audio.c

Go to the documentation of this file.

/*
 * audio.c -- Audio gadget driver
 *
 * Copyright (C) 2008 Bryan Wu <[email protected]>
 * 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/module.h>
#include <linux/usb/composite.h>

#include "gadget_chips.h"
#define DRIVER_DESC     "Linux USB Audio Gadget"
#define DRIVER_VERSION      "Feb 2, 2012"

USB_GADGET_COMPOSITE_OPTIONS();

/* string IDs are assigned dynamically */

static struct usb_string strings_dev[] = {
    [USB_GADGET_MANUFACTURER_IDX].s = "",
    [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
    [USB_GADGET_SERIAL_IDX].s = "",
    {  } /* end of list */
};

static struct usb_gadget_strings stringtab_dev = {
    .language = 0x0409, /* en-us */
    .strings = strings_dev,
};

static struct usb_gadget_strings *audio_strings[] = {
    &stringtab_dev,
    NULL,
};

#ifdef CONFIG_GADGET_UAC1
#include "u_uac1.h"
#include "u_uac1.c"
#include "f_uac1.c"
#else
#include "f_uac2.c"
#endif

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

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

/* Thanks to Linux Foundation for donating this product ID. */
#define AUDIO_VENDOR_NUM        0x1d6b  /* Linux Foundation */
#define AUDIO_PRODUCT_NUM       0x0101  /* 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),

#ifdef CONFIG_GADGET_UAC1
    .bDeviceClass =     USB_CLASS_PER_INTERFACE,
    .bDeviceSubClass =  0,
    .bDeviceProtocol =  0,
#else
    .bDeviceClass =     USB_CLASS_MISC,
    .bDeviceSubClass =  0x02,
    .bDeviceProtocol =  0x01,
#endif
    /* .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,
};

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

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,
    .bConfigurationValue    = 1,
    /* .iConfiguration = DYNAMIC */
    .bmAttributes       = USB_CONFIG_ATT_SELFPOWER,
#ifndef CONFIG_GADGET_UAC1
    .unbind         = uac2_unbind_config,
#endif
};

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

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

    status = usb_string_ids_tab(cdev, strings_dev);
    if (status < 0)
        goto fail;
    device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
    device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;

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

    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)
{
#ifdef CONFIG_GADGET_UAC1
    gaudio_cleanup();
#endif
    return 0;
}

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

static int __init init(void)
{
    return usb_composite_probe(&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 <[email protected]>");
MODULE_LICENSE("GPL");