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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/device.h>
 15#include <linux/atomic.h>
 16
 17#include "u_audio.h"
 18
 19#define OUT_EP_MAX_PACKET_SIZE	200
 20static int req_buf_size = OUT_EP_MAX_PACKET_SIZE;
 21module_param(req_buf_size, int, S_IRUGO);
 22MODULE_PARM_DESC(req_buf_size, "ISO OUT endpoint request buffer size");
 23
 24static int req_count = 256;
 25module_param(req_count, int, S_IRUGO);
 26MODULE_PARM_DESC(req_count, "ISO OUT endpoint request count");
 27
 28static int audio_buf_size = 48000;
 29module_param(audio_buf_size, int, S_IRUGO);
 30MODULE_PARM_DESC(audio_buf_size, "Audio buffer size");
 31
 32static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value);
 33static int generic_get_cmd(struct usb_audio_control *con, u8 cmd);
 34
 35/*
 36 * DESCRIPTORS ... most are static, but strings and full
 37 * configuration descriptors are built on demand.
 38 */
 39
 40/*
 41 * We have two interfaces- AudioControl and AudioStreaming
 42 * TODO: only supcard playback currently
 43 */
 44#define F_AUDIO_AC_INTERFACE	0
 45#define F_AUDIO_AS_INTERFACE	1
 46#define F_AUDIO_NUM_INTERFACES	2
 47
 48/* B.3.1  Standard AC Interface Descriptor */
 49static struct usb_interface_descriptor ac_interface_desc __initdata = {
 50	.bLength =		USB_DT_INTERFACE_SIZE,
 51	.bDescriptorType =	USB_DT_INTERFACE,
 52	.bNumEndpoints =	0,
 53	.bInterfaceClass =	USB_CLASS_AUDIO,
 54	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOCONTROL,
 55};
 56
 57DECLARE_UAC_AC_HEADER_DESCRIPTOR(2);
 58
 59#define UAC_DT_AC_HEADER_LENGTH	UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
 60/* 1 input terminal, 1 output terminal and 1 feature unit */
 61#define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH + UAC_DT_INPUT_TERMINAL_SIZE \
 62	+ UAC_DT_OUTPUT_TERMINAL_SIZE + UAC_DT_FEATURE_UNIT_SIZE(0))
 63/* B.3.2  Class-Specific AC Interface Descriptor */
 64static struct uac1_ac_header_descriptor_2 ac_header_desc = {
 65	.bLength =		UAC_DT_AC_HEADER_LENGTH,
 66	.bDescriptorType =	USB_DT_CS_INTERFACE,
 67	.bDescriptorSubtype =	UAC_HEADER,
 68	.bcdADC =		__constant_cpu_to_le16(0x0100),
 69	.wTotalLength =		__constant_cpu_to_le16(UAC_DT_TOTAL_LENGTH),
 70	.bInCollection =	F_AUDIO_NUM_INTERFACES,
 71	.baInterfaceNr = {
 72		[0] =		F_AUDIO_AC_INTERFACE,
 73		[1] =		F_AUDIO_AS_INTERFACE,
 74	}
 75};
 76
 77#define INPUT_TERMINAL_ID	1
 78static struct uac_input_terminal_descriptor input_terminal_desc = {
 79	.bLength =		UAC_DT_INPUT_TERMINAL_SIZE,
 80	.bDescriptorType =	USB_DT_CS_INTERFACE,
 81	.bDescriptorSubtype =	UAC_INPUT_TERMINAL,
 82	.bTerminalID =		INPUT_TERMINAL_ID,
 83	.wTerminalType =	UAC_TERMINAL_STREAMING,
 84	.bAssocTerminal =	0,
 85	.wChannelConfig =	0x3,
 86};
 87
 88DECLARE_UAC_FEATURE_UNIT_DESCRIPTOR(0);
 89
 90#define FEATURE_UNIT_ID		2
 91static struct uac_feature_unit_descriptor_0 feature_unit_desc = {
 92	.bLength		= UAC_DT_FEATURE_UNIT_SIZE(0),
 93	.bDescriptorType	= USB_DT_CS_INTERFACE,
 94	.bDescriptorSubtype	= UAC_FEATURE_UNIT,
 95	.bUnitID		= FEATURE_UNIT_ID,
 96	.bSourceID		= INPUT_TERMINAL_ID,
 97	.bControlSize		= 2,
 98	.bmaControls[0]		= (UAC_FU_MUTE | UAC_FU_VOLUME),
 99};
100
101static struct usb_audio_control mute_control = {
102	.list = LIST_HEAD_INIT(mute_control.list),
103	.name = "Mute Control",
104	.type = UAC_FU_MUTE,
105	/* Todo: add real Mute control code */
106	.set = generic_set_cmd,
107	.get = generic_get_cmd,
108};
109
110static struct usb_audio_control volume_control = {
111	.list = LIST_HEAD_INIT(volume_control.list),
112	.name = "Volume Control",
113	.type = UAC_FU_VOLUME,
114	/* Todo: add real Volume control code */
115	.set = generic_set_cmd,
116	.get = generic_get_cmd,
117};
118
119static struct usb_audio_control_selector feature_unit = {
120	.list = LIST_HEAD_INIT(feature_unit.list),
121	.id = FEATURE_UNIT_ID,
122	.name = "Mute & Volume Control",
123	.type = UAC_FEATURE_UNIT,
124	.desc = (struct usb_descriptor_header *)&feature_unit_desc,
125};
126
127#define OUTPUT_TERMINAL_ID	3
128static struct uac1_output_terminal_descriptor output_terminal_desc = {
129	.bLength		= UAC_DT_OUTPUT_TERMINAL_SIZE,
130	.bDescriptorType	= USB_DT_CS_INTERFACE,
131	.bDescriptorSubtype	= UAC_OUTPUT_TERMINAL,
132	.bTerminalID		= OUTPUT_TERMINAL_ID,
133	.wTerminalType		= UAC_OUTPUT_TERMINAL_SPEAKER,
134	.bAssocTerminal		= FEATURE_UNIT_ID,
135	.bSourceID		= FEATURE_UNIT_ID,
136};
137
138/* B.4.1  Standard AS Interface Descriptor */
139static struct usb_interface_descriptor as_interface_alt_0_desc = {
140	.bLength =		USB_DT_INTERFACE_SIZE,
141	.bDescriptorType =	USB_DT_INTERFACE,
142	.bAlternateSetting =	0,
143	.bNumEndpoints =	0,
144	.bInterfaceClass =	USB_CLASS_AUDIO,
145	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
146};
147
148static struct usb_interface_descriptor as_interface_alt_1_desc = {
149	.bLength =		USB_DT_INTERFACE_SIZE,
150	.bDescriptorType =	USB_DT_INTERFACE,
151	.bAlternateSetting =	1,
152	.bNumEndpoints =	1,
153	.bInterfaceClass =	USB_CLASS_AUDIO,
154	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
155};
156
157/* B.4.2  Class-Specific AS Interface Descriptor */
158static struct uac1_as_header_descriptor as_header_desc = {
159	.bLength =		UAC_DT_AS_HEADER_SIZE,
160	.bDescriptorType =	USB_DT_CS_INTERFACE,
161	.bDescriptorSubtype =	UAC_AS_GENERAL,
162	.bTerminalLink =	INPUT_TERMINAL_ID,
163	.bDelay =		1,
164	.wFormatTag =		UAC_FORMAT_TYPE_I_PCM,
165};
166
167DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
168
169static struct uac_format_type_i_discrete_descriptor_1 as_type_i_desc = {
170	.bLength =		UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
171	.bDescriptorType =	USB_DT_CS_INTERFACE,
172	.bDescriptorSubtype =	UAC_FORMAT_TYPE,
173	.bFormatType =		UAC_FORMAT_TYPE_I,
174	.bSubframeSize =	2,
175	.bBitResolution =	16,
176	.bSamFreqType =		1,
177};
178
179/* Standard ISO OUT Endpoint Descriptor */
180static struct usb_endpoint_descriptor as_out_ep_desc  = {
181	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
182	.bDescriptorType =	USB_DT_ENDPOINT,
183	.bEndpointAddress =	USB_DIR_OUT,
184	.bmAttributes =		USB_ENDPOINT_SYNC_ADAPTIVE
185				| USB_ENDPOINT_XFER_ISOC,
186	.wMaxPacketSize =	__constant_cpu_to_le16(OUT_EP_MAX_PACKET_SIZE),
187	.bInterval =		4,
188};
189
190/* Class-specific AS ISO OUT Endpoint Descriptor */
191static struct uac_iso_endpoint_descriptor as_iso_out_desc __initdata = {
192	.bLength =		UAC_ISO_ENDPOINT_DESC_SIZE,
193	.bDescriptorType =	USB_DT_CS_ENDPOINT,
194	.bDescriptorSubtype =	UAC_EP_GENERAL,
195	.bmAttributes = 	1,
196	.bLockDelayUnits =	1,
197	.wLockDelay =		__constant_cpu_to_le16(1),
198};
199
200static struct usb_descriptor_header *f_audio_desc[] __initdata = {
201	(struct usb_descriptor_header *)&ac_interface_desc,
202	(struct usb_descriptor_header *)&ac_header_desc,
203
204	(struct usb_descriptor_header *)&input_terminal_desc,
205	(struct usb_descriptor_header *)&output_terminal_desc,
206	(struct usb_descriptor_header *)&feature_unit_desc,
207
208	(struct usb_descriptor_header *)&as_interface_alt_0_desc,
209	(struct usb_descriptor_header *)&as_interface_alt_1_desc,
210	(struct usb_descriptor_header *)&as_header_desc,
211
212	(struct usb_descriptor_header *)&as_type_i_desc,
213
214	(struct usb_descriptor_header *)&as_out_ep_desc,
215	(struct usb_descriptor_header *)&as_iso_out_desc,
216	NULL,
217};
218
219/* string IDs are assigned dynamically */
220
221#define STRING_MANUFACTURER_IDX		0
222#define STRING_PRODUCT_IDX		1
223
224static char manufacturer[50];
225
226static struct usb_string strings_dev[] = {
227	[STRING_MANUFACTURER_IDX].s = manufacturer,
228	[STRING_PRODUCT_IDX].s = DRIVER_DESC,
229	{  } /* end of list */
230};
231
232static struct usb_gadget_strings stringtab_dev = {
233	.language	= 0x0409,	/* en-us */
234	.strings	= strings_dev,
235};
236
237static struct usb_gadget_strings *audio_strings[] = {
238	&stringtab_dev,
239	NULL,
240};
241
242/*
243 * This function is an ALSA sound card following USB Audio Class Spec 1.0.
244 */
245
246/*-------------------------------------------------------------------------*/
247struct f_audio_buf {
248	u8 *buf;
249	int actual;
250	struct list_head list;
251};
252
253static 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
270static void f_audio_buffer_free(struct f_audio_buf *audio_buf)
271{
272	kfree(audio_buf->buf);
273	kfree(audio_buf);
274}
275/*-------------------------------------------------------------------------*/
276
277struct 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
294static 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
301static 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
321static 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	int err;
327
328	if (!copy_buf)
329		return -EINVAL;
330
331	/* Copy buffer is full, add it to the play_queue */
332	if (audio_buf_size - copy_buf->actual < req->actual) {
333		list_add_tail(&copy_buf->list, &audio->play_queue);
334		schedule_work(&audio->playback_work);
335		copy_buf = f_audio_buffer_alloc(audio_buf_size);
336		if (IS_ERR(copy_buf))
337			return -ENOMEM;
338	}
339
340	memcpy(copy_buf->buf + copy_buf->actual, req->buf, req->actual);
341	copy_buf->actual += req->actual;
342	audio->copy_buf = copy_buf;
343
344	err = usb_ep_queue(ep, req, GFP_ATOMIC);
345	if (err)
346		ERROR(cdev, "%s queue req: %d\n", ep->name, err);
347
348	return 0;
349
350}
351
352static void f_audio_complete(struct usb_ep *ep, struct usb_request *req)
353{
354	struct f_audio *audio = req->context;
355	int status = req->status;
356	u32 data = 0;
357	struct usb_ep *out_ep = audio->out_ep;
358
359	switch (status) {
360
361	case 0:				/* normal completion? */
362		if (ep == out_ep)
363			f_audio_out_ep_complete(ep, req);
364		else if (audio->set_con) {
365			memcpy(&data, req->buf, req->length);
366			audio->set_con->set(audio->set_con, audio->set_cmd,
367					le16_to_cpu(data));
368			audio->set_con = NULL;
369		}
370		break;
371	default:
372		break;
373	}
374}
375
376static int audio_set_intf_req(struct usb_function *f,
377		const struct usb_ctrlrequest *ctrl)
378{
379	struct f_audio		*audio = func_to_audio(f);
380	struct usb_composite_dev *cdev = f->config->cdev;
381	struct usb_request	*req = cdev->req;
382	u8			id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
383	u16			len = le16_to_cpu(ctrl->wLength);
384	u16			w_value = le16_to_cpu(ctrl->wValue);
385	u8			con_sel = (w_value >> 8) & 0xFF;
386	u8			cmd = (ctrl->bRequest & 0x0F);
387	struct usb_audio_control_selector *cs;
388	struct usb_audio_control *con;
389
390	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
391			ctrl->bRequest, w_value, len, id);
392
393	list_for_each_entry(cs, &audio->cs, list) {
394		if (cs->id == id) {
395			list_for_each_entry(con, &cs->control, list) {
396				if (con->type == con_sel) {
397					audio->set_con = con;
398					break;
399				}
400			}
401			break;
402		}
403	}
404
405	audio->set_cmd = cmd;
406	req->context = audio;
407	req->complete = f_audio_complete;
408
409	return len;
410}
411
412static int audio_get_intf_req(struct usb_function *f,
413		const struct usb_ctrlrequest *ctrl)
414{
415	struct f_audio		*audio = func_to_audio(f);
416	struct usb_composite_dev *cdev = f->config->cdev;
417	struct usb_request	*req = cdev->req;
418	int			value = -EOPNOTSUPP;
419	u8			id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
420	u16			len = le16_to_cpu(ctrl->wLength);
421	u16			w_value = le16_to_cpu(ctrl->wValue);
422	u8			con_sel = (w_value >> 8) & 0xFF;
423	u8			cmd = (ctrl->bRequest & 0x0F);
424	struct usb_audio_control_selector *cs;
425	struct usb_audio_control *con;
426
427	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
428			ctrl->bRequest, w_value, len, id);
429
430	list_for_each_entry(cs, &audio->cs, list) {
431		if (cs->id == id) {
432			list_for_each_entry(con, &cs->control, list) {
433				if (con->type == con_sel && con->get) {
434					value = con->get(con, cmd);
435					break;
436				}
437			}
438			break;
439		}
440	}
441
442	req->context = audio;
443	req->complete = f_audio_complete;
444	memcpy(req->buf, &value, len);
445
446	return len;
447}
448
449static int audio_set_endpoint_req(struct usb_function *f,
450		const struct usb_ctrlrequest *ctrl)
451{
452	struct usb_composite_dev *cdev = f->config->cdev;
453	int			value = -EOPNOTSUPP;
454	u16			ep = le16_to_cpu(ctrl->wIndex);
455	u16			len = le16_to_cpu(ctrl->wLength);
456	u16			w_value = le16_to_cpu(ctrl->wValue);
457
458	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
459			ctrl->bRequest, w_value, len, ep);
460
461	switch (ctrl->bRequest) {
462	case UAC_SET_CUR:
463		value = 0;
464		break;
465
466	case UAC_SET_MIN:
467		break;
468
469	case UAC_SET_MAX:
470		break;
471
472	case UAC_SET_RES:
473		break;
474
475	case UAC_SET_MEM:
476		break;
477
478	default:
479		break;
480	}
481
482	return value;
483}
484
485static int audio_get_endpoint_req(struct usb_function *f,
486		const struct usb_ctrlrequest *ctrl)
487{
488	struct usb_composite_dev *cdev = f->config->cdev;
489	int value = -EOPNOTSUPP;
490	u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
491	u16 len = le16_to_cpu(ctrl->wLength);
492	u16 w_value = le16_to_cpu(ctrl->wValue);
493
494	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
495			ctrl->bRequest, w_value, len, ep);
496
497	switch (ctrl->bRequest) {
498	case UAC_GET_CUR:
499	case UAC_GET_MIN:
500	case UAC_GET_MAX:
501	case UAC_GET_RES:
502		value = 3;
503		break;
504	case UAC_GET_MEM:
505		break;
506	default:
507		break;
508	}
509
510	return value;
511}
512
513static int
514f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
515{
516	struct usb_composite_dev *cdev = f->config->cdev;
517	struct usb_request	*req = cdev->req;
518	int			value = -EOPNOTSUPP;
519	u16			w_index = le16_to_cpu(ctrl->wIndex);
520	u16			w_value = le16_to_cpu(ctrl->wValue);
521	u16			w_length = le16_to_cpu(ctrl->wLength);
522
523	/* composite driver infrastructure handles everything; interface
524	 * activation uses set_alt().
525	 */
526	switch (ctrl->bRequestType) {
527	case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
528		value = audio_set_intf_req(f, ctrl);
529		break;
530
531	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
532		value = audio_get_intf_req(f, ctrl);
533		break;
534
535	case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
536		value = audio_set_endpoint_req(f, ctrl);
537		break;
538
539	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
540		value = audio_get_endpoint_req(f, ctrl);
541		break;
542
543	default:
544		ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
545			ctrl->bRequestType, ctrl->bRequest,
546			w_value, w_index, w_length);
547	}
548
549	/* respond with data transfer or status phase? */
550	if (value >= 0) {
551		DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
552			ctrl->bRequestType, ctrl->bRequest,
553			w_value, w_index, w_length);
554		req->zero = 0;
555		req->length = value;
556		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
557		if (value < 0)
558			ERROR(cdev, "audio response on err %d\n", value);
559	}
560
561	/* device either stalls (value < 0) or reports success */
562	return value;
563}
564
565static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
566{
567	struct f_audio		*audio = func_to_audio(f);
568	struct usb_composite_dev *cdev = f->config->cdev;
569	struct usb_ep *out_ep = audio->out_ep;
570	struct usb_request *req;
571	int i = 0, err = 0;
572
573	DBG(cdev, "intf %d, alt %d\n", intf, alt);
574
575	if (intf == 1) {
576		if (alt == 1) {
577			usb_ep_enable(out_ep);
578			out_ep->driver_data = audio;
579			audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
580			if (IS_ERR(audio->copy_buf))
581				return -ENOMEM;
582
583			/*
584			 * allocate a bunch of read buffers
585			 * and queue them all at once.
586			 */
587			for (i = 0; i < req_count && err == 0; i++) {
588				req = usb_ep_alloc_request(out_ep, GFP_ATOMIC);
589				if (req) {
590					req->buf = kzalloc(req_buf_size,
591							GFP_ATOMIC);
592					if (req->buf) {
593						req->length = req_buf_size;
594						req->context = audio;
595						req->complete =
596							f_audio_complete;
597						err = usb_ep_queue(out_ep,
598							req, GFP_ATOMIC);
599						if (err)
600							ERROR(cdev,
601							"%s queue req: %d\n",
602							out_ep->name, err);
603					} else
604						err = -ENOMEM;
605				} else
606					err = -ENOMEM;
607			}
608
609		} else {
610			struct f_audio_buf *copy_buf = audio->copy_buf;
611			if (copy_buf) {
612				list_add_tail(&copy_buf->list,
613						&audio->play_queue);
614				schedule_work(&audio->playback_work);
615			}
616		}
617	}
618
619	return err;
620}
621
622static void f_audio_disable(struct usb_function *f)
623{
624	return;
625}
626
627/*-------------------------------------------------------------------------*/
628
629static void f_audio_build_desc(struct f_audio *audio)
630{
631	struct gaudio *card = &audio->card;
632	u8 *sam_freq;
633	int rate;
634
635	/* Set channel numbers */
636	input_terminal_desc.bNrChannels = u_audio_get_playback_channels(card);
637	as_type_i_desc.bNrChannels = u_audio_get_playback_channels(card);
638
639	/* Set sample rates */
640	rate = u_audio_get_playback_rate(card);
641	sam_freq = as_type_i_desc.tSamFreq[0];
642	memcpy(sam_freq, &rate, 3);
643
644	/* Todo: Set Sample bits and other parameters */
645
646	return;
647}
648
649/* audio function driver setup/binding */
650static int __init
651f_audio_bind(struct usb_configuration *c, struct usb_function *f)
652{
653	struct usb_composite_dev *cdev = c->cdev;
654	struct f_audio		*audio = func_to_audio(f);
655	int			status;
656	struct usb_ep		*ep;
657
658	f_audio_build_desc(audio);
659
660	/* allocate instance-specific interface IDs, and patch descriptors */
661	status = usb_interface_id(c, f);
662	if (status < 0)
663		goto fail;
664	ac_interface_desc.bInterfaceNumber = status;
665
666	status = usb_interface_id(c, f);
667	if (status < 0)
668		goto fail;
669	as_interface_alt_0_desc.bInterfaceNumber = status;
670	as_interface_alt_1_desc.bInterfaceNumber = status;
671
672	status = -ENODEV;
673
674	/* allocate instance-specific endpoints */
675	ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
676	if (!ep)
677		goto fail;
678	audio->out_ep = ep;
679	audio->out_ep->desc = &as_out_ep_desc;
680	ep->driver_data = cdev;	/* claim */
681
682	status = -ENOMEM;
683
684	/* supcard all relevant hardware speeds... we expect that when
685	 * hardware is dual speed, all bulk-capable endpoints work at
686	 * both speeds
687	 */
688
689	/* copy descriptors, and track endpoint copies */
690	if (gadget_is_dualspeed(c->cdev->gadget)) {
691		c->highspeed = true;
692		f->hs_descriptors = usb_copy_descriptors(f_audio_desc);
693	} else
694		f->descriptors = usb_copy_descriptors(f_audio_desc);
695
696	return 0;
697
698fail:
699
700	return status;
701}
702
703static void
704f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
705{
706	struct f_audio		*audio = func_to_audio(f);
707
708	usb_free_descriptors(f->descriptors);
709	usb_free_descriptors(f->hs_descriptors);
710	kfree(audio);
711}
712
713/*-------------------------------------------------------------------------*/
714
715static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value)
716{
717	con->data[cmd] = value;
718
719	return 0;
720}
721
722static int generic_get_cmd(struct usb_audio_control *con, u8 cmd)
723{
724	return con->data[cmd];
725}
726
727/* Todo: add more control selecotor dynamically */
728int __init control_selector_init(struct f_audio *audio)
729{
730	INIT_LIST_HEAD(&audio->cs);
731	list_add(&feature_unit.list, &audio->cs);
732
733	INIT_LIST_HEAD(&feature_unit.control);
734	list_add(&mute_control.list, &feature_unit.control);
735	list_add(&volume_control.list, &feature_unit.control);
736
737	volume_control.data[UAC__CUR] = 0xffc0;
738	volume_control.data[UAC__MIN] = 0xe3a0;
739	volume_control.data[UAC__MAX] = 0xfff0;
740	volume_control.data[UAC__RES] = 0x0030;
741
742	return 0;
743}
744
745/**
746 * audio_bind_config - add USB audio function to a configuration
747 * @c: the configuration to supcard the USB audio function
748 * Context: single threaded during gadget setup
749 *
750 * Returns zero on success, else negative errno.
751 */
752int __init audio_bind_config(struct usb_configuration *c)
753{
754	struct f_audio *audio;
755	int status;
756
757	/* allocate and initialize one new instance */
758	audio = kzalloc(sizeof *audio, GFP_KERNEL);
759	if (!audio)
760		return -ENOMEM;
761
762	audio->card.func.name = "g_audio";
763	audio->card.gadget = c->cdev->gadget;
764
765	INIT_LIST_HEAD(&audio->play_queue);
766	spin_lock_init(&audio->lock);
767
768	/* set up ASLA audio devices */
769	status = gaudio_setup(&audio->card);
770	if (status < 0)
771		goto setup_fail;
772
773	audio->card.func.strings = audio_strings;
774	audio->card.func.bind = f_audio_bind;
775	audio->card.func.unbind = f_audio_unbind;
776	audio->card.func.set_alt = f_audio_set_alt;
777	audio->card.func.setup = f_audio_setup;
778	audio->card.func.disable = f_audio_disable;
779
780	control_selector_init(audio);
781
782	INIT_WORK(&audio->playback_work, f_audio_playback_work);
783
784	status = usb_add_function(c, &audio->card.func);
785	if (status)
786		goto add_fail;
787
788	INFO(c->cdev, "audio_buf_size %d, req_buf_size %d, req_count %d\n",
789		audio_buf_size, req_buf_size, req_count);
790
791	return status;
792
793add_fail:
794	gaudio_cleanup();
795setup_fail:
796	kfree(audio);
797	return status;
798}