drivers/usb/gadget/legacy/cdc2.c

Source file repositories/reference/linux-study-clean/drivers/usb/gadget/legacy/cdc2.c

File Facts

System
Linux kernel
Corpus path
drivers/usb/gadget/legacy/cdc2.c
Extension
.c
Size
5870 bytes
Lines
240
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 fail1;
		}
		usb_otg_descriptor_init(gadget, usb_desc);
		otg_desc[0] = usb_desc;
		otg_desc[1] = NULL;
	}

	/* register our configuration */
	status = usb_add_config(cdev, &cdc_config_driver, cdc_do_config);
	if (status < 0)
		goto fail2;

	usb_composite_overwrite_options(cdev, &coverwrite);
	dev_info(&gadget->dev, "%s, version: " DRIVER_VERSION "\n",
			DRIVER_DESC);

	return 0;

fail2:
	kfree(otg_desc[0]);
	otg_desc[0] = NULL;
fail1:
	usb_put_function_instance(fi_serial);
fail:
	usb_put_function_instance(fi_ecm);
	return status;
}

static int cdc_unbind(struct usb_composite_dev *cdev)
{
	usb_put_function(f_acm);
	usb_put_function_instance(fi_serial);
	if (!IS_ERR_OR_NULL(f_ecm))
		usb_put_function(f_ecm);
	if (!IS_ERR_OR_NULL(fi_ecm))
		usb_put_function_instance(fi_ecm);
	kfree(otg_desc[0]);
	otg_desc[0] = NULL;

	return 0;
}

static struct usb_composite_driver cdc_driver = {
	.name		= "g_cdc",
	.dev		= &device_desc,
	.strings	= dev_strings,
	.max_speed	= USB_SPEED_SUPER,
	.bind		= cdc_bind,
	.unbind		= cdc_unbind,
};

module_usb_composite_driver(cdc_driver);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("David Brownell");
MODULE_LICENSE("GPL");

Annotation

Implementation Notes