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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
42struct 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
76static inline struct f_acm *func_to_acm(struct usb_function *f)
77{
78 return container_of(f, struct f_acm, port.func);
79}
80
81static 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
95static struct usb_interface_assoc_descriptor
96acm_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
109static 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
120static 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
131static 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
138static struct usb_cdc_call_mgmt_descriptor
139acm_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
147static 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
154static 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
164static 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
173static 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
180static 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
187static 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
203static 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
212static 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
219static 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
226static 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 */
247static 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
254static struct usb_gadget_strings acm_string_table = {
255 .language = 0x0409, /* en-us */
256 .strings = acm_string_defs,
257};
258
259static 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
272static 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
303static 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:
362invalid:
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
385static 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
428static 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 */
455static 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
496static 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
515static 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
535static 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
543static 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
551static 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 */
568static int
569acm_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
654fail:
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
671static void
672acm_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 ... */
684static 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 */
702int 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}
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/module.h>
20#include <linux/device.h>
21#include <linux/err.h>
22
23#include "u_serial.h"
24#include "gadget_chips.h"
25
26
27/*
28 * This CDC ACM function support just wraps control functions and
29 * notifications around the generic serial-over-usb code.
30 *
31 * Because CDC ACM is standardized by the USB-IF, many host operating
32 * systems have drivers for it. Accordingly, ACM is the preferred
33 * interop solution for serial-port type connections. The control
34 * models are often not necessary, and in any case don't do much in
35 * this bare-bones implementation.
36 *
37 * Note that even MS-Windows has some support for ACM. However, that
38 * support is somewhat broken because when you use ACM in a composite
39 * device, having multiple interfaces confuses the poor OS. It doesn't
40 * seem to understand CDC Union descriptors. The new "association"
41 * descriptors (roughly equivalent to CDC Unions) may sometimes help.
42 */
43
44struct f_acm {
45 struct gserial port;
46 u8 ctrl_id, data_id;
47 u8 port_num;
48
49 u8 pending;
50
51 /* lock is mostly for pending and notify_req ... they get accessed
52 * by callbacks both from tty (open/close/break) under its spinlock,
53 * and notify_req.complete() which can't use that lock.
54 */
55 spinlock_t lock;
56
57 struct usb_ep *notify;
58 struct usb_request *notify_req;
59
60 struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */
61
62 /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
63 u16 port_handshake_bits;
64#define ACM_CTRL_RTS (1 << 1) /* unused with full duplex */
65#define ACM_CTRL_DTR (1 << 0) /* host is ready for data r/w */
66
67 /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
68 u16 serial_state;
69#define ACM_CTRL_OVERRUN (1 << 6)
70#define ACM_CTRL_PARITY (1 << 5)
71#define ACM_CTRL_FRAMING (1 << 4)
72#define ACM_CTRL_RI (1 << 3)
73#define ACM_CTRL_BRK (1 << 2)
74#define ACM_CTRL_DSR (1 << 1)
75#define ACM_CTRL_DCD (1 << 0)
76};
77
78static inline struct f_acm *func_to_acm(struct usb_function *f)
79{
80 return container_of(f, struct f_acm, port.func);
81}
82
83static inline struct f_acm *port_to_acm(struct gserial *p)
84{
85 return container_of(p, struct f_acm, port);
86}
87
88/*-------------------------------------------------------------------------*/
89
90/* notification endpoint uses smallish and infrequent fixed-size messages */
91
92#define GS_NOTIFY_INTERVAL_MS 32
93#define GS_NOTIFY_MAXPACKET 10 /* notification + 2 bytes */
94
95/* interface and class descriptors: */
96
97static struct usb_interface_assoc_descriptor
98acm_iad_descriptor = {
99 .bLength = sizeof acm_iad_descriptor,
100 .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
101
102 /* .bFirstInterface = DYNAMIC, */
103 .bInterfaceCount = 2, // control + data
104 .bFunctionClass = USB_CLASS_COMM,
105 .bFunctionSubClass = USB_CDC_SUBCLASS_ACM,
106 .bFunctionProtocol = USB_CDC_ACM_PROTO_AT_V25TER,
107 /* .iFunction = DYNAMIC */
108};
109
110
111static struct usb_interface_descriptor acm_control_interface_desc = {
112 .bLength = USB_DT_INTERFACE_SIZE,
113 .bDescriptorType = USB_DT_INTERFACE,
114 /* .bInterfaceNumber = DYNAMIC */
115 .bNumEndpoints = 1,
116 .bInterfaceClass = USB_CLASS_COMM,
117 .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
118 .bInterfaceProtocol = USB_CDC_ACM_PROTO_AT_V25TER,
119 /* .iInterface = DYNAMIC */
120};
121
122static struct usb_interface_descriptor acm_data_interface_desc = {
123 .bLength = USB_DT_INTERFACE_SIZE,
124 .bDescriptorType = USB_DT_INTERFACE,
125 /* .bInterfaceNumber = DYNAMIC */
126 .bNumEndpoints = 2,
127 .bInterfaceClass = USB_CLASS_CDC_DATA,
128 .bInterfaceSubClass = 0,
129 .bInterfaceProtocol = 0,
130 /* .iInterface = DYNAMIC */
131};
132
133static struct usb_cdc_header_desc acm_header_desc = {
134 .bLength = sizeof(acm_header_desc),
135 .bDescriptorType = USB_DT_CS_INTERFACE,
136 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
137 .bcdCDC = cpu_to_le16(0x0110),
138};
139
140static struct usb_cdc_call_mgmt_descriptor
141acm_call_mgmt_descriptor = {
142 .bLength = sizeof(acm_call_mgmt_descriptor),
143 .bDescriptorType = USB_DT_CS_INTERFACE,
144 .bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE,
145 .bmCapabilities = 0,
146 /* .bDataInterface = DYNAMIC */
147};
148
149static struct usb_cdc_acm_descriptor acm_descriptor = {
150 .bLength = sizeof(acm_descriptor),
151 .bDescriptorType = USB_DT_CS_INTERFACE,
152 .bDescriptorSubType = USB_CDC_ACM_TYPE,
153 .bmCapabilities = USB_CDC_CAP_LINE,
154};
155
156static struct usb_cdc_union_desc acm_union_desc = {
157 .bLength = sizeof(acm_union_desc),
158 .bDescriptorType = USB_DT_CS_INTERFACE,
159 .bDescriptorSubType = USB_CDC_UNION_TYPE,
160 /* .bMasterInterface0 = DYNAMIC */
161 /* .bSlaveInterface0 = DYNAMIC */
162};
163
164/* full speed support: */
165
166static struct usb_endpoint_descriptor acm_fs_notify_desc = {
167 .bLength = USB_DT_ENDPOINT_SIZE,
168 .bDescriptorType = USB_DT_ENDPOINT,
169 .bEndpointAddress = USB_DIR_IN,
170 .bmAttributes = USB_ENDPOINT_XFER_INT,
171 .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET),
172 .bInterval = GS_NOTIFY_INTERVAL_MS,
173};
174
175static struct usb_endpoint_descriptor acm_fs_in_desc = {
176 .bLength = USB_DT_ENDPOINT_SIZE,
177 .bDescriptorType = USB_DT_ENDPOINT,
178 .bEndpointAddress = USB_DIR_IN,
179 .bmAttributes = USB_ENDPOINT_XFER_BULK,
180};
181
182static struct usb_endpoint_descriptor acm_fs_out_desc = {
183 .bLength = USB_DT_ENDPOINT_SIZE,
184 .bDescriptorType = USB_DT_ENDPOINT,
185 .bEndpointAddress = USB_DIR_OUT,
186 .bmAttributes = USB_ENDPOINT_XFER_BULK,
187};
188
189static struct usb_descriptor_header *acm_fs_function[] = {
190 (struct usb_descriptor_header *) &acm_iad_descriptor,
191 (struct usb_descriptor_header *) &acm_control_interface_desc,
192 (struct usb_descriptor_header *) &acm_header_desc,
193 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
194 (struct usb_descriptor_header *) &acm_descriptor,
195 (struct usb_descriptor_header *) &acm_union_desc,
196 (struct usb_descriptor_header *) &acm_fs_notify_desc,
197 (struct usb_descriptor_header *) &acm_data_interface_desc,
198 (struct usb_descriptor_header *) &acm_fs_in_desc,
199 (struct usb_descriptor_header *) &acm_fs_out_desc,
200 NULL,
201};
202
203/* high speed support: */
204static struct usb_endpoint_descriptor acm_hs_notify_desc = {
205 .bLength = USB_DT_ENDPOINT_SIZE,
206 .bDescriptorType = USB_DT_ENDPOINT,
207 .bEndpointAddress = USB_DIR_IN,
208 .bmAttributes = USB_ENDPOINT_XFER_INT,
209 .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET),
210 .bInterval = USB_MS_TO_HS_INTERVAL(GS_NOTIFY_INTERVAL_MS),
211};
212
213static struct usb_endpoint_descriptor acm_hs_in_desc = {
214 .bLength = USB_DT_ENDPOINT_SIZE,
215 .bDescriptorType = USB_DT_ENDPOINT,
216 .bmAttributes = USB_ENDPOINT_XFER_BULK,
217 .wMaxPacketSize = cpu_to_le16(512),
218};
219
220static struct usb_endpoint_descriptor acm_hs_out_desc = {
221 .bLength = USB_DT_ENDPOINT_SIZE,
222 .bDescriptorType = USB_DT_ENDPOINT,
223 .bmAttributes = USB_ENDPOINT_XFER_BULK,
224 .wMaxPacketSize = cpu_to_le16(512),
225};
226
227static struct usb_descriptor_header *acm_hs_function[] = {
228 (struct usb_descriptor_header *) &acm_iad_descriptor,
229 (struct usb_descriptor_header *) &acm_control_interface_desc,
230 (struct usb_descriptor_header *) &acm_header_desc,
231 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
232 (struct usb_descriptor_header *) &acm_descriptor,
233 (struct usb_descriptor_header *) &acm_union_desc,
234 (struct usb_descriptor_header *) &acm_hs_notify_desc,
235 (struct usb_descriptor_header *) &acm_data_interface_desc,
236 (struct usb_descriptor_header *) &acm_hs_in_desc,
237 (struct usb_descriptor_header *) &acm_hs_out_desc,
238 NULL,
239};
240
241static struct usb_endpoint_descriptor acm_ss_in_desc = {
242 .bLength = USB_DT_ENDPOINT_SIZE,
243 .bDescriptorType = USB_DT_ENDPOINT,
244 .bmAttributes = USB_ENDPOINT_XFER_BULK,
245 .wMaxPacketSize = cpu_to_le16(1024),
246};
247
248static struct usb_endpoint_descriptor acm_ss_out_desc = {
249 .bLength = USB_DT_ENDPOINT_SIZE,
250 .bDescriptorType = USB_DT_ENDPOINT,
251 .bmAttributes = USB_ENDPOINT_XFER_BULK,
252 .wMaxPacketSize = cpu_to_le16(1024),
253};
254
255static struct usb_ss_ep_comp_descriptor acm_ss_bulk_comp_desc = {
256 .bLength = sizeof acm_ss_bulk_comp_desc,
257 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
258};
259
260static struct usb_descriptor_header *acm_ss_function[] = {
261 (struct usb_descriptor_header *) &acm_iad_descriptor,
262 (struct usb_descriptor_header *) &acm_control_interface_desc,
263 (struct usb_descriptor_header *) &acm_header_desc,
264 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
265 (struct usb_descriptor_header *) &acm_descriptor,
266 (struct usb_descriptor_header *) &acm_union_desc,
267 (struct usb_descriptor_header *) &acm_hs_notify_desc,
268 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
269 (struct usb_descriptor_header *) &acm_data_interface_desc,
270 (struct usb_descriptor_header *) &acm_ss_in_desc,
271 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
272 (struct usb_descriptor_header *) &acm_ss_out_desc,
273 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
274 NULL,
275};
276
277/* string descriptors: */
278
279#define ACM_CTRL_IDX 0
280#define ACM_DATA_IDX 1
281#define ACM_IAD_IDX 2
282
283/* static strings, in UTF-8 */
284static struct usb_string acm_string_defs[] = {
285 [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
286 [ACM_DATA_IDX].s = "CDC ACM Data",
287 [ACM_IAD_IDX ].s = "CDC Serial",
288 { } /* end of list */
289};
290
291static struct usb_gadget_strings acm_string_table = {
292 .language = 0x0409, /* en-us */
293 .strings = acm_string_defs,
294};
295
296static struct usb_gadget_strings *acm_strings[] = {
297 &acm_string_table,
298 NULL,
299};
300
301/*-------------------------------------------------------------------------*/
302
303/* ACM control ... data handling is delegated to tty library code.
304 * The main task of this function is to activate and deactivate
305 * that code based on device state; track parameters like line
306 * speed, handshake state, and so on; and issue notifications.
307 */
308
309static void acm_complete_set_line_coding(struct usb_ep *ep,
310 struct usb_request *req)
311{
312 struct f_acm *acm = ep->driver_data;
313 struct usb_composite_dev *cdev = acm->port.func.config->cdev;
314
315 if (req->status != 0) {
316 DBG(cdev, "acm ttyGS%d completion, err %d\n",
317 acm->port_num, req->status);
318 return;
319 }
320
321 /* normal completion */
322 if (req->actual != sizeof(acm->port_line_coding)) {
323 DBG(cdev, "acm ttyGS%d short resp, len %d\n",
324 acm->port_num, req->actual);
325 usb_ep_set_halt(ep);
326 } else {
327 struct usb_cdc_line_coding *value = req->buf;
328
329 /* REVISIT: we currently just remember this data.
330 * If we change that, (a) validate it first, then
331 * (b) update whatever hardware needs updating,
332 * (c) worry about locking. This is information on
333 * the order of 9600-8-N-1 ... most of which means
334 * nothing unless we control a real RS232 line.
335 */
336 acm->port_line_coding = *value;
337 }
338}
339
340static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
341{
342 struct f_acm *acm = func_to_acm(f);
343 struct usb_composite_dev *cdev = f->config->cdev;
344 struct usb_request *req = cdev->req;
345 int value = -EOPNOTSUPP;
346 u16 w_index = le16_to_cpu(ctrl->wIndex);
347 u16 w_value = le16_to_cpu(ctrl->wValue);
348 u16 w_length = le16_to_cpu(ctrl->wLength);
349
350 /* composite driver infrastructure handles everything except
351 * CDC class messages; interface activation uses set_alt().
352 *
353 * Note CDC spec table 4 lists the ACM request profile. It requires
354 * encapsulated command support ... we don't handle any, and respond
355 * to them by stalling. Options include get/set/clear comm features
356 * (not that useful) and SEND_BREAK.
357 */
358 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
359
360 /* SET_LINE_CODING ... just read and save what the host sends */
361 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
362 | USB_CDC_REQ_SET_LINE_CODING:
363 if (w_length != sizeof(struct usb_cdc_line_coding)
364 || w_index != acm->ctrl_id)
365 goto invalid;
366
367 value = w_length;
368 cdev->gadget->ep0->driver_data = acm;
369 req->complete = acm_complete_set_line_coding;
370 break;
371
372 /* GET_LINE_CODING ... return what host sent, or initial value */
373 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
374 | USB_CDC_REQ_GET_LINE_CODING:
375 if (w_index != acm->ctrl_id)
376 goto invalid;
377
378 value = min_t(unsigned, w_length,
379 sizeof(struct usb_cdc_line_coding));
380 memcpy(req->buf, &acm->port_line_coding, value);
381 break;
382
383 /* SET_CONTROL_LINE_STATE ... save what the host sent */
384 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
385 | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
386 if (w_index != acm->ctrl_id)
387 goto invalid;
388
389 value = 0;
390
391 /* FIXME we should not allow data to flow until the
392 * host sets the ACM_CTRL_DTR bit; and when it clears
393 * that bit, we should return to that no-flow state.
394 */
395 acm->port_handshake_bits = w_value;
396 break;
397
398 default:
399invalid:
400 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
401 ctrl->bRequestType, ctrl->bRequest,
402 w_value, w_index, w_length);
403 }
404
405 /* respond with data transfer or status phase? */
406 if (value >= 0) {
407 DBG(cdev, "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
408 acm->port_num, ctrl->bRequestType, ctrl->bRequest,
409 w_value, w_index, w_length);
410 req->zero = 0;
411 req->length = value;
412 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
413 if (value < 0)
414 ERROR(cdev, "acm response on ttyGS%d, err %d\n",
415 acm->port_num, value);
416 }
417
418 /* device either stalls (value < 0) or reports success */
419 return value;
420}
421
422static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
423{
424 struct f_acm *acm = func_to_acm(f);
425 struct usb_composite_dev *cdev = f->config->cdev;
426
427 /* we know alt == 0, so this is an activation or a reset */
428
429 if (intf == acm->ctrl_id) {
430 if (acm->notify->driver_data) {
431 VDBG(cdev, "reset acm control interface %d\n", intf);
432 usb_ep_disable(acm->notify);
433 } else {
434 VDBG(cdev, "init acm ctrl interface %d\n", intf);
435 if (config_ep_by_speed(cdev->gadget, f, acm->notify))
436 return -EINVAL;
437 }
438 usb_ep_enable(acm->notify);
439 acm->notify->driver_data = acm;
440
441 } else if (intf == acm->data_id) {
442 if (acm->port.in->driver_data) {
443 DBG(cdev, "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 DBG(cdev, "activate acm ttyGS%d\n", acm->port_num);
448 if (config_ep_by_speed(cdev->gadget, f,
449 acm->port.in) ||
450 config_ep_by_speed(cdev->gadget, f,
451 acm->port.out)) {
452 acm->port.in->desc = NULL;
453 acm->port.out->desc = NULL;
454 return -EINVAL;
455 }
456 }
457 gserial_connect(&acm->port, acm->port_num);
458
459 } else
460 return -EINVAL;
461
462 return 0;
463}
464
465static void acm_disable(struct usb_function *f)
466{
467 struct f_acm *acm = func_to_acm(f);
468 struct usb_composite_dev *cdev = f->config->cdev;
469
470 DBG(cdev, "acm ttyGS%d deactivated\n", acm->port_num);
471 gserial_disconnect(&acm->port);
472 usb_ep_disable(acm->notify);
473 acm->notify->driver_data = NULL;
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 */
492static 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
533static 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
538 spin_lock(&acm->lock);
539 if (acm->notify_req) {
540 DBG(cdev, "acm ttyGS%d serial state %04x\n",
541 acm->port_num, acm->serial_state);
542 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
543 0, &acm->serial_state, sizeof(acm->serial_state));
544 } else {
545 acm->pending = true;
546 status = 0;
547 }
548 spin_unlock(&acm->lock);
549 return status;
550}
551
552static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
553{
554 struct f_acm *acm = req->context;
555 u8 doit = false;
556
557 /* on this call path we do NOT hold the port spinlock,
558 * which is why ACM needs its own spinlock
559 */
560 spin_lock(&acm->lock);
561 if (req->status != -ESHUTDOWN)
562 doit = acm->pending;
563 acm->notify_req = req;
564 spin_unlock(&acm->lock);
565
566 if (doit)
567 acm_notify_serial_state(acm);
568}
569
570/* connect == the TTY link is open */
571
572static void acm_connect(struct gserial *port)
573{
574 struct f_acm *acm = port_to_acm(port);
575
576 acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
577 acm_notify_serial_state(acm);
578}
579
580static void acm_disconnect(struct gserial *port)
581{
582 struct f_acm *acm = port_to_acm(port);
583
584 acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
585 acm_notify_serial_state(acm);
586}
587
588static int acm_send_break(struct gserial *port, int duration)
589{
590 struct f_acm *acm = port_to_acm(port);
591 u16 state;
592
593 state = acm->serial_state;
594 state &= ~ACM_CTRL_BRK;
595 if (duration)
596 state |= ACM_CTRL_BRK;
597
598 acm->serial_state = state;
599 return acm_notify_serial_state(acm);
600}
601
602/*-------------------------------------------------------------------------*/
603
604/* ACM function driver setup/binding */
605static int
606acm_bind(struct usb_configuration *c, struct usb_function *f)
607{
608 struct usb_composite_dev *cdev = c->cdev;
609 struct f_acm *acm = func_to_acm(f);
610 struct usb_string *us;
611 int status;
612 struct usb_ep *ep;
613
614 /* REVISIT might want instance-specific strings to help
615 * distinguish instances ...
616 */
617
618 /* maybe allocate device-global string IDs, and patch descriptors */
619 us = usb_gstrings_attach(cdev, acm_strings,
620 ARRAY_SIZE(acm_string_defs));
621 if (IS_ERR(us))
622 return PTR_ERR(us);
623 acm_control_interface_desc.iInterface = us[ACM_CTRL_IDX].id;
624 acm_data_interface_desc.iInterface = us[ACM_DATA_IDX].id;
625 acm_iad_descriptor.iFunction = us[ACM_IAD_IDX].id;
626
627 /* allocate instance-specific interface IDs, and patch descriptors */
628 status = usb_interface_id(c, f);
629 if (status < 0)
630 goto fail;
631 acm->ctrl_id = status;
632 acm_iad_descriptor.bFirstInterface = status;
633
634 acm_control_interface_desc.bInterfaceNumber = status;
635 acm_union_desc .bMasterInterface0 = status;
636
637 status = usb_interface_id(c, f);
638 if (status < 0)
639 goto fail;
640 acm->data_id = status;
641
642 acm_data_interface_desc.bInterfaceNumber = status;
643 acm_union_desc.bSlaveInterface0 = status;
644 acm_call_mgmt_descriptor.bDataInterface = status;
645
646 status = -ENODEV;
647
648 /* allocate instance-specific endpoints */
649 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
650 if (!ep)
651 goto fail;
652 acm->port.in = ep;
653 ep->driver_data = cdev; /* claim */
654
655 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
656 if (!ep)
657 goto fail;
658 acm->port.out = ep;
659 ep->driver_data = cdev; /* claim */
660
661 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
662 if (!ep)
663 goto fail;
664 acm->notify = ep;
665 ep->driver_data = cdev; /* claim */
666
667 /* allocate notification */
668 acm->notify_req = gs_alloc_req(ep,
669 sizeof(struct usb_cdc_notification) + 2,
670 GFP_KERNEL);
671 if (!acm->notify_req)
672 goto fail;
673
674 acm->notify_req->complete = acm_cdc_notify_complete;
675 acm->notify_req->context = acm;
676
677 /* support all relevant hardware speeds... we expect that when
678 * hardware is dual speed, all bulk-capable endpoints work at
679 * both speeds
680 */
681 acm_hs_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
682 acm_hs_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
683 acm_hs_notify_desc.bEndpointAddress =
684 acm_fs_notify_desc.bEndpointAddress;
685
686 acm_ss_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
687 acm_ss_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
688
689 status = usb_assign_descriptors(f, acm_fs_function, acm_hs_function,
690 acm_ss_function);
691 if (status)
692 goto fail;
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
702fail:
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
719static void acm_unbind(struct usb_configuration *c, struct usb_function *f)
720{
721 struct f_acm *acm = func_to_acm(f);
722
723 acm_string_defs[0].id = 0;
724 usb_free_all_descriptors(f);
725 if (acm->notify_req)
726 gs_free_req(acm->notify, acm->notify_req);
727}
728
729static void acm_free_func(struct usb_function *f)
730{
731 struct f_acm *acm = func_to_acm(f);
732
733 kfree(acm);
734}
735
736static struct usb_function *acm_alloc_func(struct usb_function_instance *fi)
737{
738 struct f_serial_opts *opts;
739 struct f_acm *acm;
740
741 acm = kzalloc(sizeof(*acm), GFP_KERNEL);
742 if (!acm)
743 return ERR_PTR(-ENOMEM);
744
745 spin_lock_init(&acm->lock);
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.set_alt = acm_set_alt;
756 acm->port.func.setup = acm_setup;
757 acm->port.func.disable = acm_disable;
758
759 opts = container_of(fi, struct f_serial_opts, func_inst);
760 acm->port_num = opts->port_num;
761 acm->port.func.unbind = acm_unbind;
762 acm->port.func.free_func = acm_free_func;
763
764 return &acm->port.func;
765}
766
767static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
768{
769 return container_of(to_config_group(item), struct f_serial_opts,
770 func_inst.group);
771}
772
773CONFIGFS_ATTR_STRUCT(f_serial_opts);
774static ssize_t f_acm_attr_show(struct config_item *item,
775 struct configfs_attribute *attr,
776 char *page)
777{
778 struct f_serial_opts *opts = to_f_serial_opts(item);
779 struct f_serial_opts_attribute *f_serial_opts_attr =
780 container_of(attr, struct f_serial_opts_attribute, attr);
781 ssize_t ret = 0;
782
783 if (f_serial_opts_attr->show)
784 ret = f_serial_opts_attr->show(opts, page);
785 return ret;
786}
787
788static void acm_attr_release(struct config_item *item)
789{
790 struct f_serial_opts *opts = to_f_serial_opts(item);
791
792 usb_put_function_instance(&opts->func_inst);
793}
794
795static struct configfs_item_operations acm_item_ops = {
796 .release = acm_attr_release,
797 .show_attribute = f_acm_attr_show,
798};
799
800static ssize_t f_acm_port_num_show(struct f_serial_opts *opts, char *page)
801{
802 return sprintf(page, "%u\n", opts->port_num);
803}
804
805static struct f_serial_opts_attribute f_acm_port_num =
806 __CONFIGFS_ATTR_RO(port_num, f_acm_port_num_show);
807
808
809static struct configfs_attribute *acm_attrs[] = {
810 &f_acm_port_num.attr,
811 NULL,
812};
813
814static struct config_item_type acm_func_type = {
815 .ct_item_ops = &acm_item_ops,
816 .ct_attrs = acm_attrs,
817 .ct_owner = THIS_MODULE,
818};
819
820static void acm_free_instance(struct usb_function_instance *fi)
821{
822 struct f_serial_opts *opts;
823
824 opts = container_of(fi, struct f_serial_opts, func_inst);
825 gserial_free_line(opts->port_num);
826 kfree(opts);
827}
828
829static struct usb_function_instance *acm_alloc_instance(void)
830{
831 struct f_serial_opts *opts;
832 int ret;
833
834 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
835 if (!opts)
836 return ERR_PTR(-ENOMEM);
837 opts->func_inst.free_func_inst = acm_free_instance;
838 ret = gserial_alloc_line(&opts->port_num);
839 if (ret) {
840 kfree(opts);
841 return ERR_PTR(ret);
842 }
843 config_group_init_type_name(&opts->func_inst.group, "",
844 &acm_func_type);
845 return &opts->func_inst;
846}
847DECLARE_USB_FUNCTION_INIT(acm, acm_alloc_instance, acm_alloc_func);
848MODULE_LICENSE("GPL");