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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	1
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 /*
46  * The number of AudioStreaming and MIDIStreaming interfaces
47  * in the Audio Interface Collection
48  */
49 DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
50 
51 #define UAC_DT_AC_HEADER_LENGTH	UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
52 /* 1 input terminal, 1 output terminal and 1 feature unit */
53 #define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH + UAC_DT_INPUT_TERMINAL_SIZE \
54 	+ UAC_DT_OUTPUT_TERMINAL_SIZE + UAC_DT_FEATURE_UNIT_SIZE(0))
55 /* B.3.2  Class-Specific AC Interface Descriptor */
56 static struct uac1_ac_header_descriptor_1 ac_header_desc = {
57 	.bLength =		UAC_DT_AC_HEADER_LENGTH,
58 	.bDescriptorType =	USB_DT_CS_INTERFACE,
59 	.bDescriptorSubtype =	UAC_HEADER,
60 	.bcdADC =		__constant_cpu_to_le16(0x0100),
61 	.wTotalLength =		__constant_cpu_to_le16(UAC_DT_TOTAL_LENGTH),
62 	.bInCollection =	F_AUDIO_NUM_INTERFACES,
63 	.baInterfaceNr = {
64 	/* Interface number of the first AudioStream interface */
65 		[0] =		1,
66 	}
67 };
68 
69 #define INPUT_TERMINAL_ID	1
70 static struct uac_input_terminal_descriptor input_terminal_desc = {
71 	.bLength =		UAC_DT_INPUT_TERMINAL_SIZE,
72 	.bDescriptorType =	USB_DT_CS_INTERFACE,
73 	.bDescriptorSubtype =	UAC_INPUT_TERMINAL,
74 	.bTerminalID =		INPUT_TERMINAL_ID,
75 	.wTerminalType =	UAC_TERMINAL_STREAMING,
76 	.bAssocTerminal =	0,
77 	.wChannelConfig =	0x3,
78 };
79 
80 DECLARE_UAC_FEATURE_UNIT_DESCRIPTOR(0);
81 
82 #define FEATURE_UNIT_ID		2
83 static struct uac_feature_unit_descriptor_0 feature_unit_desc = {
84 	.bLength		= UAC_DT_FEATURE_UNIT_SIZE(0),
85 	.bDescriptorType	= USB_DT_CS_INTERFACE,
86 	.bDescriptorSubtype	= UAC_FEATURE_UNIT,
87 	.bUnitID		= FEATURE_UNIT_ID,
88 	.bSourceID		= INPUT_TERMINAL_ID,
89 	.bControlSize		= 2,
90 	.bmaControls[0]		= (UAC_FU_MUTE | UAC_FU_VOLUME),
91 };
92 
93 static struct usb_audio_control mute_control = {
94 	.list = LIST_HEAD_INIT(mute_control.list),
95 	.name = "Mute Control",
96 	.type = UAC_FU_MUTE,
97 	/* Todo: add real Mute control code */
98 	.set = generic_set_cmd,
99 	.get = generic_get_cmd,
100 };
101 
102 static struct usb_audio_control volume_control = {
103 	.list = LIST_HEAD_INIT(volume_control.list),
104 	.name = "Volume Control",
105 	.type = UAC_FU_VOLUME,
106 	/* Todo: add real Volume control code */
107 	.set = generic_set_cmd,
108 	.get = generic_get_cmd,
109 };
110 
111 static struct usb_audio_control_selector feature_unit = {
112 	.list = LIST_HEAD_INIT(feature_unit.list),
113 	.id = FEATURE_UNIT_ID,
114 	.name = "Mute & Volume Control",
115 	.type = UAC_FEATURE_UNIT,
116 	.desc = (struct usb_descriptor_header *)&feature_unit_desc,
117 };
118 
119 #define OUTPUT_TERMINAL_ID	3
120 static struct uac1_output_terminal_descriptor output_terminal_desc = {
121 	.bLength		= UAC_DT_OUTPUT_TERMINAL_SIZE,
122 	.bDescriptorType	= USB_DT_CS_INTERFACE,
123 	.bDescriptorSubtype	= UAC_OUTPUT_TERMINAL,
124 	.bTerminalID		= OUTPUT_TERMINAL_ID,
125 	.wTerminalType		= UAC_OUTPUT_TERMINAL_SPEAKER,
126 	.bAssocTerminal		= FEATURE_UNIT_ID,
127 	.bSourceID		= FEATURE_UNIT_ID,
128 };
129 
130 /* B.4.1  Standard AS Interface Descriptor */
131 static struct usb_interface_descriptor as_interface_alt_0_desc = {
132 	.bLength =		USB_DT_INTERFACE_SIZE,
133 	.bDescriptorType =	USB_DT_INTERFACE,
134 	.bAlternateSetting =	0,
135 	.bNumEndpoints =	0,
136 	.bInterfaceClass =	USB_CLASS_AUDIO,
137 	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
138 };
139 
140 static struct usb_interface_descriptor as_interface_alt_1_desc = {
141 	.bLength =		USB_DT_INTERFACE_SIZE,
142 	.bDescriptorType =	USB_DT_INTERFACE,
143 	.bAlternateSetting =	1,
144 	.bNumEndpoints =	1,
145 	.bInterfaceClass =	USB_CLASS_AUDIO,
146 	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
147 };
148 
149 /* B.4.2  Class-Specific AS Interface Descriptor */
150 static struct uac1_as_header_descriptor as_header_desc = {
151 	.bLength =		UAC_DT_AS_HEADER_SIZE,
152 	.bDescriptorType =	USB_DT_CS_INTERFACE,
153 	.bDescriptorSubtype =	UAC_AS_GENERAL,
154 	.bTerminalLink =	INPUT_TERMINAL_ID,
155 	.bDelay =		1,
156 	.wFormatTag =		UAC_FORMAT_TYPE_I_PCM,
157 };
158 
159 DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
160 
161 static struct uac_format_type_i_discrete_descriptor_1 as_type_i_desc = {
162 	.bLength =		UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
163 	.bDescriptorType =	USB_DT_CS_INTERFACE,
164 	.bDescriptorSubtype =	UAC_FORMAT_TYPE,
165 	.bFormatType =		UAC_FORMAT_TYPE_I,
166 	.bSubframeSize =	2,
167 	.bBitResolution =	16,
168 	.bSamFreqType =		1,
169 };
170 
171 /* Standard ISO OUT Endpoint Descriptor */
172 static struct usb_endpoint_descriptor as_out_ep_desc  = {
173 	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
174 	.bDescriptorType =	USB_DT_ENDPOINT,
175 	.bEndpointAddress =	USB_DIR_OUT,
176 	.bmAttributes =		USB_ENDPOINT_SYNC_ADAPTIVE
177 				| USB_ENDPOINT_XFER_ISOC,
178 	.wMaxPacketSize	=	cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
179 	.bInterval =		4,
180 };
181 
182 /* Class-specific AS ISO OUT Endpoint Descriptor */
183 static struct uac_iso_endpoint_descriptor as_iso_out_desc = {
184 	.bLength =		UAC_ISO_ENDPOINT_DESC_SIZE,
185 	.bDescriptorType =	USB_DT_CS_ENDPOINT,
186 	.bDescriptorSubtype =	UAC_EP_GENERAL,
187 	.bmAttributes = 	1,
188 	.bLockDelayUnits =	1,
189 	.wLockDelay =		__constant_cpu_to_le16(1),
190 };
191 
192 static struct usb_descriptor_header *f_audio_desc[] = {
193 	(struct usb_descriptor_header *)&ac_interface_desc,
194 	(struct usb_descriptor_header *)&ac_header_desc,
195 
196 	(struct usb_descriptor_header *)&input_terminal_desc,
197 	(struct usb_descriptor_header *)&output_terminal_desc,
198 	(struct usb_descriptor_header *)&feature_unit_desc,
199 
200 	(struct usb_descriptor_header *)&as_interface_alt_0_desc,
201 	(struct usb_descriptor_header *)&as_interface_alt_1_desc,
202 	(struct usb_descriptor_header *)&as_header_desc,
203 
204 	(struct usb_descriptor_header *)&as_type_i_desc,
205 
206 	(struct usb_descriptor_header *)&as_out_ep_desc,
207 	(struct usb_descriptor_header *)&as_iso_out_desc,
208 	NULL,
209 };
210 
211 enum {
212 	STR_AC_IF,
213 	STR_INPUT_TERMINAL,
214 	STR_INPUT_TERMINAL_CH_NAMES,
215 	STR_FEAT_DESC_0,
216 	STR_OUTPUT_TERMINAL,
217 	STR_AS_IF_ALT0,
218 	STR_AS_IF_ALT1,
219 };
220 
221 static struct usb_string strings_uac1[] = {
222 	[STR_AC_IF].s = "AC Interface",
223 	[STR_INPUT_TERMINAL].s = "Input terminal",
224 	[STR_INPUT_TERMINAL_CH_NAMES].s = "Channels",
225 	[STR_FEAT_DESC_0].s = "Volume control & mute",
226 	[STR_OUTPUT_TERMINAL].s = "Output terminal",
227 	[STR_AS_IF_ALT0].s = "AS Interface",
228 	[STR_AS_IF_ALT1].s = "AS Interface",
229 	{ },
230 };
231 
232 static struct usb_gadget_strings str_uac1 = {
233 	.language = 0x0409,	/* en-us */
234 	.strings = strings_uac1,
235 };
236 
237 static struct usb_gadget_strings *uac1_strings[] = {
238 	&str_uac1,
239 	NULL,
240 };
241 
242 /*
243  * This function is an ALSA sound card following USB Audio Class Spec 1.0.
244  */
245 
246 /*-------------------------------------------------------------------------*/
247 struct f_audio_buf {
248 	u8 *buf;
249 	int actual;
250 	struct list_head list;
251 };
252 
f_audio_buffer_alloc(int buf_size)253 static struct f_audio_buf *f_audio_buffer_alloc(int buf_size)
254 {
255 	struct f_audio_buf *copy_buf;
256 
257 	copy_buf = kzalloc(sizeof *copy_buf, GFP_ATOMIC);
258 	if (!copy_buf)
259 		return ERR_PTR(-ENOMEM);
260 
261 	copy_buf->buf = kzalloc(buf_size, GFP_ATOMIC);
262 	if (!copy_buf->buf) {
263 		kfree(copy_buf);
264 		return ERR_PTR(-ENOMEM);
265 	}
266 
267 	return copy_buf;
268 }
269 
f_audio_buffer_free(struct f_audio_buf * audio_buf)270 static void f_audio_buffer_free(struct f_audio_buf *audio_buf)
271 {
272 	kfree(audio_buf->buf);
273 	kfree(audio_buf);
274 }
275 /*-------------------------------------------------------------------------*/
276 
277 struct f_audio {
278 	struct gaudio			card;
279 
280 	/* endpoints handle full and/or high speeds */
281 	struct usb_ep			*out_ep;
282 
283 	spinlock_t			lock;
284 	struct f_audio_buf *copy_buf;
285 	struct work_struct playback_work;
286 	struct list_head play_queue;
287 
288 	/* Control Set command */
289 	struct list_head cs;
290 	u8 set_cmd;
291 	struct usb_audio_control *set_con;
292 };
293 
func_to_audio(struct usb_function * f)294 static inline struct f_audio *func_to_audio(struct usb_function *f)
295 {
296 	return container_of(f, struct f_audio, card.func);
297 }
298 
299 /*-------------------------------------------------------------------------*/
300 
f_audio_playback_work(struct work_struct * data)301 static void f_audio_playback_work(struct work_struct *data)
302 {
303 	struct f_audio *audio = container_of(data, struct f_audio,
304 					playback_work);
305 	struct f_audio_buf *play_buf;
306 
307 	spin_lock_irq(&audio->lock);
308 	if (list_empty(&audio->play_queue)) {
309 		spin_unlock_irq(&audio->lock);
310 		return;
311 	}
312 	play_buf = list_first_entry(&audio->play_queue,
313 			struct f_audio_buf, list);
314 	list_del(&play_buf->list);
315 	spin_unlock_irq(&audio->lock);
316 
317 	u_audio_playback(&audio->card, play_buf->buf, play_buf->actual);
318 	f_audio_buffer_free(play_buf);
319 }
320 
f_audio_out_ep_complete(struct usb_ep * ep,struct usb_request * req)321 static int f_audio_out_ep_complete(struct usb_ep *ep, struct usb_request *req)
322 {
323 	struct f_audio *audio = req->context;
324 	struct usb_composite_dev *cdev = audio->card.func.config->cdev;
325 	struct f_audio_buf *copy_buf = audio->copy_buf;
326 	struct f_uac1_opts *opts;
327 	int audio_buf_size;
328 	int err;
329 
330 	opts = container_of(audio->card.func.fi, struct f_uac1_opts,
331 			    func_inst);
332 	audio_buf_size = opts->audio_buf_size;
333 
334 	if (!copy_buf)
335 		return -EINVAL;
336 
337 	/* Copy buffer is full, add it to the play_queue */
338 	if (audio_buf_size - copy_buf->actual < req->actual) {
339 		spin_lock_irq(&audio->lock);
340 		list_add_tail(&copy_buf->list, &audio->play_queue);
341 		spin_unlock_irq(&audio->lock);
342 		schedule_work(&audio->playback_work);
343 		copy_buf = f_audio_buffer_alloc(audio_buf_size);
344 		if (IS_ERR(copy_buf))
345 			return -ENOMEM;
346 	}
347 
348 	memcpy(copy_buf->buf + copy_buf->actual, req->buf, req->actual);
349 	copy_buf->actual += req->actual;
350 	audio->copy_buf = copy_buf;
351 
352 	err = usb_ep_queue(ep, req, GFP_ATOMIC);
353 	if (err)
354 		ERROR(cdev, "%s queue req: %d\n", ep->name, err);
355 
356 	return 0;
357 
358 }
359 
f_audio_complete(struct usb_ep * ep,struct usb_request * req)360 static void f_audio_complete(struct usb_ep *ep, struct usb_request *req)
361 {
362 	struct f_audio *audio = req->context;
363 	int status = req->status;
364 	u32 data = 0;
365 	struct usb_ep *out_ep = audio->out_ep;
366 
367 	switch (status) {
368 
369 	case 0:				/* normal completion? */
370 		if (ep == out_ep)
371 			f_audio_out_ep_complete(ep, req);
372 		else if (audio->set_con) {
373 			memcpy(&data, req->buf, req->length);
374 			audio->set_con->set(audio->set_con, audio->set_cmd,
375 					le16_to_cpu(data));
376 			audio->set_con = NULL;
377 		}
378 		break;
379 	default:
380 		break;
381 	}
382 }
383 
audio_set_intf_req(struct usb_function * f,const struct usb_ctrlrequest * ctrl)384 static int audio_set_intf_req(struct usb_function *f,
385 		const struct usb_ctrlrequest *ctrl)
386 {
387 	struct f_audio		*audio = func_to_audio(f);
388 	struct usb_composite_dev *cdev = f->config->cdev;
389 	struct usb_request	*req = cdev->req;
390 	u8			id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
391 	u16			len = le16_to_cpu(ctrl->wLength);
392 	u16			w_value = le16_to_cpu(ctrl->wValue);
393 	u8			con_sel = (w_value >> 8) & 0xFF;
394 	u8			cmd = (ctrl->bRequest & 0x0F);
395 	struct usb_audio_control_selector *cs;
396 	struct usb_audio_control *con;
397 
398 	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
399 			ctrl->bRequest, w_value, len, id);
400 
401 	list_for_each_entry(cs, &audio->cs, list) {
402 		if (cs->id == id) {
403 			list_for_each_entry(con, &cs->control, list) {
404 				if (con->type == con_sel) {
405 					audio->set_con = con;
406 					break;
407 				}
408 			}
409 			break;
410 		}
411 	}
412 
413 	audio->set_cmd = cmd;
414 	req->context = audio;
415 	req->complete = f_audio_complete;
416 
417 	return len;
418 }
419 
audio_get_intf_req(struct usb_function * f,const struct usb_ctrlrequest * ctrl)420 static int audio_get_intf_req(struct usb_function *f,
421 		const struct usb_ctrlrequest *ctrl)
422 {
423 	struct f_audio		*audio = func_to_audio(f);
424 	struct usb_composite_dev *cdev = f->config->cdev;
425 	struct usb_request	*req = cdev->req;
426 	int			value = -EOPNOTSUPP;
427 	u8			id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
428 	u16			len = le16_to_cpu(ctrl->wLength);
429 	u16			w_value = le16_to_cpu(ctrl->wValue);
430 	u8			con_sel = (w_value >> 8) & 0xFF;
431 	u8			cmd = (ctrl->bRequest & 0x0F);
432 	struct usb_audio_control_selector *cs;
433 	struct usb_audio_control *con;
434 
435 	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
436 			ctrl->bRequest, w_value, len, id);
437 
438 	list_for_each_entry(cs, &audio->cs, list) {
439 		if (cs->id == id) {
440 			list_for_each_entry(con, &cs->control, list) {
441 				if (con->type == con_sel && con->get) {
442 					value = con->get(con, cmd);
443 					break;
444 				}
445 			}
446 			break;
447 		}
448 	}
449 
450 	req->context = audio;
451 	req->complete = f_audio_complete;
452 	len = min_t(size_t, sizeof(value), len);
453 	memcpy(req->buf, &value, len);
454 
455 	return len;
456 }
457 
audio_set_endpoint_req(struct usb_function * f,const struct usb_ctrlrequest * ctrl)458 static int audio_set_endpoint_req(struct usb_function *f,
459 		const struct usb_ctrlrequest *ctrl)
460 {
461 	struct usb_composite_dev *cdev = f->config->cdev;
462 	int			value = -EOPNOTSUPP;
463 	u16			ep = le16_to_cpu(ctrl->wIndex);
464 	u16			len = le16_to_cpu(ctrl->wLength);
465 	u16			w_value = le16_to_cpu(ctrl->wValue);
466 
467 	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
468 			ctrl->bRequest, w_value, len, ep);
469 
470 	switch (ctrl->bRequest) {
471 	case UAC_SET_CUR:
472 		value = len;
473 		break;
474 
475 	case UAC_SET_MIN:
476 		break;
477 
478 	case UAC_SET_MAX:
479 		break;
480 
481 	case UAC_SET_RES:
482 		break;
483 
484 	case UAC_SET_MEM:
485 		break;
486 
487 	default:
488 		break;
489 	}
490 
491 	return value;
492 }
493 
audio_get_endpoint_req(struct usb_function * f,const struct usb_ctrlrequest * ctrl)494 static int audio_get_endpoint_req(struct usb_function *f,
495 		const struct usb_ctrlrequest *ctrl)
496 {
497 	struct usb_composite_dev *cdev = f->config->cdev;
498 	int value = -EOPNOTSUPP;
499 	u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
500 	u16 len = le16_to_cpu(ctrl->wLength);
501 	u16 w_value = le16_to_cpu(ctrl->wValue);
502 
503 	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
504 			ctrl->bRequest, w_value, len, ep);
505 
506 	switch (ctrl->bRequest) {
507 	case UAC_GET_CUR:
508 	case UAC_GET_MIN:
509 	case UAC_GET_MAX:
510 	case UAC_GET_RES:
511 		value = len;
512 		break;
513 	case UAC_GET_MEM:
514 		break;
515 	default:
516 		break;
517 	}
518 
519 	return value;
520 }
521 
522 static int
f_audio_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)523 f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
524 {
525 	struct usb_composite_dev *cdev = f->config->cdev;
526 	struct usb_request	*req = cdev->req;
527 	int			value = -EOPNOTSUPP;
528 	u16			w_index = le16_to_cpu(ctrl->wIndex);
529 	u16			w_value = le16_to_cpu(ctrl->wValue);
530 	u16			w_length = le16_to_cpu(ctrl->wLength);
531 
532 	/* composite driver infrastructure handles everything; interface
533 	 * activation uses set_alt().
534 	 */
535 	switch (ctrl->bRequestType) {
536 	case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
537 		value = audio_set_intf_req(f, ctrl);
538 		break;
539 
540 	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
541 		value = audio_get_intf_req(f, ctrl);
542 		break;
543 
544 	case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
545 		value = audio_set_endpoint_req(f, ctrl);
546 		break;
547 
548 	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
549 		value = audio_get_endpoint_req(f, ctrl);
550 		break;
551 
552 	default:
553 		ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
554 			ctrl->bRequestType, ctrl->bRequest,
555 			w_value, w_index, w_length);
556 	}
557 
558 	/* respond with data transfer or status phase? */
559 	if (value >= 0) {
560 		DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
561 			ctrl->bRequestType, ctrl->bRequest,
562 			w_value, w_index, w_length);
563 		req->zero = 0;
564 		req->length = value;
565 		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
566 		if (value < 0)
567 			ERROR(cdev, "audio response on err %d\n", value);
568 	}
569 
570 	/* device either stalls (value < 0) or reports success */
571 	return value;
572 }
573 
f_audio_set_alt(struct usb_function * f,unsigned intf,unsigned alt)574 static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
575 {
576 	struct f_audio		*audio = func_to_audio(f);
577 	struct usb_composite_dev *cdev = f->config->cdev;
578 	struct usb_ep *out_ep = audio->out_ep;
579 	struct usb_request *req;
580 	struct f_uac1_opts *opts;
581 	int req_buf_size, req_count, audio_buf_size;
582 	int i = 0, err = 0;
583 
584 	DBG(cdev, "intf %d, alt %d\n", intf, alt);
585 
586 	opts = container_of(f->fi, struct f_uac1_opts, func_inst);
587 	req_buf_size = opts->req_buf_size;
588 	req_count = opts->req_count;
589 	audio_buf_size = opts->audio_buf_size;
590 
591 	if (intf == 1) {
592 		if (alt == 1) {
593 			err = config_ep_by_speed(cdev->gadget, f, out_ep);
594 			if (err)
595 				return err;
596 
597 			usb_ep_enable(out_ep);
598 			audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
599 			if (IS_ERR(audio->copy_buf))
600 				return -ENOMEM;
601 
602 			/*
603 			 * allocate a bunch of read buffers
604 			 * and queue them all at once.
605 			 */
606 			for (i = 0; i < req_count && err == 0; i++) {
607 				req = usb_ep_alloc_request(out_ep, GFP_ATOMIC);
608 				if (req) {
609 					req->buf = kzalloc(req_buf_size,
610 							GFP_ATOMIC);
611 					if (req->buf) {
612 						req->length = req_buf_size;
613 						req->context = audio;
614 						req->complete =
615 							f_audio_complete;
616 						err = usb_ep_queue(out_ep,
617 							req, GFP_ATOMIC);
618 						if (err)
619 							ERROR(cdev,
620 							"%s queue req: %d\n",
621 							out_ep->name, err);
622 					} else
623 						err = -ENOMEM;
624 				} else
625 					err = -ENOMEM;
626 			}
627 
628 		} else {
629 			struct f_audio_buf *copy_buf = audio->copy_buf;
630 			if (copy_buf) {
631 				list_add_tail(&copy_buf->list,
632 						&audio->play_queue);
633 				schedule_work(&audio->playback_work);
634 			}
635 		}
636 	}
637 
638 	return err;
639 }
640 
f_audio_disable(struct usb_function * f)641 static void f_audio_disable(struct usb_function *f)
642 {
643 	return;
644 }
645 
646 /*-------------------------------------------------------------------------*/
647 
f_audio_build_desc(struct f_audio * audio)648 static void f_audio_build_desc(struct f_audio *audio)
649 {
650 	struct gaudio *card = &audio->card;
651 	u8 *sam_freq;
652 	int rate;
653 
654 	/* Set channel numbers */
655 	input_terminal_desc.bNrChannels = u_audio_get_playback_channels(card);
656 	as_type_i_desc.bNrChannels = u_audio_get_playback_channels(card);
657 
658 	/* Set sample rates */
659 	rate = u_audio_get_playback_rate(card);
660 	sam_freq = as_type_i_desc.tSamFreq[0];
661 	memcpy(sam_freq, &rate, 3);
662 
663 	/* Todo: Set Sample bits and other parameters */
664 
665 	return;
666 }
667 
668 /* audio function driver setup/binding */
669 static int
f_audio_bind(struct usb_configuration * c,struct usb_function * f)670 f_audio_bind(struct usb_configuration *c, struct usb_function *f)
671 {
672 	struct usb_composite_dev *cdev = c->cdev;
673 	struct f_audio		*audio = func_to_audio(f);
674 	struct usb_string	*us;
675 	int			status;
676 	struct usb_ep		*ep = NULL;
677 	struct f_uac1_opts	*audio_opts;
678 
679 	audio_opts = container_of(f->fi, struct f_uac1_opts, func_inst);
680 	audio->card.gadget = c->cdev->gadget;
681 	/* set up ASLA audio devices */
682 	if (!audio_opts->bound) {
683 		status = gaudio_setup(&audio->card);
684 		if (status < 0)
685 			return status;
686 		audio_opts->bound = true;
687 	}
688 	us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1));
689 	if (IS_ERR(us))
690 		return PTR_ERR(us);
691 	ac_interface_desc.iInterface = us[STR_AC_IF].id;
692 	input_terminal_desc.iTerminal = us[STR_INPUT_TERMINAL].id;
693 	input_terminal_desc.iChannelNames = us[STR_INPUT_TERMINAL_CH_NAMES].id;
694 	feature_unit_desc.iFeature = us[STR_FEAT_DESC_0].id;
695 	output_terminal_desc.iTerminal = us[STR_OUTPUT_TERMINAL].id;
696 	as_interface_alt_0_desc.iInterface = us[STR_AS_IF_ALT0].id;
697 	as_interface_alt_1_desc.iInterface = us[STR_AS_IF_ALT1].id;
698 
699 
700 	f_audio_build_desc(audio);
701 
702 	/* allocate instance-specific interface IDs, and patch descriptors */
703 	status = usb_interface_id(c, f);
704 	if (status < 0)
705 		goto fail;
706 	ac_interface_desc.bInterfaceNumber = status;
707 
708 	status = usb_interface_id(c, f);
709 	if (status < 0)
710 		goto fail;
711 	as_interface_alt_0_desc.bInterfaceNumber = status;
712 	as_interface_alt_1_desc.bInterfaceNumber = status;
713 
714 	status = -ENODEV;
715 
716 	/* allocate instance-specific endpoints */
717 	ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
718 	if (!ep)
719 		goto fail;
720 	audio->out_ep = ep;
721 	audio->out_ep->desc = &as_out_ep_desc;
722 
723 	status = -ENOMEM;
724 
725 	/* copy descriptors, and track endpoint copies */
726 	status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL);
727 	if (status)
728 		goto fail;
729 	return 0;
730 
731 fail:
732 	gaudio_cleanup(&audio->card);
733 	return status;
734 }
735 
736 /*-------------------------------------------------------------------------*/
737 
generic_set_cmd(struct usb_audio_control * con,u8 cmd,int value)738 static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value)
739 {
740 	con->data[cmd] = value;
741 
742 	return 0;
743 }
744 
generic_get_cmd(struct usb_audio_control * con,u8 cmd)745 static int generic_get_cmd(struct usb_audio_control *con, u8 cmd)
746 {
747 	return con->data[cmd];
748 }
749 
750 /* Todo: add more control selecotor dynamically */
control_selector_init(struct f_audio * audio)751 static int control_selector_init(struct f_audio *audio)
752 {
753 	INIT_LIST_HEAD(&audio->cs);
754 	list_add(&feature_unit.list, &audio->cs);
755 
756 	INIT_LIST_HEAD(&feature_unit.control);
757 	list_add(&mute_control.list, &feature_unit.control);
758 	list_add(&volume_control.list, &feature_unit.control);
759 
760 	volume_control.data[UAC__CUR] = 0xffc0;
761 	volume_control.data[UAC__MIN] = 0xe3a0;
762 	volume_control.data[UAC__MAX] = 0xfff0;
763 	volume_control.data[UAC__RES] = 0x0030;
764 
765 	return 0;
766 }
767 
to_f_uac1_opts(struct config_item * item)768 static inline struct f_uac1_opts *to_f_uac1_opts(struct config_item *item)
769 {
770 	return container_of(to_config_group(item), struct f_uac1_opts,
771 			    func_inst.group);
772 }
773 
f_uac1_attr_release(struct config_item * item)774 static void f_uac1_attr_release(struct config_item *item)
775 {
776 	struct f_uac1_opts *opts = to_f_uac1_opts(item);
777 
778 	usb_put_function_instance(&opts->func_inst);
779 }
780 
781 static struct configfs_item_operations f_uac1_item_ops = {
782 	.release	= f_uac1_attr_release,
783 };
784 
785 #define UAC1_INT_ATTRIBUTE(name)					\
786 static ssize_t f_uac1_opts_##name##_show(struct config_item *item,	\
787 					 char *page)			\
788 {									\
789 	struct f_uac1_opts *opts = to_f_uac1_opts(item);		\
790 	int result;							\
791 									\
792 	mutex_lock(&opts->lock);					\
793 	result = sprintf(page, "%u\n", opts->name);			\
794 	mutex_unlock(&opts->lock);					\
795 									\
796 	return result;							\
797 }									\
798 									\
799 static ssize_t f_uac1_opts_##name##_store(struct config_item *item,		\
800 					  const char *page, size_t len)	\
801 {									\
802 	struct f_uac1_opts *opts = to_f_uac1_opts(item);		\
803 	int ret;							\
804 	u32 num;							\
805 									\
806 	mutex_lock(&opts->lock);					\
807 	if (opts->refcnt) {						\
808 		ret = -EBUSY;						\
809 		goto end;						\
810 	}								\
811 									\
812 	ret = kstrtou32(page, 0, &num);					\
813 	if (ret)							\
814 		goto end;						\
815 									\
816 	opts->name = num;						\
817 	ret = len;							\
818 									\
819 end:									\
820 	mutex_unlock(&opts->lock);					\
821 	return ret;							\
822 }									\
823 									\
824 CONFIGFS_ATTR(f_uac1_opts_, name)
825 
826 UAC1_INT_ATTRIBUTE(req_buf_size);
827 UAC1_INT_ATTRIBUTE(req_count);
828 UAC1_INT_ATTRIBUTE(audio_buf_size);
829 
830 #define UAC1_STR_ATTRIBUTE(name)					\
831 static ssize_t f_uac1_opts_##name##_show(struct config_item *item,	\
832 					 char *page)			\
833 {									\
834 	struct f_uac1_opts *opts = to_f_uac1_opts(item);		\
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 config_item *item,	\
845 					  const char *page, size_t len)	\
846 {									\
847 	struct f_uac1_opts *opts = to_f_uac1_opts(item);		\
848 	int ret = -EBUSY;						\
849 	char *tmp;							\
850 									\
851 	mutex_lock(&opts->lock);					\
852 	if (opts->refcnt)						\
853 		goto end;						\
854 									\
855 	tmp = kstrndup(page, len, GFP_KERNEL);				\
856 	if (tmp) {							\
857 		ret = -ENOMEM;						\
858 		goto end;						\
859 	}								\
860 	if (opts->name##_alloc)						\
861 		kfree(opts->name);					\
862 	opts->name##_alloc = true;					\
863 	opts->name = tmp;						\
864 	ret = len;							\
865 									\
866 end:									\
867 	mutex_unlock(&opts->lock);					\
868 	return ret;							\
869 }									\
870 									\
871 CONFIGFS_ATTR(f_uac1_opts_, name)
872 
873 UAC1_STR_ATTRIBUTE(fn_play);
874 UAC1_STR_ATTRIBUTE(fn_cap);
875 UAC1_STR_ATTRIBUTE(fn_cntl);
876 
877 static struct configfs_attribute *f_uac1_attrs[] = {
878 	&f_uac1_opts_attr_req_buf_size,
879 	&f_uac1_opts_attr_req_count,
880 	&f_uac1_opts_attr_audio_buf_size,
881 	&f_uac1_opts_attr_fn_play,
882 	&f_uac1_opts_attr_fn_cap,
883 	&f_uac1_opts_attr_fn_cntl,
884 	NULL,
885 };
886 
887 static struct config_item_type f_uac1_func_type = {
888 	.ct_item_ops	= &f_uac1_item_ops,
889 	.ct_attrs	= f_uac1_attrs,
890 	.ct_owner	= THIS_MODULE,
891 };
892 
f_audio_free_inst(struct usb_function_instance * f)893 static void f_audio_free_inst(struct usb_function_instance *f)
894 {
895 	struct f_uac1_opts *opts;
896 
897 	opts = container_of(f, struct f_uac1_opts, func_inst);
898 	if (opts->fn_play_alloc)
899 		kfree(opts->fn_play);
900 	if (opts->fn_cap_alloc)
901 		kfree(opts->fn_cap);
902 	if (opts->fn_cntl_alloc)
903 		kfree(opts->fn_cntl);
904 	kfree(opts);
905 }
906 
f_audio_alloc_inst(void)907 static struct usb_function_instance *f_audio_alloc_inst(void)
908 {
909 	struct f_uac1_opts *opts;
910 
911 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
912 	if (!opts)
913 		return ERR_PTR(-ENOMEM);
914 
915 	mutex_init(&opts->lock);
916 	opts->func_inst.free_func_inst = f_audio_free_inst;
917 
918 	config_group_init_type_name(&opts->func_inst.group, "",
919 				    &f_uac1_func_type);
920 
921 	opts->req_buf_size = UAC1_OUT_EP_MAX_PACKET_SIZE;
922 	opts->req_count = UAC1_REQ_COUNT;
923 	opts->audio_buf_size = UAC1_AUDIO_BUF_SIZE;
924 	opts->fn_play = FILE_PCM_PLAYBACK;
925 	opts->fn_cap = FILE_PCM_CAPTURE;
926 	opts->fn_cntl = FILE_CONTROL;
927 	return &opts->func_inst;
928 }
929 
f_audio_free(struct usb_function * f)930 static void f_audio_free(struct usb_function *f)
931 {
932 	struct f_audio *audio = func_to_audio(f);
933 	struct f_uac1_opts *opts;
934 
935 	gaudio_cleanup(&audio->card);
936 	opts = container_of(f->fi, struct f_uac1_opts, func_inst);
937 	kfree(audio);
938 	mutex_lock(&opts->lock);
939 	--opts->refcnt;
940 	mutex_unlock(&opts->lock);
941 }
942 
f_audio_unbind(struct usb_configuration * c,struct usb_function * f)943 static void f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
944 {
945 	usb_free_all_descriptors(f);
946 }
947 
f_audio_alloc(struct usb_function_instance * fi)948 static struct usb_function *f_audio_alloc(struct usb_function_instance *fi)
949 {
950 	struct f_audio *audio;
951 	struct f_uac1_opts *opts;
952 
953 	/* allocate and initialize one new instance */
954 	audio = kzalloc(sizeof(*audio), GFP_KERNEL);
955 	if (!audio)
956 		return ERR_PTR(-ENOMEM);
957 
958 	audio->card.func.name = "g_audio";
959 
960 	opts = container_of(fi, struct f_uac1_opts, func_inst);
961 	mutex_lock(&opts->lock);
962 	++opts->refcnt;
963 	mutex_unlock(&opts->lock);
964 	INIT_LIST_HEAD(&audio->play_queue);
965 	spin_lock_init(&audio->lock);
966 
967 	audio->card.func.bind = f_audio_bind;
968 	audio->card.func.unbind = f_audio_unbind;
969 	audio->card.func.set_alt = f_audio_set_alt;
970 	audio->card.func.setup = f_audio_setup;
971 	audio->card.func.disable = f_audio_disable;
972 	audio->card.func.free_func = f_audio_free;
973 
974 	control_selector_init(audio);
975 
976 	INIT_WORK(&audio->playback_work, f_audio_playback_work);
977 
978 	return &audio->card.func;
979 }
980 
981 DECLARE_USB_FUNCTION_INIT(uac1, f_audio_alloc_inst, f_audio_alloc);
982 MODULE_LICENSE("GPL");
983 MODULE_AUTHOR("Bryan Wu");
984