xref: /linux/drivers/usb/gadget/function/f_uac1.c (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
1 /*
2  * f_audio.c -- USB Audio class function driver
3   *
4  * Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
5  * Copyright (C) 2008 Analog Devices, Inc
6  *
7  * Enter bugs at http://blackfin.uclinux.org/
8  *
9  * Licensed under the GPL-2 or later.
10  */
11 
12 #include <linux/slab.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/device.h>
16 #include <linux/atomic.h>
17 
18 #include "u_uac1.h"
19 
20 static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value);
21 static int generic_get_cmd(struct usb_audio_control *con, u8 cmd);
22 
23 /*
24  * DESCRIPTORS ... most are static, but strings and full
25  * configuration descriptors are built on demand.
26  */
27 
28 /*
29  * We have two interfaces- AudioControl and AudioStreaming
30  * TODO: only supcard playback currently
31  */
32 #define F_AUDIO_AC_INTERFACE	0
33 #define F_AUDIO_AS_INTERFACE	1
34 #define F_AUDIO_NUM_INTERFACES	2
35 
36 /* B.3.1  Standard AC Interface Descriptor */
37 static struct usb_interface_descriptor ac_interface_desc = {
38 	.bLength =		USB_DT_INTERFACE_SIZE,
39 	.bDescriptorType =	USB_DT_INTERFACE,
40 	.bNumEndpoints =	0,
41 	.bInterfaceClass =	USB_CLASS_AUDIO,
42 	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOCONTROL,
43 };
44 
45 DECLARE_UAC_AC_HEADER_DESCRIPTOR(2);
46 
47 #define UAC_DT_AC_HEADER_LENGTH	UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
48 /* 1 input terminal, 1 output terminal and 1 feature unit */
49 #define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH + UAC_DT_INPUT_TERMINAL_SIZE \
50 	+ UAC_DT_OUTPUT_TERMINAL_SIZE + UAC_DT_FEATURE_UNIT_SIZE(0))
51 /* B.3.2  Class-Specific AC Interface Descriptor */
52 static struct uac1_ac_header_descriptor_2 ac_header_desc = {
53 	.bLength =		UAC_DT_AC_HEADER_LENGTH,
54 	.bDescriptorType =	USB_DT_CS_INTERFACE,
55 	.bDescriptorSubtype =	UAC_HEADER,
56 	.bcdADC =		__constant_cpu_to_le16(0x0100),
57 	.wTotalLength =		__constant_cpu_to_le16(UAC_DT_TOTAL_LENGTH),
58 	.bInCollection =	F_AUDIO_NUM_INTERFACES,
59 	.baInterfaceNr = {
60 		[0] =		F_AUDIO_AC_INTERFACE,
61 		[1] =		F_AUDIO_AS_INTERFACE,
62 	}
63 };
64 
65 #define INPUT_TERMINAL_ID	1
66 static struct uac_input_terminal_descriptor input_terminal_desc = {
67 	.bLength =		UAC_DT_INPUT_TERMINAL_SIZE,
68 	.bDescriptorType =	USB_DT_CS_INTERFACE,
69 	.bDescriptorSubtype =	UAC_INPUT_TERMINAL,
70 	.bTerminalID =		INPUT_TERMINAL_ID,
71 	.wTerminalType =	UAC_TERMINAL_STREAMING,
72 	.bAssocTerminal =	0,
73 	.wChannelConfig =	0x3,
74 };
75 
76 DECLARE_UAC_FEATURE_UNIT_DESCRIPTOR(0);
77 
78 #define FEATURE_UNIT_ID		2
79 static struct uac_feature_unit_descriptor_0 feature_unit_desc = {
80 	.bLength		= UAC_DT_FEATURE_UNIT_SIZE(0),
81 	.bDescriptorType	= USB_DT_CS_INTERFACE,
82 	.bDescriptorSubtype	= UAC_FEATURE_UNIT,
83 	.bUnitID		= FEATURE_UNIT_ID,
84 	.bSourceID		= INPUT_TERMINAL_ID,
85 	.bControlSize		= 2,
86 	.bmaControls[0]		= (UAC_FU_MUTE | UAC_FU_VOLUME),
87 };
88 
89 static struct usb_audio_control mute_control = {
90 	.list = LIST_HEAD_INIT(mute_control.list),
91 	.name = "Mute Control",
92 	.type = UAC_FU_MUTE,
93 	/* Todo: add real Mute control code */
94 	.set = generic_set_cmd,
95 	.get = generic_get_cmd,
96 };
97 
98 static struct usb_audio_control volume_control = {
99 	.list = LIST_HEAD_INIT(volume_control.list),
100 	.name = "Volume Control",
101 	.type = UAC_FU_VOLUME,
102 	/* Todo: add real Volume control code */
103 	.set = generic_set_cmd,
104 	.get = generic_get_cmd,
105 };
106 
107 static struct usb_audio_control_selector feature_unit = {
108 	.list = LIST_HEAD_INIT(feature_unit.list),
109 	.id = FEATURE_UNIT_ID,
110 	.name = "Mute & Volume Control",
111 	.type = UAC_FEATURE_UNIT,
112 	.desc = (struct usb_descriptor_header *)&feature_unit_desc,
113 };
114 
115 #define OUTPUT_TERMINAL_ID	3
116 static struct uac1_output_terminal_descriptor output_terminal_desc = {
117 	.bLength		= UAC_DT_OUTPUT_TERMINAL_SIZE,
118 	.bDescriptorType	= USB_DT_CS_INTERFACE,
119 	.bDescriptorSubtype	= UAC_OUTPUT_TERMINAL,
120 	.bTerminalID		= OUTPUT_TERMINAL_ID,
121 	.wTerminalType		= UAC_OUTPUT_TERMINAL_SPEAKER,
122 	.bAssocTerminal		= FEATURE_UNIT_ID,
123 	.bSourceID		= FEATURE_UNIT_ID,
124 };
125 
126 /* B.4.1  Standard AS Interface Descriptor */
127 static struct usb_interface_descriptor as_interface_alt_0_desc = {
128 	.bLength =		USB_DT_INTERFACE_SIZE,
129 	.bDescriptorType =	USB_DT_INTERFACE,
130 	.bAlternateSetting =	0,
131 	.bNumEndpoints =	0,
132 	.bInterfaceClass =	USB_CLASS_AUDIO,
133 	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
134 };
135 
136 static struct usb_interface_descriptor as_interface_alt_1_desc = {
137 	.bLength =		USB_DT_INTERFACE_SIZE,
138 	.bDescriptorType =	USB_DT_INTERFACE,
139 	.bAlternateSetting =	1,
140 	.bNumEndpoints =	1,
141 	.bInterfaceClass =	USB_CLASS_AUDIO,
142 	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
143 };
144 
145 /* B.4.2  Class-Specific AS Interface Descriptor */
146 static struct uac1_as_header_descriptor as_header_desc = {
147 	.bLength =		UAC_DT_AS_HEADER_SIZE,
148 	.bDescriptorType =	USB_DT_CS_INTERFACE,
149 	.bDescriptorSubtype =	UAC_AS_GENERAL,
150 	.bTerminalLink =	INPUT_TERMINAL_ID,
151 	.bDelay =		1,
152 	.wFormatTag =		UAC_FORMAT_TYPE_I_PCM,
153 };
154 
155 DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
156 
157 static struct uac_format_type_i_discrete_descriptor_1 as_type_i_desc = {
158 	.bLength =		UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
159 	.bDescriptorType =	USB_DT_CS_INTERFACE,
160 	.bDescriptorSubtype =	UAC_FORMAT_TYPE,
161 	.bFormatType =		UAC_FORMAT_TYPE_I,
162 	.bSubframeSize =	2,
163 	.bBitResolution =	16,
164 	.bSamFreqType =		1,
165 };
166 
167 /* Standard ISO OUT Endpoint Descriptor */
168 static struct usb_endpoint_descriptor as_out_ep_desc  = {
169 	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
170 	.bDescriptorType =	USB_DT_ENDPOINT,
171 	.bEndpointAddress =	USB_DIR_OUT,
172 	.bmAttributes =		USB_ENDPOINT_SYNC_ADAPTIVE
173 				| USB_ENDPOINT_XFER_ISOC,
174 	.wMaxPacketSize	=	cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
175 	.bInterval =		4,
176 };
177 
178 /* Class-specific AS ISO OUT Endpoint Descriptor */
179 static struct uac_iso_endpoint_descriptor as_iso_out_desc = {
180 	.bLength =		UAC_ISO_ENDPOINT_DESC_SIZE,
181 	.bDescriptorType =	USB_DT_CS_ENDPOINT,
182 	.bDescriptorSubtype =	UAC_EP_GENERAL,
183 	.bmAttributes = 	1,
184 	.bLockDelayUnits =	1,
185 	.wLockDelay =		__constant_cpu_to_le16(1),
186 };
187 
188 static struct usb_descriptor_header *f_audio_desc[] = {
189 	(struct usb_descriptor_header *)&ac_interface_desc,
190 	(struct usb_descriptor_header *)&ac_header_desc,
191 
192 	(struct usb_descriptor_header *)&input_terminal_desc,
193 	(struct usb_descriptor_header *)&output_terminal_desc,
194 	(struct usb_descriptor_header *)&feature_unit_desc,
195 
196 	(struct usb_descriptor_header *)&as_interface_alt_0_desc,
197 	(struct usb_descriptor_header *)&as_interface_alt_1_desc,
198 	(struct usb_descriptor_header *)&as_header_desc,
199 
200 	(struct usb_descriptor_header *)&as_type_i_desc,
201 
202 	(struct usb_descriptor_header *)&as_out_ep_desc,
203 	(struct usb_descriptor_header *)&as_iso_out_desc,
204 	NULL,
205 };
206 
207 enum {
208 	STR_AC_IF,
209 	STR_INPUT_TERMINAL,
210 	STR_INPUT_TERMINAL_CH_NAMES,
211 	STR_FEAT_DESC_0,
212 	STR_OUTPUT_TERMINAL,
213 	STR_AS_IF_ALT0,
214 	STR_AS_IF_ALT1,
215 };
216 
217 static struct usb_string strings_uac1[] = {
218 	[STR_AC_IF].s = "AC Interface",
219 	[STR_INPUT_TERMINAL].s = "Input terminal",
220 	[STR_INPUT_TERMINAL_CH_NAMES].s = "Channels",
221 	[STR_FEAT_DESC_0].s = "Volume control & mute",
222 	[STR_OUTPUT_TERMINAL].s = "Output terminal",
223 	[STR_AS_IF_ALT0].s = "AS Interface",
224 	[STR_AS_IF_ALT1].s = "AS Interface",
225 	{ },
226 };
227 
228 static struct usb_gadget_strings str_uac1 = {
229 	.language = 0x0409,	/* en-us */
230 	.strings = strings_uac1,
231 };
232 
233 static struct usb_gadget_strings *uac1_strings[] = {
234 	&str_uac1,
235 	NULL,
236 };
237 
238 /*
239  * This function is an ALSA sound card following USB Audio Class Spec 1.0.
240  */
241 
242 /*-------------------------------------------------------------------------*/
243 struct f_audio_buf {
244 	u8 *buf;
245 	int actual;
246 	struct list_head list;
247 };
248 
249 static struct f_audio_buf *f_audio_buffer_alloc(int buf_size)
250 {
251 	struct f_audio_buf *copy_buf;
252 
253 	copy_buf = kzalloc(sizeof *copy_buf, GFP_ATOMIC);
254 	if (!copy_buf)
255 		return ERR_PTR(-ENOMEM);
256 
257 	copy_buf->buf = kzalloc(buf_size, GFP_ATOMIC);
258 	if (!copy_buf->buf) {
259 		kfree(copy_buf);
260 		return ERR_PTR(-ENOMEM);
261 	}
262 
263 	return copy_buf;
264 }
265 
266 static void f_audio_buffer_free(struct f_audio_buf *audio_buf)
267 {
268 	kfree(audio_buf->buf);
269 	kfree(audio_buf);
270 }
271 /*-------------------------------------------------------------------------*/
272 
273 struct f_audio {
274 	struct gaudio			card;
275 
276 	/* endpoints handle full and/or high speeds */
277 	struct usb_ep			*out_ep;
278 
279 	spinlock_t			lock;
280 	struct f_audio_buf *copy_buf;
281 	struct work_struct playback_work;
282 	struct list_head play_queue;
283 
284 	/* Control Set command */
285 	struct list_head cs;
286 	u8 set_cmd;
287 	struct usb_audio_control *set_con;
288 };
289 
290 static inline struct f_audio *func_to_audio(struct usb_function *f)
291 {
292 	return container_of(f, struct f_audio, card.func);
293 }
294 
295 /*-------------------------------------------------------------------------*/
296 
297 static void f_audio_playback_work(struct work_struct *data)
298 {
299 	struct f_audio *audio = container_of(data, struct f_audio,
300 					playback_work);
301 	struct f_audio_buf *play_buf;
302 
303 	spin_lock_irq(&audio->lock);
304 	if (list_empty(&audio->play_queue)) {
305 		spin_unlock_irq(&audio->lock);
306 		return;
307 	}
308 	play_buf = list_first_entry(&audio->play_queue,
309 			struct f_audio_buf, list);
310 	list_del(&play_buf->list);
311 	spin_unlock_irq(&audio->lock);
312 
313 	u_audio_playback(&audio->card, play_buf->buf, play_buf->actual);
314 	f_audio_buffer_free(play_buf);
315 }
316 
317 static int f_audio_out_ep_complete(struct usb_ep *ep, struct usb_request *req)
318 {
319 	struct f_audio *audio = req->context;
320 	struct usb_composite_dev *cdev = audio->card.func.config->cdev;
321 	struct f_audio_buf *copy_buf = audio->copy_buf;
322 	struct f_uac1_opts *opts;
323 	int audio_buf_size;
324 	int err;
325 
326 	opts = container_of(audio->card.func.fi, struct f_uac1_opts,
327 			    func_inst);
328 	audio_buf_size = opts->audio_buf_size;
329 
330 	if (!copy_buf)
331 		return -EINVAL;
332 
333 	/* Copy buffer is full, add it to the play_queue */
334 	if (audio_buf_size - copy_buf->actual < req->actual) {
335 		list_add_tail(&copy_buf->list, &audio->play_queue);
336 		schedule_work(&audio->playback_work);
337 		copy_buf = f_audio_buffer_alloc(audio_buf_size);
338 		if (IS_ERR(copy_buf))
339 			return -ENOMEM;
340 	}
341 
342 	memcpy(copy_buf->buf + copy_buf->actual, req->buf, req->actual);
343 	copy_buf->actual += req->actual;
344 	audio->copy_buf = copy_buf;
345 
346 	err = usb_ep_queue(ep, req, GFP_ATOMIC);
347 	if (err)
348 		ERROR(cdev, "%s queue req: %d\n", ep->name, err);
349 
350 	return 0;
351 
352 }
353 
354 static void f_audio_complete(struct usb_ep *ep, struct usb_request *req)
355 {
356 	struct f_audio *audio = req->context;
357 	int status = req->status;
358 	u32 data = 0;
359 	struct usb_ep *out_ep = audio->out_ep;
360 
361 	switch (status) {
362 
363 	case 0:				/* normal completion? */
364 		if (ep == out_ep)
365 			f_audio_out_ep_complete(ep, req);
366 		else if (audio->set_con) {
367 			memcpy(&data, req->buf, req->length);
368 			audio->set_con->set(audio->set_con, audio->set_cmd,
369 					le16_to_cpu(data));
370 			audio->set_con = NULL;
371 		}
372 		break;
373 	default:
374 		break;
375 	}
376 }
377 
378 static int audio_set_intf_req(struct usb_function *f,
379 		const struct usb_ctrlrequest *ctrl)
380 {
381 	struct f_audio		*audio = func_to_audio(f);
382 	struct usb_composite_dev *cdev = f->config->cdev;
383 	struct usb_request	*req = cdev->req;
384 	u8			id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
385 	u16			len = le16_to_cpu(ctrl->wLength);
386 	u16			w_value = le16_to_cpu(ctrl->wValue);
387 	u8			con_sel = (w_value >> 8) & 0xFF;
388 	u8			cmd = (ctrl->bRequest & 0x0F);
389 	struct usb_audio_control_selector *cs;
390 	struct usb_audio_control *con;
391 
392 	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
393 			ctrl->bRequest, w_value, len, id);
394 
395 	list_for_each_entry(cs, &audio->cs, list) {
396 		if (cs->id == id) {
397 			list_for_each_entry(con, &cs->control, list) {
398 				if (con->type == con_sel) {
399 					audio->set_con = con;
400 					break;
401 				}
402 			}
403 			break;
404 		}
405 	}
406 
407 	audio->set_cmd = cmd;
408 	req->context = audio;
409 	req->complete = f_audio_complete;
410 
411 	return len;
412 }
413 
414 static int audio_get_intf_req(struct usb_function *f,
415 		const struct usb_ctrlrequest *ctrl)
416 {
417 	struct f_audio		*audio = func_to_audio(f);
418 	struct usb_composite_dev *cdev = f->config->cdev;
419 	struct usb_request	*req = cdev->req;
420 	int			value = -EOPNOTSUPP;
421 	u8			id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
422 	u16			len = le16_to_cpu(ctrl->wLength);
423 	u16			w_value = le16_to_cpu(ctrl->wValue);
424 	u8			con_sel = (w_value >> 8) & 0xFF;
425 	u8			cmd = (ctrl->bRequest & 0x0F);
426 	struct usb_audio_control_selector *cs;
427 	struct usb_audio_control *con;
428 
429 	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
430 			ctrl->bRequest, w_value, len, id);
431 
432 	list_for_each_entry(cs, &audio->cs, list) {
433 		if (cs->id == id) {
434 			list_for_each_entry(con, &cs->control, list) {
435 				if (con->type == con_sel && con->get) {
436 					value = con->get(con, cmd);
437 					break;
438 				}
439 			}
440 			break;
441 		}
442 	}
443 
444 	req->context = audio;
445 	req->complete = f_audio_complete;
446 	len = min_t(size_t, sizeof(value), len);
447 	memcpy(req->buf, &value, len);
448 
449 	return len;
450 }
451 
452 static int audio_set_endpoint_req(struct usb_function *f,
453 		const struct usb_ctrlrequest *ctrl)
454 {
455 	struct usb_composite_dev *cdev = f->config->cdev;
456 	int			value = -EOPNOTSUPP;
457 	u16			ep = le16_to_cpu(ctrl->wIndex);
458 	u16			len = le16_to_cpu(ctrl->wLength);
459 	u16			w_value = le16_to_cpu(ctrl->wValue);
460 
461 	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
462 			ctrl->bRequest, w_value, len, ep);
463 
464 	switch (ctrl->bRequest) {
465 	case UAC_SET_CUR:
466 		value = len;
467 		break;
468 
469 	case UAC_SET_MIN:
470 		break;
471 
472 	case UAC_SET_MAX:
473 		break;
474 
475 	case UAC_SET_RES:
476 		break;
477 
478 	case UAC_SET_MEM:
479 		break;
480 
481 	default:
482 		break;
483 	}
484 
485 	return value;
486 }
487 
488 static int audio_get_endpoint_req(struct usb_function *f,
489 		const struct usb_ctrlrequest *ctrl)
490 {
491 	struct usb_composite_dev *cdev = f->config->cdev;
492 	int value = -EOPNOTSUPP;
493 	u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
494 	u16 len = le16_to_cpu(ctrl->wLength);
495 	u16 w_value = le16_to_cpu(ctrl->wValue);
496 
497 	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
498 			ctrl->bRequest, w_value, len, ep);
499 
500 	switch (ctrl->bRequest) {
501 	case UAC_GET_CUR:
502 	case UAC_GET_MIN:
503 	case UAC_GET_MAX:
504 	case UAC_GET_RES:
505 		value = len;
506 		break;
507 	case UAC_GET_MEM:
508 		break;
509 	default:
510 		break;
511 	}
512 
513 	return value;
514 }
515 
516 static int
517 f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
518 {
519 	struct usb_composite_dev *cdev = f->config->cdev;
520 	struct usb_request	*req = cdev->req;
521 	int			value = -EOPNOTSUPP;
522 	u16			w_index = le16_to_cpu(ctrl->wIndex);
523 	u16			w_value = le16_to_cpu(ctrl->wValue);
524 	u16			w_length = le16_to_cpu(ctrl->wLength);
525 
526 	/* composite driver infrastructure handles everything; interface
527 	 * activation uses set_alt().
528 	 */
529 	switch (ctrl->bRequestType) {
530 	case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
531 		value = audio_set_intf_req(f, ctrl);
532 		break;
533 
534 	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
535 		value = audio_get_intf_req(f, ctrl);
536 		break;
537 
538 	case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
539 		value = audio_set_endpoint_req(f, ctrl);
540 		break;
541 
542 	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
543 		value = audio_get_endpoint_req(f, ctrl);
544 		break;
545 
546 	default:
547 		ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
548 			ctrl->bRequestType, ctrl->bRequest,
549 			w_value, w_index, w_length);
550 	}
551 
552 	/* respond with data transfer or status phase? */
553 	if (value >= 0) {
554 		DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
555 			ctrl->bRequestType, ctrl->bRequest,
556 			w_value, w_index, w_length);
557 		req->zero = 0;
558 		req->length = value;
559 		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
560 		if (value < 0)
561 			ERROR(cdev, "audio response on err %d\n", value);
562 	}
563 
564 	/* device either stalls (value < 0) or reports success */
565 	return value;
566 }
567 
568 static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
569 {
570 	struct f_audio		*audio = func_to_audio(f);
571 	struct usb_composite_dev *cdev = f->config->cdev;
572 	struct usb_ep *out_ep = audio->out_ep;
573 	struct usb_request *req;
574 	struct f_uac1_opts *opts;
575 	int req_buf_size, req_count, audio_buf_size;
576 	int i = 0, err = 0;
577 
578 	DBG(cdev, "intf %d, alt %d\n", intf, alt);
579 
580 	opts = container_of(f->fi, struct f_uac1_opts, func_inst);
581 	req_buf_size = opts->req_buf_size;
582 	req_count = opts->req_count;
583 	audio_buf_size = opts->audio_buf_size;
584 
585 	if (intf == 1) {
586 		if (alt == 1) {
587 			usb_ep_enable(out_ep);
588 			out_ep->driver_data = audio;
589 			audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
590 			if (IS_ERR(audio->copy_buf))
591 				return -ENOMEM;
592 
593 			/*
594 			 * allocate a bunch of read buffers
595 			 * and queue them all at once.
596 			 */
597 			for (i = 0; i < req_count && err == 0; i++) {
598 				req = usb_ep_alloc_request(out_ep, GFP_ATOMIC);
599 				if (req) {
600 					req->buf = kzalloc(req_buf_size,
601 							GFP_ATOMIC);
602 					if (req->buf) {
603 						req->length = req_buf_size;
604 						req->context = audio;
605 						req->complete =
606 							f_audio_complete;
607 						err = usb_ep_queue(out_ep,
608 							req, GFP_ATOMIC);
609 						if (err)
610 							ERROR(cdev,
611 							"%s queue req: %d\n",
612 							out_ep->name, err);
613 					} else
614 						err = -ENOMEM;
615 				} else
616 					err = -ENOMEM;
617 			}
618 
619 		} else {
620 			struct f_audio_buf *copy_buf = audio->copy_buf;
621 			if (copy_buf) {
622 				list_add_tail(&copy_buf->list,
623 						&audio->play_queue);
624 				schedule_work(&audio->playback_work);
625 			}
626 		}
627 	}
628 
629 	return err;
630 }
631 
632 static void f_audio_disable(struct usb_function *f)
633 {
634 	return;
635 }
636 
637 /*-------------------------------------------------------------------------*/
638 
639 static void f_audio_build_desc(struct f_audio *audio)
640 {
641 	struct gaudio *card = &audio->card;
642 	u8 *sam_freq;
643 	int rate;
644 
645 	/* Set channel numbers */
646 	input_terminal_desc.bNrChannels = u_audio_get_playback_channels(card);
647 	as_type_i_desc.bNrChannels = u_audio_get_playback_channels(card);
648 
649 	/* Set sample rates */
650 	rate = u_audio_get_playback_rate(card);
651 	sam_freq = as_type_i_desc.tSamFreq[0];
652 	memcpy(sam_freq, &rate, 3);
653 
654 	/* Todo: Set Sample bits and other parameters */
655 
656 	return;
657 }
658 
659 /* audio function driver setup/binding */
660 static int
661 f_audio_bind(struct usb_configuration *c, struct usb_function *f)
662 {
663 	struct usb_composite_dev *cdev = c->cdev;
664 	struct f_audio		*audio = func_to_audio(f);
665 	struct usb_string	*us;
666 	int			status;
667 	struct usb_ep		*ep = NULL;
668 	struct f_uac1_opts	*audio_opts;
669 
670 	audio_opts = container_of(f->fi, struct f_uac1_opts, func_inst);
671 	audio->card.gadget = c->cdev->gadget;
672 	audio_opts->card = &audio->card;
673 	/* set up ASLA audio devices */
674 	if (!audio_opts->bound) {
675 		status = gaudio_setup(&audio->card);
676 		if (status < 0)
677 			return status;
678 		audio_opts->bound = true;
679 	}
680 	us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1));
681 	if (IS_ERR(us))
682 		return PTR_ERR(us);
683 	ac_interface_desc.iInterface = us[STR_AC_IF].id;
684 	input_terminal_desc.iTerminal = us[STR_INPUT_TERMINAL].id;
685 	input_terminal_desc.iChannelNames = us[STR_INPUT_TERMINAL_CH_NAMES].id;
686 	feature_unit_desc.iFeature = us[STR_FEAT_DESC_0].id;
687 	output_terminal_desc.iTerminal = us[STR_OUTPUT_TERMINAL].id;
688 	as_interface_alt_0_desc.iInterface = us[STR_AS_IF_ALT0].id;
689 	as_interface_alt_1_desc.iInterface = us[STR_AS_IF_ALT1].id;
690 
691 
692 	f_audio_build_desc(audio);
693 
694 	/* allocate instance-specific interface IDs, and patch descriptors */
695 	status = usb_interface_id(c, f);
696 	if (status < 0)
697 		goto fail;
698 	ac_interface_desc.bInterfaceNumber = status;
699 
700 	status = usb_interface_id(c, f);
701 	if (status < 0)
702 		goto fail;
703 	as_interface_alt_0_desc.bInterfaceNumber = status;
704 	as_interface_alt_1_desc.bInterfaceNumber = status;
705 
706 	status = -ENODEV;
707 
708 	/* allocate instance-specific endpoints */
709 	ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
710 	if (!ep)
711 		goto fail;
712 	audio->out_ep = ep;
713 	audio->out_ep->desc = &as_out_ep_desc;
714 	ep->driver_data = cdev;	/* claim */
715 
716 	status = -ENOMEM;
717 
718 	/* copy descriptors, and track endpoint copies */
719 	status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL);
720 	if (status)
721 		goto fail;
722 	return 0;
723 
724 fail:
725 	gaudio_cleanup(&audio->card);
726 	if (ep)
727 		ep->driver_data = NULL;
728 	return status;
729 }
730 
731 /*-------------------------------------------------------------------------*/
732 
733 static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value)
734 {
735 	con->data[cmd] = value;
736 
737 	return 0;
738 }
739 
740 static int generic_get_cmd(struct usb_audio_control *con, u8 cmd)
741 {
742 	return con->data[cmd];
743 }
744 
745 /* Todo: add more control selecotor dynamically */
746 static int control_selector_init(struct f_audio *audio)
747 {
748 	INIT_LIST_HEAD(&audio->cs);
749 	list_add(&feature_unit.list, &audio->cs);
750 
751 	INIT_LIST_HEAD(&feature_unit.control);
752 	list_add(&mute_control.list, &feature_unit.control);
753 	list_add(&volume_control.list, &feature_unit.control);
754 
755 	volume_control.data[UAC__CUR] = 0xffc0;
756 	volume_control.data[UAC__MIN] = 0xe3a0;
757 	volume_control.data[UAC__MAX] = 0xfff0;
758 	volume_control.data[UAC__RES] = 0x0030;
759 
760 	return 0;
761 }
762 
763 static inline struct f_uac1_opts *to_f_uac1_opts(struct config_item *item)
764 {
765 	return container_of(to_config_group(item), struct f_uac1_opts,
766 			    func_inst.group);
767 }
768 
769 CONFIGFS_ATTR_STRUCT(f_uac1_opts);
770 CONFIGFS_ATTR_OPS(f_uac1_opts);
771 
772 static void f_uac1_attr_release(struct config_item *item)
773 {
774 	struct f_uac1_opts *opts = to_f_uac1_opts(item);
775 
776 	usb_put_function_instance(&opts->func_inst);
777 }
778 
779 static struct configfs_item_operations f_uac1_item_ops = {
780 	.release	= f_uac1_attr_release,
781 	.show_attribute	= f_uac1_opts_attr_show,
782 	.store_attribute = f_uac1_opts_attr_store,
783 };
784 
785 #define UAC1_INT_ATTRIBUTE(name)					\
786 static ssize_t f_uac1_opts_##name##_show(struct f_uac1_opts *opts,	\
787 					 char *page)			\
788 {									\
789 	int result;							\
790 									\
791 	mutex_lock(&opts->lock);					\
792 	result = sprintf(page, "%u\n", opts->name);			\
793 	mutex_unlock(&opts->lock);					\
794 									\
795 	return result;							\
796 }									\
797 									\
798 static ssize_t f_uac1_opts_##name##_store(struct f_uac1_opts *opts,	\
799 					  const char *page, size_t len)	\
800 {									\
801 	int ret;							\
802 	u32 num;							\
803 									\
804 	mutex_lock(&opts->lock);					\
805 	if (opts->refcnt) {						\
806 		ret = -EBUSY;						\
807 		goto end;						\
808 	}								\
809 									\
810 	ret = kstrtou32(page, 0, &num);					\
811 	if (ret)							\
812 		goto end;						\
813 									\
814 	opts->name = num;						\
815 	ret = len;							\
816 									\
817 end:									\
818 	mutex_unlock(&opts->lock);					\
819 	return ret;							\
820 }									\
821 									\
822 static struct f_uac1_opts_attribute f_uac1_opts_##name =		\
823 	__CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR,			\
824 			f_uac1_opts_##name##_show,			\
825 			f_uac1_opts_##name##_store)
826 
827 UAC1_INT_ATTRIBUTE(req_buf_size);
828 UAC1_INT_ATTRIBUTE(req_count);
829 UAC1_INT_ATTRIBUTE(audio_buf_size);
830 
831 #define UAC1_STR_ATTRIBUTE(name)					\
832 static ssize_t f_uac1_opts_##name##_show(struct f_uac1_opts *opts,	\
833 					 char *page)			\
834 {									\
835 	int result;							\
836 									\
837 	mutex_lock(&opts->lock);					\
838 	result = sprintf(page, "%s\n", opts->name);			\
839 	mutex_unlock(&opts->lock);					\
840 									\
841 	return result;							\
842 }									\
843 									\
844 static ssize_t f_uac1_opts_##name##_store(struct f_uac1_opts *opts,	\
845 					  const char *page, size_t len)	\
846 {									\
847 	int ret = -EBUSY;						\
848 	char *tmp;							\
849 									\
850 	mutex_lock(&opts->lock);					\
851 	if (opts->refcnt)						\
852 		goto end;						\
853 									\
854 	tmp = kstrndup(page, len, GFP_KERNEL);				\
855 	if (tmp) {							\
856 		ret = -ENOMEM;						\
857 		goto end;						\
858 	}								\
859 	if (opts->name##_alloc)						\
860 		kfree(opts->name);					\
861 	opts->name##_alloc = true;					\
862 	opts->name = tmp;						\
863 	ret = len;							\
864 									\
865 end:									\
866 	mutex_unlock(&opts->lock);					\
867 	return ret;							\
868 }									\
869 									\
870 static struct f_uac1_opts_attribute f_uac1_opts_##name =		\
871 	__CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR,			\
872 			f_uac1_opts_##name##_show,			\
873 			f_uac1_opts_##name##_store)
874 
875 UAC1_STR_ATTRIBUTE(fn_play);
876 UAC1_STR_ATTRIBUTE(fn_cap);
877 UAC1_STR_ATTRIBUTE(fn_cntl);
878 
879 static struct configfs_attribute *f_uac1_attrs[] = {
880 	&f_uac1_opts_req_buf_size.attr,
881 	&f_uac1_opts_req_count.attr,
882 	&f_uac1_opts_audio_buf_size.attr,
883 	&f_uac1_opts_fn_play.attr,
884 	&f_uac1_opts_fn_cap.attr,
885 	&f_uac1_opts_fn_cntl.attr,
886 	NULL,
887 };
888 
889 static struct config_item_type f_uac1_func_type = {
890 	.ct_item_ops	= &f_uac1_item_ops,
891 	.ct_attrs	= f_uac1_attrs,
892 	.ct_owner	= THIS_MODULE,
893 };
894 
895 static void f_audio_free_inst(struct usb_function_instance *f)
896 {
897 	struct f_uac1_opts *opts;
898 
899 	opts = container_of(f, struct f_uac1_opts, func_inst);
900 	if (opts->fn_play_alloc)
901 		kfree(opts->fn_play);
902 	if (opts->fn_cap_alloc)
903 		kfree(opts->fn_cap);
904 	if (opts->fn_cntl_alloc)
905 		kfree(opts->fn_cntl);
906 	kfree(opts);
907 }
908 
909 static struct usb_function_instance *f_audio_alloc_inst(void)
910 {
911 	struct f_uac1_opts *opts;
912 
913 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
914 	if (!opts)
915 		return ERR_PTR(-ENOMEM);
916 
917 	mutex_init(&opts->lock);
918 	opts->func_inst.free_func_inst = f_audio_free_inst;
919 
920 	config_group_init_type_name(&opts->func_inst.group, "",
921 				    &f_uac1_func_type);
922 
923 	opts->req_buf_size = UAC1_OUT_EP_MAX_PACKET_SIZE;
924 	opts->req_count = UAC1_REQ_COUNT;
925 	opts->audio_buf_size = UAC1_AUDIO_BUF_SIZE;
926 	opts->fn_play = FILE_PCM_PLAYBACK;
927 	opts->fn_cap = FILE_PCM_CAPTURE;
928 	opts->fn_cntl = FILE_CONTROL;
929 	return &opts->func_inst;
930 }
931 
932 static void f_audio_free(struct usb_function *f)
933 {
934 	struct f_audio *audio = func_to_audio(f);
935 	struct f_uac1_opts *opts;
936 
937 	gaudio_cleanup(&audio->card);
938 	opts = container_of(f->fi, struct f_uac1_opts, func_inst);
939 	kfree(audio);
940 	mutex_lock(&opts->lock);
941 	--opts->refcnt;
942 	mutex_unlock(&opts->lock);
943 }
944 
945 static void f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
946 {
947 	usb_free_all_descriptors(f);
948 }
949 
950 static struct usb_function *f_audio_alloc(struct usb_function_instance *fi)
951 {
952 	struct f_audio *audio;
953 	struct f_uac1_opts *opts;
954 
955 	/* allocate and initialize one new instance */
956 	audio = kzalloc(sizeof(*audio), GFP_KERNEL);
957 	if (!audio)
958 		return ERR_PTR(-ENOMEM);
959 
960 	audio->card.func.name = "g_audio";
961 
962 	opts = container_of(fi, struct f_uac1_opts, func_inst);
963 	mutex_lock(&opts->lock);
964 	++opts->refcnt;
965 	mutex_unlock(&opts->lock);
966 	INIT_LIST_HEAD(&audio->play_queue);
967 	spin_lock_init(&audio->lock);
968 
969 	audio->card.func.bind = f_audio_bind;
970 	audio->card.func.unbind = f_audio_unbind;
971 	audio->card.func.set_alt = f_audio_set_alt;
972 	audio->card.func.setup = f_audio_setup;
973 	audio->card.func.disable = f_audio_disable;
974 	audio->card.func.free_func = f_audio_free;
975 
976 	control_selector_init(audio);
977 
978 	INIT_WORK(&audio->playback_work, f_audio_playback_work);
979 
980 	return &audio->card.func;
981 }
982 
983 DECLARE_USB_FUNCTION_INIT(uac1, f_audio_alloc_inst, f_audio_alloc);
984 MODULE_LICENSE("GPL");
985 MODULE_AUTHOR("Bryan Wu");
986