linux/drivers/usb/gadget/audio.c
Jassi Brar 132fcb4608 usb: gadget: Add Audio Class 2.0 Driver
This is a flexible USB Audio Class 2.0 compliant gadget driver that
implements a simple topology with a virtual sound card exposed at
the function side.

The driver doesn't expect any real audio codec to be present on the
function - the audio streams are simply sinked to and sourced from a
virtual ALSA sound card created. The user-space application may choose
to do whatever it wants with the data received from the USB Host and
choose to provide whatever it wants as audio data to the USB Host.

Capture(USB-Out) and Playback(USB-In) can be run at independent
configurations specified via module parameters while loading the driver.

Make this new version as the default selection by a new Kconfig choice.

Signed-off-by: Yadi Brar <yadi.brar01@gmail.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2012-02-15 10:10:31 +02:00

224 lines
5.6 KiB
C

/*
* audio.c -- Audio gadget driver
*
* Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
* 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/utsname.h>
#define DRIVER_DESC "Linux USB Audio Gadget"
#define DRIVER_VERSION "Feb 2, 2012"
/*-------------------------------------------------------------------------*/
/*
* Kbuild is not very cooperative with respect to linking separately
* compiled library objects into one module. So for now we won't use
* separate compilation ... ensuring init/exit sections work to shrink
* the runtime footprint, and giving us at least some parts of what
* a "gcc --combine ... part1.c part2.c part3.c ... " build would.
*/
#include "composite.c"
#include "usbstring.c"
#include "config.c"
#include "epautoconf.c"
/* string IDs are assigned dynamically */
#define STRING_MANUFACTURER_IDX 0
#define STRING_PRODUCT_IDX 1
static char manufacturer[50];
static struct usb_string strings_dev[] = {
[STRING_MANUFACTURER_IDX].s = manufacturer,
[STRING_PRODUCT_IDX].s = DRIVER_DESC,
{ } /* 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 gcnum;
int status;
gcnum = usb_gadget_controller_number(cdev->gadget);
if (gcnum >= 0)
device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
else {
ERROR(cdev, "controller '%s' not recognized; trying %s\n",
cdev->gadget->name,
audio_config_driver.label);
device_desc.bcdDevice =
__constant_cpu_to_le16(0x0300 | 0x0099);
}
/* device descriptor strings: manufacturer, product */
snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
init_utsname()->sysname, init_utsname()->release,
cdev->gadget->name);
status = usb_string_id(cdev);
if (status < 0)
goto fail;
strings_dev[STRING_MANUFACTURER_IDX].id = status;
device_desc.iManufacturer = status;
status = usb_string_id(cdev);
if (status < 0)
goto fail;
strings_dev[STRING_PRODUCT_IDX].id = status;
device_desc.iProduct = status;
status = usb_add_config(cdev, &audio_config_driver, audio_do_config);
if (status < 0)
goto fail;
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 struct usb_composite_driver audio_driver = {
.name = "g_audio",
.dev = &device_desc,
.strings = audio_strings,
.max_speed = USB_SPEED_HIGH,
.unbind = __exit_p(audio_unbind),
};
static int __init init(void)
{
return usb_composite_probe(&audio_driver, audio_bind);
}
module_init(init);
static void __exit cleanup(void)
{
usb_composite_unregister(&audio_driver);
}
module_exit(cleanup);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Bryan Wu <cooloney@kernel.org>");
MODULE_LICENSE("GPL");