linux/drivers/usb/gadget/legacy/mass_storage.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * mass_storage.c -- Mass Storage USB Gadget
 *
 * Copyright (C) 2003-2008 Alan Stern
 * Copyright (C) 2009 Samsung Electronics
 *                    Author: Michal Nazarewicz <[email protected]>
 * All rights reserved.
 */


/*
 * The Mass Storage Gadget acts as a USB Mass Storage device,
 * appearing to the host as a disk drive or as a CD-ROM drive.  In
 * addition to providing an example of a genuinely useful gadget
 * driver for a USB device, it also illustrates a technique of
 * double-buffering for increased throughput.  Last but not least, it
 * gives an easy way to probe the behavior of the Mass Storage drivers
 * in a USB host.
 *
 * Since this file serves only administrative purposes and all the
 * business logic is implemented in f_mass_storage.* file.  Read
 * comments in this file for more detailed description.
 */


#include <linux/kernel.h>
#include <linux/usb/ch9.h>
#include <linux/module.h>

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

#define DRIVER_DESC …
#define DRIVER_VERSION …

/*
 * Thanks to NetChip Technologies for donating this product ID.
 *
 * DO NOT REUSE THESE IDs with any other driver!!  Ever!!
 * Instead:  allocate your own, using normal USB-IF procedures.
 */
#define FSG_VENDOR_ID …
#define FSG_PRODUCT_ID …

#include "f_mass_storage.h"

/*-------------------------------------------------------------------------*/
USB_GADGET_COMPOSITE_OPTIONS(…);

static struct usb_device_descriptor msg_device_desc = …;

static const struct usb_descriptor_header *otg_desc[2];

static struct usb_string strings_dev[] = …;

static struct usb_gadget_strings stringtab_dev = …;

static struct usb_gadget_strings *dev_strings[] = …;

static struct usb_function_instance *fi_msg;
static struct usb_function *f_msg;

/****************************** Configurations ******************************/

static struct fsg_module_parameters mod_data = …;
#ifdef CONFIG_USB_GADGET_DEBUG_FILES

static unsigned int fsg_num_buffers = …;

#else

/*
 * Number of buffers we will use.
 * 2 is usually enough for good buffering pipeline
 */
#define fsg_num_buffers …

#endif /* CONFIG_USB_GADGET_DEBUG_FILES */

FSG_MODULE_PARAMETERS(…);

static int msg_do_config(struct usb_configuration *c)
{ … }

static struct usb_configuration msg_config_driver = …;


/****************************** Gadget Bind ******************************/

static int msg_bind(struct usb_composite_dev *cdev)
{ … }

static int msg_unbind(struct usb_composite_dev *cdev)
{ … }

/****************************** Some noise ******************************/

static struct usb_composite_driver msg_driver = …;

module_usb_composite_driver(…);

MODULE_DESCRIPTION(…);
MODULE_AUTHOR(…) …;
MODULE_LICENSE(…) …;