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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 acm_ep_descs {
43	struct usb_endpoint_descriptor	*in;
44	struct usb_endpoint_descriptor	*out;
45	struct usb_endpoint_descriptor	*notify;
46};
47
48struct f_acm {
49	struct gserial			port;
50	u8				ctrl_id, data_id;
51	u8				port_num;
52
53	u8				pending;
54
55	/* lock is mostly for pending and notify_req ... they get accessed
56	 * by callbacks both from tty (open/close/break) under its spinlock,
57	 * and notify_req.complete() which can't use that lock.
58	 */
59	spinlock_t			lock;
60
61	struct acm_ep_descs		fs;
62	struct acm_ep_descs		hs;
63
64	struct usb_ep			*notify;
65	struct usb_endpoint_descriptor	*notify_desc;
66	struct usb_request		*notify_req;
67
68	struct usb_cdc_line_coding	port_line_coding;	/* 8-N-1 etc */
69
70	/* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
71	u16				port_handshake_bits;
72#define ACM_CTRL_RTS	(1 << 1)	/* unused with full duplex */
73#define ACM_CTRL_DTR	(1 << 0)	/* host is ready for data r/w */
74
75	/* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
76	u16				serial_state;
77#define ACM_CTRL_OVERRUN	(1 << 6)
78#define ACM_CTRL_PARITY		(1 << 5)
79#define ACM_CTRL_FRAMING	(1 << 4)
80#define ACM_CTRL_RI		(1 << 3)
81#define ACM_CTRL_BRK		(1 << 2)
82#define ACM_CTRL_DSR		(1 << 1)
83#define ACM_CTRL_DCD		(1 << 0)
84};
85
86static inline struct f_acm *func_to_acm(struct usb_function *f)
87{
88	return container_of(f, struct f_acm, port.func);
89}
90
91static inline struct f_acm *port_to_acm(struct gserial *p)
92{
93	return container_of(p, struct f_acm, port);
94}
95
96/*-------------------------------------------------------------------------*/
97
98/* notification endpoint uses smallish and infrequent fixed-size messages */
99
100#define GS_LOG2_NOTIFY_INTERVAL		5	/* 1 << 5 == 32 msec */
101#define GS_NOTIFY_MAXPACKET		10	/* notification + 2 bytes */
102
103/* interface and class descriptors: */
104
105static struct usb_interface_assoc_descriptor
106acm_iad_descriptor = {
107	.bLength =		sizeof acm_iad_descriptor,
108	.bDescriptorType =	USB_DT_INTERFACE_ASSOCIATION,
109
110	/* .bFirstInterface =	DYNAMIC, */
111	.bInterfaceCount = 	2,	// control + data
112	.bFunctionClass =	USB_CLASS_COMM,
113	.bFunctionSubClass =	USB_CDC_SUBCLASS_ACM,
114	.bFunctionProtocol =	USB_CDC_ACM_PROTO_AT_V25TER,
115	/* .iFunction =		DYNAMIC */
116};
117
118
119static struct usb_interface_descriptor acm_control_interface_desc = {
120	.bLength =		USB_DT_INTERFACE_SIZE,
121	.bDescriptorType =	USB_DT_INTERFACE,
122	/* .bInterfaceNumber = DYNAMIC */
123	.bNumEndpoints =	1,
124	.bInterfaceClass =	USB_CLASS_COMM,
125	.bInterfaceSubClass =	USB_CDC_SUBCLASS_ACM,
126	.bInterfaceProtocol =	USB_CDC_ACM_PROTO_AT_V25TER,
127	/* .iInterface = DYNAMIC */
128};
129
130static struct usb_interface_descriptor acm_data_interface_desc = {
131	.bLength =		USB_DT_INTERFACE_SIZE,
132	.bDescriptorType =	USB_DT_INTERFACE,
133	/* .bInterfaceNumber = DYNAMIC */
134	.bNumEndpoints =	2,
135	.bInterfaceClass =	USB_CLASS_CDC_DATA,
136	.bInterfaceSubClass =	0,
137	.bInterfaceProtocol =	0,
138	/* .iInterface = DYNAMIC */
139};
140
141static struct usb_cdc_header_desc acm_header_desc = {
142	.bLength =		sizeof(acm_header_desc),
143	.bDescriptorType =	USB_DT_CS_INTERFACE,
144	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
145	.bcdCDC =		cpu_to_le16(0x0110),
146};
147
148static struct usb_cdc_call_mgmt_descriptor
149acm_call_mgmt_descriptor = {
150	.bLength =		sizeof(acm_call_mgmt_descriptor),
151	.bDescriptorType =	USB_DT_CS_INTERFACE,
152	.bDescriptorSubType =	USB_CDC_CALL_MANAGEMENT_TYPE,
153	.bmCapabilities =	0,
154	/* .bDataInterface = DYNAMIC */
155};
156
157static struct usb_cdc_acm_descriptor acm_descriptor = {
158	.bLength =		sizeof(acm_descriptor),
159	.bDescriptorType =	USB_DT_CS_INTERFACE,
160	.bDescriptorSubType =	USB_CDC_ACM_TYPE,
161	.bmCapabilities =	USB_CDC_CAP_LINE,
162};
163
164static struct usb_cdc_union_desc acm_union_desc = {
165	.bLength =		sizeof(acm_union_desc),
166	.bDescriptorType =	USB_DT_CS_INTERFACE,
167	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
168	/* .bMasterInterface0 =	DYNAMIC */
169	/* .bSlaveInterface0 =	DYNAMIC */
170};
171
172/* full speed support: */
173
174static struct usb_endpoint_descriptor acm_fs_notify_desc = {
175	.bLength =		USB_DT_ENDPOINT_SIZE,
176	.bDescriptorType =	USB_DT_ENDPOINT,
177	.bEndpointAddress =	USB_DIR_IN,
178	.bmAttributes =		USB_ENDPOINT_XFER_INT,
179	.wMaxPacketSize =	cpu_to_le16(GS_NOTIFY_MAXPACKET),
180	.bInterval =		1 << GS_LOG2_NOTIFY_INTERVAL,
181};
182
183static struct usb_endpoint_descriptor acm_fs_in_desc = {
184	.bLength =		USB_DT_ENDPOINT_SIZE,
185	.bDescriptorType =	USB_DT_ENDPOINT,
186	.bEndpointAddress =	USB_DIR_IN,
187	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
188};
189
190static struct usb_endpoint_descriptor acm_fs_out_desc = {
191	.bLength =		USB_DT_ENDPOINT_SIZE,
192	.bDescriptorType =	USB_DT_ENDPOINT,
193	.bEndpointAddress =	USB_DIR_OUT,
194	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
195};
196
197static struct usb_descriptor_header *acm_fs_function[] = {
198	(struct usb_descriptor_header *) &acm_iad_descriptor,
199	(struct usb_descriptor_header *) &acm_control_interface_desc,
200	(struct usb_descriptor_header *) &acm_header_desc,
201	(struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
202	(struct usb_descriptor_header *) &acm_descriptor,
203	(struct usb_descriptor_header *) &acm_union_desc,
204	(struct usb_descriptor_header *) &acm_fs_notify_desc,
205	(struct usb_descriptor_header *) &acm_data_interface_desc,
206	(struct usb_descriptor_header *) &acm_fs_in_desc,
207	(struct usb_descriptor_header *) &acm_fs_out_desc,
208	NULL,
209};
210
211/* high speed support: */
212
213static struct usb_endpoint_descriptor acm_hs_notify_desc = {
214	.bLength =		USB_DT_ENDPOINT_SIZE,
215	.bDescriptorType =	USB_DT_ENDPOINT,
216	.bEndpointAddress =	USB_DIR_IN,
217	.bmAttributes =		USB_ENDPOINT_XFER_INT,
218	.wMaxPacketSize =	cpu_to_le16(GS_NOTIFY_MAXPACKET),
219	.bInterval =		GS_LOG2_NOTIFY_INTERVAL+4,
220};
221
222static struct usb_endpoint_descriptor acm_hs_in_desc = {
223	.bLength =		USB_DT_ENDPOINT_SIZE,
224	.bDescriptorType =	USB_DT_ENDPOINT,
225	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
226	.wMaxPacketSize =	cpu_to_le16(512),
227};
228
229static struct usb_endpoint_descriptor acm_hs_out_desc = {
230	.bLength =		USB_DT_ENDPOINT_SIZE,
231	.bDescriptorType =	USB_DT_ENDPOINT,
232	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
233	.wMaxPacketSize =	cpu_to_le16(512),
234};
235
236static struct usb_descriptor_header *acm_hs_function[] = {
237	(struct usb_descriptor_header *) &acm_iad_descriptor,
238	(struct usb_descriptor_header *) &acm_control_interface_desc,
239	(struct usb_descriptor_header *) &acm_header_desc,
240	(struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
241	(struct usb_descriptor_header *) &acm_descriptor,
242	(struct usb_descriptor_header *) &acm_union_desc,
243	(struct usb_descriptor_header *) &acm_hs_notify_desc,
244	(struct usb_descriptor_header *) &acm_data_interface_desc,
245	(struct usb_descriptor_header *) &acm_hs_in_desc,
246	(struct usb_descriptor_header *) &acm_hs_out_desc,
247	NULL,
248};
249
250/* string descriptors: */
251
252#define ACM_CTRL_IDX	0
253#define ACM_DATA_IDX	1
254#define ACM_IAD_IDX	2
255
256/* static strings, in UTF-8 */
257static struct usb_string acm_string_defs[] = {
258	[ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
259	[ACM_DATA_IDX].s = "CDC ACM Data",
260	[ACM_IAD_IDX ].s = "CDC Serial",
261	{  /* ZEROES END LIST */ },
262};
263
264static struct usb_gadget_strings acm_string_table = {
265	.language =		0x0409,	/* en-us */
266	.strings =		acm_string_defs,
267};
268
269static struct usb_gadget_strings *acm_strings[] = {
270	&acm_string_table,
271	NULL,
272};
273
274/*-------------------------------------------------------------------------*/
275
276/* ACM control ... data handling is delegated to tty library code.
277 * The main task of this function is to activate and deactivate
278 * that code based on device state; track parameters like line
279 * speed, handshake state, and so on; and issue notifications.
280 */
281
282static void acm_complete_set_line_coding(struct usb_ep *ep,
283		struct usb_request *req)
284{
285	struct f_acm	*acm = ep->driver_data;
286	struct usb_composite_dev *cdev = acm->port.func.config->cdev;
287
288	if (req->status != 0) {
289		DBG(cdev, "acm ttyGS%d completion, err %d\n",
290				acm->port_num, req->status);
291		return;
292	}
293
294	/* normal completion */
295	if (req->actual != sizeof(acm->port_line_coding)) {
296		DBG(cdev, "acm ttyGS%d short resp, len %d\n",
297				acm->port_num, req->actual);
298		usb_ep_set_halt(ep);
299	} else {
300		struct usb_cdc_line_coding	*value = req->buf;
301
302		/* REVISIT:  we currently just remember this data.
303		 * If we change that, (a) validate it first, then
304		 * (b) update whatever hardware needs updating,
305		 * (c) worry about locking.  This is information on
306		 * the order of 9600-8-N-1 ... most of which means
307		 * nothing unless we control a real RS232 line.
308		 */
309		acm->port_line_coding = *value;
310	}
311}
312
313static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
314{
315	struct f_acm		*acm = func_to_acm(f);
316	struct usb_composite_dev *cdev = f->config->cdev;
317	struct usb_request	*req = cdev->req;
318	int			value = -EOPNOTSUPP;
319	u16			w_index = le16_to_cpu(ctrl->wIndex);
320	u16			w_value = le16_to_cpu(ctrl->wValue);
321	u16			w_length = le16_to_cpu(ctrl->wLength);
322
323	/* composite driver infrastructure handles everything except
324	 * CDC class messages; interface activation uses set_alt().
325	 *
326	 * Note CDC spec table 4 lists the ACM request profile.  It requires
327	 * encapsulated command support ... we don't handle any, and respond
328	 * to them by stalling.  Options include get/set/clear comm features
329	 * (not that useful) and SEND_BREAK.
330	 */
331	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
332
333	/* SET_LINE_CODING ... just read and save what the host sends */
334	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
335			| USB_CDC_REQ_SET_LINE_CODING:
336		if (w_length != sizeof(struct usb_cdc_line_coding)
337				|| w_index != acm->ctrl_id)
338			goto invalid;
339
340		value = w_length;
341		cdev->gadget->ep0->driver_data = acm;
342		req->complete = acm_complete_set_line_coding;
343		break;
344
345	/* GET_LINE_CODING ... return what host sent, or initial value */
346	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
347			| USB_CDC_REQ_GET_LINE_CODING:
348		if (w_index != acm->ctrl_id)
349			goto invalid;
350
351		value = min_t(unsigned, w_length,
352				sizeof(struct usb_cdc_line_coding));
353		memcpy(req->buf, &acm->port_line_coding, value);
354		break;
355
356	/* SET_CONTROL_LINE_STATE ... save what the host sent */
357	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
358			| USB_CDC_REQ_SET_CONTROL_LINE_STATE:
359		if (w_index != acm->ctrl_id)
360			goto invalid;
361
362		value = 0;
363
364		acm->port_handshake_bits = w_value;
365		break;
366
367	default:
368invalid:
369		VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
370			ctrl->bRequestType, ctrl->bRequest,
371			w_value, w_index, w_length);
372	}
373
374	/* respond with data transfer or status phase? */
375	if (value >= 0) {
376		DBG(cdev, "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
377			acm->port_num, ctrl->bRequestType, ctrl->bRequest,
378			w_value, w_index, w_length);
379		req->zero = 0;
380		req->length = value;
381		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
382		if (value < 0)
383			ERROR(cdev, "acm response on ttyGS%d, err %d\n",
384					acm->port_num, value);
385	}
386
387	/* device either stalls (value < 0) or reports success */
388	return value;
389}
390
391static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
392{
393	struct f_acm		*acm = func_to_acm(f);
394	struct usb_composite_dev *cdev = f->config->cdev;
395
396	/* we know alt == 0, so this is an activation or a reset */
397
398	if (intf == acm->ctrl_id) {
399		if (acm->notify->driver_data) {
400			VDBG(cdev, "reset acm control interface %d\n", intf);
401			usb_ep_disable(acm->notify);
402		} else {
403			VDBG(cdev, "init acm ctrl interface %d\n", intf);
404			acm->notify_desc = ep_choose(cdev->gadget,
405					acm->hs.notify,
406					acm->fs.notify);
407		}
408		usb_ep_enable(acm->notify, acm->notify_desc);
409		acm->notify->driver_data = acm;
410
411	} else if (intf == acm->data_id) {
412		if (acm->port.in->driver_data) {
413			DBG(cdev, "reset acm ttyGS%d\n", acm->port_num);
414			gserial_disconnect(&acm->port);
415		} else {
416			DBG(cdev, "activate acm ttyGS%d\n", acm->port_num);
417			acm->port.in_desc = ep_choose(cdev->gadget,
418					acm->hs.in, acm->fs.in);
419			acm->port.out_desc = ep_choose(cdev->gadget,
420					acm->hs.out, acm->fs.out);
421		}
422		gserial_connect(&acm->port, acm->port_num);
423
424	} else
425		return -EINVAL;
426
427	return 0;
428}
429
430static void acm_disable(struct usb_function *f)
431{
432	struct f_acm	*acm = func_to_acm(f);
433	struct usb_composite_dev *cdev = f->config->cdev;
434
435	DBG(cdev, "acm ttyGS%d deactivated\n", acm->port_num);
436	gserial_disconnect(&acm->port);
437	usb_ep_disable(acm->notify);
438	acm->notify->driver_data = NULL;
439}
440
441/*-------------------------------------------------------------------------*/
442
443/**
444 * acm_cdc_notify - issue CDC notification to host
445 * @acm: wraps host to be notified
446 * @type: notification type
447 * @value: Refer to cdc specs, wValue field.
448 * @data: data to be sent
449 * @length: size of data
450 * Context: irqs blocked, acm->lock held, acm_notify_req non-null
451 *
452 * Returns zero on success or a negative errno.
453 *
454 * See section 6.3.5 of the CDC 1.1 specification for information
455 * about the only notification we issue:  SerialState change.
456 */
457static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
458		void *data, unsigned length)
459{
460	struct usb_ep			*ep = acm->notify;
461	struct usb_request		*req;
462	struct usb_cdc_notification	*notify;
463	const unsigned			len = sizeof(*notify) + length;
464	void				*buf;
465	int				status;
466
467	req = acm->notify_req;
468	acm->notify_req = NULL;
469	acm->pending = false;
470
471	req->length = len;
472	notify = req->buf;
473	buf = notify + 1;
474
475	notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
476			| USB_RECIP_INTERFACE;
477	notify->bNotificationType = type;
478	notify->wValue = cpu_to_le16(value);
479	notify->wIndex = cpu_to_le16(acm->ctrl_id);
480	notify->wLength = cpu_to_le16(length);
481	memcpy(buf, data, length);
482
483	/* ep_queue() can complete immediately if it fills the fifo... */
484	spin_unlock(&acm->lock);
485	status = usb_ep_queue(ep, req, GFP_ATOMIC);
486	spin_lock(&acm->lock);
487
488	if (status < 0) {
489		ERROR(acm->port.func.config->cdev,
490				"acm ttyGS%d can't notify serial state, %d\n",
491				acm->port_num, status);
492		acm->notify_req = req;
493	}
494
495	return status;
496}
497
498static int acm_notify_serial_state(struct f_acm *acm)
499{
500	struct usb_composite_dev *cdev = acm->port.func.config->cdev;
501	int			status;
502
503	spin_lock(&acm->lock);
504	if (acm->notify_req) {
505		DBG(cdev, "acm ttyGS%d serial state %04x\n",
506				acm->port_num, acm->serial_state);
507		status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
508				0, &acm->serial_state, sizeof(acm->serial_state));
509	} else {
510		acm->pending = true;
511		status = 0;
512	}
513	spin_unlock(&acm->lock);
514	return status;
515}
516
517static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
518{
519	struct f_acm		*acm = req->context;
520	u8			doit = false;
521
522	/* on this call path we do NOT hold the port spinlock,
523	 * which is why ACM needs its own spinlock
524	 */
525	spin_lock(&acm->lock);
526	if (req->status != -ESHUTDOWN)
527		doit = acm->pending;
528	acm->notify_req = req;
529	spin_unlock(&acm->lock);
530
531	if (doit)
532		acm_notify_serial_state(acm);
533}
534
535/* connect == the TTY link is open */
536
537static void acm_connect(struct gserial *port)
538{
539	struct f_acm		*acm = port_to_acm(port);
540
541	acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
542	acm_notify_serial_state(acm);
543}
544
545static void acm_disconnect(struct gserial *port)
546{
547	struct f_acm		*acm = port_to_acm(port);
548
549	acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
550	acm_notify_serial_state(acm);
551}
552
553static int acm_send_break(struct gserial *port, int duration)
554{
555	struct f_acm		*acm = port_to_acm(port);
556	u16			state;
557
558	state = acm->serial_state;
559	state &= ~ACM_CTRL_BRK;
560	if (duration)
561		state |= ACM_CTRL_BRK;
562
563	acm->serial_state = state;
564	return acm_notify_serial_state(acm);
565}
566
567/*-------------------------------------------------------------------------*/
568
569/* ACM function driver setup/binding */
570static int
571acm_bind(struct usb_configuration *c, struct usb_function *f)
572{
573	struct usb_composite_dev *cdev = c->cdev;
574	struct f_acm		*acm = func_to_acm(f);
575	int			status;
576	struct usb_ep		*ep;
577
578	/* allocate instance-specific interface IDs, and patch descriptors */
579	status = usb_interface_id(c, f);
580	if (status < 0)
581		goto fail;
582	acm->ctrl_id = status;
583	acm_iad_descriptor.bFirstInterface = status;
584
585	acm_control_interface_desc.bInterfaceNumber = status;
586	acm_union_desc .bMasterInterface0 = status;
587
588	status = usb_interface_id(c, f);
589	if (status < 0)
590		goto fail;
591	acm->data_id = status;
592
593	acm_data_interface_desc.bInterfaceNumber = status;
594	acm_union_desc.bSlaveInterface0 = status;
595	acm_call_mgmt_descriptor.bDataInterface = status;
596
597	status = -ENODEV;
598
599	/* allocate instance-specific endpoints */
600	ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
601	if (!ep)
602		goto fail;
603	acm->port.in = ep;
604	ep->driver_data = cdev;	/* claim */
605
606	ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
607	if (!ep)
608		goto fail;
609	acm->port.out = ep;
610	ep->driver_data = cdev;	/* claim */
611
612	ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
613	if (!ep)
614		goto fail;
615	acm->notify = ep;
616	ep->driver_data = cdev;	/* claim */
617
618	/* allocate notification */
619	acm->notify_req = gs_alloc_req(ep,
620			sizeof(struct usb_cdc_notification) + 2,
621			GFP_KERNEL);
622	if (!acm->notify_req)
623		goto fail;
624
625	acm->notify_req->complete = acm_cdc_notify_complete;
626	acm->notify_req->context = acm;
627
628	/* copy descriptors, and track endpoint copies */
629	f->descriptors = usb_copy_descriptors(acm_fs_function);
630	if (!f->descriptors)
631		goto fail;
632
633	acm->fs.in = usb_find_endpoint(acm_fs_function,
634			f->descriptors, &acm_fs_in_desc);
635	acm->fs.out = usb_find_endpoint(acm_fs_function,
636			f->descriptors, &acm_fs_out_desc);
637	acm->fs.notify = usb_find_endpoint(acm_fs_function,
638			f->descriptors, &acm_fs_notify_desc);
639
640	/* support all relevant hardware speeds... we expect that when
641	 * hardware is dual speed, all bulk-capable endpoints work at
642	 * both speeds
643	 */
644	if (gadget_is_dualspeed(c->cdev->gadget)) {
645		acm_hs_in_desc.bEndpointAddress =
646				acm_fs_in_desc.bEndpointAddress;
647		acm_hs_out_desc.bEndpointAddress =
648				acm_fs_out_desc.bEndpointAddress;
649		acm_hs_notify_desc.bEndpointAddress =
650				acm_fs_notify_desc.bEndpointAddress;
651
652		/* copy descriptors, and track endpoint copies */
653		f->hs_descriptors = usb_copy_descriptors(acm_hs_function);
654
655		acm->hs.in = usb_find_endpoint(acm_hs_function,
656				f->hs_descriptors, &acm_hs_in_desc);
657		acm->hs.out = usb_find_endpoint(acm_hs_function,
658				f->hs_descriptors, &acm_hs_out_desc);
659		acm->hs.notify = usb_find_endpoint(acm_hs_function,
660				f->hs_descriptors, &acm_hs_notify_desc);
661	}
662
663	DBG(cdev, "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
664			acm->port_num,
665			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
666			acm->port.in->name, acm->port.out->name,
667			acm->notify->name);
668	return 0;
669
670fail:
671	if (acm->notify_req)
672		gs_free_req(acm->notify, acm->notify_req);
673
674	/* we might as well release our claims on endpoints */
675	if (acm->notify)
676		acm->notify->driver_data = NULL;
677	if (acm->port.out)
678		acm->port.out->driver_data = NULL;
679	if (acm->port.in)
680		acm->port.in->driver_data = NULL;
681
682	ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
683
684	return status;
685}
686
687static void
688acm_unbind(struct usb_configuration *c, struct usb_function *f)
689{
690	struct f_acm		*acm = func_to_acm(f);
691
692	if (gadget_is_dualspeed(c->cdev->gadget))
693		usb_free_descriptors(f->hs_descriptors);
694	usb_free_descriptors(f->descriptors);
695	gs_free_req(acm->notify, acm->notify_req);
696	kfree(acm);
697}
698
699/* Some controllers can't support CDC ACM ... */
700static inline bool can_support_cdc(struct usb_configuration *c)
701{
702	/* everything else is *probably* fine ... */
703	return true;
704}
705
706/**
707 * acm_bind_config - add a CDC ACM function to a configuration
708 * @c: the configuration to support the CDC ACM instance
709 * @port_num: /dev/ttyGS* port this interface will use
710 * Context: single threaded during gadget setup
711 *
712 * Returns zero on success, else negative errno.
713 *
714 * Caller must have called @gserial_setup() with enough ports to
715 * handle all the ones it binds.  Caller is also responsible
716 * for calling @gserial_cleanup() before module unload.
717 */
718int acm_bind_config(struct usb_configuration *c, u8 port_num)
719{
720	struct f_acm	*acm;
721	int		status;
722
723	if (!can_support_cdc(c))
724		return -EINVAL;
725
726	/* REVISIT might want instance-specific strings to help
727	 * distinguish instances ...
728	 */
729
730	/* maybe allocate device-global string IDs, and patch descriptors */
731	if (acm_string_defs[ACM_CTRL_IDX].id == 0) {
732		status = usb_string_id(c->cdev);
733		if (status < 0)
734			return status;
735		acm_string_defs[ACM_CTRL_IDX].id = status;
736
737		acm_control_interface_desc.iInterface = status;
738
739		status = usb_string_id(c->cdev);
740		if (status < 0)
741			return status;
742		acm_string_defs[ACM_DATA_IDX].id = status;
743
744		acm_data_interface_desc.iInterface = status;
745
746		status = usb_string_id(c->cdev);
747		if (status < 0)
748			return status;
749		acm_string_defs[ACM_IAD_IDX].id = status;
750
751		acm_iad_descriptor.iFunction = status;
752	}
753
754	/* allocate and initialize one new instance */
755	acm = kzalloc(sizeof *acm, GFP_KERNEL);
756	if (!acm)
757		return -ENOMEM;
758
759	spin_lock_init(&acm->lock);
760
761	acm->port_num = port_num;
762
763	acm->port.connect = acm_connect;
764	acm->port.disconnect = acm_disconnect;
765	acm->port.send_break = acm_send_break;
766
767	acm->port.func.name = "acm";
768	acm->port.func.strings = acm_strings;
769	/* descriptors are per-instance copies */
770	acm->port.func.bind = acm_bind;
771	acm->port.func.unbind = acm_unbind;
772	acm->port.func.set_alt = acm_set_alt;
773	acm->port.func.setup = acm_setup;
774	acm->port.func.disable = acm_disable;
775
776	status = usb_add_function(c, &acm->port.func);
777	if (status)
778		kfree(acm);
779	return status;
780}
781