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
51 static 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
75 static 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
85 static const struct usb_descriptor_header *otg_desc[] = {
86 (struct usb_descriptor_header *) &otg_descriptor,
87 NULL,
88 };
89
90 /*-------------------------------------------------------------------------*/
91
audio_do_config(struct usb_configuration * c)92 static 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
106 static struct usb_configuration audio_config_driver = {
107 .label = DRIVER_DESC,
108 .bConfigurationValue = 1,
109 /* .iConfiguration = DYNAMIC */
110 .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
111 };
112
113 /*-------------------------------------------------------------------------*/
114
audio_bind(struct usb_composite_dev * cdev)115 static int __init audio_bind(struct usb_composite_dev *cdev)
116 {
117 int gcnum;
118 int status;
119
120 gcnum = usb_gadget_controller_number(cdev->gadget);
121 if (gcnum >= 0)
122 device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
123 else {
124 ERROR(cdev, "controller '%s' not recognized; trying %s\n",
125 cdev->gadget->name,
126 audio_config_driver.label);
127 device_desc.bcdDevice =
128 __constant_cpu_to_le16(0x0300 | 0x0099);
129 }
130
131 /* device descriptor strings: manufacturer, product */
132 snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
133 init_utsname()->sysname, init_utsname()->release,
134 cdev->gadget->name);
135 status = usb_string_id(cdev);
136 if (status < 0)
137 goto fail;
138 strings_dev[STRING_MANUFACTURER_IDX].id = status;
139 device_desc.iManufacturer = status;
140
141 status = usb_string_id(cdev);
142 if (status < 0)
143 goto fail;
144 strings_dev[STRING_PRODUCT_IDX].id = status;
145 device_desc.iProduct = status;
146
147 status = usb_add_config(cdev, &audio_config_driver, audio_do_config);
148 if (status < 0)
149 goto fail;
150
151 INFO(cdev, "%s, version: %s\n", DRIVER_DESC, DRIVER_VERSION);
152 return 0;
153
154 fail:
155 return status;
156 }
157
audio_unbind(struct usb_composite_dev * cdev)158 static int __exit audio_unbind(struct usb_composite_dev *cdev)
159 {
160 gaudio_cleanup();
161 return 0;
162 }
163
164 static struct usb_composite_driver audio_driver = {
165 .name = "g_audio",
166 .dev = &device_desc,
167 .strings = audio_strings,
168 .max_speed = USB_SPEED_HIGH,
169 .unbind = __exit_p(audio_unbind),
170 };
171
init(void)172 static int __init init(void)
173 {
174 return usb_composite_probe(&audio_driver, audio_bind);
175 }
176 module_init(init);
177
cleanup(void)178 static void __exit cleanup(void)
179 {
180 usb_composite_unregister(&audio_driver);
181 }
182 module_exit(cleanup);
183
184 MODULE_DESCRIPTION(DRIVER_DESC);
185 MODULE_AUTHOR("Bryan Wu <cooloney@kernel.org>");
186 MODULE_LICENSE("GPL");
187
188