interface_descriptor acm_control_interface_desc = {
108 .bLength = USB_DT_INTERFACE_SIZE,
109 .bDescriptorType = USB_DT_INTERFACE,
110 /* .bInterfaceNumber = DYNAMIC */
111 .bNumEndpoints = 1,
112 .bInterfaceClass = USB_CLASS_COMM,
113 .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
114 .bInterfaceProtocol = USB_CDC_ACM_PROTO_AT_V25TER,
115 /* .iInterface = DYNAMIC */
116 };
117
118 static struct usb_interface_descriptor acm_data_interface_desc = {
119 .bLength = USB_DT_INTERFACE_SIZE,
120 .bDescriptorType = USB_DT_INTERFACE,
121 /* .bInterfaceNumber = DYNAMIC */
122 .bNumEndpoints = 2,
123 .bInterfaceClass = USB_CLASS_CDC_DATA,
124 .bInterfaceSubClass = 0,
125 .bInterfaceProtocol = 0,
126 /* .iInterface = DYNAMIC */
127 };
128
129 static struct usb_cdc_header_desc acm_header_desc = {
130 .bLength = sizeof(acm_header_desc),
131 .bDescriptorType = USB_DT_CS_INTERFACE,
132 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
133 .bcdCDC = cpu_to_le16(0x0110),
134 };
135
136 static struct usb_cdc_call_mgmt_descriptor
137 acm_call_mgmt_descriptor = {
138 .bLength = sizeof(acm_call_mgmt_descriptor),
139 .bDescriptorType = USB_DT_CS_INTERFACE,
140 .bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE,
141 .bmCapabilities = 0,
142 /* .bDataInterface = DYNAMIC */
143 };
144
145 static struct usb_cdc_acm_descriptor acm_descriptor = {
146 .bLength = sizeof(acm_descriptor),
147 .bDescriptorType = USB_DT_CS_INTERFACE,
148 .bDescriptorSubType = USB_CDC_ACM_TYPE,
149 .bmCapabilities = USB_CDC_CAP_LINE,
150 };
151
152 static struct usb_cdc_union_desc acm_union_desc = {
153 .bLength = sizeof(acm_union_desc),
154 .bDescriptorType = USB_DT_CS_INTERFACE,
155 .bDescriptorSubType = USB_CDC_UNION_TYPE,
156 /* .bMasterInterface0 = DYNAMIC */
157 /* .bSlaveInterface0 = DYNAMIC */
158 };
159
160 /* full speed support: */
161
162 static struct usb_endpoint_descriptor acm_fs_notify_desc = {
163 .bLength = USB_DT_ENDPOINT_SIZE,
164 .bDescriptorType = USB_DT_ENDPOINT,
165 .bEndpointAddress = USB_DIR_IN,
166 .bmAttributes = USB_ENDPOINT_XFER_INT,
167 .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET),
168 .bInterval = GS_NOTIFY_INTERVAL_MS,
169 };
170
171 static struct usb_endpoint_descriptor acm_fs_in_desc = {
172 .bLength = USB_DT_ENDPOINT_SIZE,
173 .bDescriptorType = USB_DT_ENDPOINT,
174 .bEndpointAddress = USB_DIR_IN,
175 .bmAttributes = USB_ENDPOINT_XFER_BULK,
176 };
177
178 static struct usb_endpoint_descriptor acm_fs_out_desc = {
179 .bLength = USB_DT_ENDPOINT_SIZE,
180 .bDescriptorType = USB_DT_ENDPOINT,
181 .bEndpointAddress = USB_DIR_OUT,
182 .bmAttributes = USB_ENDPOINT_XFER_BULK,
183 };
184
185 static struct usb_descriptor_header *acm_fs_function[] = {
186 (struct usb_descriptor_header *) &acm_iad_descriptor,
187 (struct usb_descriptor_header *) &acm_control_interface_desc,
188 (struct usb_descriptor_header *) &acm_header_desc,
189 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
190 (struct usb_descriptor_header *) &acm_descriptor,
191 (struct usb_descriptor_header *) &acm_union_desc,
192 (struct usb_descriptor_header *) &acm_fs_notify_desc,
193 (struct usb_descriptor_header *) &acm_data_interface_desc,
194 (struct usb_descriptor_header *) &acm_fs_in_desc,
195 (struct usb_descriptor_header *) &acm_fs_out_desc,
196 NULL,
197 };
198
199 /* high speed support: */
200 static struct usb_endpoint_descriptor acm_hs_notify_desc = {
201 .bLength = USB_DT_ENDPOINT_SIZE,
202 .bDescriptorType = USB_DT_ENDPOINT,
203 .bEndpointAddress = USB_DIR_IN,
204 .bmAttributes = USB_ENDPOINT_XFER_INT,
205 .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET),
206 .bInterval = USB_MS_TO_HS_INTERVAL(GS_NOTIFY_INTERVAL_MS),
207 };
208
209 static struct usb_endpoint_descriptor acm_hs_in_desc = {
210 .bLength = USB_DT_ENDPOINT_SIZE,
211 .bDescriptorType = USB_DT_ENDPOINT,
212 .bmAttributes = USB_ENDPOINT_XFER_BULK,
213 .wMaxPacketSize = cpu_to_le16(512),
214 };
215
216 static struct usb_endpoint_descriptor acm_hs_out_desc = {
217 .bLength = USB_DT_ENDPOINT_SIZE,
218 .bDescriptorType = USB_DT_ENDPOINT,
219 .bmAttributes = USB_ENDPOINT_XFER_BULK,
220 .wMaxPacketSize = cpu_to_le16(512),
221 };
222
223 static struct usb_descriptor_header *acm_hs_function[] = {
224 (struct usb_descriptor_header *) &acm_iad_descriptor,
225 (struct usb_descriptor_header *) &acm_control_interface_desc,
226 (struct usb_descriptor_header *) &acm_header_desc,
227 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
228 (struct usb_descriptor_header *) &acm_descriptor,
229 (struct usb_descriptor_header *) &acm_union_desc,
230 (struct usb_descriptor_header *) &acm_hs_notify_desc,
231 (struct usb_descriptor_header *) &acm_data_interface_desc,
232 (struct usb_descriptor_header *) &acm_hs_in_desc,
233 (struct usb_descriptor_header *) &acm_hs_out_desc,
234 NULL,
235 };
236
237 static struct usb_endpoint_descriptor acm_ss_in_desc = {
238 .bLength = USB_DT_ENDPOINT_SIZE,
239 .bDescriptorType = USB_DT_ENDPOINT,
240 .bmAttributes = USB_ENDPOINT_XFER_BULK,
241 .wMaxPacketSize = cpu_to_le16(1024),
242 };
243
244 static struct usb_endpoint_descriptor acm_ss_out_desc = {
245 .bLength = USB_DT_ENDPOINT_SIZE,
246 .bDescriptorType = USB_DT_ENDPOINT,
247 .bmAttributes = USB_ENDPOINT_XFER_BULK,
248 .wMaxPacketSize = cpu_to_le16(1024),
249 };
250
251 static struct usb_ss_ep_comp_descriptor acm_ss_bulk_comp_desc = {
252 .bLength = sizeof acm_ss_bulk_comp_desc,
253 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
254 };
255
256 static struct usb_descriptor_header *acm_ss_function[] = {
257 (struct usb_descriptor_header *) &acm_iad_descriptor,
258 (struct usb_descriptor_header *) &acm_control_interface_desc,
259 (struct usb_descriptor_header *) &acm_header_desc,
260 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
261 (struct usb_descriptor_header *) &acm_descriptor,
262 (struct usb_descriptor_header *) &acm_union_desc,
263 (struct usb_descriptor_header *) &acm_hs_notify_desc,
264 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
265 (struct usb_descriptor_header *) &acm_data_interface_desc,
266 (struct usb_descriptor_header *) &acm_ss_in_desc,
267 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
268 (struct usb_descriptor_header *) &acm_ss_out_desc,
269 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
270 NULL,
271 };
272
273 /* string descriptors: */
274
275 #define ACM_CTRL_IDX 0
276 #define ACM_DATA_IDX 1
277 #define ACM_IAD_IDX 2
278
279 /* static strings, in UTF-8 */
280 static struct usb_string acm_string_defs[] = {
281 [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
282 [ACM_DATA_IDX].s = "CDC ACM Data",
283 [ACM_IAD_IDX ].s = "CDC Serial",
284 { } /* end of list */
285 };
286
287 static struct usb_gadget_strings acm_string_table = {
288 .language = 0x0409, /* en-us */
289 .strings = acm_string_defs,
290 };
291
292 static struct usb_gadget_strings *acm_strings[] = {
293 &acm_string_table,
294 NULL,
295 };
296
297 /*-------------------------------------------------------------------------*/
298
299 /* ACM control ... data handling is delegated to tty library code.
300 * The main task of this function is to activate and deactivate
301 * that code based on device state; track parameters like line
302 * speed, handshake state, and so on; and issue notifications.
303 */
304
acm_complete_set_line_coding(struct usb_ep * ep,struct usb_request * req)305 static void acm_complete_set_line_coding(struct usb_ep *ep,
306 struct usb_request *req)
307 {
308 struct f_acm *acm = ep->driver_data;
309 struct usb_composite_dev *cdev = acm->port.func.config->cdev;
310
311 if (req->status != 0) {
312 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d completion, err %d\n",
313 acm->port_num, req->status);
314 return;
315 }
316
317 /* normal completion */
318 if (req->actual != sizeof(acm->port_line_coding)) {
319 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d short resp, len %d\n",
320 acm->port_num, req->actual);
321 usb_ep_set_halt(ep);
322 } else {
323 struct usb_cdc_line_coding *value = req->buf;
324
325 /* REVISIT: we currently just remember this data.
326 * If we change that, (a) validate it first, then
327 * (b) update whatever hardware needs updating,
328 * (c) worry about locking. This is information on
329 * the order of 9600-8-N-1 ... most of which means
330 * nothing unless we control a real RS232 line.
331 */
332 acm->port_line_coding = *value;
333 }
334 }
335
acm_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)336 static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
337 {
338 struct f_acm *acm = func_to_acm(f);
339 struct usb_composite_dev *cdev = f->config->cdev;
340 struct usb_request *req = cdev->req;
341 int value = -EOPNOTSUPP;
342 u16 w_index = le16_to_cpu(ctrl->wIndex);
343 u16 w_value = le16_to_cpu(ctrl->wValue);
344 u16 w_length = le16_to_cpu(ctrl->wLength);
345
346 /* composite driver infrastructure handles everything except
347 * CDC class messages; interface activation uses set_alt().
348 *
349 * Note CDC spec table 4 lists the ACM request profile. It requires
350 * encapsulated command support ... we don't handle any, and respond
351 * to them by stalling. Options include get/set/clear comm features
352 * (not that useful) and SEND_BREAK.
353 */
354 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
355
356 /* SET_LINE_CODING ... just read and save what the host sends */
357 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
358 | USB_CDC_REQ_SET_LINE_CODING:
359 if (w_length != sizeof(struct usb_cdc_line_coding)
360 || w_index != acm->ctrl_id)
361 goto invalid;
362
363 value = w_length;
364 cdev->gadget->ep0->driver_data = acm;
365 req->complete = acm_complete_set_line_coding;
366 break;
367
368 /* GET_LINE_CODING ... return what host sent, or initial value */
369 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
370 | USB_CDC_REQ_GET_LINE_CODING:
371 if (w_index != acm->ctrl_id)
372 goto invalid;
373
374 value = min_t(unsigned, w_length,
375 sizeof(struct usb_cdc_line_coding));
376 memcpy(req->buf, &acm->port_line_coding, value);
377 break;
378
379 /* SET_CONTROL_LINE_STATE ... save what the host sent */
380 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
381 | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
382 if (w_index != acm->ctrl_id)
383 goto invalid;
384
385 value = 0;
386
387 /* FIXME we should not allow data to flow until the
388 * host sets the ACM_CTRL_DTR bit; and when it clears
389 * that bit, we should return to that no-flow state.
390 */
391 acm->port_handshake_bits = w_value;
392 break;
393
394 default:
395 invalid:
396 dev_vdbg(&cdev->gadget->dev,
397 "invalid control req%02x.%02x v%04x i%04x l%d\n",
398 ctrl->bRequestType, ctrl->bRequest,
399 w_value, w_index, w_length);
400 }
401
402 /* respond with data transfer or status phase? */
403 if (value >= 0) {
404 dev_dbg(&cdev->gadget->dev,
405 "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
406 acm->port_num, ctrl->bRequestType, ctrl->bRequest,
407 w_value, w_index, w_length);
408 req->zero = 0;
409 req->length = value;
410 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
411 if (value < 0)
412 ERROR(cdev, "acm response on ttyGS%d, err %d\n",
413 acm->port_num, value);
414 }
415
416 /* device either stalls (value < 0) or reports success */
417 return value;
418 }
419
acm_set_alt(struct usb_function * f,unsigned intf,unsigned alt)420 static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
421 {
422 struct f_acm *acm = func_to_acm(f);
423 struct usb_composite_dev *cdev = f->config->cdev;
424
425 /* we know alt == 0, so this is an activation or a reset */
426
427 if (intf == acm->ctrl_id) {
428 if (acm->notify->enabled) {
429 dev_vdbg(&cdev->gadget->dev,
430 "reset acm control interface %d\n", intf);
431 usb_ep_disable(acm->notify);
432 }
433
434 if (!acm->notify->desc)
435 if (config_ep_by_speed(cdev->gadget, f, acm->notify))
436 return -EINVAL;
437
438 usb_ep_enable(acm->notify);
439
440 } else if (intf == acm->data_id) {
441 if (acm->notify->enabled) {
442 dev_dbg(&cdev->gadget->dev,
443 "reset acm ttyGS%d\n", acm->port_num);
444 gserial_disconnect(&acm->port);
445 }
446 if (!acm->port.in->desc || !acm->port.out->desc) {
447 dev_dbg(&cdev->gadget->dev,
448 "activate acm ttyGS%d\n", acm->port_num);
449 if (config_ep_by_speed(cdev->gadget, f,
450 acm->port.in) ||
451 config_ep_by_speed(cdev->gadget, f,
452 acm->port.out)) {
453 acm->port.in->desc = NULL;
454 acm->port.out->desc = NULL;
455 return -EINVAL;
456 }
457 }
458 gserial_connect(&acm->port, acm->port_num);
459
460 } else
461 return -EINVAL;
462
463 return 0;
464 }
465
acm_disable(struct usb_function * f)466 static void acm_disable(struct usb_function *f)
467 {
468 struct f_acm *acm = func_to_acm(f);
469 struct usb_composite_dev *cdev = f->config->cdev;
470
471 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d deactivated\n", acm->port_num);
472 gserial_disconnect(&acm->port);
473 usb_ep_disable(acm->notify);
474 }
475
476 /*-------------------------------------------------------------------------*/
477
478 /**
479 * acm_cdc_notify - issue CDC notification to host
480 * @acm: wraps host to be notified
481 * @type: notification type
482 * @value: Refer to cdc specs, wValue field.
483 * @data: data to be sent
484 * @length: size of data
485 * Context: irqs blocked, acm->lock held, acm_notify_req non-null
486 *
487 * Returns zero on success or a negative errno.
488 *
489 * See section 6.3.5 of the CDC 1.1 specification for information
490 * about the only notification we issue: SerialState change.
491 */
acm_cdc_notify(struct f_acm * acm,u8 type,u16 value,void * data,unsigned length)492 static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
493 void *data, unsigned length)
494 {
495 struct usb_ep *ep = acm->notify;
496 struct usb_request *req;
497 struct usb_cdc_notification *notify;
498 const unsigned len = sizeof(*notify) + length;
499 void *buf;
500 int status;
501
502 req = acm->notify_req;
503 acm->notify_req = NULL;
504 acm->pending = false;
505
506 req->length = len;
507 notify = req->buf;
508 buf = notify + 1;
509
510 notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
511 | USB_RECIP_INTERFACE;
512 notify->bNotificationType = type;
513 notify->wValue = cpu_to_le16(value);
514 notify->wIndex = cpu_to_le16(acm->ctrl_id);
515 notify->wLength = cpu_to_le16(length);
516 memcpy(buf, data, length);
517
518 /* ep_queue() can complete immediately if it fills the fifo... */
519 spin_unlock(&acm->lock);
520 status = usb_ep_queue(ep, req, GFP_ATOMIC);
521 spin_lock(&acm->lock);
522
523 if (status < 0) {
524 ERROR(acm->port.func.config->cdev,
525 "acm ttyGS%d can't notify serial state, %d\n",
526 acm->port_num, status);
527 acm->notify_req = req;
528 }
529
530 return status;
531 }
532
acm_notify_serial_state(struct f_acm * acm)533 static int acm_notify_serial_state(struct f_acm *acm)
534 {
535 struct usb_composite_dev *cdev = acm->port.func.config->cdev;
536 int status;
537 __le16 serial_state;
538
539 spin_lock(&acm->lock);
540 if (acm->notify_req) {
541 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d serial state %04x\n",
542 acm->port_num, acm->serial_state);
543 serial_state = cpu_to_le16(acm->serial_state);
544 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
545 0, &serial_state, sizeof(acm->serial_state));
546 } else {
547 acm->pending = true;
548 status = 0;
549 }
550 spin_unlock(&acm->lock);
551 return status;
552 }
553
acm_cdc_notify_complete(struct usb_ep * ep,struct usb_request * req)554 static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
555 {
556 struct f_acm *acm = req->context;
557 u8 doit = false;
558
559 /* on this call path we do NOT hold the port spinlock,
560 * which is why ACM needs its own spinlock
561 */
562 spin_lock(&acm->lock);
563 if (req->status != -ESHUTDOWN)
564 doit = acm->pending;
565 acm->notify_req = req;
566 spin_unlock(&acm->lock);
567
568 if (doit)
569 acm_notify_serial_state(acm);
570 }
571
572 /* connect == the TTY link is open */
573
acm_connect(struct gserial * port)574 static void acm_connect(struct gserial *port)
575 {
576 struct f_acm *acm = port_to_acm(port);
577
578 acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
579 acm_notify_serial_state(acm);
580 }
581
acm_disconnect(struct gserial * port)582 static void acm_disconnect(struct gserial *port)
583 {
584 struct f_acm *acm = port_to_acm(port);
585
586 acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
587 acm_notify_serial_state(acm);
588 }
589
acm_send_break(struct gserial * port,int duration)590 static int acm_send_break(struct gserial *port, int duration)
591 {
592 struct f_acm *acm = port_to_acm(port);
593 u16 state;
594
595 state = acm->serial_state;
596 state &= ~ACM_CTRL_BRK;
597 if (duration)
598 state |= ACM_CTRL_BRK;
599
600 acm->serial_state = state;
601 return acm_notify_serial_state(acm);
602 }
603
604 /*-------------------------------------------------------------------------*/
605
606 /* ACM function driver setup/binding */
607 static int
acm_bind(struct usb_configuration * c,struct usb_function * f)608 acm_bind(struct usb_configuration *c, struct usb_function *f)
609 {
610 struct usb_composite_dev *cdev = c->cdev;
611 struct f_acm *acm = func_to_acm(f);
612 struct usb_string *us;
613 int status;
614 struct usb_ep *ep;
615
616 /* REVISIT might want instance-specific strings to help
617 * distinguish instances ...
618 */
619
620 /* maybe allocate device-global string IDs, and patch descriptors */
621 us = usb_gstrings_attach(cdev, acm_strings,
622 ARRAY_SIZE(acm_string_defs));
623 if (IS_ERR(us))
624 return PTR_ERR(us);
625 acm_control_interface_desc.iInterface = us[ACM_CTRL_IDX].id;
626 acm_data_interface_desc.iInterface = us[ACM_DATA_IDX].id;
627 acm_iad_descriptor.iFunction = us[ACM_IAD_IDX].id;
628
629 /* allocate instance-specific interface IDs, and patch descriptors */
630 status = usb_interface_id(c, f);
631 if (status < 0)
632 goto fail;
633 acm->ctrl_id = status;
634 acm_iad_descriptor.bFirstInterface = status;
635
636 acm_control_interface_desc.bInterfaceNumber = status;
637 acm_union_desc .bMasterInterface0 = status;
638
639 status = usb_interface_id(c, f);
640 if (status < 0)
641 goto fail;
642 acm->data_id = status;
643
644 acm_data_interface_desc.bInterfaceNumber = status;
645 acm_union_desc.bSlaveInterface0 = status;
646 acm_call_mgmt_descriptor.bDataInterface = status;
647
648 status = -ENODEV;
649
650 /* allocate instance-specific endpoints */
651 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
652 if (!ep)
653 goto fail;
654 acm->port.in = ep;
655
656 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
657 if (!ep)
658 goto fail;
659 acm->port.out = ep;
660
661 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
662 if (!ep)
663 goto fail;
664 acm->notify = ep;
665
666 /* allocate notification */
667 acm->notify_req = gs_alloc_req(ep,
668 sizeof(struct usb_cdc_notification) + 2,
669 GFP_KERNEL);
670 if (!acm->notify_req)
671 goto fail;
672
673 acm->notify_req->complete = acm_cdc_notify_complete;
674 acm->notify_req->context = acm;
675
676 /* support all relevant hardware speeds... we expect that when
677 * hardware is dual speed, all bulk-capable endpoints work at
678 * both speeds
679 */
680 acm_hs_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
681 acm_hs_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
682 acm_hs_notify_desc.bEndpointAddress =
683 acm_fs_notify_desc.bEndpointAddress;
684
685 acm_ss_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
686 acm_ss_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
687
688 status = usb_assign_descriptors(f, acm_fs_function, acm_hs_function,
689 acm_ss_function, acm_ss_function);
690 if (status)
691 goto fail;
692
693 dev_dbg(&cdev->gadget->dev,
694 "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 ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
707
708 return status;
709 }
710
acm_unbind(struct usb_configuration * c,struct usb_function * f)711 static void acm_unbind(struct usb_configuration *c, struct usb_function *f)
712 {
713 struct f_acm *acm = func_to_acm(f);
714
715 acm_string_defs[0].id = 0;
716 usb_free_all_descriptors(f);
717 if (acm->notify_req)
718 gs_free_req(acm->notify, acm->notify_req);
719 }
720
acm_free_func(struct usb_function * f)721 static void acm_free_func(struct usb_function *f)
722 {
723 struct f_acm *acm = func_to_acm(f);
724
725 kfree(acm);
726 }
727
acm_resume(struct usb_function * f)728 static void acm_resume(struct usb_function *f)
729 {
730 struct f_acm *acm = func_to_acm(f);
731
732 gserial_resume(&acm->port);
733 }
734
acm_suspend(struct usb_function * f)735 static void acm_suspend(struct usb_function *f)
736 {
737 struct f_acm *acm = func_to_acm(f);
738
739 gserial_suspend(&acm->port);
740 }
741
acm_alloc_func(struct usb_function_instance * fi)742 static struct usb_function *acm_alloc_func(struct usb_function_instance *fi)
743 {
744 struct f_serial_opts *opts;
745 struct f_acm *acm;
746
747 acm = kzalloc(sizeof(*acm), GFP_KERNEL);
748 if (!acm)
749 return ERR_PTR(-ENOMEM);
750
751 spin_lock_init(&acm->lock);
752
753 acm->port.connect = acm_connect;
754 acm->port.disconnect = acm_disconnect;
755 acm->port.send_break = acm_send_break;
756
757 acm->port.func.name = "acm";
758 acm->port.func.strings = acm_strings;
759 /* descriptors are per-instance copies */
760 acm->port.func.bind = acm_bind;
761 acm->port.func.set_alt = acm_set_alt;
762 acm->port.func.setup = acm_setup;
763 acm->port.func.disable = acm_disable;
764
765 opts = container_of(fi, struct f_serial_opts, func_inst);
766 acm->port_num = opts->port_num;
767 acm->port.func.unbind = acm_unbind;
768 acm->port.func.free_func = acm_free_func;
769 acm->port.func.resume = acm_resume;
770 acm->port.func.suspend = acm_suspend;
771
772 return &acm->port.func;
773 }
774
to_f_serial_opts(struct config_item * item)775 static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
776 {
777 return container_of(to_config_group(item), struct f_serial_opts,
778 func_inst.group);
779 }
780
acm_attr_release(struct config_item * item)781 static void acm_attr_release(struct config_item *item)
782 {
783 struct f_serial_opts *opts = to_f_serial_opts(item);
784
785 usb_put_function_instance(&opts->func_inst);
786 }
787
788 static struct configfs_item_operations acm_item_ops = {
789 .release = acm_attr_release,
790 };
791
792 #ifdef CONFIG_U_SERIAL_CONSOLE
793
f_acm_console_store(struct config_item * item,const char * page,size_t count)794 static ssize_t f_acm_console_store(struct config_item *item,
795 const char *page, size_t count)
796 {
797 return gserial_set_console(to_f_serial_opts(item)->port_num,
798 page, count);
799 }
800
f_acm_console_show(struct config_item * item,char * page)801 static ssize_t f_acm_console_show(struct config_item *item, char *page)
802 {
803 return gserial_get_console(to_f_serial_opts(item)->port_num, page);
804 }
805
806 CONFIGFS_ATTR(f_acm_, console);
807
808 #endif /* CONFIG_U_SERIAL_CONSOLE */
809
f_acm_port_num_show(struct config_item * item,char * page)810 static ssize_t f_acm_port_num_show(struct config_item *item, char *page)
811 {
812 return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num);
813 }
814
815 CONFIGFS_ATTR_RO(f_acm_, port_num);
816
817 static struct configfs_attribute *acm_attrs[] = {
818 #ifdef CONFIG_U_SERIAL_CONSOLE
819 &f_acm_attr_console,
820 #endif
821 &f_acm_attr_port_num,
822 NULL,
823 };
824
825 static const struct config_item_type acm_func_type = {
826 .ct_item_ops = &acm_item_ops,
827 .ct_attrs = acm_attrs,
828 .ct_owner = THIS_MODULE,
829 };
830
acm_free_instance(struct usb_function_instance * fi)831 static void acm_free_instance(struct usb_function_instance *fi)
832 {
833 struct f_serial_opts *opts;
834
835 opts = container_of(fi, struct f_serial_opts, func_inst);
836 gserial_free_line(opts->port_num);
837 kfree(opts);
838 }
839
acm_alloc_instance(void)840 static struct usb_function_instance *acm_alloc_instance(void)
841 {
842 struct f_serial_opts *opts;
843 int ret;
844
845 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
846 if (!opts)
847 return ERR_PTR(-ENOMEM);
848 opts->func_inst.free_func_inst = acm_free_instance;
849 ret = gserial_alloc_line(&opts->port_num);
850 if (ret) {
851 kfree(opts);
852 return ERR_PTR(ret);
853 }
854 config_group_init_type_name(&opts->func_inst.group, "",
855 &acm_func_type);
856 return &opts->func_inst;
857 }
858 DECLARE_USB_FUNCTION_INIT(acm, acm_alloc_instance, acm_alloc_func);
859 MODULE_LICENSE("GPL");
860