1 /*
2  * f_uac2.c -- USB Audio Class 2.0 Function
3  *
4  * Copyright (C) 2011
5  *    Yadwinder Singh (yadi.brar01@gmail.com)
6  *    Jaswinder Singh (jaswinder.singh@linaro.org)
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  */
13 
14 #include <linux/usb/audio.h>
15 #include <linux/usb/audio-v2.h>
16 #include <linux/module.h>
17 
18 #include "u_audio.h"
19 #include "u_uac2.h"
20 
21 /*
22  * The driver implements a simple UAC_2 topology.
23  * USB-OUT -> IT_1 -> OT_3 -> ALSA_Capture
24  * ALSA_Playback -> IT_2 -> OT_4 -> USB-IN
25  * Capture and Playback sampling rates are independently
26  *  controlled by two clock sources :
27  *    CLK_5 := c_srate, and CLK_6 := p_srate
28  */
29 #define USB_OUT_IT_ID	1
30 #define IO_IN_IT_ID	2
31 #define IO_OUT_OT_ID	3
32 #define USB_IN_OT_ID	4
33 #define USB_OUT_CLK_ID	5
34 #define USB_IN_CLK_ID	6
35 
36 #define CONTROL_ABSENT	0
37 #define CONTROL_RDONLY	1
38 #define CONTROL_RDWR	3
39 
40 #define CLK_FREQ_CTRL	0
41 #define CLK_VLD_CTRL	2
42 
43 #define COPY_CTRL	0
44 #define CONN_CTRL	2
45 #define OVRLD_CTRL	4
46 #define CLSTR_CTRL	6
47 #define UNFLW_CTRL	8
48 #define OVFLW_CTRL	10
49 
50 struct f_uac2 {
51 	struct g_audio g_audio;
52 	u8 ac_intf, as_in_intf, as_out_intf;
53 	u8 ac_alt, as_in_alt, as_out_alt;	/* needed for get_alt() */
54 };
55 
56 static inline struct f_uac2 *func_to_uac2(struct usb_function *f)
57 {
58 	return container_of(f, struct f_uac2, g_audio.func);
59 }
60 
61 static inline
62 struct f_uac2_opts *g_audio_to_uac2_opts(struct g_audio *agdev)
63 {
64 	return container_of(agdev->func.fi, struct f_uac2_opts, func_inst);
65 }
66 
67 /* --------- USB Function Interface ------------- */
68 
69 enum {
70 	STR_ASSOC,
71 	STR_IF_CTRL,
72 	STR_CLKSRC_IN,
73 	STR_CLKSRC_OUT,
74 	STR_USB_IT,
75 	STR_IO_IT,
76 	STR_USB_OT,
77 	STR_IO_OT,
78 	STR_AS_OUT_ALT0,
79 	STR_AS_OUT_ALT1,
80 	STR_AS_IN_ALT0,
81 	STR_AS_IN_ALT1,
82 };
83 
84 static char clksrc_in[8];
85 static char clksrc_out[8];
86 
87 static struct usb_string strings_fn[] = {
88 	[STR_ASSOC].s = "Source/Sink",
89 	[STR_IF_CTRL].s = "Topology Control",
90 	[STR_CLKSRC_IN].s = clksrc_in,
91 	[STR_CLKSRC_OUT].s = clksrc_out,
92 	[STR_USB_IT].s = "USBH Out",
93 	[STR_IO_IT].s = "USBD Out",
94 	[STR_USB_OT].s = "USBH In",
95 	[STR_IO_OT].s = "USBD In",
96 	[STR_AS_OUT_ALT0].s = "Playback Inactive",
97 	[STR_AS_OUT_ALT1].s = "Playback Active",
98 	[STR_AS_IN_ALT0].s = "Capture Inactive",
99 	[STR_AS_IN_ALT1].s = "Capture Active",
100 	{ },
101 };
102 
103 static struct usb_gadget_strings str_fn = {
104 	.language = 0x0409,	/* en-us */
105 	.strings = strings_fn,
106 };
107 
108 static struct usb_gadget_strings *fn_strings[] = {
109 	&str_fn,
110 	NULL,
111 };
112 
113 static struct usb_interface_assoc_descriptor iad_desc = {
114 	.bLength = sizeof iad_desc,
115 	.bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
116 
117 	.bFirstInterface = 0,
118 	.bInterfaceCount = 3,
119 	.bFunctionClass = USB_CLASS_AUDIO,
120 	.bFunctionSubClass = UAC2_FUNCTION_SUBCLASS_UNDEFINED,
121 	.bFunctionProtocol = UAC_VERSION_2,
122 };
123 
124 /* Audio Control Interface */
125 static struct usb_interface_descriptor std_ac_if_desc = {
126 	.bLength = sizeof std_ac_if_desc,
127 	.bDescriptorType = USB_DT_INTERFACE,
128 
129 	.bAlternateSetting = 0,
130 	.bNumEndpoints = 0,
131 	.bInterfaceClass = USB_CLASS_AUDIO,
132 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL,
133 	.bInterfaceProtocol = UAC_VERSION_2,
134 };
135 
136 /* Clock source for IN traffic */
137 static struct uac_clock_source_descriptor in_clk_src_desc = {
138 	.bLength = sizeof in_clk_src_desc,
139 	.bDescriptorType = USB_DT_CS_INTERFACE,
140 
141 	.bDescriptorSubtype = UAC2_CLOCK_SOURCE,
142 	.bClockID = USB_IN_CLK_ID,
143 	.bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
144 	.bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
145 	.bAssocTerminal = 0,
146 };
147 
148 /* Clock source for OUT traffic */
149 static struct uac_clock_source_descriptor out_clk_src_desc = {
150 	.bLength = sizeof out_clk_src_desc,
151 	.bDescriptorType = USB_DT_CS_INTERFACE,
152 
153 	.bDescriptorSubtype = UAC2_CLOCK_SOURCE,
154 	.bClockID = USB_OUT_CLK_ID,
155 	.bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
156 	.bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
157 	.bAssocTerminal = 0,
158 };
159 
160 /* Input Terminal for USB_OUT */
161 static struct uac2_input_terminal_descriptor usb_out_it_desc = {
162 	.bLength = sizeof usb_out_it_desc,
163 	.bDescriptorType = USB_DT_CS_INTERFACE,
164 
165 	.bDescriptorSubtype = UAC_INPUT_TERMINAL,
166 	.bTerminalID = USB_OUT_IT_ID,
167 	.wTerminalType = cpu_to_le16(UAC_TERMINAL_STREAMING),
168 	.bAssocTerminal = 0,
169 	.bCSourceID = USB_OUT_CLK_ID,
170 	.iChannelNames = 0,
171 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
172 };
173 
174 /* Input Terminal for I/O-In */
175 static struct uac2_input_terminal_descriptor io_in_it_desc = {
176 	.bLength = sizeof io_in_it_desc,
177 	.bDescriptorType = USB_DT_CS_INTERFACE,
178 
179 	.bDescriptorSubtype = UAC_INPUT_TERMINAL,
180 	.bTerminalID = IO_IN_IT_ID,
181 	.wTerminalType = cpu_to_le16(UAC_INPUT_TERMINAL_UNDEFINED),
182 	.bAssocTerminal = 0,
183 	.bCSourceID = USB_IN_CLK_ID,
184 	.iChannelNames = 0,
185 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
186 };
187 
188 /* Ouput Terminal for USB_IN */
189 static struct uac2_output_terminal_descriptor usb_in_ot_desc = {
190 	.bLength = sizeof usb_in_ot_desc,
191 	.bDescriptorType = USB_DT_CS_INTERFACE,
192 
193 	.bDescriptorSubtype = UAC_OUTPUT_TERMINAL,
194 	.bTerminalID = USB_IN_OT_ID,
195 	.wTerminalType = cpu_to_le16(UAC_TERMINAL_STREAMING),
196 	.bAssocTerminal = 0,
197 	.bSourceID = IO_IN_IT_ID,
198 	.bCSourceID = USB_IN_CLK_ID,
199 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
200 };
201 
202 /* Ouput Terminal for I/O-Out */
203 static struct uac2_output_terminal_descriptor io_out_ot_desc = {
204 	.bLength = sizeof io_out_ot_desc,
205 	.bDescriptorType = USB_DT_CS_INTERFACE,
206 
207 	.bDescriptorSubtype = UAC_OUTPUT_TERMINAL,
208 	.bTerminalID = IO_OUT_OT_ID,
209 	.wTerminalType = cpu_to_le16(UAC_OUTPUT_TERMINAL_UNDEFINED),
210 	.bAssocTerminal = 0,
211 	.bSourceID = USB_OUT_IT_ID,
212 	.bCSourceID = USB_OUT_CLK_ID,
213 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
214 };
215 
216 static struct uac2_ac_header_descriptor ac_hdr_desc = {
217 	.bLength = sizeof ac_hdr_desc,
218 	.bDescriptorType = USB_DT_CS_INTERFACE,
219 
220 	.bDescriptorSubtype = UAC_MS_HEADER,
221 	.bcdADC = cpu_to_le16(0x200),
222 	.bCategory = UAC2_FUNCTION_IO_BOX,
223 	.wTotalLength = sizeof in_clk_src_desc + sizeof out_clk_src_desc
224 			 + sizeof usb_out_it_desc + sizeof io_in_it_desc
225 			+ sizeof usb_in_ot_desc + sizeof io_out_ot_desc,
226 	.bmControls = 0,
227 };
228 
229 /* Audio Streaming OUT Interface - Alt0 */
230 static struct usb_interface_descriptor std_as_out_if0_desc = {
231 	.bLength = sizeof std_as_out_if0_desc,
232 	.bDescriptorType = USB_DT_INTERFACE,
233 
234 	.bAlternateSetting = 0,
235 	.bNumEndpoints = 0,
236 	.bInterfaceClass = USB_CLASS_AUDIO,
237 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
238 	.bInterfaceProtocol = UAC_VERSION_2,
239 };
240 
241 /* Audio Streaming OUT Interface - Alt1 */
242 static struct usb_interface_descriptor std_as_out_if1_desc = {
243 	.bLength = sizeof std_as_out_if1_desc,
244 	.bDescriptorType = USB_DT_INTERFACE,
245 
246 	.bAlternateSetting = 1,
247 	.bNumEndpoints = 1,
248 	.bInterfaceClass = USB_CLASS_AUDIO,
249 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
250 	.bInterfaceProtocol = UAC_VERSION_2,
251 };
252 
253 /* Audio Stream OUT Intface Desc */
254 static struct uac2_as_header_descriptor as_out_hdr_desc = {
255 	.bLength = sizeof as_out_hdr_desc,
256 	.bDescriptorType = USB_DT_CS_INTERFACE,
257 
258 	.bDescriptorSubtype = UAC_AS_GENERAL,
259 	.bTerminalLink = USB_OUT_IT_ID,
260 	.bmControls = 0,
261 	.bFormatType = UAC_FORMAT_TYPE_I,
262 	.bmFormats = cpu_to_le32(UAC_FORMAT_TYPE_I_PCM),
263 	.iChannelNames = 0,
264 };
265 
266 /* Audio USB_OUT Format */
267 static struct uac2_format_type_i_descriptor as_out_fmt1_desc = {
268 	.bLength = sizeof as_out_fmt1_desc,
269 	.bDescriptorType = USB_DT_CS_INTERFACE,
270 	.bDescriptorSubtype = UAC_FORMAT_TYPE,
271 	.bFormatType = UAC_FORMAT_TYPE_I,
272 };
273 
274 /* STD AS ISO OUT Endpoint */
275 static struct usb_endpoint_descriptor fs_epout_desc = {
276 	.bLength = USB_DT_ENDPOINT_SIZE,
277 	.bDescriptorType = USB_DT_ENDPOINT,
278 
279 	.bEndpointAddress = USB_DIR_OUT,
280 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
281 	.wMaxPacketSize = cpu_to_le16(1023),
282 	.bInterval = 1,
283 };
284 
285 static struct usb_endpoint_descriptor hs_epout_desc = {
286 	.bLength = USB_DT_ENDPOINT_SIZE,
287 	.bDescriptorType = USB_DT_ENDPOINT,
288 
289 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
290 	.wMaxPacketSize = cpu_to_le16(1024),
291 	.bInterval = 4,
292 };
293 
294 /* CS AS ISO OUT Endpoint */
295 static struct uac2_iso_endpoint_descriptor as_iso_out_desc = {
296 	.bLength = sizeof as_iso_out_desc,
297 	.bDescriptorType = USB_DT_CS_ENDPOINT,
298 
299 	.bDescriptorSubtype = UAC_EP_GENERAL,
300 	.bmAttributes = 0,
301 	.bmControls = 0,
302 	.bLockDelayUnits = 0,
303 	.wLockDelay = 0,
304 };
305 
306 /* Audio Streaming IN Interface - Alt0 */
307 static struct usb_interface_descriptor std_as_in_if0_desc = {
308 	.bLength = sizeof std_as_in_if0_desc,
309 	.bDescriptorType = USB_DT_INTERFACE,
310 
311 	.bAlternateSetting = 0,
312 	.bNumEndpoints = 0,
313 	.bInterfaceClass = USB_CLASS_AUDIO,
314 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
315 	.bInterfaceProtocol = UAC_VERSION_2,
316 };
317 
318 /* Audio Streaming IN Interface - Alt1 */
319 static struct usb_interface_descriptor std_as_in_if1_desc = {
320 	.bLength = sizeof std_as_in_if1_desc,
321 	.bDescriptorType = USB_DT_INTERFACE,
322 
323 	.bAlternateSetting = 1,
324 	.bNumEndpoints = 1,
325 	.bInterfaceClass = USB_CLASS_AUDIO,
326 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
327 	.bInterfaceProtocol = UAC_VERSION_2,
328 };
329 
330 /* Audio Stream IN Intface Desc */
331 static struct uac2_as_header_descriptor as_in_hdr_desc = {
332 	.bLength = sizeof as_in_hdr_desc,
333 	.bDescriptorType = USB_DT_CS_INTERFACE,
334 
335 	.bDescriptorSubtype = UAC_AS_GENERAL,
336 	.bTerminalLink = USB_IN_OT_ID,
337 	.bmControls = 0,
338 	.bFormatType = UAC_FORMAT_TYPE_I,
339 	.bmFormats = cpu_to_le32(UAC_FORMAT_TYPE_I_PCM),
340 	.iChannelNames = 0,
341 };
342 
343 /* Audio USB_IN Format */
344 static struct uac2_format_type_i_descriptor as_in_fmt1_desc = {
345 	.bLength = sizeof as_in_fmt1_desc,
346 	.bDescriptorType = USB_DT_CS_INTERFACE,
347 	.bDescriptorSubtype = UAC_FORMAT_TYPE,
348 	.bFormatType = UAC_FORMAT_TYPE_I,
349 };
350 
351 /* STD AS ISO IN Endpoint */
352 static struct usb_endpoint_descriptor fs_epin_desc = {
353 	.bLength = USB_DT_ENDPOINT_SIZE,
354 	.bDescriptorType = USB_DT_ENDPOINT,
355 
356 	.bEndpointAddress = USB_DIR_IN,
357 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
358 	.wMaxPacketSize = cpu_to_le16(1023),
359 	.bInterval = 1,
360 };
361 
362 static struct usb_endpoint_descriptor hs_epin_desc = {
363 	.bLength = USB_DT_ENDPOINT_SIZE,
364 	.bDescriptorType = USB_DT_ENDPOINT,
365 
366 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
367 	.wMaxPacketSize = cpu_to_le16(1024),
368 	.bInterval = 4,
369 };
370 
371 /* CS AS ISO IN Endpoint */
372 static struct uac2_iso_endpoint_descriptor as_iso_in_desc = {
373 	.bLength = sizeof as_iso_in_desc,
374 	.bDescriptorType = USB_DT_CS_ENDPOINT,
375 
376 	.bDescriptorSubtype = UAC_EP_GENERAL,
377 	.bmAttributes = 0,
378 	.bmControls = 0,
379 	.bLockDelayUnits = 0,
380 	.wLockDelay = 0,
381 };
382 
383 static struct usb_descriptor_header *fs_audio_desc[] = {
384 	(struct usb_descriptor_header *)&iad_desc,
385 	(struct usb_descriptor_header *)&std_ac_if_desc,
386 
387 	(struct usb_descriptor_header *)&ac_hdr_desc,
388 	(struct usb_descriptor_header *)&in_clk_src_desc,
389 	(struct usb_descriptor_header *)&out_clk_src_desc,
390 	(struct usb_descriptor_header *)&usb_out_it_desc,
391 	(struct usb_descriptor_header *)&io_in_it_desc,
392 	(struct usb_descriptor_header *)&usb_in_ot_desc,
393 	(struct usb_descriptor_header *)&io_out_ot_desc,
394 
395 	(struct usb_descriptor_header *)&std_as_out_if0_desc,
396 	(struct usb_descriptor_header *)&std_as_out_if1_desc,
397 
398 	(struct usb_descriptor_header *)&as_out_hdr_desc,
399 	(struct usb_descriptor_header *)&as_out_fmt1_desc,
400 	(struct usb_descriptor_header *)&fs_epout_desc,
401 	(struct usb_descriptor_header *)&as_iso_out_desc,
402 
403 	(struct usb_descriptor_header *)&std_as_in_if0_desc,
404 	(struct usb_descriptor_header *)&std_as_in_if1_desc,
405 
406 	(struct usb_descriptor_header *)&as_in_hdr_desc,
407 	(struct usb_descriptor_header *)&as_in_fmt1_desc,
408 	(struct usb_descriptor_header *)&fs_epin_desc,
409 	(struct usb_descriptor_header *)&as_iso_in_desc,
410 	NULL,
411 };
412 
413 static struct usb_descriptor_header *hs_audio_desc[] = {
414 	(struct usb_descriptor_header *)&iad_desc,
415 	(struct usb_descriptor_header *)&std_ac_if_desc,
416 
417 	(struct usb_descriptor_header *)&ac_hdr_desc,
418 	(struct usb_descriptor_header *)&in_clk_src_desc,
419 	(struct usb_descriptor_header *)&out_clk_src_desc,
420 	(struct usb_descriptor_header *)&usb_out_it_desc,
421 	(struct usb_descriptor_header *)&io_in_it_desc,
422 	(struct usb_descriptor_header *)&usb_in_ot_desc,
423 	(struct usb_descriptor_header *)&io_out_ot_desc,
424 
425 	(struct usb_descriptor_header *)&std_as_out_if0_desc,
426 	(struct usb_descriptor_header *)&std_as_out_if1_desc,
427 
428 	(struct usb_descriptor_header *)&as_out_hdr_desc,
429 	(struct usb_descriptor_header *)&as_out_fmt1_desc,
430 	(struct usb_descriptor_header *)&hs_epout_desc,
431 	(struct usb_descriptor_header *)&as_iso_out_desc,
432 
433 	(struct usb_descriptor_header *)&std_as_in_if0_desc,
434 	(struct usb_descriptor_header *)&std_as_in_if1_desc,
435 
436 	(struct usb_descriptor_header *)&as_in_hdr_desc,
437 	(struct usb_descriptor_header *)&as_in_fmt1_desc,
438 	(struct usb_descriptor_header *)&hs_epin_desc,
439 	(struct usb_descriptor_header *)&as_iso_in_desc,
440 	NULL,
441 };
442 
443 struct cntrl_cur_lay3 {
444 	__u32	dCUR;
445 };
446 
447 struct cntrl_range_lay3 {
448 	__u16	wNumSubRanges;
449 	__u32	dMIN;
450 	__u32	dMAX;
451 	__u32	dRES;
452 } __packed;
453 
454 static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
455 	struct usb_endpoint_descriptor *ep_desc,
456 	unsigned int factor, bool is_playback)
457 {
458 	int chmask, srate, ssize;
459 	u16 max_packet_size;
460 
461 	if (is_playback) {
462 		chmask = uac2_opts->p_chmask;
463 		srate = uac2_opts->p_srate;
464 		ssize = uac2_opts->p_ssize;
465 	} else {
466 		chmask = uac2_opts->c_chmask;
467 		srate = uac2_opts->c_srate;
468 		ssize = uac2_opts->c_ssize;
469 	}
470 
471 	max_packet_size = num_channels(chmask) * ssize *
472 		DIV_ROUND_UP(srate, factor / (1 << (ep_desc->bInterval - 1)));
473 	ep_desc->wMaxPacketSize = cpu_to_le16(min_t(u16, max_packet_size,
474 				le16_to_cpu(ep_desc->wMaxPacketSize)));
475 }
476 
477 static int
478 afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
479 {
480 	struct f_uac2 *uac2 = func_to_uac2(fn);
481 	struct g_audio *agdev = func_to_g_audio(fn);
482 	struct usb_composite_dev *cdev = cfg->cdev;
483 	struct usb_gadget *gadget = cdev->gadget;
484 	struct device *dev = &gadget->dev;
485 	struct f_uac2_opts *uac2_opts;
486 	struct usb_string *us;
487 	int ret;
488 
489 	uac2_opts = container_of(fn->fi, struct f_uac2_opts, func_inst);
490 
491 	us = usb_gstrings_attach(cdev, fn_strings, ARRAY_SIZE(strings_fn));
492 	if (IS_ERR(us))
493 		return PTR_ERR(us);
494 	iad_desc.iFunction = us[STR_ASSOC].id;
495 	std_ac_if_desc.iInterface = us[STR_IF_CTRL].id;
496 	in_clk_src_desc.iClockSource = us[STR_CLKSRC_IN].id;
497 	out_clk_src_desc.iClockSource = us[STR_CLKSRC_OUT].id;
498 	usb_out_it_desc.iTerminal = us[STR_USB_IT].id;
499 	io_in_it_desc.iTerminal = us[STR_IO_IT].id;
500 	usb_in_ot_desc.iTerminal = us[STR_USB_OT].id;
501 	io_out_ot_desc.iTerminal = us[STR_IO_OT].id;
502 	std_as_out_if0_desc.iInterface = us[STR_AS_OUT_ALT0].id;
503 	std_as_out_if1_desc.iInterface = us[STR_AS_OUT_ALT1].id;
504 	std_as_in_if0_desc.iInterface = us[STR_AS_IN_ALT0].id;
505 	std_as_in_if1_desc.iInterface = us[STR_AS_IN_ALT1].id;
506 
507 
508 	/* Initialize the configurable parameters */
509 	usb_out_it_desc.bNrChannels = num_channels(uac2_opts->c_chmask);
510 	usb_out_it_desc.bmChannelConfig = cpu_to_le32(uac2_opts->c_chmask);
511 	io_in_it_desc.bNrChannels = num_channels(uac2_opts->p_chmask);
512 	io_in_it_desc.bmChannelConfig = cpu_to_le32(uac2_opts->p_chmask);
513 	as_out_hdr_desc.bNrChannels = num_channels(uac2_opts->c_chmask);
514 	as_out_hdr_desc.bmChannelConfig = cpu_to_le32(uac2_opts->c_chmask);
515 	as_in_hdr_desc.bNrChannels = num_channels(uac2_opts->p_chmask);
516 	as_in_hdr_desc.bmChannelConfig = cpu_to_le32(uac2_opts->p_chmask);
517 	as_out_fmt1_desc.bSubslotSize = uac2_opts->c_ssize;
518 	as_out_fmt1_desc.bBitResolution = uac2_opts->c_ssize * 8;
519 	as_in_fmt1_desc.bSubslotSize = uac2_opts->p_ssize;
520 	as_in_fmt1_desc.bBitResolution = uac2_opts->p_ssize * 8;
521 
522 	snprintf(clksrc_in, sizeof(clksrc_in), "%uHz", uac2_opts->p_srate);
523 	snprintf(clksrc_out, sizeof(clksrc_out), "%uHz", uac2_opts->c_srate);
524 
525 	ret = usb_interface_id(cfg, fn);
526 	if (ret < 0) {
527 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
528 		return ret;
529 	}
530 	std_ac_if_desc.bInterfaceNumber = ret;
531 	uac2->ac_intf = ret;
532 	uac2->ac_alt = 0;
533 
534 	ret = usb_interface_id(cfg, fn);
535 	if (ret < 0) {
536 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
537 		return ret;
538 	}
539 	std_as_out_if0_desc.bInterfaceNumber = ret;
540 	std_as_out_if1_desc.bInterfaceNumber = ret;
541 	uac2->as_out_intf = ret;
542 	uac2->as_out_alt = 0;
543 
544 	ret = usb_interface_id(cfg, fn);
545 	if (ret < 0) {
546 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
547 		return ret;
548 	}
549 	std_as_in_if0_desc.bInterfaceNumber = ret;
550 	std_as_in_if1_desc.bInterfaceNumber = ret;
551 	uac2->as_in_intf = ret;
552 	uac2->as_in_alt = 0;
553 
554 	/* Calculate wMaxPacketSize according to audio bandwidth */
555 	set_ep_max_packet_size(uac2_opts, &fs_epin_desc, 1000, true);
556 	set_ep_max_packet_size(uac2_opts, &fs_epout_desc, 1000, false);
557 	set_ep_max_packet_size(uac2_opts, &hs_epin_desc, 8000, true);
558 	set_ep_max_packet_size(uac2_opts, &hs_epout_desc, 8000, false);
559 
560 	agdev->out_ep = usb_ep_autoconfig(gadget, &fs_epout_desc);
561 	if (!agdev->out_ep) {
562 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
563 		return ret;
564 	}
565 
566 	agdev->in_ep = usb_ep_autoconfig(gadget, &fs_epin_desc);
567 	if (!agdev->in_ep) {
568 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
569 		return ret;
570 	}
571 
572 	agdev->in_ep_maxpsize = max(fs_epin_desc.wMaxPacketSize,
573 					hs_epin_desc.wMaxPacketSize);
574 	agdev->out_ep_maxpsize = max(fs_epout_desc.wMaxPacketSize,
575 					hs_epout_desc.wMaxPacketSize);
576 
577 	hs_epout_desc.bEndpointAddress = fs_epout_desc.bEndpointAddress;
578 	hs_epin_desc.bEndpointAddress = fs_epin_desc.bEndpointAddress;
579 
580 	ret = usb_assign_descriptors(fn, fs_audio_desc, hs_audio_desc, NULL,
581 				     NULL);
582 	if (ret)
583 		return ret;
584 
585 	agdev->gadget = gadget;
586 
587 	agdev->params.p_chmask = uac2_opts->p_chmask;
588 	agdev->params.p_srate = uac2_opts->p_srate;
589 	agdev->params.p_ssize = uac2_opts->p_ssize;
590 	agdev->params.c_chmask = uac2_opts->c_chmask;
591 	agdev->params.c_srate = uac2_opts->c_srate;
592 	agdev->params.c_ssize = uac2_opts->c_ssize;
593 	agdev->params.req_number = uac2_opts->req_number;
594 	ret = g_audio_setup(agdev, "UAC2 PCM", "UAC2_Gadget");
595 	if (ret)
596 		goto err_free_descs;
597 	return 0;
598 
599 err_free_descs:
600 	usb_free_all_descriptors(fn);
601 	agdev->gadget = NULL;
602 	return ret;
603 }
604 
605 static int
606 afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt)
607 {
608 	struct usb_composite_dev *cdev = fn->config->cdev;
609 	struct f_uac2 *uac2 = func_to_uac2(fn);
610 	struct usb_gadget *gadget = cdev->gadget;
611 	struct device *dev = &gadget->dev;
612 	int ret = 0;
613 
614 	/* No i/f has more than 2 alt settings */
615 	if (alt > 1) {
616 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
617 		return -EINVAL;
618 	}
619 
620 	if (intf == uac2->ac_intf) {
621 		/* Control I/f has only 1 AltSetting - 0 */
622 		if (alt) {
623 			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
624 			return -EINVAL;
625 		}
626 		return 0;
627 	}
628 
629 	if (intf == uac2->as_out_intf) {
630 		uac2->as_out_alt = alt;
631 
632 		if (alt)
633 			ret = u_audio_start_capture(&uac2->g_audio);
634 		else
635 			u_audio_stop_capture(&uac2->g_audio);
636 	} else if (intf == uac2->as_in_intf) {
637 		uac2->as_in_alt = alt;
638 
639 		if (alt)
640 			ret = u_audio_start_playback(&uac2->g_audio);
641 		else
642 			u_audio_stop_playback(&uac2->g_audio);
643 	} else {
644 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
645 		return -EINVAL;
646 	}
647 
648 	return ret;
649 }
650 
651 static int
652 afunc_get_alt(struct usb_function *fn, unsigned intf)
653 {
654 	struct f_uac2 *uac2 = func_to_uac2(fn);
655 	struct g_audio *agdev = func_to_g_audio(fn);
656 
657 	if (intf == uac2->ac_intf)
658 		return uac2->ac_alt;
659 	else if (intf == uac2->as_out_intf)
660 		return uac2->as_out_alt;
661 	else if (intf == uac2->as_in_intf)
662 		return uac2->as_in_alt;
663 	else
664 		dev_err(&agdev->gadget->dev,
665 			"%s:%d Invalid Interface %d!\n",
666 			__func__, __LINE__, intf);
667 
668 	return -EINVAL;
669 }
670 
671 static void
672 afunc_disable(struct usb_function *fn)
673 {
674 	struct f_uac2 *uac2 = func_to_uac2(fn);
675 
676 	uac2->as_in_alt = 0;
677 	uac2->as_out_alt = 0;
678 	u_audio_stop_capture(&uac2->g_audio);
679 	u_audio_stop_playback(&uac2->g_audio);
680 }
681 
682 static int
683 in_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
684 {
685 	struct usb_request *req = fn->config->cdev->req;
686 	struct g_audio *agdev = func_to_g_audio(fn);
687 	struct f_uac2_opts *opts;
688 	u16 w_length = le16_to_cpu(cr->wLength);
689 	u16 w_index = le16_to_cpu(cr->wIndex);
690 	u16 w_value = le16_to_cpu(cr->wValue);
691 	u8 entity_id = (w_index >> 8) & 0xff;
692 	u8 control_selector = w_value >> 8;
693 	int value = -EOPNOTSUPP;
694 	int p_srate, c_srate;
695 
696 	opts = g_audio_to_uac2_opts(agdev);
697 	p_srate = opts->p_srate;
698 	c_srate = opts->c_srate;
699 
700 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
701 		struct cntrl_cur_lay3 c;
702 		memset(&c, 0, sizeof(struct cntrl_cur_lay3));
703 
704 		if (entity_id == USB_IN_CLK_ID)
705 			c.dCUR = p_srate;
706 		else if (entity_id == USB_OUT_CLK_ID)
707 			c.dCUR = c_srate;
708 
709 		value = min_t(unsigned, w_length, sizeof c);
710 		memcpy(req->buf, &c, value);
711 	} else if (control_selector == UAC2_CS_CONTROL_CLOCK_VALID) {
712 		*(u8 *)req->buf = 1;
713 		value = min_t(unsigned, w_length, 1);
714 	} else {
715 		dev_err(&agdev->gadget->dev,
716 			"%s:%d control_selector=%d TODO!\n",
717 			__func__, __LINE__, control_selector);
718 	}
719 
720 	return value;
721 }
722 
723 static int
724 in_rq_range(struct usb_function *fn, const struct usb_ctrlrequest *cr)
725 {
726 	struct usb_request *req = fn->config->cdev->req;
727 	struct g_audio *agdev = func_to_g_audio(fn);
728 	struct f_uac2_opts *opts;
729 	u16 w_length = le16_to_cpu(cr->wLength);
730 	u16 w_index = le16_to_cpu(cr->wIndex);
731 	u16 w_value = le16_to_cpu(cr->wValue);
732 	u8 entity_id = (w_index >> 8) & 0xff;
733 	u8 control_selector = w_value >> 8;
734 	struct cntrl_range_lay3 r;
735 	int value = -EOPNOTSUPP;
736 	int p_srate, c_srate;
737 
738 	opts = g_audio_to_uac2_opts(agdev);
739 	p_srate = opts->p_srate;
740 	c_srate = opts->c_srate;
741 
742 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
743 		if (entity_id == USB_IN_CLK_ID)
744 			r.dMIN = p_srate;
745 		else if (entity_id == USB_OUT_CLK_ID)
746 			r.dMIN = c_srate;
747 		else
748 			return -EOPNOTSUPP;
749 
750 		r.dMAX = r.dMIN;
751 		r.dRES = 0;
752 		r.wNumSubRanges = 1;
753 
754 		value = min_t(unsigned, w_length, sizeof r);
755 		memcpy(req->buf, &r, value);
756 	} else {
757 		dev_err(&agdev->gadget->dev,
758 			"%s:%d control_selector=%d TODO!\n",
759 			__func__, __LINE__, control_selector);
760 	}
761 
762 	return value;
763 }
764 
765 static int
766 ac_rq_in(struct usb_function *fn, const struct usb_ctrlrequest *cr)
767 {
768 	if (cr->bRequest == UAC2_CS_CUR)
769 		return in_rq_cur(fn, cr);
770 	else if (cr->bRequest == UAC2_CS_RANGE)
771 		return in_rq_range(fn, cr);
772 	else
773 		return -EOPNOTSUPP;
774 }
775 
776 static int
777 out_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
778 {
779 	u16 w_length = le16_to_cpu(cr->wLength);
780 	u16 w_value = le16_to_cpu(cr->wValue);
781 	u8 control_selector = w_value >> 8;
782 
783 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ)
784 		return w_length;
785 
786 	return -EOPNOTSUPP;
787 }
788 
789 static int
790 setup_rq_inf(struct usb_function *fn, const struct usb_ctrlrequest *cr)
791 {
792 	struct f_uac2 *uac2 = func_to_uac2(fn);
793 	struct g_audio *agdev = func_to_g_audio(fn);
794 	u16 w_index = le16_to_cpu(cr->wIndex);
795 	u8 intf = w_index & 0xff;
796 
797 	if (intf != uac2->ac_intf) {
798 		dev_err(&agdev->gadget->dev,
799 			"%s:%d Error!\n", __func__, __LINE__);
800 		return -EOPNOTSUPP;
801 	}
802 
803 	if (cr->bRequestType & USB_DIR_IN)
804 		return ac_rq_in(fn, cr);
805 	else if (cr->bRequest == UAC2_CS_CUR)
806 		return out_rq_cur(fn, cr);
807 
808 	return -EOPNOTSUPP;
809 }
810 
811 static int
812 afunc_setup(struct usb_function *fn, const struct usb_ctrlrequest *cr)
813 {
814 	struct usb_composite_dev *cdev = fn->config->cdev;
815 	struct g_audio *agdev = func_to_g_audio(fn);
816 	struct usb_request *req = cdev->req;
817 	u16 w_length = le16_to_cpu(cr->wLength);
818 	int value = -EOPNOTSUPP;
819 
820 	/* Only Class specific requests are supposed to reach here */
821 	if ((cr->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS)
822 		return -EOPNOTSUPP;
823 
824 	if ((cr->bRequestType & USB_RECIP_MASK) == USB_RECIP_INTERFACE)
825 		value = setup_rq_inf(fn, cr);
826 	else
827 		dev_err(&agdev->gadget->dev, "%s:%d Error!\n",
828 				__func__, __LINE__);
829 
830 	if (value >= 0) {
831 		req->length = value;
832 		req->zero = value < w_length;
833 		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
834 		if (value < 0) {
835 			dev_err(&agdev->gadget->dev,
836 				"%s:%d Error!\n", __func__, __LINE__);
837 			req->status = 0;
838 		}
839 	}
840 
841 	return value;
842 }
843 
844 static inline struct f_uac2_opts *to_f_uac2_opts(struct config_item *item)
845 {
846 	return container_of(to_config_group(item), struct f_uac2_opts,
847 			    func_inst.group);
848 }
849 
850 static void f_uac2_attr_release(struct config_item *item)
851 {
852 	struct f_uac2_opts *opts = to_f_uac2_opts(item);
853 
854 	usb_put_function_instance(&opts->func_inst);
855 }
856 
857 static struct configfs_item_operations f_uac2_item_ops = {
858 	.release	= f_uac2_attr_release,
859 };
860 
861 #define UAC2_ATTRIBUTE(name)						\
862 static ssize_t f_uac2_opts_##name##_show(struct config_item *item,	\
863 					 char *page)			\
864 {									\
865 	struct f_uac2_opts *opts = to_f_uac2_opts(item);		\
866 	int result;							\
867 									\
868 	mutex_lock(&opts->lock);					\
869 	result = sprintf(page, "%u\n", opts->name);			\
870 	mutex_unlock(&opts->lock);					\
871 									\
872 	return result;							\
873 }									\
874 									\
875 static ssize_t f_uac2_opts_##name##_store(struct config_item *item,	\
876 					  const char *page, size_t len)	\
877 {									\
878 	struct f_uac2_opts *opts = to_f_uac2_opts(item);		\
879 	int ret;							\
880 	u32 num;							\
881 									\
882 	mutex_lock(&opts->lock);					\
883 	if (opts->refcnt) {						\
884 		ret = -EBUSY;						\
885 		goto end;						\
886 	}								\
887 									\
888 	ret = kstrtou32(page, 0, &num);					\
889 	if (ret)							\
890 		goto end;						\
891 									\
892 	opts->name = num;						\
893 	ret = len;							\
894 									\
895 end:									\
896 	mutex_unlock(&opts->lock);					\
897 	return ret;							\
898 }									\
899 									\
900 CONFIGFS_ATTR(f_uac2_opts_, name)
901 
902 UAC2_ATTRIBUTE(p_chmask);
903 UAC2_ATTRIBUTE(p_srate);
904 UAC2_ATTRIBUTE(p_ssize);
905 UAC2_ATTRIBUTE(c_chmask);
906 UAC2_ATTRIBUTE(c_srate);
907 UAC2_ATTRIBUTE(c_ssize);
908 UAC2_ATTRIBUTE(req_number);
909 
910 static struct configfs_attribute *f_uac2_attrs[] = {
911 	&f_uac2_opts_attr_p_chmask,
912 	&f_uac2_opts_attr_p_srate,
913 	&f_uac2_opts_attr_p_ssize,
914 	&f_uac2_opts_attr_c_chmask,
915 	&f_uac2_opts_attr_c_srate,
916 	&f_uac2_opts_attr_c_ssize,
917 	&f_uac2_opts_attr_req_number,
918 	NULL,
919 };
920 
921 static struct config_item_type f_uac2_func_type = {
922 	.ct_item_ops	= &f_uac2_item_ops,
923 	.ct_attrs	= f_uac2_attrs,
924 	.ct_owner	= THIS_MODULE,
925 };
926 
927 static void afunc_free_inst(struct usb_function_instance *f)
928 {
929 	struct f_uac2_opts *opts;
930 
931 	opts = container_of(f, struct f_uac2_opts, func_inst);
932 	kfree(opts);
933 }
934 
935 static struct usb_function_instance *afunc_alloc_inst(void)
936 {
937 	struct f_uac2_opts *opts;
938 
939 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
940 	if (!opts)
941 		return ERR_PTR(-ENOMEM);
942 
943 	mutex_init(&opts->lock);
944 	opts->func_inst.free_func_inst = afunc_free_inst;
945 
946 	config_group_init_type_name(&opts->func_inst.group, "",
947 				    &f_uac2_func_type);
948 
949 	opts->p_chmask = UAC2_DEF_PCHMASK;
950 	opts->p_srate = UAC2_DEF_PSRATE;
951 	opts->p_ssize = UAC2_DEF_PSSIZE;
952 	opts->c_chmask = UAC2_DEF_CCHMASK;
953 	opts->c_srate = UAC2_DEF_CSRATE;
954 	opts->c_ssize = UAC2_DEF_CSSIZE;
955 	opts->req_number = UAC2_DEF_REQ_NUM;
956 	return &opts->func_inst;
957 }
958 
959 static void afunc_free(struct usb_function *f)
960 {
961 	struct g_audio *agdev;
962 	struct f_uac2_opts *opts;
963 
964 	agdev = func_to_g_audio(f);
965 	opts = container_of(f->fi, struct f_uac2_opts, func_inst);
966 	kfree(agdev);
967 	mutex_lock(&opts->lock);
968 	--opts->refcnt;
969 	mutex_unlock(&opts->lock);
970 }
971 
972 static void afunc_unbind(struct usb_configuration *c, struct usb_function *f)
973 {
974 	struct g_audio *agdev = func_to_g_audio(f);
975 
976 	g_audio_cleanup(agdev);
977 	usb_free_all_descriptors(f);
978 
979 	agdev->gadget = NULL;
980 }
981 
982 static struct usb_function *afunc_alloc(struct usb_function_instance *fi)
983 {
984 	struct f_uac2	*uac2;
985 	struct f_uac2_opts *opts;
986 
987 	uac2 = kzalloc(sizeof(*uac2), GFP_KERNEL);
988 	if (uac2 == NULL)
989 		return ERR_PTR(-ENOMEM);
990 
991 	opts = container_of(fi, struct f_uac2_opts, func_inst);
992 	mutex_lock(&opts->lock);
993 	++opts->refcnt;
994 	mutex_unlock(&opts->lock);
995 
996 	uac2->g_audio.func.name = "uac2_func";
997 	uac2->g_audio.func.bind = afunc_bind;
998 	uac2->g_audio.func.unbind = afunc_unbind;
999 	uac2->g_audio.func.set_alt = afunc_set_alt;
1000 	uac2->g_audio.func.get_alt = afunc_get_alt;
1001 	uac2->g_audio.func.disable = afunc_disable;
1002 	uac2->g_audio.func.setup = afunc_setup;
1003 	uac2->g_audio.func.free_func = afunc_free;
1004 
1005 	return &uac2->g_audio.func;
1006 }
1007 
1008 DECLARE_USB_FUNCTION_INIT(uac2, afunc_alloc_inst, afunc_alloc);
1009 MODULE_LICENSE("GPL");
1010 MODULE_AUTHOR("Yadwinder Singh");
1011 MODULE_AUTHOR("Jaswinder Singh");
1012