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
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
59 static 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
72 static 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
83 static const struct usb_descriptor_header *otg_desc[] = {
84 (struct usb_descriptor_header *) &otg_descriptor,
85 NULL,
86 };
87
88
89 /****************************** Configurations ******************************/
90
91 static struct fsg_module_parameters mod_data = {
92 .stall = 1
93 };
94 FSG_MODULE_PARAMETERS(/* no prefix */, mod_data);
95
96 static unsigned long msg_registered;
97 static void msg_cleanup(void);
98
msg_thread_exits(struct fsg_common * common)99 static int msg_thread_exits(struct fsg_common *common)
100 {
101 msg_cleanup();
102 return 0;
103 }
104
msg_do_config(struct usb_configuration * c)105 static 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
133 static 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
msg_bind(struct usb_composite_dev * cdev)142 static 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
159 static 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
167 MODULE_DESCRIPTION(DRIVER_DESC);
168 MODULE_AUTHOR("Michal Nazarewicz");
169 MODULE_LICENSE("GPL");
170
msg_init(void)171 static int __init msg_init(void)
172 {
173 return usb_composite_probe(&msg_driver, msg_bind);
174 }
175 module_init(msg_init);
176
msg_cleanup(void)177 static void msg_cleanup(void)
178 {
179 if (test_and_clear_bit(0, &msg_registered))
180 usb_composite_unregister(&msg_driver);
181 }
182 module_exit(msg_cleanup);
183