1/*
  2 * mass_storage.c -- Mass Storage USB Gadget
  3 *
  4 * Copyright (C) 2003-2008 Alan Stern
  5 * Copyright (C) 2009 Samsung Electronics
  6 *                    Author: Michal Nazarewicz <mina86@mina86.com>
  7 * All rights reserved.
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License as published by
 11 * the Free Software Foundation; either version 2 of the License, or
 12 * (at your option) any later version.
 13 */
 14
 15
 16/*
 17 * The Mass Storage Gadget acts as a USB Mass Storage device,
 18 * appearing to the host as a disk drive or as a CD-ROM drive.  In
 19 * addition to providing an example of a genuinely useful gadget
 20 * driver for a USB device, it also illustrates a technique of
 21 * double-buffering for increased throughput.  Last but not least, it
 22 * gives an easy way to probe the behavior of the Mass Storage drivers
 23 * in a USB host.
 24 *
 25 * Since this file serves only administrative purposes and all the
 26 * business logic is implemented in f_mass_storage.* file.  Read
 27 * comments in this file for more detailed description.
 28 */
 29
 30
 31#include <linux/kernel.h>
 32#include <linux/utsname.h>
 33#include <linux/usb/ch9.h>
 34
 35
 36/*-------------------------------------------------------------------------*/
 37
 38#define DRIVER_DESC		"Mass Storage Gadget"
 39#define DRIVER_VERSION		"2009/09/11"
 40
 41/*-------------------------------------------------------------------------*/
 42
 43/*
 44 * kbuild is not very cooperative with respect to linking separately
 45 * compiled library objects into one module.  So for now we won't use
 46 * separate compilation ... ensuring init/exit sections work to shrink
 47 * the runtime footprint, and giving us at least some parts of what
 48 * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
 49 */
 50
 51#include "composite.c"
 52#include "usbstring.c"
 53#include "config.c"
 54#include "epautoconf.c"
 55#include "f_mass_storage.c"
 56
 57/*-------------------------------------------------------------------------*/
 58
 59static struct usb_device_descriptor msg_device_desc = {
 60	.bLength =		sizeof msg_device_desc,
 61	.bDescriptorType =	USB_DT_DEVICE,
 62
 63	.bcdUSB =		cpu_to_le16(0x0200),
 64	.bDeviceClass =		USB_CLASS_PER_INTERFACE,
 65
 66	/* Vendor and product id can be overridden by module parameters.  */
 67	.idVendor =		cpu_to_le16(FSG_VENDOR_ID),
 68	.idProduct =		cpu_to_le16(FSG_PRODUCT_ID),
 69	.bNumConfigurations =	1,
 70};
 71
 72static struct usb_otg_descriptor otg_descriptor = {
 73	.bLength =		sizeof otg_descriptor,
 74	.bDescriptorType =	USB_DT_OTG,
 75
 76	/*
 77	 * REVISIT SRP-only hardware is possible, although
 78	 * it would not be called "OTG" ...
 79	 */
 80	.bmAttributes =		USB_OTG_SRP | USB_OTG_HNP,
 81};
 82
 83static const struct usb_descriptor_header *otg_desc[] = {
 84	(struct usb_descriptor_header *) &otg_descriptor,
 85	NULL,
 86};
 87
 88
 89/****************************** Configurations ******************************/
 90
 91static struct fsg_module_parameters mod_data = {
 92	.stall = 1
 93};
 94FSG_MODULE_PARAMETERS(/* no prefix */, mod_data);
 95
 96static unsigned long msg_registered;
 97static void msg_cleanup(void);
 98
 99static int msg_thread_exits(struct fsg_common *common)
100{
101	msg_cleanup();
102	return 0;
103}
104
105static int __init msg_do_config(struct usb_configuration *c)
106{
107	static const struct fsg_operations ops = {
108		.thread_exits = msg_thread_exits,
109	};
110	static struct fsg_common common;
111
112	struct fsg_common *retp;
113	struct fsg_config config;
114	int ret;
115
116	if (gadget_is_otg(c->cdev->gadget)) {
117		c->descriptors = otg_desc;
118		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
119	}
120
121	fsg_config_from_params(&config, &mod_data);
122	config.ops = &ops;
123
124	retp = fsg_common_init(&common, c->cdev, &config);
125	if (IS_ERR(retp))
126		return PTR_ERR(retp);
127
128	ret = fsg_bind_config(c->cdev, c, &common);
129	fsg_common_put(&common);
130	return ret;
131}
132
133static struct usb_configuration msg_config_driver = {
134	.label			= "Linux File-Backed Storage",
135	.bConfigurationValue	= 1,
136	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
137};
138
139
140/****************************** Gadget Bind ******************************/
141
142static int __init msg_bind(struct usb_composite_dev *cdev)
143{
144	int status;
145
146	status = usb_add_config(cdev, &msg_config_driver, msg_do_config);
147	if (status < 0)
148		return status;
149
150	dev_info(&cdev->gadget->dev,
151		 DRIVER_DESC ", version: " DRIVER_VERSION "\n");
152	set_bit(0, &msg_registered);
153	return 0;
154}
155
156
157/****************************** Some noise ******************************/
158
159static struct usb_composite_driver msg_driver = {
160	.name		= "g_mass_storage",
161	.dev		= &msg_device_desc,
162	.iProduct	= DRIVER_DESC,
163	.max_speed	= USB_SPEED_SUPER,
164	.needs_serial	= 1,
165};
166
167MODULE_DESCRIPTION(DRIVER_DESC);
168MODULE_AUTHOR("Michal Nazarewicz");
169MODULE_LICENSE("GPL");
170
171static int __init msg_init(void)
172{
173	return usb_composite_probe(&msg_driver, msg_bind);
174}
175module_init(msg_init);
176
177static void msg_cleanup(void)
178{
179	if (test_and_clear_bit(0, &msg_registered))
180		usb_composite_unregister(&msg_driver);
181}
182module_exit(msg_cleanup);