1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * mass_storage.c -- Mass Storage USB Gadget |
4 | * |
5 | * Copyright (C) 2003-2008 Alan Stern |
6 | * Copyright (C) 2009 Samsung Electronics |
7 | * Author: Michal Nazarewicz <mina86@mina86.com> |
8 | * All rights reserved. |
9 | */ |
10 | |
11 | |
12 | /* |
13 | * The Mass Storage Gadget acts as a USB Mass Storage device, |
14 | * appearing to the host as a disk drive or as a CD-ROM drive. In |
15 | * addition to providing an example of a genuinely useful gadget |
16 | * driver for a USB device, it also illustrates a technique of |
17 | * double-buffering for increased throughput. Last but not least, it |
18 | * gives an easy way to probe the behavior of the Mass Storage drivers |
19 | * in a USB host. |
20 | * |
21 | * Since this file serves only administrative purposes and all the |
22 | * business logic is implemented in f_mass_storage.* file. Read |
23 | * comments in this file for more detailed description. |
24 | */ |
25 | |
26 | |
27 | #include <linux/kernel.h> |
28 | #include <linux/usb/ch9.h> |
29 | #include <linux/module.h> |
30 | |
31 | /*-------------------------------------------------------------------------*/ |
32 | |
33 | #define DRIVER_DESC "Mass Storage Gadget" |
34 | #define DRIVER_VERSION "2009/09/11" |
35 | |
36 | /* |
37 | * Thanks to NetChip Technologies for donating this product ID. |
38 | * |
39 | * DO NOT REUSE THESE IDs with any other driver!! Ever!! |
40 | * Instead: allocate your own, using normal USB-IF procedures. |
41 | */ |
42 | #define FSG_VENDOR_ID 0x0525 /* NetChip */ |
43 | #define FSG_PRODUCT_ID 0xa4a5 /* Linux-USB File-backed Storage Gadget */ |
44 | |
45 | #include "f_mass_storage.h" |
46 | |
47 | /*-------------------------------------------------------------------------*/ |
48 | USB_GADGET_COMPOSITE_OPTIONS(); |
49 | |
50 | static struct usb_device_descriptor msg_device_desc = { |
51 | .bLength = sizeof msg_device_desc, |
52 | .bDescriptorType = USB_DT_DEVICE, |
53 | |
54 | /* .bcdUSB = DYNAMIC */ |
55 | .bDeviceClass = USB_CLASS_PER_INTERFACE, |
56 | |
57 | /* Vendor and product id can be overridden by module parameters. */ |
58 | .idVendor = cpu_to_le16(FSG_VENDOR_ID), |
59 | .idProduct = cpu_to_le16(FSG_PRODUCT_ID), |
60 | .bNumConfigurations = 1, |
61 | }; |
62 | |
63 | static const struct usb_descriptor_header *otg_desc[2]; |
64 | |
65 | static struct usb_string strings_dev[] = { |
66 | [USB_GADGET_MANUFACTURER_IDX].s = "" , |
67 | [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC, |
68 | [USB_GADGET_SERIAL_IDX].s = "" , |
69 | { } /* end of list */ |
70 | }; |
71 | |
72 | static struct usb_gadget_strings stringtab_dev = { |
73 | .language = 0x0409, /* en-us */ |
74 | .strings = strings_dev, |
75 | }; |
76 | |
77 | static struct usb_gadget_strings *dev_strings[] = { |
78 | &stringtab_dev, |
79 | NULL, |
80 | }; |
81 | |
82 | static struct usb_function_instance *fi_msg; |
83 | static struct usb_function *f_msg; |
84 | |
85 | /****************************** Configurations ******************************/ |
86 | |
87 | static struct fsg_module_parameters mod_data = { |
88 | .stall = 1 |
89 | }; |
90 | #ifdef CONFIG_USB_GADGET_DEBUG_FILES |
91 | |
92 | static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS; |
93 | |
94 | #else |
95 | |
96 | /* |
97 | * Number of buffers we will use. |
98 | * 2 is usually enough for good buffering pipeline |
99 | */ |
100 | #define fsg_num_buffers CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS |
101 | |
102 | #endif /* CONFIG_USB_GADGET_DEBUG_FILES */ |
103 | |
104 | FSG_MODULE_PARAMETERS(/* no prefix */, mod_data); |
105 | |
106 | static int msg_do_config(struct usb_configuration *c) |
107 | { |
108 | int ret; |
109 | |
110 | if (gadget_is_otg(g: c->cdev->gadget)) { |
111 | c->descriptors = otg_desc; |
112 | c->bmAttributes |= USB_CONFIG_ATT_WAKEUP; |
113 | } |
114 | |
115 | f_msg = usb_get_function(fi: fi_msg); |
116 | if (IS_ERR(ptr: f_msg)) |
117 | return PTR_ERR(ptr: f_msg); |
118 | |
119 | ret = usb_add_function(c, f_msg); |
120 | if (ret) |
121 | goto put_func; |
122 | |
123 | return 0; |
124 | |
125 | put_func: |
126 | usb_put_function(f: f_msg); |
127 | return ret; |
128 | } |
129 | |
130 | static struct usb_configuration msg_config_driver = { |
131 | .label = "Linux File-Backed Storage" , |
132 | .bConfigurationValue = 1, |
133 | .bmAttributes = USB_CONFIG_ATT_SELFPOWER, |
134 | }; |
135 | |
136 | |
137 | /****************************** Gadget Bind ******************************/ |
138 | |
139 | static int msg_bind(struct usb_composite_dev *cdev) |
140 | { |
141 | struct fsg_opts *opts; |
142 | struct fsg_config config; |
143 | int status; |
144 | |
145 | fi_msg = usb_get_function_instance(name: "mass_storage" ); |
146 | if (IS_ERR(ptr: fi_msg)) |
147 | return PTR_ERR(ptr: fi_msg); |
148 | |
149 | fsg_config_from_params(cfg: &config, params: &mod_data, fsg_num_buffers); |
150 | opts = fsg_opts_from_func_inst(fi: fi_msg); |
151 | |
152 | opts->no_configfs = true; |
153 | status = fsg_common_set_num_buffers(common: opts->common, n: fsg_num_buffers); |
154 | if (status) |
155 | goto fail; |
156 | |
157 | status = fsg_common_set_cdev(common: opts->common, cdev, can_stall: config.can_stall); |
158 | if (status) |
159 | goto fail_set_cdev; |
160 | |
161 | fsg_common_set_sysfs(common: opts->common, sysfs: true); |
162 | status = fsg_common_create_luns(common: opts->common, cfg: &config); |
163 | if (status) |
164 | goto fail_set_cdev; |
165 | |
166 | fsg_common_set_inquiry_string(common: opts->common, vn: config.vendor_name, |
167 | pn: config.product_name); |
168 | |
169 | status = usb_string_ids_tab(c: cdev, str: strings_dev); |
170 | if (status < 0) |
171 | goto fail_string_ids; |
172 | msg_device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id; |
173 | |
174 | if (gadget_is_otg(g: cdev->gadget) && !otg_desc[0]) { |
175 | struct usb_descriptor_header *usb_desc; |
176 | |
177 | usb_desc = usb_otg_descriptor_alloc(gadget: cdev->gadget); |
178 | if (!usb_desc) { |
179 | status = -ENOMEM; |
180 | goto fail_string_ids; |
181 | } |
182 | usb_otg_descriptor_init(gadget: cdev->gadget, otg_desc: usb_desc); |
183 | otg_desc[0] = usb_desc; |
184 | otg_desc[1] = NULL; |
185 | } |
186 | |
187 | status = usb_add_config(cdev, &msg_config_driver, msg_do_config); |
188 | if (status < 0) |
189 | goto fail_otg_desc; |
190 | |
191 | usb_composite_overwrite_options(cdev, covr: &coverwrite); |
192 | dev_info(&cdev->gadget->dev, |
193 | DRIVER_DESC ", version: " DRIVER_VERSION "\n" ); |
194 | return 0; |
195 | |
196 | fail_otg_desc: |
197 | kfree(objp: otg_desc[0]); |
198 | otg_desc[0] = NULL; |
199 | fail_string_ids: |
200 | fsg_common_remove_luns(common: opts->common); |
201 | fail_set_cdev: |
202 | fsg_common_free_buffers(common: opts->common); |
203 | fail: |
204 | usb_put_function_instance(fi: fi_msg); |
205 | return status; |
206 | } |
207 | |
208 | static int msg_unbind(struct usb_composite_dev *cdev) |
209 | { |
210 | if (!IS_ERR(ptr: f_msg)) |
211 | usb_put_function(f: f_msg); |
212 | |
213 | if (!IS_ERR(ptr: fi_msg)) |
214 | usb_put_function_instance(fi: fi_msg); |
215 | |
216 | kfree(objp: otg_desc[0]); |
217 | otg_desc[0] = NULL; |
218 | |
219 | return 0; |
220 | } |
221 | |
222 | /****************************** Some noise ******************************/ |
223 | |
224 | static struct usb_composite_driver msg_driver = { |
225 | .name = "g_mass_storage" , |
226 | .dev = &msg_device_desc, |
227 | .max_speed = USB_SPEED_SUPER_PLUS, |
228 | .needs_serial = 1, |
229 | .strings = dev_strings, |
230 | .bind = msg_bind, |
231 | .unbind = msg_unbind, |
232 | }; |
233 | |
234 | module_usb_composite_driver(msg_driver); |
235 | |
236 | MODULE_DESCRIPTION(DRIVER_DESC); |
237 | MODULE_AUTHOR("Michal Nazarewicz" ); |
238 | MODULE_LICENSE("GPL" ); |
239 | |