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/usb/ch9.h>
33 #include <linux/module.h>
34
35 /*-------------------------------------------------------------------------*/
36
37 #define DRIVER_DESC "Mass Storage Gadget"
38 #define DRIVER_VERSION "2009/09/11"
39
40 /*
41 * Thanks to NetChip Technologies for donating this product ID.
42 *
43 * DO NOT REUSE THESE IDs with any other driver!! Ever!!
44 * Instead: allocate your own, using normal USB-IF procedures.
45 */
46 #define FSG_VENDOR_ID 0x0525 /* NetChip */
47 #define FSG_PRODUCT_ID 0xa4a5 /* Linux-USB File-backed Storage Gadget */
48
49 #include "f_mass_storage.h"
50
51 /*-------------------------------------------------------------------------*/
52 USB_GADGET_COMPOSITE_OPTIONS();
53
54 static struct usb_device_descriptor msg_device_desc = {
55 .bLength = sizeof msg_device_desc,
56 .bDescriptorType = USB_DT_DEVICE,
57
58 .bcdUSB = cpu_to_le16(0x0200),
59 .bDeviceClass = USB_CLASS_PER_INTERFACE,
60
61 /* Vendor and product id can be overridden by module parameters. */
62 .idVendor = cpu_to_le16(FSG_VENDOR_ID),
63 .idProduct = cpu_to_le16(FSG_PRODUCT_ID),
64 .bNumConfigurations = 1,
65 };
66
67 static struct usb_otg_descriptor otg_descriptor = {
68 .bLength = sizeof otg_descriptor,
69 .bDescriptorType = USB_DT_OTG,
70
71 /*
72 * REVISIT SRP-only hardware is possible, although
73 * it would not be called "OTG" ...
74 */
75 .bmAttributes = USB_OTG_SRP | USB_OTG_HNP,
76 };
77
78 static const struct usb_descriptor_header *otg_desc[] = {
79 (struct usb_descriptor_header *) &otg_descriptor,
80 NULL,
81 };
82
83 static struct usb_string strings_dev[] = {
84 [USB_GADGET_MANUFACTURER_IDX].s = "",
85 [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
86 [USB_GADGET_SERIAL_IDX].s = "",
87 { } /* end of list */
88 };
89
90 static struct usb_gadget_strings stringtab_dev = {
91 .language = 0x0409, /* en-us */
92 .strings = strings_dev,
93 };
94
95 static struct usb_gadget_strings *dev_strings[] = {
96 &stringtab_dev,
97 NULL,
98 };
99
100 static struct usb_function_instance *fi_msg;
101 static struct usb_function *f_msg;
102
103 /****************************** Configurations ******************************/
104
105 static struct fsg_module_parameters mod_data = {
106 .stall = 1
107 };
108 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
109
110 static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS;
111
112 #else
113
114 /*
115 * Number of buffers we will use.
116 * 2 is usually enough for good buffering pipeline
117 */
118 #define fsg_num_buffers CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS
119
120 #endif /* CONFIG_USB_GADGET_DEBUG_FILES */
121
122 FSG_MODULE_PARAMETERS(/* no prefix */, mod_data);
123
124 static unsigned long msg_registered;
125 static void msg_cleanup(void);
126
msg_thread_exits(struct fsg_common * common)127 static int msg_thread_exits(struct fsg_common *common)
128 {
129 msg_cleanup();
130 return 0;
131 }
132
msg_do_config(struct usb_configuration * c)133 static int msg_do_config(struct usb_configuration *c)
134 {
135 struct fsg_opts *opts;
136 int ret;
137
138 if (gadget_is_otg(c->cdev->gadget)) {
139 c->descriptors = otg_desc;
140 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
141 }
142
143 opts = fsg_opts_from_func_inst(fi_msg);
144
145 f_msg = usb_get_function(fi_msg);
146 if (IS_ERR(f_msg))
147 return PTR_ERR(f_msg);
148
149 ret = usb_add_function(c, f_msg);
150 if (ret)
151 goto put_func;
152
153 return 0;
154
155 put_func:
156 usb_put_function(f_msg);
157 return ret;
158 }
159
160 static struct usb_configuration msg_config_driver = {
161 .label = "Linux File-Backed Storage",
162 .bConfigurationValue = 1,
163 .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
164 };
165
166
167 /****************************** Gadget Bind ******************************/
168
msg_bind(struct usb_composite_dev * cdev)169 static int msg_bind(struct usb_composite_dev *cdev)
170 {
171 static const struct fsg_operations ops = {
172 .thread_exits = msg_thread_exits,
173 };
174 struct fsg_opts *opts;
175 struct fsg_config config;
176 int status;
177
178 fi_msg = usb_get_function_instance("mass_storage");
179 if (IS_ERR(fi_msg))
180 return PTR_ERR(fi_msg);
181
182 fsg_config_from_params(&config, &mod_data, fsg_num_buffers);
183 opts = fsg_opts_from_func_inst(fi_msg);
184
185 opts->no_configfs = true;
186 status = fsg_common_set_num_buffers(opts->common, fsg_num_buffers);
187 if (status)
188 goto fail;
189
190 fsg_common_set_ops(opts->common, &ops);
191
192 status = fsg_common_set_cdev(opts->common, cdev, config.can_stall);
193 if (status)
194 goto fail_set_cdev;
195
196 fsg_common_set_sysfs(opts->common, true);
197 status = fsg_common_create_luns(opts->common, &config);
198 if (status)
199 goto fail_set_cdev;
200
201 fsg_common_set_inquiry_string(opts->common, config.vendor_name,
202 config.product_name);
203
204 status = usb_string_ids_tab(cdev, strings_dev);
205 if (status < 0)
206 goto fail_string_ids;
207 msg_device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
208
209 status = usb_add_config(cdev, &msg_config_driver, msg_do_config);
210 if (status < 0)
211 goto fail_string_ids;
212
213 usb_composite_overwrite_options(cdev, &coverwrite);
214 dev_info(&cdev->gadget->dev,
215 DRIVER_DESC ", version: " DRIVER_VERSION "\n");
216 set_bit(0, &msg_registered);
217 return 0;
218
219 fail_string_ids:
220 fsg_common_remove_luns(opts->common);
221 fail_set_cdev:
222 fsg_common_free_buffers(opts->common);
223 fail:
224 usb_put_function_instance(fi_msg);
225 return status;
226 }
227
msg_unbind(struct usb_composite_dev * cdev)228 static int msg_unbind(struct usb_composite_dev *cdev)
229 {
230 if (!IS_ERR(f_msg))
231 usb_put_function(f_msg);
232
233 if (!IS_ERR(fi_msg))
234 usb_put_function_instance(fi_msg);
235
236 return 0;
237 }
238
239 /****************************** Some noise ******************************/
240
241 static struct usb_composite_driver msg_driver = {
242 .name = "g_mass_storage",
243 .dev = &msg_device_desc,
244 .max_speed = USB_SPEED_SUPER,
245 .needs_serial = 1,
246 .strings = dev_strings,
247 .bind = msg_bind,
248 .unbind = msg_unbind,
249 };
250
251 MODULE_DESCRIPTION(DRIVER_DESC);
252 MODULE_AUTHOR("Michal Nazarewicz");
253 MODULE_LICENSE("GPL");
254
msg_init(void)255 static int __init msg_init(void)
256 {
257 return usb_composite_probe(&msg_driver);
258 }
259 module_init(msg_init);
260
msg_cleanup(void)261 static void msg_cleanup(void)
262 {
263 if (test_and_clear_bit(0, &msg_registered))
264 usb_composite_unregister(&msg_driver);
265 }
266 module_exit(msg_cleanup);
267