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 <m.nazarewicz@samsung.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 * This program is distributed in the hope that it will be useful,
 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 17 * GNU General Public License for more details.
 18 *
 19 * You should have received a copy of the GNU General Public License
 20 * along with this program; if not, write to the Free Software
 21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 22 */
 23
 24
 25/*
 26 * The Mass Storage Gadget acts as a USB Mass Storage device,
 27 * appearing to the host as a disk drive or as a CD-ROM drive.  In
 28 * addition to providing an example of a genuinely useful gadget
 29 * driver for a USB device, it also illustrates a technique of
 30 * double-buffering for increased throughput.  Last but not least, it
 31 * gives an easy way to probe the behavior of the Mass Storage drivers
 32 * in a USB host.
 33 *
 34 * Since this file serves only administrative purposes and all the
 35 * business logic is implemented in f_mass_storage.* file.  Read
 36 * comments in this file for more detailed description.
 37 */
 38
 39
 40#include <linux/kernel.h>
 41#include <linux/utsname.h>
 42#include <linux/usb/ch9.h>
 43
 44
 45/*-------------------------------------------------------------------------*/
 46
 47#define DRIVER_DESC		"Mass Storage Gadget"
 48#define DRIVER_VERSION		"2009/09/11"
 49
 50/*-------------------------------------------------------------------------*/
 51
 52/*
 53 * kbuild is not very cooperative with respect to linking separately
 54 * compiled library objects into one module.  So for now we won't use
 55 * separate compilation ... ensuring init/exit sections work to shrink
 56 * the runtime footprint, and giving us at least some parts of what
 57 * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
 58 */
 59
 60#include "composite.c"
 61#include "usbstring.c"
 62#include "config.c"
 63#include "epautoconf.c"
 64#include "f_mass_storage.c"
 65
 66/*-------------------------------------------------------------------------*/
 67
 68static struct usb_device_descriptor msg_device_desc = {
 69	.bLength =		sizeof msg_device_desc,
 70	.bDescriptorType =	USB_DT_DEVICE,
 71
 72	.bcdUSB =		cpu_to_le16(0x0200),
 73	.bDeviceClass =		USB_CLASS_PER_INTERFACE,
 74
 75	/* Vendor and product id can be overridden by module parameters.  */
 76	.idVendor =		cpu_to_le16(FSG_VENDOR_ID),
 77	.idProduct =		cpu_to_le16(FSG_PRODUCT_ID),
 78	.bNumConfigurations =	1,
 79};
 80
 81static struct usb_otg_descriptor otg_descriptor = {
 82	.bLength =		sizeof otg_descriptor,
 83	.bDescriptorType =	USB_DT_OTG,
 84
 85	/*
 86	 * REVISIT SRP-only hardware is possible, although
 87	 * it would not be called "OTG" ...
 88	 */
 89	.bmAttributes =		USB_OTG_SRP | USB_OTG_HNP,
 90};
 91
 92static const struct usb_descriptor_header *otg_desc[] = {
 93	(struct usb_descriptor_header *) &otg_descriptor,
 94	NULL,
 95};
 96
 97
 98/****************************** Configurations ******************************/
 99
100static struct fsg_module_parameters mod_data = {
101	.stall = 1
102};
103FSG_MODULE_PARAMETERS(/* no prefix */, mod_data);
104
105static unsigned long msg_registered;
106static void msg_cleanup(void);
107
108static int msg_thread_exits(struct fsg_common *common)
109{
110	msg_cleanup();
111	return 0;
112}
113
114static int __init msg_do_config(struct usb_configuration *c)
115{
116	static const struct fsg_operations ops = {
117		.thread_exits = msg_thread_exits,
118	};
119	static struct fsg_common common;
120
121	struct fsg_common *retp;
122	struct fsg_config config;
123	int ret;
124
125	if (gadget_is_otg(c->cdev->gadget)) {
126		c->descriptors = otg_desc;
127		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
128	}
129
130	fsg_config_from_params(&config, &mod_data);
131	config.ops = &ops;
132
133	retp = fsg_common_init(&common, c->cdev, &config);
134	if (IS_ERR(retp))
135		return PTR_ERR(retp);
136
137	ret = fsg_bind_config(c->cdev, c, &common);
138	fsg_common_put(&common);
139	return ret;
140}
141
142static struct usb_configuration msg_config_driver = {
143	.label			= "Linux File-Backed Storage",
144	.bConfigurationValue	= 1,
145	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
146};
147
148
149/****************************** Gadget Bind ******************************/
150
151static int __init msg_bind(struct usb_composite_dev *cdev)
152{
153	int status;
154
155	status = usb_add_config(cdev, &msg_config_driver, msg_do_config);
156	if (status < 0)
157		return status;
158
159	dev_info(&cdev->gadget->dev,
160		 DRIVER_DESC ", version: " DRIVER_VERSION "\n");
161	set_bit(0, &msg_registered);
162	return 0;
163}
164
165
166/****************************** Some noise ******************************/
167
168static struct usb_composite_driver msg_driver = {
169	.name		= "g_mass_storage",
170	.dev		= &msg_device_desc,
171	.iProduct	= DRIVER_DESC,
172	.max_speed	= USB_SPEED_HIGH,
173	.needs_serial	= 1,
174};
175
176MODULE_DESCRIPTION(DRIVER_DESC);
177MODULE_AUTHOR("Michal Nazarewicz");
178MODULE_LICENSE("GPL");
179
180static int __init msg_init(void)
181{
182	return usb_composite_probe(&msg_driver, msg_bind);
183}
184module_init(msg_init);
185
186static void msg_cleanup(void)
187{
188	if (test_and_clear_bit(0, &msg_registered))
189		usb_composite_unregister(&msg_driver);
190}
191module_exit(msg_cleanup);