tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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 .needs_serial = 1,
173};
174
175MODULE_DESCRIPTION(DRIVER_DESC);
176MODULE_AUTHOR("Michal Nazarewicz");
177MODULE_LICENSE("GPL");
178
179static int __init msg_init(void)
180{
181 return usb_composite_probe(&msg_driver, msg_bind);
182}
183module_init(msg_init);
184
185static void msg_cleanup(void)
186{
187 if (test_and_clear_bit(0, &msg_registered))
188 usb_composite_unregister(&msg_driver);
189}
190module_exit(msg_cleanup);