aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/gadget/mass_storage.c
blob: 4723d1b04cffe1386bff26e7bc405b3e89727730 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
/*
 * mass_storage.c -- Mass Storage USB Gadget
 *
 * Copyright (C) 2003-2008 Alan Stern
 * Copyright (C) 2009 Samsung Electronics
 *                    Author: Michal Nazarewicz <mina86@mina86.com>
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */


/*
 * 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		"Mass Storage Gadget"
#define DRIVER_VERSION		"2009/09/11"

/*
 * 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	0x0525	/* NetChip */
#define FSG_PRODUCT_ID	0xa4a5	/* Linux-USB File-backed Storage Gadget */

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

/*
 * kbuild is not very cooperative with respect to linking separately
 * compiled library objects into one module.  So for now we won't use
 * separate compilation ... ensuring init/exit sections work to shrink
 * the runtime footprint, and giving us at least some parts of what
 * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
 */
#include "f_mass_storage.c"

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

static struct usb_device_descriptor msg_device_desc = {
	.bLength =		sizeof msg_device_desc,
	.bDescriptorType =	USB_DT_DEVICE,

	.bcdUSB =		cpu_to_le16(0x0200),
	.bDeviceClass =		USB_CLASS_PER_INTERFACE,

	/* Vendor and product id can be overridden by module parameters.  */
	.idVendor =		cpu_to_le16(FSG_VENDOR_ID),
	.idProduct =		cpu_to_le16(FSG_PRODUCT_ID),
	.bNumConfigurations =	1,
};

static struct usb_otg_descriptor otg_descriptor = {
	.bLength =		sizeof otg_descriptor,
	.bDescriptorType =	USB_DT_OTG,

	/*
	 * REVISIT SRP-only hardware is possible, although
	 * it would not be called "OTG" ...
	 */
	.bmAttributes =		USB_OTG_SRP | USB_OTG_HNP,
};

static const struct usb_descriptor_header *otg_desc[] = {
	(struct usb_descriptor_header *) &otg_descriptor,
	NULL,
};

static struct usb_string strings_dev[] = {
	[USB_GADGET_MANUFACTURER_IDX].s = "",
	[USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
	[USB_GADGET_SERIAL_IDX].s = "",
	{  } /* end of list */
};

static struct usb_gadget_strings stringtab_dev = {
	.language       = 0x0409,       /* en-us */
	.strings        = strings_dev,
};

static struct usb_gadget_strings *dev_strings[] = {
	&stringtab_dev,
	NULL,
};

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

static struct fsg_module_parameters mod_data = {
	.stall = 1
};
#ifdef CONFIG_USB_GADGET_DEBUG_FILES

static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS;

#else

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

#endif /* CONFIG_USB_GADGET_DEBUG_FILES */

FSG_MODULE_PARAMETERS(/* no prefix */, mod_data);

static unsigned long msg_registered;
static void msg_cleanup(void);

static int msg_thread_exits(struct fsg_common *common)
{
	msg_cleanup();
	return 0;
}

static int __init msg_do_config(struct usb_configuration *c)
{
	static const struct fsg_operations ops = {
		.thread_exits = msg_thread_exits,
	};
	static struct fsg_common common;

	struct fsg_common *retp;
	struct fsg_config config;
	int ret;

	if (gadget_is_otg(c->cdev->gadget)) {
		c->descriptors = otg_desc;
		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
	}

	fsg_config_from_params(&config, &mod_data, fsg_num_buffers);
	config.ops = &ops;

	retp = fsg_common_init(&common, c->cdev, &config);
	if (IS_ERR(retp))
		return PTR_ERR(retp);

	ret = fsg_bind_config(c->cdev, c, &common);
	fsg_common_put(&common);
	return ret;
}

static struct usb_configuration msg_config_driver = {
	.label			= "Linux File-Backed Storage",
	.bConfigurationValue	= 1,
	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
};


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

static int __init msg_bind(struct usb_composite_dev *cdev)
{
	int status;

	status = usb_string_ids_tab(cdev, strings_dev);
	if (status < 0)
		return status;
	msg_device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;

	status = usb_add_config(cdev, &msg_config_driver, msg_do_config);
	if (status < 0)
		return status;
	usb_composite_overwrite_options(cdev, &coverwrite);
	dev_info(&cdev->gadget->dev,
		 DRIVER_DESC ", version: " DRIVER_VERSION "\n");
	set_bit(0, &msg_registered);
	return 0;
}


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

static __refdata struct usb_composite_driver msg_driver = {
	.name		= "g_mass_storage",
	.dev		= &msg_device_desc,
	.max_speed	= USB_SPEED_SUPER,
	.needs_serial	= 1,
	.strings	= dev_strings,
	.bind		= msg_bind,
};

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Michal Nazarewicz");
MODULE_LICENSE("GPL");

static int __init msg_init(void)
{
	return usb_composite_probe(&msg_driver);
}
module_init(msg_init);

static void msg_cleanup(void)
{
	if (test_and_clear_bit(0, &msg_registered))
		usb_composite_unregister(&msg_driver);
}
module_exit(msg_cleanup);