drivers/usb/gadget/audio.c

   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
  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         .bind                   = audio_do_config,
 109         .bConfigurationValue    = 1,
 110         /* .iConfiguration = DYNAMIC */
 111         .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
 112 };
 113
 114 /*-------------------------------------------------------------------------*/
 115
 116 static 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
 155 fail:
 156         return status;
 157 }
 158
 159 static int __exit audio_unbind(struct usb_composite_dev *cdev)
 160 {
 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         .bind           = audio_bind,
 169         .unbind         = __exit_p(audio_unbind),
 170 };
 171
 172 static int __init init(void)
 173 {
 174         return usb_composite_register(&audio_driver);
 175 }
 176 module_init(init);
 177
 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