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 "gadget_chips.h"
  18 #define DRIVER_DESC             "Linux USB Audio Gadget"
  19 #define DRIVER_VERSION          "Feb 2, 2012"
  20
  21 /*-------------------------------------------------------------------------*/
  22
  23 /*
  24  * Kbuild is not very cooperative with respect to linking separately
  25  * compiled library objects into one module.  So for now we won't use
  26  * separate compilation ... ensuring init/exit sections work to shrink
  27  * the runtime footprint, and giving us at least some parts of what
  28  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  29  */
  30 #include "composite.c"
  31
  32 /* string IDs are assigned dynamically */
  33
  34 #define STRING_MANUFACTURER_IDX         0
  35 #define STRING_PRODUCT_IDX              1
  36
  37 static char manufacturer[50];
  38
  39 static struct usb_string strings_dev[] = {
  40         [STRING_MANUFACTURER_IDX].s = manufacturer,
  41         [STRING_PRODUCT_IDX].s = DRIVER_DESC,
  42         {  } /* end of list */
  43 };
  44
  45 static struct usb_gadget_strings stringtab_dev = {
  46         .language = 0x0409,     /* en-us */
  47         .strings = strings_dev,
  48 };
  49
  50 static struct usb_gadget_strings *audio_strings[] = {
  51         &stringtab_dev,
  52         NULL,
  53 };
  54
  55 #ifdef CONFIG_GADGET_UAC1
  56 #include "u_uac1.h"
  57 #include "u_uac1.c"
  58 #include "f_uac1.c"
  59 #else
  60 #include "f_uac2.c"
  61 #endif
  62
  63 /*-------------------------------------------------------------------------*/
  64
  65 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  66  * Instead:  allocate your own, using normal USB-IF procedures.
  67  */
  68
  69 /* Thanks to Linux Foundation for donating this product ID. */
  70 #define AUDIO_VENDOR_NUM                0x1d6b  /* Linux Foundation */
  71 #define AUDIO_PRODUCT_NUM               0x0101  /* Linux-USB Audio Gadget */
  72
  73 /*-------------------------------------------------------------------------*/
  74
  75 static struct usb_device_descriptor device_desc = {
  76         .bLength =              sizeof device_desc,
  77         .bDescriptorType =      USB_DT_DEVICE,
  78
  79         .bcdUSB =               __constant_cpu_to_le16(0x200),
  80
  81 #ifdef CONFIG_GADGET_UAC1
  82         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
  83         .bDeviceSubClass =      0,
  84         .bDeviceProtocol =      0,
  85 #else
  86         .bDeviceClass =         USB_CLASS_MISC,
  87         .bDeviceSubClass =      0x02,
  88         .bDeviceProtocol =      0x01,
  89 #endif
  90         /* .bMaxPacketSize0 = f(hardware) */
  91
  92         /* Vendor and product id defaults change according to what configs
  93          * we support.  (As does bNumConfigurations.)  These values can
  94          * also be overridden by module parameters.
  95          */
  96         .idVendor =             __constant_cpu_to_le16(AUDIO_VENDOR_NUM),
  97         .idProduct =            __constant_cpu_to_le16(AUDIO_PRODUCT_NUM),
  98         /* .bcdDevice = f(hardware) */
  99         /* .iManufacturer = DYNAMIC */
 100         /* .iProduct = DYNAMIC */
 101         /* NO SERIAL NUMBER */
 102         .bNumConfigurations =   1,
 103 };
 104
 105 static struct usb_otg_descriptor otg_descriptor = {
 106         .bLength =              sizeof otg_descriptor,
 107         .bDescriptorType =      USB_DT_OTG,
 108
 109         /* REVISIT SRP-only hardware is possible, although
 110          * it would not be called "OTG" ...
 111          */
 112         .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
 113 };
 114
 115 static const struct usb_descriptor_header *otg_desc[] = {
 116         (struct usb_descriptor_header *) &otg_descriptor,
 117         NULL,
 118 };
 119
 120 /*-------------------------------------------------------------------------*/
 121
 122 static int __init audio_do_config(struct usb_configuration *c)
 123 {
 124         /* FIXME alloc iConfiguration string, set it in c->strings */
 125
 126         if (gadget_is_otg(c->cdev->gadget)) {
 127                 c->descriptors = otg_desc;
 128                 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 129         }
 130
 131         audio_bind_config(c);
 132
 133         return 0;
 134 }
 135
 136 static struct usb_configuration audio_config_driver = {
 137         .label                  = DRIVER_DESC,
 138         .bConfigurationValue    = 1,
 139         /* .iConfiguration = DYNAMIC */
 140         .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
 141 #ifndef CONFIG_GADGET_UAC1
 142         .unbind                 = uac2_unbind_config,
 143 #endif
 144 };
 145
 146 /*-------------------------------------------------------------------------*/
 147
 148 static int __init audio_bind(struct usb_composite_dev *cdev)
 149 {
 150         int                     gcnum;
 151         int                     status;
 152
 153         gcnum = usb_gadget_controller_number(cdev->gadget);
 154         if (gcnum >= 0)
 155                 device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
 156         else {
 157                 ERROR(cdev, "controller '%s' not recognized; trying %s\n",
 158                         cdev->gadget->name,
 159                         audio_config_driver.label);
 160                 device_desc.bcdDevice =
 161                         __constant_cpu_to_le16(0x0300 | 0x0099);
 162         }
 163
 164         /* device descriptor strings: manufacturer, product */
 165         snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
 166                 init_utsname()->sysname, init_utsname()->release,
 167                 cdev->gadget->name);
 168         status = usb_string_ids_tab(cdev, strings_dev);
 169         if (status < 0)
 170                 goto fail;
 171         device_desc.iManufacturer = strings_dev[STRING_MANUFACTURER_IDX].id;
 172         device_desc.iProduct = strings_dev[STRING_PRODUCT_IDX].id;
 173
 174         status = usb_add_config(cdev, &audio_config_driver, audio_do_config);
 175         if (status < 0)
 176                 goto fail;
 177
 178         INFO(cdev, "%s, version: %s\n", DRIVER_DESC, DRIVER_VERSION);
 179         return 0;
 180
 181 fail:
 182         return status;
 183 }
 184
 185 static int __exit audio_unbind(struct usb_composite_dev *cdev)
 186 {
 187 #ifdef CONFIG_GADGET_UAC1
 188         gaudio_cleanup();
 189 #endif
 190         return 0;
 191 }
 192
 193 static __refdata struct usb_composite_driver audio_driver = {
 194         .name           = "g_audio",
 195         .dev            = &device_desc,
 196         .strings        = audio_strings,
 197         .max_speed      = USB_SPEED_HIGH,
 198         .bind           = audio_bind,
 199         .unbind         = __exit_p(audio_unbind),
 200 };
 201
 202 static int __init init(void)
 203 {
 204         return usb_composite_probe(&audio_driver);
 205 }
 206 module_init(init);
 207
 208 static void __exit cleanup(void)
 209 {
 210         usb_composite_unregister(&audio_driver);
 211 }
 212 module_exit(cleanup);
 213
 214 MODULE_DESCRIPTION(DRIVER_DESC);
 215 MODULE_AUTHOR("Bryan Wu <cooloney@kernel.org>");
 216 MODULE_LICENSE("GPL");
 217