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1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * f_uac1.c -- USB Audio Class 1.0 Function (using u_audio API)
4  *
5  * Copyright (C) 2016 Ruslan Bilovol <ruslan.bilovol@gmail.com>
6  *
7  * This driver doesn't expect any real Audio codec to be present
8  * on the device - the audio streams are simply sinked to and
9  * sourced from a virtual ALSA sound card created.
10  *
11  * This file is based on f_uac1.c which is
12  *   Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
13  *   Copyright (C) 2008 Analog Devices, Inc
14  */
15 
16 #include <linux/usb/audio.h>
17 #include <linux/module.h>
18 
19 #include "u_audio.h"
20 #include "u_uac1.h"
21 
22 /* UAC1 spec: 3.7.2.3 Audio Channel Cluster Format */
23 #define UAC1_CHANNEL_MASK 0x0FFF
24 
25 struct f_uac1 {
26 	struct g_audio g_audio;
27 	u8 ac_intf, as_in_intf, as_out_intf;
28 	u8 ac_alt, as_in_alt, as_out_alt;	/* needed for get_alt() */
29 };
30 
func_to_uac1(struct usb_function * f)31 static inline struct f_uac1 *func_to_uac1(struct usb_function *f)
32 {
33 	return container_of(f, struct f_uac1, g_audio.func);
34 }
35 
g_audio_to_uac1_opts(struct g_audio * audio)36 static inline struct f_uac1_opts *g_audio_to_uac1_opts(struct g_audio *audio)
37 {
38 	return container_of(audio->func.fi, struct f_uac1_opts, func_inst);
39 }
40 
41 /*
42  * DESCRIPTORS ... most are static, but strings and full
43  * configuration descriptors are built on demand.
44  */
45 
46 /*
47  * We have three interfaces - one AudioControl and two AudioStreaming
48  *
49  * The driver implements a simple UAC_1 topology.
50  * USB-OUT -> IT_1 -> OT_2 -> ALSA_Capture
51  * ALSA_Playback -> IT_3 -> OT_4 -> USB-IN
52  */
53 #define F_AUDIO_AC_INTERFACE		0
54 #define F_AUDIO_AS_OUT_INTERFACE	1
55 #define F_AUDIO_AS_IN_INTERFACE		2
56 /* Number of streaming interfaces */
57 #define F_AUDIO_NUM_INTERFACES		2
58 
59 /* B.3.1  Standard AC Interface Descriptor */
60 static struct usb_interface_descriptor ac_interface_desc = {
61 	.bLength =		USB_DT_INTERFACE_SIZE,
62 	.bDescriptorType =	USB_DT_INTERFACE,
63 	.bNumEndpoints =	0,
64 	.bInterfaceClass =	USB_CLASS_AUDIO,
65 	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOCONTROL,
66 };
67 
68 /*
69  * The number of AudioStreaming and MIDIStreaming interfaces
70  * in the Audio Interface Collection
71  */
72 DECLARE_UAC_AC_HEADER_DESCRIPTOR(2);
73 
74 #define UAC_DT_AC_HEADER_LENGTH	UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
75 /* 2 input terminals and 2 output terminals */
76 #define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH \
77 	+ 2*UAC_DT_INPUT_TERMINAL_SIZE + 2*UAC_DT_OUTPUT_TERMINAL_SIZE)
78 /* B.3.2  Class-Specific AC Interface Descriptor */
79 static struct uac1_ac_header_descriptor_2 ac_header_desc = {
80 	.bLength =		UAC_DT_AC_HEADER_LENGTH,
81 	.bDescriptorType =	USB_DT_CS_INTERFACE,
82 	.bDescriptorSubtype =	UAC_HEADER,
83 	.bcdADC =		cpu_to_le16(0x0100),
84 	.wTotalLength =		cpu_to_le16(UAC_DT_TOTAL_LENGTH),
85 	.bInCollection =	F_AUDIO_NUM_INTERFACES,
86 	.baInterfaceNr = {
87 	/* Interface number of the AudioStream interfaces */
88 		[0] =		1,
89 		[1] =		2,
90 	}
91 };
92 
93 #define USB_OUT_IT_ID	1
94 static struct uac_input_terminal_descriptor usb_out_it_desc = {
95 	.bLength =		UAC_DT_INPUT_TERMINAL_SIZE,
96 	.bDescriptorType =	USB_DT_CS_INTERFACE,
97 	.bDescriptorSubtype =	UAC_INPUT_TERMINAL,
98 	.bTerminalID =		USB_OUT_IT_ID,
99 	.wTerminalType =	cpu_to_le16(UAC_TERMINAL_STREAMING),
100 	.bAssocTerminal =	0,
101 	.wChannelConfig =	cpu_to_le16(0x3),
102 };
103 
104 #define IO_OUT_OT_ID	2
105 static struct uac1_output_terminal_descriptor io_out_ot_desc = {
106 	.bLength		= UAC_DT_OUTPUT_TERMINAL_SIZE,
107 	.bDescriptorType	= USB_DT_CS_INTERFACE,
108 	.bDescriptorSubtype	= UAC_OUTPUT_TERMINAL,
109 	.bTerminalID		= IO_OUT_OT_ID,
110 	.wTerminalType		= cpu_to_le16(UAC_OUTPUT_TERMINAL_SPEAKER),
111 	.bAssocTerminal		= 0,
112 	.bSourceID		= USB_OUT_IT_ID,
113 };
114 
115 #define IO_IN_IT_ID	3
116 static struct uac_input_terminal_descriptor io_in_it_desc = {
117 	.bLength		= UAC_DT_INPUT_TERMINAL_SIZE,
118 	.bDescriptorType	= USB_DT_CS_INTERFACE,
119 	.bDescriptorSubtype	= UAC_INPUT_TERMINAL,
120 	.bTerminalID		= IO_IN_IT_ID,
121 	.wTerminalType		= cpu_to_le16(UAC_INPUT_TERMINAL_MICROPHONE),
122 	.bAssocTerminal		= 0,
123 	.wChannelConfig		= cpu_to_le16(0x3),
124 };
125 
126 #define USB_IN_OT_ID	4
127 static struct uac1_output_terminal_descriptor usb_in_ot_desc = {
128 	.bLength =		UAC_DT_OUTPUT_TERMINAL_SIZE,
129 	.bDescriptorType =	USB_DT_CS_INTERFACE,
130 	.bDescriptorSubtype =	UAC_OUTPUT_TERMINAL,
131 	.bTerminalID =		USB_IN_OT_ID,
132 	.wTerminalType =	cpu_to_le16(UAC_TERMINAL_STREAMING),
133 	.bAssocTerminal =	0,
134 	.bSourceID =		IO_IN_IT_ID,
135 };
136 
137 /* B.4.1  Standard AS Interface Descriptor */
138 static struct usb_interface_descriptor as_out_interface_alt_0_desc = {
139 	.bLength =		USB_DT_INTERFACE_SIZE,
140 	.bDescriptorType =	USB_DT_INTERFACE,
141 	.bAlternateSetting =	0,
142 	.bNumEndpoints =	0,
143 	.bInterfaceClass =	USB_CLASS_AUDIO,
144 	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
145 };
146 
147 static struct usb_interface_descriptor as_out_interface_alt_1_desc = {
148 	.bLength =		USB_DT_INTERFACE_SIZE,
149 	.bDescriptorType =	USB_DT_INTERFACE,
150 	.bAlternateSetting =	1,
151 	.bNumEndpoints =	1,
152 	.bInterfaceClass =	USB_CLASS_AUDIO,
153 	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
154 };
155 
156 static struct usb_interface_descriptor as_in_interface_alt_0_desc = {
157 	.bLength =		USB_DT_INTERFACE_SIZE,
158 	.bDescriptorType =	USB_DT_INTERFACE,
159 	.bAlternateSetting =	0,
160 	.bNumEndpoints =	0,
161 	.bInterfaceClass =	USB_CLASS_AUDIO,
162 	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
163 };
164 
165 static struct usb_interface_descriptor as_in_interface_alt_1_desc = {
166 	.bLength =		USB_DT_INTERFACE_SIZE,
167 	.bDescriptorType =	USB_DT_INTERFACE,
168 	.bAlternateSetting =	1,
169 	.bNumEndpoints =	1,
170 	.bInterfaceClass =	USB_CLASS_AUDIO,
171 	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
172 };
173 
174 /* B.4.2  Class-Specific AS Interface Descriptor */
175 static struct uac1_as_header_descriptor as_out_header_desc = {
176 	.bLength =		UAC_DT_AS_HEADER_SIZE,
177 	.bDescriptorType =	USB_DT_CS_INTERFACE,
178 	.bDescriptorSubtype =	UAC_AS_GENERAL,
179 	.bTerminalLink =	USB_OUT_IT_ID,
180 	.bDelay =		1,
181 	.wFormatTag =		cpu_to_le16(UAC_FORMAT_TYPE_I_PCM),
182 };
183 
184 static struct uac1_as_header_descriptor as_in_header_desc = {
185 	.bLength =		UAC_DT_AS_HEADER_SIZE,
186 	.bDescriptorType =	USB_DT_CS_INTERFACE,
187 	.bDescriptorSubtype =	UAC_AS_GENERAL,
188 	.bTerminalLink =	USB_IN_OT_ID,
189 	.bDelay =		1,
190 	.wFormatTag =		cpu_to_le16(UAC_FORMAT_TYPE_I_PCM),
191 };
192 
193 DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
194 
195 static struct uac_format_type_i_discrete_descriptor_1 as_out_type_i_desc = {
196 	.bLength =		UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
197 	.bDescriptorType =	USB_DT_CS_INTERFACE,
198 	.bDescriptorSubtype =	UAC_FORMAT_TYPE,
199 	.bFormatType =		UAC_FORMAT_TYPE_I,
200 	.bSubframeSize =	2,
201 	.bBitResolution =	16,
202 	.bSamFreqType =		1,
203 };
204 
205 /* Standard ISO OUT Endpoint Descriptor */
206 static struct usb_endpoint_descriptor as_out_ep_desc  = {
207 	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
208 	.bDescriptorType =	USB_DT_ENDPOINT,
209 	.bEndpointAddress =	USB_DIR_OUT,
210 	.bmAttributes =		USB_ENDPOINT_SYNC_ADAPTIVE
211 				| USB_ENDPOINT_XFER_ISOC,
212 	.wMaxPacketSize	=	cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
213 	.bInterval =		4,
214 };
215 
216 /* Class-specific AS ISO OUT Endpoint Descriptor */
217 static struct uac_iso_endpoint_descriptor as_iso_out_desc = {
218 	.bLength =		UAC_ISO_ENDPOINT_DESC_SIZE,
219 	.bDescriptorType =	USB_DT_CS_ENDPOINT,
220 	.bDescriptorSubtype =	UAC_EP_GENERAL,
221 	.bmAttributes =		1,
222 	.bLockDelayUnits =	1,
223 	.wLockDelay =		cpu_to_le16(1),
224 };
225 
226 static struct uac_format_type_i_discrete_descriptor_1 as_in_type_i_desc = {
227 	.bLength =		UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
228 	.bDescriptorType =	USB_DT_CS_INTERFACE,
229 	.bDescriptorSubtype =	UAC_FORMAT_TYPE,
230 	.bFormatType =		UAC_FORMAT_TYPE_I,
231 	.bSubframeSize =	2,
232 	.bBitResolution =	16,
233 	.bSamFreqType =		1,
234 };
235 
236 /* Standard ISO OUT Endpoint Descriptor */
237 static struct usb_endpoint_descriptor as_in_ep_desc  = {
238 	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
239 	.bDescriptorType =	USB_DT_ENDPOINT,
240 	.bEndpointAddress =	USB_DIR_IN,
241 	.bmAttributes =		USB_ENDPOINT_SYNC_ASYNC
242 				| USB_ENDPOINT_XFER_ISOC,
243 	.wMaxPacketSize	=	cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
244 	.bInterval =		4,
245 };
246 
247 /* Class-specific AS ISO OUT Endpoint Descriptor */
248 static struct uac_iso_endpoint_descriptor as_iso_in_desc = {
249 	.bLength =		UAC_ISO_ENDPOINT_DESC_SIZE,
250 	.bDescriptorType =	USB_DT_CS_ENDPOINT,
251 	.bDescriptorSubtype =	UAC_EP_GENERAL,
252 	.bmAttributes =		1,
253 	.bLockDelayUnits =	0,
254 	.wLockDelay =		0,
255 };
256 
257 static struct usb_descriptor_header *f_audio_desc[] = {
258 	(struct usb_descriptor_header *)&ac_interface_desc,
259 	(struct usb_descriptor_header *)&ac_header_desc,
260 
261 	(struct usb_descriptor_header *)&usb_out_it_desc,
262 	(struct usb_descriptor_header *)&io_out_ot_desc,
263 	(struct usb_descriptor_header *)&io_in_it_desc,
264 	(struct usb_descriptor_header *)&usb_in_ot_desc,
265 
266 	(struct usb_descriptor_header *)&as_out_interface_alt_0_desc,
267 	(struct usb_descriptor_header *)&as_out_interface_alt_1_desc,
268 	(struct usb_descriptor_header *)&as_out_header_desc,
269 
270 	(struct usb_descriptor_header *)&as_out_type_i_desc,
271 
272 	(struct usb_descriptor_header *)&as_out_ep_desc,
273 	(struct usb_descriptor_header *)&as_iso_out_desc,
274 
275 	(struct usb_descriptor_header *)&as_in_interface_alt_0_desc,
276 	(struct usb_descriptor_header *)&as_in_interface_alt_1_desc,
277 	(struct usb_descriptor_header *)&as_in_header_desc,
278 
279 	(struct usb_descriptor_header *)&as_in_type_i_desc,
280 
281 	(struct usb_descriptor_header *)&as_in_ep_desc,
282 	(struct usb_descriptor_header *)&as_iso_in_desc,
283 	NULL,
284 };
285 
286 enum {
287 	STR_AC_IF,
288 	STR_USB_OUT_IT,
289 	STR_USB_OUT_IT_CH_NAMES,
290 	STR_IO_OUT_OT,
291 	STR_IO_IN_IT,
292 	STR_IO_IN_IT_CH_NAMES,
293 	STR_USB_IN_OT,
294 	STR_AS_OUT_IF_ALT0,
295 	STR_AS_OUT_IF_ALT1,
296 	STR_AS_IN_IF_ALT0,
297 	STR_AS_IN_IF_ALT1,
298 };
299 
300 static struct usb_string strings_uac1[] = {
301 	[STR_AC_IF].s = "AC Interface",
302 	[STR_USB_OUT_IT].s = "Playback Input terminal",
303 	[STR_USB_OUT_IT_CH_NAMES].s = "Playback Channels",
304 	[STR_IO_OUT_OT].s = "Playback Output terminal",
305 	[STR_IO_IN_IT].s = "Capture Input terminal",
306 	[STR_IO_IN_IT_CH_NAMES].s = "Capture Channels",
307 	[STR_USB_IN_OT].s = "Capture Output terminal",
308 	[STR_AS_OUT_IF_ALT0].s = "Playback Inactive",
309 	[STR_AS_OUT_IF_ALT1].s = "Playback Active",
310 	[STR_AS_IN_IF_ALT0].s = "Capture Inactive",
311 	[STR_AS_IN_IF_ALT1].s = "Capture Active",
312 	{ },
313 };
314 
315 static struct usb_gadget_strings str_uac1 = {
316 	.language = 0x0409,	/* en-us */
317 	.strings = strings_uac1,
318 };
319 
320 static struct usb_gadget_strings *uac1_strings[] = {
321 	&str_uac1,
322 	NULL,
323 };
324 
325 /*
326  * This function is an ALSA sound card following USB Audio Class Spec 1.0.
327  */
328 
audio_set_endpoint_req(struct usb_function * f,const struct usb_ctrlrequest * ctrl)329 static int audio_set_endpoint_req(struct usb_function *f,
330 		const struct usb_ctrlrequest *ctrl)
331 {
332 	struct usb_composite_dev *cdev = f->config->cdev;
333 	int			value = -EOPNOTSUPP;
334 	u16			ep = le16_to_cpu(ctrl->wIndex);
335 	u16			len = le16_to_cpu(ctrl->wLength);
336 	u16			w_value = le16_to_cpu(ctrl->wValue);
337 
338 	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
339 			ctrl->bRequest, w_value, len, ep);
340 
341 	switch (ctrl->bRequest) {
342 	case UAC_SET_CUR:
343 		value = len;
344 		break;
345 
346 	case UAC_SET_MIN:
347 		break;
348 
349 	case UAC_SET_MAX:
350 		break;
351 
352 	case UAC_SET_RES:
353 		break;
354 
355 	case UAC_SET_MEM:
356 		break;
357 
358 	default:
359 		break;
360 	}
361 
362 	return value;
363 }
364 
audio_get_endpoint_req(struct usb_function * f,const struct usb_ctrlrequest * ctrl)365 static int audio_get_endpoint_req(struct usb_function *f,
366 		const struct usb_ctrlrequest *ctrl)
367 {
368 	struct usb_composite_dev *cdev = f->config->cdev;
369 	int value = -EOPNOTSUPP;
370 	u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
371 	u16 len = le16_to_cpu(ctrl->wLength);
372 	u16 w_value = le16_to_cpu(ctrl->wValue);
373 
374 	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
375 			ctrl->bRequest, w_value, len, ep);
376 
377 	switch (ctrl->bRequest) {
378 	case UAC_GET_CUR:
379 	case UAC_GET_MIN:
380 	case UAC_GET_MAX:
381 	case UAC_GET_RES:
382 		value = len;
383 		break;
384 	case UAC_GET_MEM:
385 		break;
386 	default:
387 		break;
388 	}
389 
390 	return value;
391 }
392 
393 static int
f_audio_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)394 f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
395 {
396 	struct usb_composite_dev *cdev = f->config->cdev;
397 	struct usb_request	*req = cdev->req;
398 	int			value = -EOPNOTSUPP;
399 	u16			w_index = le16_to_cpu(ctrl->wIndex);
400 	u16			w_value = le16_to_cpu(ctrl->wValue);
401 	u16			w_length = le16_to_cpu(ctrl->wLength);
402 
403 	/* composite driver infrastructure handles everything; interface
404 	 * activation uses set_alt().
405 	 */
406 	switch (ctrl->bRequestType) {
407 	case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
408 		value = audio_set_endpoint_req(f, ctrl);
409 		break;
410 
411 	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
412 		value = audio_get_endpoint_req(f, ctrl);
413 		break;
414 
415 	default:
416 		ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
417 			ctrl->bRequestType, ctrl->bRequest,
418 			w_value, w_index, w_length);
419 	}
420 
421 	/* respond with data transfer or status phase? */
422 	if (value >= 0) {
423 		DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
424 			ctrl->bRequestType, ctrl->bRequest,
425 			w_value, w_index, w_length);
426 		req->zero = 0;
427 		req->length = value;
428 		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
429 		if (value < 0)
430 			ERROR(cdev, "audio response on err %d\n", value);
431 	}
432 
433 	/* device either stalls (value < 0) or reports success */
434 	return value;
435 }
436 
f_audio_set_alt(struct usb_function * f,unsigned intf,unsigned alt)437 static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
438 {
439 	struct usb_composite_dev *cdev = f->config->cdev;
440 	struct usb_gadget *gadget = cdev->gadget;
441 	struct device *dev = &gadget->dev;
442 	struct f_uac1 *uac1 = func_to_uac1(f);
443 	int ret = 0;
444 
445 	/* No i/f has more than 2 alt settings */
446 	if (alt > 1) {
447 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
448 		return -EINVAL;
449 	}
450 
451 	if (intf == uac1->ac_intf) {
452 		/* Control I/f has only 1 AltSetting - 0 */
453 		if (alt) {
454 			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
455 			return -EINVAL;
456 		}
457 		return 0;
458 	}
459 
460 	if (intf == uac1->as_out_intf) {
461 		uac1->as_out_alt = alt;
462 
463 		if (alt)
464 			ret = u_audio_start_capture(&uac1->g_audio);
465 		else
466 			u_audio_stop_capture(&uac1->g_audio);
467 	} else if (intf == uac1->as_in_intf) {
468 		uac1->as_in_alt = alt;
469 
470 		if (alt)
471 			ret = u_audio_start_playback(&uac1->g_audio);
472 		else
473 			u_audio_stop_playback(&uac1->g_audio);
474 	} else {
475 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
476 		return -EINVAL;
477 	}
478 
479 	return ret;
480 }
481 
f_audio_get_alt(struct usb_function * f,unsigned intf)482 static int f_audio_get_alt(struct usb_function *f, unsigned intf)
483 {
484 	struct usb_composite_dev *cdev = f->config->cdev;
485 	struct usb_gadget *gadget = cdev->gadget;
486 	struct device *dev = &gadget->dev;
487 	struct f_uac1 *uac1 = func_to_uac1(f);
488 
489 	if (intf == uac1->ac_intf)
490 		return uac1->ac_alt;
491 	else if (intf == uac1->as_out_intf)
492 		return uac1->as_out_alt;
493 	else if (intf == uac1->as_in_intf)
494 		return uac1->as_in_alt;
495 	else
496 		dev_err(dev, "%s:%d Invalid Interface %d!\n",
497 			__func__, __LINE__, intf);
498 
499 	return -EINVAL;
500 }
501 
502 
f_audio_disable(struct usb_function * f)503 static void f_audio_disable(struct usb_function *f)
504 {
505 	struct f_uac1 *uac1 = func_to_uac1(f);
506 
507 	uac1->as_out_alt = 0;
508 	uac1->as_in_alt = 0;
509 
510 	u_audio_stop_playback(&uac1->g_audio);
511 	u_audio_stop_capture(&uac1->g_audio);
512 }
513 
514 /*-------------------------------------------------------------------------*/
515 
f_audio_validate_opts(struct g_audio * audio,struct device * dev)516 static int f_audio_validate_opts(struct g_audio *audio, struct device *dev)
517 {
518 	struct f_uac1_opts *opts = g_audio_to_uac1_opts(audio);
519 
520 	if (!opts->p_chmask && !opts->c_chmask) {
521 		dev_err(dev, "Error: no playback and capture channels\n");
522 		return -EINVAL;
523 	} else if (opts->p_chmask & ~UAC1_CHANNEL_MASK) {
524 		dev_err(dev, "Error: unsupported playback channels mask\n");
525 		return -EINVAL;
526 	} else if (opts->c_chmask & ~UAC1_CHANNEL_MASK) {
527 		dev_err(dev, "Error: unsupported capture channels mask\n");
528 		return -EINVAL;
529 	} else if ((opts->p_ssize < 1) || (opts->p_ssize > 4)) {
530 		dev_err(dev, "Error: incorrect playback sample size\n");
531 		return -EINVAL;
532 	} else if ((opts->c_ssize < 1) || (opts->c_ssize > 4)) {
533 		dev_err(dev, "Error: incorrect capture sample size\n");
534 		return -EINVAL;
535 	} else if (!opts->p_srate) {
536 		dev_err(dev, "Error: incorrect playback sampling rate\n");
537 		return -EINVAL;
538 	} else if (!opts->c_srate) {
539 		dev_err(dev, "Error: incorrect capture sampling rate\n");
540 		return -EINVAL;
541 	}
542 
543 	return 0;
544 }
545 
546 /* audio function driver setup/binding */
f_audio_bind(struct usb_configuration * c,struct usb_function * f)547 static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
548 {
549 	struct usb_composite_dev	*cdev = c->cdev;
550 	struct usb_gadget		*gadget = cdev->gadget;
551 	struct device			*dev = &gadget->dev;
552 	struct f_uac1			*uac1 = func_to_uac1(f);
553 	struct g_audio			*audio = func_to_g_audio(f);
554 	struct f_uac1_opts		*audio_opts;
555 	struct usb_ep			*ep = NULL;
556 	struct usb_string		*us;
557 	u8				*sam_freq;
558 	int				rate;
559 	int				status;
560 
561 	status = f_audio_validate_opts(audio, dev);
562 	if (status)
563 		return status;
564 
565 	audio_opts = container_of(f->fi, struct f_uac1_opts, func_inst);
566 
567 	us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1));
568 	if (IS_ERR(us))
569 		return PTR_ERR(us);
570 	ac_interface_desc.iInterface = us[STR_AC_IF].id;
571 	usb_out_it_desc.iTerminal = us[STR_USB_OUT_IT].id;
572 	usb_out_it_desc.iChannelNames = us[STR_USB_OUT_IT_CH_NAMES].id;
573 	io_out_ot_desc.iTerminal = us[STR_IO_OUT_OT].id;
574 	as_out_interface_alt_0_desc.iInterface = us[STR_AS_OUT_IF_ALT0].id;
575 	as_out_interface_alt_1_desc.iInterface = us[STR_AS_OUT_IF_ALT1].id;
576 	io_in_it_desc.iTerminal = us[STR_IO_IN_IT].id;
577 	io_in_it_desc.iChannelNames = us[STR_IO_IN_IT_CH_NAMES].id;
578 	usb_in_ot_desc.iTerminal = us[STR_USB_IN_OT].id;
579 	as_in_interface_alt_0_desc.iInterface = us[STR_AS_IN_IF_ALT0].id;
580 	as_in_interface_alt_1_desc.iInterface = us[STR_AS_IN_IF_ALT1].id;
581 
582 	/* Set channel numbers */
583 	usb_out_it_desc.bNrChannels = num_channels(audio_opts->c_chmask);
584 	usb_out_it_desc.wChannelConfig = cpu_to_le16(audio_opts->c_chmask);
585 	as_out_type_i_desc.bNrChannels = num_channels(audio_opts->c_chmask);
586 	as_out_type_i_desc.bSubframeSize = audio_opts->c_ssize;
587 	as_out_type_i_desc.bBitResolution = audio_opts->c_ssize * 8;
588 	io_in_it_desc.bNrChannels = num_channels(audio_opts->p_chmask);
589 	io_in_it_desc.wChannelConfig = cpu_to_le16(audio_opts->p_chmask);
590 	as_in_type_i_desc.bNrChannels = num_channels(audio_opts->p_chmask);
591 	as_in_type_i_desc.bSubframeSize = audio_opts->p_ssize;
592 	as_in_type_i_desc.bBitResolution = audio_opts->p_ssize * 8;
593 
594 	/* Set sample rates */
595 	rate = audio_opts->c_srate;
596 	sam_freq = as_out_type_i_desc.tSamFreq[0];
597 	memcpy(sam_freq, &rate, 3);
598 	rate = audio_opts->p_srate;
599 	sam_freq = as_in_type_i_desc.tSamFreq[0];
600 	memcpy(sam_freq, &rate, 3);
601 
602 	/* allocate instance-specific interface IDs, and patch descriptors */
603 	status = usb_interface_id(c, f);
604 	if (status < 0)
605 		goto fail;
606 	ac_interface_desc.bInterfaceNumber = status;
607 	uac1->ac_intf = status;
608 	uac1->ac_alt = 0;
609 
610 	status = usb_interface_id(c, f);
611 	if (status < 0)
612 		goto fail;
613 	as_out_interface_alt_0_desc.bInterfaceNumber = status;
614 	as_out_interface_alt_1_desc.bInterfaceNumber = status;
615 	ac_header_desc.baInterfaceNr[0] = status;
616 	uac1->as_out_intf = status;
617 	uac1->as_out_alt = 0;
618 
619 	status = usb_interface_id(c, f);
620 	if (status < 0)
621 		goto fail;
622 	as_in_interface_alt_0_desc.bInterfaceNumber = status;
623 	as_in_interface_alt_1_desc.bInterfaceNumber = status;
624 	ac_header_desc.baInterfaceNr[1] = status;
625 	uac1->as_in_intf = status;
626 	uac1->as_in_alt = 0;
627 
628 	audio->gadget = gadget;
629 
630 	status = -ENODEV;
631 
632 	/* allocate instance-specific endpoints */
633 	ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
634 	if (!ep)
635 		goto fail;
636 	audio->out_ep = ep;
637 	audio->out_ep->desc = &as_out_ep_desc;
638 
639 	ep = usb_ep_autoconfig(cdev->gadget, &as_in_ep_desc);
640 	if (!ep)
641 		goto fail;
642 	audio->in_ep = ep;
643 	audio->in_ep->desc = &as_in_ep_desc;
644 
645 	/* copy descriptors, and track endpoint copies */
646 	status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL,
647 					NULL);
648 	if (status)
649 		goto fail;
650 
651 	audio->out_ep_maxpsize = le16_to_cpu(as_out_ep_desc.wMaxPacketSize);
652 	audio->in_ep_maxpsize = le16_to_cpu(as_in_ep_desc.wMaxPacketSize);
653 	audio->params.c_chmask = audio_opts->c_chmask;
654 	audio->params.c_srate = audio_opts->c_srate;
655 	audio->params.c_ssize = audio_opts->c_ssize;
656 	audio->params.p_chmask = audio_opts->p_chmask;
657 	audio->params.p_srate = audio_opts->p_srate;
658 	audio->params.p_ssize = audio_opts->p_ssize;
659 	audio->params.req_number = audio_opts->req_number;
660 
661 	status = g_audio_setup(audio, "UAC1_PCM", "UAC1_Gadget");
662 	if (status)
663 		goto err_card_register;
664 
665 	return 0;
666 
667 err_card_register:
668 	usb_free_all_descriptors(f);
669 fail:
670 	return status;
671 }
672 
673 /*-------------------------------------------------------------------------*/
674 
to_f_uac1_opts(struct config_item * item)675 static inline struct f_uac1_opts *to_f_uac1_opts(struct config_item *item)
676 {
677 	return container_of(to_config_group(item), struct f_uac1_opts,
678 			    func_inst.group);
679 }
680 
f_uac1_attr_release(struct config_item * item)681 static void f_uac1_attr_release(struct config_item *item)
682 {
683 	struct f_uac1_opts *opts = to_f_uac1_opts(item);
684 
685 	usb_put_function_instance(&opts->func_inst);
686 }
687 
688 static struct configfs_item_operations f_uac1_item_ops = {
689 	.release	= f_uac1_attr_release,
690 };
691 
692 #define UAC1_ATTRIBUTE(name)						\
693 static ssize_t f_uac1_opts_##name##_show(				\
694 					  struct config_item *item,	\
695 					  char *page)			\
696 {									\
697 	struct f_uac1_opts *opts = to_f_uac1_opts(item);		\
698 	int result;							\
699 									\
700 	mutex_lock(&opts->lock);					\
701 	result = sprintf(page, "%u\n", opts->name);			\
702 	mutex_unlock(&opts->lock);					\
703 									\
704 	return result;							\
705 }									\
706 									\
707 static ssize_t f_uac1_opts_##name##_store(				\
708 					  struct config_item *item,	\
709 					  const char *page, size_t len)	\
710 {									\
711 	struct f_uac1_opts *opts = to_f_uac1_opts(item);		\
712 	int ret;							\
713 	u32 num;							\
714 									\
715 	mutex_lock(&opts->lock);					\
716 	if (opts->refcnt) {						\
717 		ret = -EBUSY;						\
718 		goto end;						\
719 	}								\
720 									\
721 	ret = kstrtou32(page, 0, &num);					\
722 	if (ret)							\
723 		goto end;						\
724 									\
725 	opts->name = num;						\
726 	ret = len;							\
727 									\
728 end:									\
729 	mutex_unlock(&opts->lock);					\
730 	return ret;							\
731 }									\
732 									\
733 CONFIGFS_ATTR(f_uac1_opts_, name)
734 
735 UAC1_ATTRIBUTE(c_chmask);
736 UAC1_ATTRIBUTE(c_srate);
737 UAC1_ATTRIBUTE(c_ssize);
738 UAC1_ATTRIBUTE(p_chmask);
739 UAC1_ATTRIBUTE(p_srate);
740 UAC1_ATTRIBUTE(p_ssize);
741 UAC1_ATTRIBUTE(req_number);
742 
743 static struct configfs_attribute *f_uac1_attrs[] = {
744 	&f_uac1_opts_attr_c_chmask,
745 	&f_uac1_opts_attr_c_srate,
746 	&f_uac1_opts_attr_c_ssize,
747 	&f_uac1_opts_attr_p_chmask,
748 	&f_uac1_opts_attr_p_srate,
749 	&f_uac1_opts_attr_p_ssize,
750 	&f_uac1_opts_attr_req_number,
751 	NULL,
752 };
753 
754 static const struct config_item_type f_uac1_func_type = {
755 	.ct_item_ops	= &f_uac1_item_ops,
756 	.ct_attrs	= f_uac1_attrs,
757 	.ct_owner	= THIS_MODULE,
758 };
759 
f_audio_free_inst(struct usb_function_instance * f)760 static void f_audio_free_inst(struct usb_function_instance *f)
761 {
762 	struct f_uac1_opts *opts;
763 
764 	opts = container_of(f, struct f_uac1_opts, func_inst);
765 	kfree(opts);
766 }
767 
f_audio_alloc_inst(void)768 static struct usb_function_instance *f_audio_alloc_inst(void)
769 {
770 	struct f_uac1_opts *opts;
771 
772 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
773 	if (!opts)
774 		return ERR_PTR(-ENOMEM);
775 
776 	mutex_init(&opts->lock);
777 	opts->func_inst.free_func_inst = f_audio_free_inst;
778 
779 	config_group_init_type_name(&opts->func_inst.group, "",
780 				    &f_uac1_func_type);
781 
782 	opts->c_chmask = UAC1_DEF_CCHMASK;
783 	opts->c_srate = UAC1_DEF_CSRATE;
784 	opts->c_ssize = UAC1_DEF_CSSIZE;
785 	opts->p_chmask = UAC1_DEF_PCHMASK;
786 	opts->p_srate = UAC1_DEF_PSRATE;
787 	opts->p_ssize = UAC1_DEF_PSSIZE;
788 	opts->req_number = UAC1_DEF_REQ_NUM;
789 	return &opts->func_inst;
790 }
791 
f_audio_free(struct usb_function * f)792 static void f_audio_free(struct usb_function *f)
793 {
794 	struct g_audio *audio;
795 	struct f_uac1_opts *opts;
796 
797 	audio = func_to_g_audio(f);
798 	opts = container_of(f->fi, struct f_uac1_opts, func_inst);
799 	kfree(audio);
800 	mutex_lock(&opts->lock);
801 	--opts->refcnt;
802 	mutex_unlock(&opts->lock);
803 }
804 
f_audio_unbind(struct usb_configuration * c,struct usb_function * f)805 static void f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
806 {
807 	struct g_audio *audio = func_to_g_audio(f);
808 
809 	g_audio_cleanup(audio);
810 	usb_free_all_descriptors(f);
811 
812 	audio->gadget = NULL;
813 }
814 
f_audio_alloc(struct usb_function_instance * fi)815 static struct usb_function *f_audio_alloc(struct usb_function_instance *fi)
816 {
817 	struct f_uac1 *uac1;
818 	struct f_uac1_opts *opts;
819 
820 	/* allocate and initialize one new instance */
821 	uac1 = kzalloc(sizeof(*uac1), GFP_KERNEL);
822 	if (!uac1)
823 		return ERR_PTR(-ENOMEM);
824 
825 	opts = container_of(fi, struct f_uac1_opts, func_inst);
826 	mutex_lock(&opts->lock);
827 	++opts->refcnt;
828 	mutex_unlock(&opts->lock);
829 
830 	uac1->g_audio.func.name = "uac1_func";
831 	uac1->g_audio.func.bind = f_audio_bind;
832 	uac1->g_audio.func.unbind = f_audio_unbind;
833 	uac1->g_audio.func.set_alt = f_audio_set_alt;
834 	uac1->g_audio.func.get_alt = f_audio_get_alt;
835 	uac1->g_audio.func.setup = f_audio_setup;
836 	uac1->g_audio.func.disable = f_audio_disable;
837 	uac1->g_audio.func.free_func = f_audio_free;
838 
839 	return &uac1->g_audio.func;
840 }
841 
842 DECLARE_USB_FUNCTION_INIT(uac1, f_audio_alloc_inst, f_audio_alloc);
843 MODULE_LICENSE("GPL");
844 MODULE_AUTHOR("Ruslan Bilovol");
845