tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * audio.c -- Audio gadget driver
3 *
4 * Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
5 * Copyright (C) 2008 Analog Devices, Inc
6 *
7 * Enter bugs at http://blackfin.uclinux.org/
8 *
9 * Licensed under the GPL-2 or later.
10 */
11
12/* #define VERBOSE_DEBUG */
13
14#include <linux/kernel.h>
15#include <linux/utsname.h>
16
17#include "u_audio.h"
18
19#define DRIVER_DESC "Linux USB Audio Gadget"
20#define DRIVER_VERSION "Dec 18, 2008"
21
22/*-------------------------------------------------------------------------*/
23
24/*
25 * Kbuild is not very cooperative with respect to linking separately
26 * compiled library objects into one module. So for now we won't use
27 * separate compilation ... ensuring init/exit sections work to shrink
28 * the runtime footprint, and giving us at least some parts of what
29 * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
30 */
31#include "composite.c"
32#include "usbstring.c"
33#include "config.c"
34#include "epautoconf.c"
35
36#include "u_audio.c"
37#include "f_audio.c"
38
39/*-------------------------------------------------------------------------*/
40
41/* DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!!
42 * Instead: allocate your own, using normal USB-IF procedures.
43 */
44
45/* Thanks to Linux Foundation for donating this product ID. */
46#define AUDIO_VENDOR_NUM 0x1d6b /* Linux Foundation */
47#define AUDIO_PRODUCT_NUM 0x0101 /* Linux-USB Audio Gadget */
48
49/*-------------------------------------------------------------------------*/
50
51static struct usb_device_descriptor device_desc = {
52 .bLength = sizeof device_desc,
53 .bDescriptorType = USB_DT_DEVICE,
54
55 .bcdUSB = __constant_cpu_to_le16(0x200),
56
57 .bDeviceClass = USB_CLASS_PER_INTERFACE,
58 .bDeviceSubClass = 0,
59 .bDeviceProtocol = 0,
60 /* .bMaxPacketSize0 = f(hardware) */
61
62 /* Vendor and product id defaults change according to what configs
63 * we support. (As does bNumConfigurations.) These values can
64 * also be overridden by module parameters.
65 */
66 .idVendor = __constant_cpu_to_le16(AUDIO_VENDOR_NUM),
67 .idProduct = __constant_cpu_to_le16(AUDIO_PRODUCT_NUM),
68 /* .bcdDevice = f(hardware) */
69 /* .iManufacturer = DYNAMIC */
70 /* .iProduct = DYNAMIC */
71 /* NO SERIAL NUMBER */
72 .bNumConfigurations = 1,
73};
74
75static struct usb_otg_descriptor otg_descriptor = {
76 .bLength = sizeof otg_descriptor,
77 .bDescriptorType = USB_DT_OTG,
78
79 /* REVISIT SRP-only hardware is possible, although
80 * it would not be called "OTG" ...
81 */
82 .bmAttributes = USB_OTG_SRP | USB_OTG_HNP,
83};
84
85static const struct usb_descriptor_header *otg_desc[] = {
86 (struct usb_descriptor_header *) &otg_descriptor,
87 NULL,
88};
89
90/*-------------------------------------------------------------------------*/
91
92static int __init audio_do_config(struct usb_configuration *c)
93{
94 /* FIXME alloc iConfiguration string, set it in c->strings */
95
96 if (gadget_is_otg(c->cdev->gadget)) {
97 c->descriptors = otg_desc;
98 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
99 }
100
101 audio_bind_config(c);
102
103 return 0;
104}
105
106static struct usb_configuration audio_config_driver = {
107 .label = DRIVER_DESC,
108 .bind = audio_do_config,
109 .bConfigurationValue = 1,
110 /* .iConfiguration = DYNAMIC */
111 .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
112};
113
114/*-------------------------------------------------------------------------*/
115
116static int __init audio_bind(struct usb_composite_dev *cdev)
117{
118 int gcnum;
119 int status;
120
121 gcnum = usb_gadget_controller_number(cdev->gadget);
122 if (gcnum >= 0)
123 device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
124 else {
125 ERROR(cdev, "controller '%s' not recognized; trying %s\n",
126 cdev->gadget->name,
127 audio_config_driver.label);
128 device_desc.bcdDevice =
129 __constant_cpu_to_le16(0x0300 | 0x0099);
130 }
131
132 /* device descriptor strings: manufacturer, product */
133 snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
134 init_utsname()->sysname, init_utsname()->release,
135 cdev->gadget->name);
136 status = usb_string_id(cdev);
137 if (status < 0)
138 goto fail;
139 strings_dev[STRING_MANUFACTURER_IDX].id = status;
140 device_desc.iManufacturer = status;
141
142 status = usb_string_id(cdev);
143 if (status < 0)
144 goto fail;
145 strings_dev[STRING_PRODUCT_IDX].id = status;
146 device_desc.iProduct = status;
147
148 status = usb_add_config(cdev, &audio_config_driver);
149 if (status < 0)
150 goto fail;
151
152 INFO(cdev, "%s, version: %s\n", DRIVER_DESC, DRIVER_VERSION);
153 return 0;
154
155fail:
156 return status;
157}
158
159static int __exit audio_unbind(struct usb_composite_dev *cdev)
160{
161 gaudio_cleanup();
162 return 0;
163}
164
165static struct usb_composite_driver audio_driver = {
166 .name = "g_audio",
167 .dev = &device_desc,
168 .strings = audio_strings,
169 .bind = audio_bind,
170 .unbind = __exit_p(audio_unbind),
171};
172
173static int __init init(void)
174{
175 return usb_composite_register(&audio_driver);
176}
177module_init(init);
178
179static void __exit cleanup(void)
180{
181 usb_composite_unregister(&audio_driver);
182}
183module_exit(cleanup);
184
185MODULE_DESCRIPTION(DRIVER_DESC);
186MODULE_AUTHOR("Bryan Wu <cooloney@kernel.org>");
187MODULE_LICENSE("GPL");
188