xref: /openbmc/linux/drivers/usb/gadget/function/f_uac2.c (revision 7f2e85840871f199057e65232ebde846192ed989)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * f_uac2.c -- USB Audio Class 2.0 Function
4  *
5  * Copyright (C) 2011
6  *    Yadwinder Singh (yadi.brar01@gmail.com)
7  *    Jaswinder Singh (jaswinder.singh@linaro.org)
8  */
9 
10 #include <linux/usb/audio.h>
11 #include <linux/usb/audio-v2.h>
12 #include <linux/module.h>
13 
14 #include "u_audio.h"
15 #include "u_uac2.h"
16 
17 /*
18  * The driver implements a simple UAC_2 topology.
19  * USB-OUT -> IT_1 -> OT_3 -> ALSA_Capture
20  * ALSA_Playback -> IT_2 -> OT_4 -> USB-IN
21  * Capture and Playback sampling rates are independently
22  *  controlled by two clock sources :
23  *    CLK_5 := c_srate, and CLK_6 := p_srate
24  */
25 #define USB_OUT_IT_ID	1
26 #define IO_IN_IT_ID	2
27 #define IO_OUT_OT_ID	3
28 #define USB_IN_OT_ID	4
29 #define USB_OUT_CLK_ID	5
30 #define USB_IN_CLK_ID	6
31 
32 #define CONTROL_ABSENT	0
33 #define CONTROL_RDONLY	1
34 #define CONTROL_RDWR	3
35 
36 #define CLK_FREQ_CTRL	0
37 #define CLK_VLD_CTRL	2
38 
39 #define COPY_CTRL	0
40 #define CONN_CTRL	2
41 #define OVRLD_CTRL	4
42 #define CLSTR_CTRL	6
43 #define UNFLW_CTRL	8
44 #define OVFLW_CTRL	10
45 
46 struct f_uac2 {
47 	struct g_audio g_audio;
48 	u8 ac_intf, as_in_intf, as_out_intf;
49 	u8 ac_alt, as_in_alt, as_out_alt;	/* needed for get_alt() */
50 };
51 
52 static inline struct f_uac2 *func_to_uac2(struct usb_function *f)
53 {
54 	return container_of(f, struct f_uac2, g_audio.func);
55 }
56 
57 static inline
58 struct f_uac2_opts *g_audio_to_uac2_opts(struct g_audio *agdev)
59 {
60 	return container_of(agdev->func.fi, struct f_uac2_opts, func_inst);
61 }
62 
63 /* --------- USB Function Interface ------------- */
64 
65 enum {
66 	STR_ASSOC,
67 	STR_IF_CTRL,
68 	STR_CLKSRC_IN,
69 	STR_CLKSRC_OUT,
70 	STR_USB_IT,
71 	STR_IO_IT,
72 	STR_USB_OT,
73 	STR_IO_OT,
74 	STR_AS_OUT_ALT0,
75 	STR_AS_OUT_ALT1,
76 	STR_AS_IN_ALT0,
77 	STR_AS_IN_ALT1,
78 };
79 
80 static char clksrc_in[8];
81 static char clksrc_out[8];
82 
83 static struct usb_string strings_fn[] = {
84 	[STR_ASSOC].s = "Source/Sink",
85 	[STR_IF_CTRL].s = "Topology Control",
86 	[STR_CLKSRC_IN].s = clksrc_in,
87 	[STR_CLKSRC_OUT].s = clksrc_out,
88 	[STR_USB_IT].s = "USBH Out",
89 	[STR_IO_IT].s = "USBD Out",
90 	[STR_USB_OT].s = "USBH In",
91 	[STR_IO_OT].s = "USBD In",
92 	[STR_AS_OUT_ALT0].s = "Playback Inactive",
93 	[STR_AS_OUT_ALT1].s = "Playback Active",
94 	[STR_AS_IN_ALT0].s = "Capture Inactive",
95 	[STR_AS_IN_ALT1].s = "Capture Active",
96 	{ },
97 };
98 
99 static struct usb_gadget_strings str_fn = {
100 	.language = 0x0409,	/* en-us */
101 	.strings = strings_fn,
102 };
103 
104 static struct usb_gadget_strings *fn_strings[] = {
105 	&str_fn,
106 	NULL,
107 };
108 
109 static struct usb_interface_assoc_descriptor iad_desc = {
110 	.bLength = sizeof iad_desc,
111 	.bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
112 
113 	.bFirstInterface = 0,
114 	.bInterfaceCount = 3,
115 	.bFunctionClass = USB_CLASS_AUDIO,
116 	.bFunctionSubClass = UAC2_FUNCTION_SUBCLASS_UNDEFINED,
117 	.bFunctionProtocol = UAC_VERSION_2,
118 };
119 
120 /* Audio Control Interface */
121 static struct usb_interface_descriptor std_ac_if_desc = {
122 	.bLength = sizeof std_ac_if_desc,
123 	.bDescriptorType = USB_DT_INTERFACE,
124 
125 	.bAlternateSetting = 0,
126 	.bNumEndpoints = 0,
127 	.bInterfaceClass = USB_CLASS_AUDIO,
128 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL,
129 	.bInterfaceProtocol = UAC_VERSION_2,
130 };
131 
132 /* Clock source for IN traffic */
133 static struct uac_clock_source_descriptor in_clk_src_desc = {
134 	.bLength = sizeof in_clk_src_desc,
135 	.bDescriptorType = USB_DT_CS_INTERFACE,
136 
137 	.bDescriptorSubtype = UAC2_CLOCK_SOURCE,
138 	.bClockID = USB_IN_CLK_ID,
139 	.bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
140 	.bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
141 	.bAssocTerminal = 0,
142 };
143 
144 /* Clock source for OUT traffic */
145 static struct uac_clock_source_descriptor out_clk_src_desc = {
146 	.bLength = sizeof out_clk_src_desc,
147 	.bDescriptorType = USB_DT_CS_INTERFACE,
148 
149 	.bDescriptorSubtype = UAC2_CLOCK_SOURCE,
150 	.bClockID = USB_OUT_CLK_ID,
151 	.bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
152 	.bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
153 	.bAssocTerminal = 0,
154 };
155 
156 /* Input Terminal for USB_OUT */
157 static struct uac2_input_terminal_descriptor usb_out_it_desc = {
158 	.bLength = sizeof usb_out_it_desc,
159 	.bDescriptorType = USB_DT_CS_INTERFACE,
160 
161 	.bDescriptorSubtype = UAC_INPUT_TERMINAL,
162 	.bTerminalID = USB_OUT_IT_ID,
163 	.wTerminalType = cpu_to_le16(UAC_TERMINAL_STREAMING),
164 	.bAssocTerminal = 0,
165 	.bCSourceID = USB_OUT_CLK_ID,
166 	.iChannelNames = 0,
167 	.bmControls = cpu_to_le16(CONTROL_RDWR << COPY_CTRL),
168 };
169 
170 /* Input Terminal for I/O-In */
171 static struct uac2_input_terminal_descriptor io_in_it_desc = {
172 	.bLength = sizeof io_in_it_desc,
173 	.bDescriptorType = USB_DT_CS_INTERFACE,
174 
175 	.bDescriptorSubtype = UAC_INPUT_TERMINAL,
176 	.bTerminalID = IO_IN_IT_ID,
177 	.wTerminalType = cpu_to_le16(UAC_INPUT_TERMINAL_UNDEFINED),
178 	.bAssocTerminal = 0,
179 	.bCSourceID = USB_IN_CLK_ID,
180 	.iChannelNames = 0,
181 	.bmControls = cpu_to_le16(CONTROL_RDWR << COPY_CTRL),
182 };
183 
184 /* Ouput Terminal for USB_IN */
185 static struct uac2_output_terminal_descriptor usb_in_ot_desc = {
186 	.bLength = sizeof usb_in_ot_desc,
187 	.bDescriptorType = USB_DT_CS_INTERFACE,
188 
189 	.bDescriptorSubtype = UAC_OUTPUT_TERMINAL,
190 	.bTerminalID = USB_IN_OT_ID,
191 	.wTerminalType = cpu_to_le16(UAC_TERMINAL_STREAMING),
192 	.bAssocTerminal = 0,
193 	.bSourceID = IO_IN_IT_ID,
194 	.bCSourceID = USB_IN_CLK_ID,
195 	.bmControls = cpu_to_le16(CONTROL_RDWR << COPY_CTRL),
196 };
197 
198 /* Ouput Terminal for I/O-Out */
199 static struct uac2_output_terminal_descriptor io_out_ot_desc = {
200 	.bLength = sizeof io_out_ot_desc,
201 	.bDescriptorType = USB_DT_CS_INTERFACE,
202 
203 	.bDescriptorSubtype = UAC_OUTPUT_TERMINAL,
204 	.bTerminalID = IO_OUT_OT_ID,
205 	.wTerminalType = cpu_to_le16(UAC_OUTPUT_TERMINAL_UNDEFINED),
206 	.bAssocTerminal = 0,
207 	.bSourceID = USB_OUT_IT_ID,
208 	.bCSourceID = USB_OUT_CLK_ID,
209 	.bmControls = cpu_to_le16(CONTROL_RDWR << COPY_CTRL),
210 };
211 
212 static struct uac2_ac_header_descriptor ac_hdr_desc = {
213 	.bLength = sizeof ac_hdr_desc,
214 	.bDescriptorType = USB_DT_CS_INTERFACE,
215 
216 	.bDescriptorSubtype = UAC_MS_HEADER,
217 	.bcdADC = cpu_to_le16(0x200),
218 	.bCategory = UAC2_FUNCTION_IO_BOX,
219 	.wTotalLength = cpu_to_le16(sizeof in_clk_src_desc
220 			+ sizeof out_clk_src_desc + sizeof usb_out_it_desc
221 			+ sizeof io_in_it_desc + sizeof usb_in_ot_desc
222 			+ sizeof io_out_ot_desc),
223 	.bmControls = 0,
224 };
225 
226 /* Audio Streaming OUT Interface - Alt0 */
227 static struct usb_interface_descriptor std_as_out_if0_desc = {
228 	.bLength = sizeof std_as_out_if0_desc,
229 	.bDescriptorType = USB_DT_INTERFACE,
230 
231 	.bAlternateSetting = 0,
232 	.bNumEndpoints = 0,
233 	.bInterfaceClass = USB_CLASS_AUDIO,
234 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
235 	.bInterfaceProtocol = UAC_VERSION_2,
236 };
237 
238 /* Audio Streaming OUT Interface - Alt1 */
239 static struct usb_interface_descriptor std_as_out_if1_desc = {
240 	.bLength = sizeof std_as_out_if1_desc,
241 	.bDescriptorType = USB_DT_INTERFACE,
242 
243 	.bAlternateSetting = 1,
244 	.bNumEndpoints = 1,
245 	.bInterfaceClass = USB_CLASS_AUDIO,
246 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
247 	.bInterfaceProtocol = UAC_VERSION_2,
248 };
249 
250 /* Audio Stream OUT Intface Desc */
251 static struct uac2_as_header_descriptor as_out_hdr_desc = {
252 	.bLength = sizeof as_out_hdr_desc,
253 	.bDescriptorType = USB_DT_CS_INTERFACE,
254 
255 	.bDescriptorSubtype = UAC_AS_GENERAL,
256 	.bTerminalLink = USB_OUT_IT_ID,
257 	.bmControls = 0,
258 	.bFormatType = UAC_FORMAT_TYPE_I,
259 	.bmFormats = cpu_to_le32(UAC_FORMAT_TYPE_I_PCM),
260 	.iChannelNames = 0,
261 };
262 
263 /* Audio USB_OUT Format */
264 static struct uac2_format_type_i_descriptor as_out_fmt1_desc = {
265 	.bLength = sizeof as_out_fmt1_desc,
266 	.bDescriptorType = USB_DT_CS_INTERFACE,
267 	.bDescriptorSubtype = UAC_FORMAT_TYPE,
268 	.bFormatType = UAC_FORMAT_TYPE_I,
269 };
270 
271 /* STD AS ISO OUT Endpoint */
272 static struct usb_endpoint_descriptor fs_epout_desc = {
273 	.bLength = USB_DT_ENDPOINT_SIZE,
274 	.bDescriptorType = USB_DT_ENDPOINT,
275 
276 	.bEndpointAddress = USB_DIR_OUT,
277 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
278 	.wMaxPacketSize = cpu_to_le16(1023),
279 	.bInterval = 1,
280 };
281 
282 static struct usb_endpoint_descriptor hs_epout_desc = {
283 	.bLength = USB_DT_ENDPOINT_SIZE,
284 	.bDescriptorType = USB_DT_ENDPOINT,
285 
286 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
287 	.wMaxPacketSize = cpu_to_le16(1024),
288 	.bInterval = 4,
289 };
290 
291 /* CS AS ISO OUT Endpoint */
292 static struct uac2_iso_endpoint_descriptor as_iso_out_desc = {
293 	.bLength = sizeof as_iso_out_desc,
294 	.bDescriptorType = USB_DT_CS_ENDPOINT,
295 
296 	.bDescriptorSubtype = UAC_EP_GENERAL,
297 	.bmAttributes = 0,
298 	.bmControls = 0,
299 	.bLockDelayUnits = 0,
300 	.wLockDelay = 0,
301 };
302 
303 /* Audio Streaming IN Interface - Alt0 */
304 static struct usb_interface_descriptor std_as_in_if0_desc = {
305 	.bLength = sizeof std_as_in_if0_desc,
306 	.bDescriptorType = USB_DT_INTERFACE,
307 
308 	.bAlternateSetting = 0,
309 	.bNumEndpoints = 0,
310 	.bInterfaceClass = USB_CLASS_AUDIO,
311 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
312 	.bInterfaceProtocol = UAC_VERSION_2,
313 };
314 
315 /* Audio Streaming IN Interface - Alt1 */
316 static struct usb_interface_descriptor std_as_in_if1_desc = {
317 	.bLength = sizeof std_as_in_if1_desc,
318 	.bDescriptorType = USB_DT_INTERFACE,
319 
320 	.bAlternateSetting = 1,
321 	.bNumEndpoints = 1,
322 	.bInterfaceClass = USB_CLASS_AUDIO,
323 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
324 	.bInterfaceProtocol = UAC_VERSION_2,
325 };
326 
327 /* Audio Stream IN Intface Desc */
328 static struct uac2_as_header_descriptor as_in_hdr_desc = {
329 	.bLength = sizeof as_in_hdr_desc,
330 	.bDescriptorType = USB_DT_CS_INTERFACE,
331 
332 	.bDescriptorSubtype = UAC_AS_GENERAL,
333 	.bTerminalLink = USB_IN_OT_ID,
334 	.bmControls = 0,
335 	.bFormatType = UAC_FORMAT_TYPE_I,
336 	.bmFormats = cpu_to_le32(UAC_FORMAT_TYPE_I_PCM),
337 	.iChannelNames = 0,
338 };
339 
340 /* Audio USB_IN Format */
341 static struct uac2_format_type_i_descriptor as_in_fmt1_desc = {
342 	.bLength = sizeof as_in_fmt1_desc,
343 	.bDescriptorType = USB_DT_CS_INTERFACE,
344 	.bDescriptorSubtype = UAC_FORMAT_TYPE,
345 	.bFormatType = UAC_FORMAT_TYPE_I,
346 };
347 
348 /* STD AS ISO IN Endpoint */
349 static struct usb_endpoint_descriptor fs_epin_desc = {
350 	.bLength = USB_DT_ENDPOINT_SIZE,
351 	.bDescriptorType = USB_DT_ENDPOINT,
352 
353 	.bEndpointAddress = USB_DIR_IN,
354 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
355 	.wMaxPacketSize = cpu_to_le16(1023),
356 	.bInterval = 1,
357 };
358 
359 static struct usb_endpoint_descriptor hs_epin_desc = {
360 	.bLength = USB_DT_ENDPOINT_SIZE,
361 	.bDescriptorType = USB_DT_ENDPOINT,
362 
363 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
364 	.wMaxPacketSize = cpu_to_le16(1024),
365 	.bInterval = 4,
366 };
367 
368 /* CS AS ISO IN Endpoint */
369 static struct uac2_iso_endpoint_descriptor as_iso_in_desc = {
370 	.bLength = sizeof as_iso_in_desc,
371 	.bDescriptorType = USB_DT_CS_ENDPOINT,
372 
373 	.bDescriptorSubtype = UAC_EP_GENERAL,
374 	.bmAttributes = 0,
375 	.bmControls = 0,
376 	.bLockDelayUnits = 0,
377 	.wLockDelay = 0,
378 };
379 
380 static struct usb_descriptor_header *fs_audio_desc[] = {
381 	(struct usb_descriptor_header *)&iad_desc,
382 	(struct usb_descriptor_header *)&std_ac_if_desc,
383 
384 	(struct usb_descriptor_header *)&ac_hdr_desc,
385 	(struct usb_descriptor_header *)&in_clk_src_desc,
386 	(struct usb_descriptor_header *)&out_clk_src_desc,
387 	(struct usb_descriptor_header *)&usb_out_it_desc,
388 	(struct usb_descriptor_header *)&io_in_it_desc,
389 	(struct usb_descriptor_header *)&usb_in_ot_desc,
390 	(struct usb_descriptor_header *)&io_out_ot_desc,
391 
392 	(struct usb_descriptor_header *)&std_as_out_if0_desc,
393 	(struct usb_descriptor_header *)&std_as_out_if1_desc,
394 
395 	(struct usb_descriptor_header *)&as_out_hdr_desc,
396 	(struct usb_descriptor_header *)&as_out_fmt1_desc,
397 	(struct usb_descriptor_header *)&fs_epout_desc,
398 	(struct usb_descriptor_header *)&as_iso_out_desc,
399 
400 	(struct usb_descriptor_header *)&std_as_in_if0_desc,
401 	(struct usb_descriptor_header *)&std_as_in_if1_desc,
402 
403 	(struct usb_descriptor_header *)&as_in_hdr_desc,
404 	(struct usb_descriptor_header *)&as_in_fmt1_desc,
405 	(struct usb_descriptor_header *)&fs_epin_desc,
406 	(struct usb_descriptor_header *)&as_iso_in_desc,
407 	NULL,
408 };
409 
410 static struct usb_descriptor_header *hs_audio_desc[] = {
411 	(struct usb_descriptor_header *)&iad_desc,
412 	(struct usb_descriptor_header *)&std_ac_if_desc,
413 
414 	(struct usb_descriptor_header *)&ac_hdr_desc,
415 	(struct usb_descriptor_header *)&in_clk_src_desc,
416 	(struct usb_descriptor_header *)&out_clk_src_desc,
417 	(struct usb_descriptor_header *)&usb_out_it_desc,
418 	(struct usb_descriptor_header *)&io_in_it_desc,
419 	(struct usb_descriptor_header *)&usb_in_ot_desc,
420 	(struct usb_descriptor_header *)&io_out_ot_desc,
421 
422 	(struct usb_descriptor_header *)&std_as_out_if0_desc,
423 	(struct usb_descriptor_header *)&std_as_out_if1_desc,
424 
425 	(struct usb_descriptor_header *)&as_out_hdr_desc,
426 	(struct usb_descriptor_header *)&as_out_fmt1_desc,
427 	(struct usb_descriptor_header *)&hs_epout_desc,
428 	(struct usb_descriptor_header *)&as_iso_out_desc,
429 
430 	(struct usb_descriptor_header *)&std_as_in_if0_desc,
431 	(struct usb_descriptor_header *)&std_as_in_if1_desc,
432 
433 	(struct usb_descriptor_header *)&as_in_hdr_desc,
434 	(struct usb_descriptor_header *)&as_in_fmt1_desc,
435 	(struct usb_descriptor_header *)&hs_epin_desc,
436 	(struct usb_descriptor_header *)&as_iso_in_desc,
437 	NULL,
438 };
439 
440 struct cntrl_cur_lay3 {
441 	__u32	dCUR;
442 };
443 
444 struct cntrl_range_lay3 {
445 	__u16	wNumSubRanges;
446 	__u32	dMIN;
447 	__u32	dMAX;
448 	__u32	dRES;
449 } __packed;
450 
451 static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
452 	struct usb_endpoint_descriptor *ep_desc,
453 	unsigned int factor, bool is_playback)
454 {
455 	int chmask, srate, ssize;
456 	u16 max_packet_size;
457 
458 	if (is_playback) {
459 		chmask = uac2_opts->p_chmask;
460 		srate = uac2_opts->p_srate;
461 		ssize = uac2_opts->p_ssize;
462 	} else {
463 		chmask = uac2_opts->c_chmask;
464 		srate = uac2_opts->c_srate;
465 		ssize = uac2_opts->c_ssize;
466 	}
467 
468 	max_packet_size = num_channels(chmask) * ssize *
469 		DIV_ROUND_UP(srate, factor / (1 << (ep_desc->bInterval - 1)));
470 	ep_desc->wMaxPacketSize = cpu_to_le16(min_t(u16, max_packet_size,
471 				le16_to_cpu(ep_desc->wMaxPacketSize)));
472 }
473 
474 static int
475 afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
476 {
477 	struct f_uac2 *uac2 = func_to_uac2(fn);
478 	struct g_audio *agdev = func_to_g_audio(fn);
479 	struct usb_composite_dev *cdev = cfg->cdev;
480 	struct usb_gadget *gadget = cdev->gadget;
481 	struct device *dev = &gadget->dev;
482 	struct f_uac2_opts *uac2_opts;
483 	struct usb_string *us;
484 	int ret;
485 
486 	uac2_opts = container_of(fn->fi, struct f_uac2_opts, func_inst);
487 
488 	us = usb_gstrings_attach(cdev, fn_strings, ARRAY_SIZE(strings_fn));
489 	if (IS_ERR(us))
490 		return PTR_ERR(us);
491 	iad_desc.iFunction = us[STR_ASSOC].id;
492 	std_ac_if_desc.iInterface = us[STR_IF_CTRL].id;
493 	in_clk_src_desc.iClockSource = us[STR_CLKSRC_IN].id;
494 	out_clk_src_desc.iClockSource = us[STR_CLKSRC_OUT].id;
495 	usb_out_it_desc.iTerminal = us[STR_USB_IT].id;
496 	io_in_it_desc.iTerminal = us[STR_IO_IT].id;
497 	usb_in_ot_desc.iTerminal = us[STR_USB_OT].id;
498 	io_out_ot_desc.iTerminal = us[STR_IO_OT].id;
499 	std_as_out_if0_desc.iInterface = us[STR_AS_OUT_ALT0].id;
500 	std_as_out_if1_desc.iInterface = us[STR_AS_OUT_ALT1].id;
501 	std_as_in_if0_desc.iInterface = us[STR_AS_IN_ALT0].id;
502 	std_as_in_if1_desc.iInterface = us[STR_AS_IN_ALT1].id;
503 
504 
505 	/* Initialize the configurable parameters */
506 	usb_out_it_desc.bNrChannels = num_channels(uac2_opts->c_chmask);
507 	usb_out_it_desc.bmChannelConfig = cpu_to_le32(uac2_opts->c_chmask);
508 	io_in_it_desc.bNrChannels = num_channels(uac2_opts->p_chmask);
509 	io_in_it_desc.bmChannelConfig = cpu_to_le32(uac2_opts->p_chmask);
510 	as_out_hdr_desc.bNrChannels = num_channels(uac2_opts->c_chmask);
511 	as_out_hdr_desc.bmChannelConfig = cpu_to_le32(uac2_opts->c_chmask);
512 	as_in_hdr_desc.bNrChannels = num_channels(uac2_opts->p_chmask);
513 	as_in_hdr_desc.bmChannelConfig = cpu_to_le32(uac2_opts->p_chmask);
514 	as_out_fmt1_desc.bSubslotSize = uac2_opts->c_ssize;
515 	as_out_fmt1_desc.bBitResolution = uac2_opts->c_ssize * 8;
516 	as_in_fmt1_desc.bSubslotSize = uac2_opts->p_ssize;
517 	as_in_fmt1_desc.bBitResolution = uac2_opts->p_ssize * 8;
518 
519 	snprintf(clksrc_in, sizeof(clksrc_in), "%uHz", uac2_opts->p_srate);
520 	snprintf(clksrc_out, sizeof(clksrc_out), "%uHz", uac2_opts->c_srate);
521 
522 	ret = usb_interface_id(cfg, fn);
523 	if (ret < 0) {
524 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
525 		return ret;
526 	}
527 	std_ac_if_desc.bInterfaceNumber = ret;
528 	uac2->ac_intf = ret;
529 	uac2->ac_alt = 0;
530 
531 	ret = usb_interface_id(cfg, fn);
532 	if (ret < 0) {
533 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
534 		return ret;
535 	}
536 	std_as_out_if0_desc.bInterfaceNumber = ret;
537 	std_as_out_if1_desc.bInterfaceNumber = ret;
538 	uac2->as_out_intf = ret;
539 	uac2->as_out_alt = 0;
540 
541 	ret = usb_interface_id(cfg, fn);
542 	if (ret < 0) {
543 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
544 		return ret;
545 	}
546 	std_as_in_if0_desc.bInterfaceNumber = ret;
547 	std_as_in_if1_desc.bInterfaceNumber = ret;
548 	uac2->as_in_intf = ret;
549 	uac2->as_in_alt = 0;
550 
551 	/* Calculate wMaxPacketSize according to audio bandwidth */
552 	set_ep_max_packet_size(uac2_opts, &fs_epin_desc, 1000, true);
553 	set_ep_max_packet_size(uac2_opts, &fs_epout_desc, 1000, false);
554 	set_ep_max_packet_size(uac2_opts, &hs_epin_desc, 8000, true);
555 	set_ep_max_packet_size(uac2_opts, &hs_epout_desc, 8000, false);
556 
557 	agdev->out_ep = usb_ep_autoconfig(gadget, &fs_epout_desc);
558 	if (!agdev->out_ep) {
559 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
560 		return ret;
561 	}
562 
563 	agdev->in_ep = usb_ep_autoconfig(gadget, &fs_epin_desc);
564 	if (!agdev->in_ep) {
565 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
566 		return ret;
567 	}
568 
569 	agdev->in_ep_maxpsize = max_t(u16,
570 				le16_to_cpu(fs_epin_desc.wMaxPacketSize),
571 				le16_to_cpu(hs_epin_desc.wMaxPacketSize));
572 	agdev->out_ep_maxpsize = max_t(u16,
573 				le16_to_cpu(fs_epout_desc.wMaxPacketSize),
574 				le16_to_cpu(hs_epout_desc.wMaxPacketSize));
575 
576 	hs_epout_desc.bEndpointAddress = fs_epout_desc.bEndpointAddress;
577 	hs_epin_desc.bEndpointAddress = fs_epin_desc.bEndpointAddress;
578 
579 	ret = usb_assign_descriptors(fn, fs_audio_desc, hs_audio_desc, NULL,
580 				     NULL);
581 	if (ret)
582 		return ret;
583 
584 	agdev->gadget = gadget;
585 
586 	agdev->params.p_chmask = uac2_opts->p_chmask;
587 	agdev->params.p_srate = uac2_opts->p_srate;
588 	agdev->params.p_ssize = uac2_opts->p_ssize;
589 	agdev->params.c_chmask = uac2_opts->c_chmask;
590 	agdev->params.c_srate = uac2_opts->c_srate;
591 	agdev->params.c_ssize = uac2_opts->c_ssize;
592 	agdev->params.req_number = uac2_opts->req_number;
593 	ret = g_audio_setup(agdev, "UAC2 PCM", "UAC2_Gadget");
594 	if (ret)
595 		goto err_free_descs;
596 	return 0;
597 
598 err_free_descs:
599 	usb_free_all_descriptors(fn);
600 	agdev->gadget = NULL;
601 	return ret;
602 }
603 
604 static int
605 afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt)
606 {
607 	struct usb_composite_dev *cdev = fn->config->cdev;
608 	struct f_uac2 *uac2 = func_to_uac2(fn);
609 	struct usb_gadget *gadget = cdev->gadget;
610 	struct device *dev = &gadget->dev;
611 	int ret = 0;
612 
613 	/* No i/f has more than 2 alt settings */
614 	if (alt > 1) {
615 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
616 		return -EINVAL;
617 	}
618 
619 	if (intf == uac2->ac_intf) {
620 		/* Control I/f has only 1 AltSetting - 0 */
621 		if (alt) {
622 			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
623 			return -EINVAL;
624 		}
625 		return 0;
626 	}
627 
628 	if (intf == uac2->as_out_intf) {
629 		uac2->as_out_alt = alt;
630 
631 		if (alt)
632 			ret = u_audio_start_capture(&uac2->g_audio);
633 		else
634 			u_audio_stop_capture(&uac2->g_audio);
635 	} else if (intf == uac2->as_in_intf) {
636 		uac2->as_in_alt = alt;
637 
638 		if (alt)
639 			ret = u_audio_start_playback(&uac2->g_audio);
640 		else
641 			u_audio_stop_playback(&uac2->g_audio);
642 	} else {
643 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
644 		return -EINVAL;
645 	}
646 
647 	return ret;
648 }
649 
650 static int
651 afunc_get_alt(struct usb_function *fn, unsigned intf)
652 {
653 	struct f_uac2 *uac2 = func_to_uac2(fn);
654 	struct g_audio *agdev = func_to_g_audio(fn);
655 
656 	if (intf == uac2->ac_intf)
657 		return uac2->ac_alt;
658 	else if (intf == uac2->as_out_intf)
659 		return uac2->as_out_alt;
660 	else if (intf == uac2->as_in_intf)
661 		return uac2->as_in_alt;
662 	else
663 		dev_err(&agdev->gadget->dev,
664 			"%s:%d Invalid Interface %d!\n",
665 			__func__, __LINE__, intf);
666 
667 	return -EINVAL;
668 }
669 
670 static void
671 afunc_disable(struct usb_function *fn)
672 {
673 	struct f_uac2 *uac2 = func_to_uac2(fn);
674 
675 	uac2->as_in_alt = 0;
676 	uac2->as_out_alt = 0;
677 	u_audio_stop_capture(&uac2->g_audio);
678 	u_audio_stop_playback(&uac2->g_audio);
679 }
680 
681 static int
682 in_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
683 {
684 	struct usb_request *req = fn->config->cdev->req;
685 	struct g_audio *agdev = func_to_g_audio(fn);
686 	struct f_uac2_opts *opts;
687 	u16 w_length = le16_to_cpu(cr->wLength);
688 	u16 w_index = le16_to_cpu(cr->wIndex);
689 	u16 w_value = le16_to_cpu(cr->wValue);
690 	u8 entity_id = (w_index >> 8) & 0xff;
691 	u8 control_selector = w_value >> 8;
692 	int value = -EOPNOTSUPP;
693 	int p_srate, c_srate;
694 
695 	opts = g_audio_to_uac2_opts(agdev);
696 	p_srate = opts->p_srate;
697 	c_srate = opts->c_srate;
698 
699 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
700 		struct cntrl_cur_lay3 c;
701 		memset(&c, 0, sizeof(struct cntrl_cur_lay3));
702 
703 		if (entity_id == USB_IN_CLK_ID)
704 			c.dCUR = p_srate;
705 		else if (entity_id == USB_OUT_CLK_ID)
706 			c.dCUR = c_srate;
707 
708 		value = min_t(unsigned, w_length, sizeof c);
709 		memcpy(req->buf, &c, value);
710 	} else if (control_selector == UAC2_CS_CONTROL_CLOCK_VALID) {
711 		*(u8 *)req->buf = 1;
712 		value = min_t(unsigned, w_length, 1);
713 	} else {
714 		dev_err(&agdev->gadget->dev,
715 			"%s:%d control_selector=%d TODO!\n",
716 			__func__, __LINE__, control_selector);
717 	}
718 
719 	return value;
720 }
721 
722 static int
723 in_rq_range(struct usb_function *fn, const struct usb_ctrlrequest *cr)
724 {
725 	struct usb_request *req = fn->config->cdev->req;
726 	struct g_audio *agdev = func_to_g_audio(fn);
727 	struct f_uac2_opts *opts;
728 	u16 w_length = le16_to_cpu(cr->wLength);
729 	u16 w_index = le16_to_cpu(cr->wIndex);
730 	u16 w_value = le16_to_cpu(cr->wValue);
731 	u8 entity_id = (w_index >> 8) & 0xff;
732 	u8 control_selector = w_value >> 8;
733 	struct cntrl_range_lay3 r;
734 	int value = -EOPNOTSUPP;
735 	int p_srate, c_srate;
736 
737 	opts = g_audio_to_uac2_opts(agdev);
738 	p_srate = opts->p_srate;
739 	c_srate = opts->c_srate;
740 
741 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
742 		if (entity_id == USB_IN_CLK_ID)
743 			r.dMIN = p_srate;
744 		else if (entity_id == USB_OUT_CLK_ID)
745 			r.dMIN = c_srate;
746 		else
747 			return -EOPNOTSUPP;
748 
749 		r.dMAX = r.dMIN;
750 		r.dRES = 0;
751 		r.wNumSubRanges = 1;
752 
753 		value = min_t(unsigned, w_length, sizeof r);
754 		memcpy(req->buf, &r, value);
755 	} else {
756 		dev_err(&agdev->gadget->dev,
757 			"%s:%d control_selector=%d TODO!\n",
758 			__func__, __LINE__, control_selector);
759 	}
760 
761 	return value;
762 }
763 
764 static int
765 ac_rq_in(struct usb_function *fn, const struct usb_ctrlrequest *cr)
766 {
767 	if (cr->bRequest == UAC2_CS_CUR)
768 		return in_rq_cur(fn, cr);
769 	else if (cr->bRequest == UAC2_CS_RANGE)
770 		return in_rq_range(fn, cr);
771 	else
772 		return -EOPNOTSUPP;
773 }
774 
775 static int
776 out_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
777 {
778 	u16 w_length = le16_to_cpu(cr->wLength);
779 	u16 w_value = le16_to_cpu(cr->wValue);
780 	u8 control_selector = w_value >> 8;
781 
782 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ)
783 		return w_length;
784 
785 	return -EOPNOTSUPP;
786 }
787 
788 static int
789 setup_rq_inf(struct usb_function *fn, const struct usb_ctrlrequest *cr)
790 {
791 	struct f_uac2 *uac2 = func_to_uac2(fn);
792 	struct g_audio *agdev = func_to_g_audio(fn);
793 	u16 w_index = le16_to_cpu(cr->wIndex);
794 	u8 intf = w_index & 0xff;
795 
796 	if (intf != uac2->ac_intf) {
797 		dev_err(&agdev->gadget->dev,
798 			"%s:%d Error!\n", __func__, __LINE__);
799 		return -EOPNOTSUPP;
800 	}
801 
802 	if (cr->bRequestType & USB_DIR_IN)
803 		return ac_rq_in(fn, cr);
804 	else if (cr->bRequest == UAC2_CS_CUR)
805 		return out_rq_cur(fn, cr);
806 
807 	return -EOPNOTSUPP;
808 }
809 
810 static int
811 afunc_setup(struct usb_function *fn, const struct usb_ctrlrequest *cr)
812 {
813 	struct usb_composite_dev *cdev = fn->config->cdev;
814 	struct g_audio *agdev = func_to_g_audio(fn);
815 	struct usb_request *req = cdev->req;
816 	u16 w_length = le16_to_cpu(cr->wLength);
817 	int value = -EOPNOTSUPP;
818 
819 	/* Only Class specific requests are supposed to reach here */
820 	if ((cr->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS)
821 		return -EOPNOTSUPP;
822 
823 	if ((cr->bRequestType & USB_RECIP_MASK) == USB_RECIP_INTERFACE)
824 		value = setup_rq_inf(fn, cr);
825 	else
826 		dev_err(&agdev->gadget->dev, "%s:%d Error!\n",
827 				__func__, __LINE__);
828 
829 	if (value >= 0) {
830 		req->length = value;
831 		req->zero = value < w_length;
832 		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
833 		if (value < 0) {
834 			dev_err(&agdev->gadget->dev,
835 				"%s:%d Error!\n", __func__, __LINE__);
836 			req->status = 0;
837 		}
838 	}
839 
840 	return value;
841 }
842 
843 static inline struct f_uac2_opts *to_f_uac2_opts(struct config_item *item)
844 {
845 	return container_of(to_config_group(item), struct f_uac2_opts,
846 			    func_inst.group);
847 }
848 
849 static void f_uac2_attr_release(struct config_item *item)
850 {
851 	struct f_uac2_opts *opts = to_f_uac2_opts(item);
852 
853 	usb_put_function_instance(&opts->func_inst);
854 }
855 
856 static struct configfs_item_operations f_uac2_item_ops = {
857 	.release	= f_uac2_attr_release,
858 };
859 
860 #define UAC2_ATTRIBUTE(name)						\
861 static ssize_t f_uac2_opts_##name##_show(struct config_item *item,	\
862 					 char *page)			\
863 {									\
864 	struct f_uac2_opts *opts = to_f_uac2_opts(item);		\
865 	int result;							\
866 									\
867 	mutex_lock(&opts->lock);					\
868 	result = sprintf(page, "%u\n", opts->name);			\
869 	mutex_unlock(&opts->lock);					\
870 									\
871 	return result;							\
872 }									\
873 									\
874 static ssize_t f_uac2_opts_##name##_store(struct config_item *item,	\
875 					  const char *page, size_t len)	\
876 {									\
877 	struct f_uac2_opts *opts = to_f_uac2_opts(item);		\
878 	int ret;							\
879 	u32 num;							\
880 									\
881 	mutex_lock(&opts->lock);					\
882 	if (opts->refcnt) {						\
883 		ret = -EBUSY;						\
884 		goto end;						\
885 	}								\
886 									\
887 	ret = kstrtou32(page, 0, &num);					\
888 	if (ret)							\
889 		goto end;						\
890 									\
891 	opts->name = num;						\
892 	ret = len;							\
893 									\
894 end:									\
895 	mutex_unlock(&opts->lock);					\
896 	return ret;							\
897 }									\
898 									\
899 CONFIGFS_ATTR(f_uac2_opts_, name)
900 
901 UAC2_ATTRIBUTE(p_chmask);
902 UAC2_ATTRIBUTE(p_srate);
903 UAC2_ATTRIBUTE(p_ssize);
904 UAC2_ATTRIBUTE(c_chmask);
905 UAC2_ATTRIBUTE(c_srate);
906 UAC2_ATTRIBUTE(c_ssize);
907 UAC2_ATTRIBUTE(req_number);
908 
909 static struct configfs_attribute *f_uac2_attrs[] = {
910 	&f_uac2_opts_attr_p_chmask,
911 	&f_uac2_opts_attr_p_srate,
912 	&f_uac2_opts_attr_p_ssize,
913 	&f_uac2_opts_attr_c_chmask,
914 	&f_uac2_opts_attr_c_srate,
915 	&f_uac2_opts_attr_c_ssize,
916 	&f_uac2_opts_attr_req_number,
917 	NULL,
918 };
919 
920 static const struct config_item_type f_uac2_func_type = {
921 	.ct_item_ops	= &f_uac2_item_ops,
922 	.ct_attrs	= f_uac2_attrs,
923 	.ct_owner	= THIS_MODULE,
924 };
925 
926 static void afunc_free_inst(struct usb_function_instance *f)
927 {
928 	struct f_uac2_opts *opts;
929 
930 	opts = container_of(f, struct f_uac2_opts, func_inst);
931 	kfree(opts);
932 }
933 
934 static struct usb_function_instance *afunc_alloc_inst(void)
935 {
936 	struct f_uac2_opts *opts;
937 
938 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
939 	if (!opts)
940 		return ERR_PTR(-ENOMEM);
941 
942 	mutex_init(&opts->lock);
943 	opts->func_inst.free_func_inst = afunc_free_inst;
944 
945 	config_group_init_type_name(&opts->func_inst.group, "",
946 				    &f_uac2_func_type);
947 
948 	opts->p_chmask = UAC2_DEF_PCHMASK;
949 	opts->p_srate = UAC2_DEF_PSRATE;
950 	opts->p_ssize = UAC2_DEF_PSSIZE;
951 	opts->c_chmask = UAC2_DEF_CCHMASK;
952 	opts->c_srate = UAC2_DEF_CSRATE;
953 	opts->c_ssize = UAC2_DEF_CSSIZE;
954 	opts->req_number = UAC2_DEF_REQ_NUM;
955 	return &opts->func_inst;
956 }
957 
958 static void afunc_free(struct usb_function *f)
959 {
960 	struct g_audio *agdev;
961 	struct f_uac2_opts *opts;
962 
963 	agdev = func_to_g_audio(f);
964 	opts = container_of(f->fi, struct f_uac2_opts, func_inst);
965 	kfree(agdev);
966 	mutex_lock(&opts->lock);
967 	--opts->refcnt;
968 	mutex_unlock(&opts->lock);
969 }
970 
971 static void afunc_unbind(struct usb_configuration *c, struct usb_function *f)
972 {
973 	struct g_audio *agdev = func_to_g_audio(f);
974 
975 	g_audio_cleanup(agdev);
976 	usb_free_all_descriptors(f);
977 
978 	agdev->gadget = NULL;
979 }
980 
981 static struct usb_function *afunc_alloc(struct usb_function_instance *fi)
982 {
983 	struct f_uac2	*uac2;
984 	struct f_uac2_opts *opts;
985 
986 	uac2 = kzalloc(sizeof(*uac2), GFP_KERNEL);
987 	if (uac2 == NULL)
988 		return ERR_PTR(-ENOMEM);
989 
990 	opts = container_of(fi, struct f_uac2_opts, func_inst);
991 	mutex_lock(&opts->lock);
992 	++opts->refcnt;
993 	mutex_unlock(&opts->lock);
994 
995 	uac2->g_audio.func.name = "uac2_func";
996 	uac2->g_audio.func.bind = afunc_bind;
997 	uac2->g_audio.func.unbind = afunc_unbind;
998 	uac2->g_audio.func.set_alt = afunc_set_alt;
999 	uac2->g_audio.func.get_alt = afunc_get_alt;
1000 	uac2->g_audio.func.disable = afunc_disable;
1001 	uac2->g_audio.func.setup = afunc_setup;
1002 	uac2->g_audio.func.free_func = afunc_free;
1003 
1004 	return &uac2->g_audio.func;
1005 }
1006 
1007 DECLARE_USB_FUNCTION_INIT(uac2, afunc_alloc_inst, afunc_alloc);
1008 MODULE_LICENSE("GPL");
1009 MODULE_AUTHOR("Yadwinder Singh");
1010 MODULE_AUTHOR("Jaswinder Singh");
1011