summaryrefslogtreecommitdiffstats
path: root/drivers/usb/gadget/audio.c
blob: 94de7e864614961f322412d2855289041fdda22e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
/*
 * audio.c -- Audio gadget driver
 *
 * Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
 * Copyright (C) 2008 Analog Devices, Inc
 *
 * Enter bugs at http://blackfin.uclinux.org/
 *
 * Licensed under the GPL-2 or later.
 */

/* #define VERBOSE_DEBUG */

#include <linux/kernel.h>
#include <linux/utsname.h>

#include "u_audio.h"

#define DRIVER_DESC		"Linux USB Audio Gadget"
#define DRIVER_VERSION		"Dec 18, 2008"

/*-------------------------------------------------------------------------*/

/*
 * Kbuild is not very cooperative with respect to linking separately
 * compiled library objects into one module.  So for now we won't use
 * separate compilation ... ensuring init/exit sections work to shrink
 * the runtime footprint, and giving us at least some parts of what
 * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
 */
#include "composite.c"
#include "usbstring.c"
#include "config.c"
#include "epautoconf.c"

#include "u_audio.c"
#include "f_audio.c"

/*-------------------------------------------------------------------------*/

/* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
 * Instead:  allocate your own, using normal USB-IF procedures.
 */

/* Thanks to NetChip Technologies for donating this product ID. */
#define AUDIO_VENDOR_NUM		0x0525	/* NetChip */
#define AUDIO_PRODUCT_NUM		0xa4a1	/* Linux-USB Audio Gadget */

/*-------------------------------------------------------------------------*/

static struct usb_device_descriptor device_desc = {
	.bLength =		sizeof device_desc,
	.bDescriptorType =	USB_DT_DEVICE,

	.bcdUSB =		__constant_cpu_to_le16(0x200),

	.bDeviceClass =		USB_CLASS_PER_INTERFACE,
	.bDeviceSubClass =	0,
	.bDeviceProtocol =	0,
	/* .bMaxPacketSize0 = f(hardware) */

	/* Vendor and product id defaults change according to what configs
	 * we support.  (As does bNumConfigurations.)  These values can
	 * also be overridden by module parameters.
	 */
	.idVendor =		__constant_cpu_to_le16(AUDIO_VENDOR_NUM),
	.idProduct =		__constant_cpu_to_le16(AUDIO_PRODUCT_NUM),
	/* .bcdDevice = f(hardware) */
	/* .iManufacturer = DYNAMIC */
	/* .iProduct = DYNAMIC */
	/* NO SERIAL NUMBER */
	.bNumConfigurations =	1,
};

static struct usb_otg_descriptor otg_descriptor = {
	.bLength =		sizeof otg_descriptor,
	.bDescriptorType =	USB_DT_OTG,

	/* REVISIT SRP-only hardware is possible, although
	 * it would not be called "OTG" ...
	 */
	.bmAttributes =		USB_OTG_SRP | USB_OTG_HNP,
};

static const struct usb_descriptor_header *otg_desc[] = {
	(struct usb_descriptor_header *) &otg_descriptor,
	NULL,
};

/*-------------------------------------------------------------------------*/

/**
 * Handle USB audio endpoint set/get command in setup class request
 */

static int audio_set_endpoint_req(struct usb_configuration *c,
		const struct usb_ctrlrequest *ctrl)
{
	struct usb_composite_dev *cdev = c->cdev;
	int			value = -EOPNOTSUPP;
	u16			ep = le16_to_cpu(ctrl->wIndex);
	u16			len = le16_to_cpu(ctrl->wLength);
	u16			w_value = le16_to_cpu(ctrl->wValue);

	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
			ctrl->bRequest, w_value, len, ep);

	switch (ctrl->bRequest) {
	case SET_CUR:
		value = 0;
		break;

	case SET_MIN:
		break;

	case SET_MAX:
		break;

	case SET_RES:
		break;

	case SET_MEM:
		break;

	default:
		break;
	}

	return value;
}

static int audio_get_endpoint_req(struct usb_configuration *c,
		const struct usb_ctrlrequest *ctrl)
{
	struct usb_composite_dev *cdev = c->cdev;
	int value = -EOPNOTSUPP;
	u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
	u16 len = le16_to_cpu(ctrl->wLength);
	u16 w_value = le16_to_cpu(ctrl->wValue);

	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
			ctrl->bRequest, w_value, len, ep);

	switch (ctrl->bRequest) {
	case GET_CUR:
	case GET_MIN:
	case GET_MAX:
	case GET_RES:
		value = 3;
		break;
	case GET_MEM:
		break;
	default:
		break;
	}

	return value;
}

static int
audio_setup(struct usb_configuration *c, const struct usb_ctrlrequest *ctrl)
{
	struct usb_composite_dev *cdev = c->cdev;
	struct usb_request *req = cdev->req;
	int value = -EOPNOTSUPP;
	u16 w_index = le16_to_cpu(ctrl->wIndex);
	u16 w_value = le16_to_cpu(ctrl->wValue);
	u16 w_length = le16_to_cpu(ctrl->wLength);

	/* composite driver infrastructure handles everything except
	 * Audio class messages; interface activation uses set_alt().
	 */
	switch (ctrl->bRequestType) {
	case USB_AUDIO_SET_ENDPOINT:
		value = audio_set_endpoint_req(c, ctrl);
		break;

	case USB_AUDIO_GET_ENDPOINT:
		value = audio_get_endpoint_req(c, ctrl);
		break;

	default:
		ERROR(cdev, "Invalid control req%02x.%02x v%04x i%04x l%d\n",
			ctrl->bRequestType, ctrl->bRequest,
			w_value, w_index, w_length);
	}

	/* respond with data transfer or status phase? */
	if (value >= 0) {
		DBG(cdev, "Audio req%02x.%02x v%04x i%04x l%d\n",
			ctrl->bRequestType, ctrl->bRequest,
			w_value, w_index, w_length);
		req->zero = 0;
		req->length = value;
		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
		if (value < 0)
			ERROR(cdev, "Audio response on err %d\n", value);
	}

	/* device either stalls (value < 0) or reports success */
	return value;
}

/*-------------------------------------------------------------------------*/

static int __init audio_do_config(struct usb_configuration *c)
{
	/* FIXME alloc iConfiguration string, set it in c->strings */

	if (gadget_is_otg(c->cdev->gadget)) {
		c->descriptors = otg_desc;
		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
	}

	audio_bind_config(c);

	return 0;
}

static struct usb_configuration audio_config_driver = {
	.label			= DRIVER_DESC,
	.bind			= audio_do_config,
	.setup			= audio_setup,
	.bConfigurationValue	= 1,
	/* .iConfiguration = DYNAMIC */
	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
};

/*-------------------------------------------------------------------------*/

static int __init audio_bind(struct usb_composite_dev *cdev)
{
	int			gcnum;
	int			status;

	gcnum = usb_gadget_controller_number(cdev->gadget);
	if (gcnum >= 0)
		device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
	else {
		ERROR(cdev, "controller '%s' not recognized; trying %s\n",
			cdev->gadget->name,
			audio_config_driver.label);
		device_desc.bcdDevice =
			__constant_cpu_to_le16(0x0300 | 0x0099);
	}

	/* device descriptor strings: manufacturer, product */
	snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
		init_utsname()->sysname, init_utsname()->release,
		cdev->gadget->name);
	status = usb_string_id(cdev);
	if (status < 0)
		goto fail;
	strings_dev[STRING_MANUFACTURER_IDX].id = status;
	device_desc.iManufacturer = status;

	status = usb_string_id(cdev);
	if (status < 0)
		goto fail;
	strings_dev[STRING_PRODUCT_IDX].id = status;
	device_desc.iProduct = status;

	status = usb_add_config(cdev, &audio_config_driver);
	if (status < 0)
		goto fail;

	INFO(cdev, "%s, version: %s\n", DRIVER_DESC, DRIVER_VERSION);
	return 0;

fail:
	return status;
}

static int __exit audio_unbind(struct usb_composite_dev *cdev)
{
	return 0;
}

static struct usb_composite_driver audio_driver = {
	.name		= "g_audio",
	.dev		= &device_desc,
	.strings	= audio_strings,
	.bind		= audio_bind,
	.unbind		= __exit_p(audio_unbind),
};

static int __init init(void)
{
	return usb_composite_register(&audio_driver);
}
module_init(init);

static void __exit cleanup(void)
{
	usb_composite_unregister(&audio_driver);
}
module_exit(cleanup);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Bryan Wu <cooloney@kernel.org>");
MODULE_LICENSE("GPL");

OpenPOWER on IntegriCloud