drivers/usb/gadget/legacy/audio.c

Source file repositories/reference/linux-study-clean/drivers/usb/gadget/legacy/audio.c

File Facts

System
Linux kernel
Corpus path
drivers/usb/gadget/legacy/audio.c
Extension
.c
Size
11000 bytes
Lines
399
Domain
Driver Families
Bucket
drivers/usb
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (!usb_desc) {
			status = -ENOMEM;
			goto fail;
		}
		usb_otg_descriptor_init(cdev->gadget, usb_desc);
		otg_desc[0] = usb_desc;
		otg_desc[1] = NULL;
	}

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

	INFO(cdev, "%s, version: %s\n", DRIVER_DESC, DRIVER_VERSION);
	return 0;

fail_otg_desc:
	kfree(otg_desc[0]);
	otg_desc[0] = NULL;
fail:
#ifndef CONFIG_GADGET_UAC1
	usb_put_function_instance(fi_uac2);
#else
	usb_put_function_instance(fi_uac1);
#endif
	return status;
}

static int audio_unbind(struct usb_composite_dev *cdev)
{
#ifdef CONFIG_GADGET_UAC1
	if (!IS_ERR_OR_NULL(f_uac1))
		usb_put_function(f_uac1);
	if (!IS_ERR_OR_NULL(fi_uac1))
		usb_put_function_instance(fi_uac1);
#else
	if (!IS_ERR_OR_NULL(f_uac2))
		usb_put_function(f_uac2);
	if (!IS_ERR_OR_NULL(fi_uac2))
		usb_put_function_instance(fi_uac2);
#endif
	kfree(otg_desc[0]);
	otg_desc[0] = NULL;

	return 0;
}

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

module_usb_composite_driver(audio_driver);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Bryan Wu <cooloney@kernel.org>");
MODULE_LICENSE("GPL");

Annotation

Implementation Notes