Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * usb/gadget/config.c -- simplify building config descriptors | |
3 | * | |
4 | * Copyright (C) 2003 David Brownell | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
1da177e4 LT |
10 | */ |
11 | ||
12 | #include <linux/errno.h> | |
5a0e3ad6 | 13 | #include <linux/slab.h> |
1da177e4 | 14 | #include <linux/kernel.h> |
0ba16dea | 15 | #include <linux/module.h> |
1da177e4 LT |
16 | #include <linux/list.h> |
17 | #include <linux/string.h> | |
18 | #include <linux/device.h> | |
19 | ||
5f848137 | 20 | #include <linux/usb/ch9.h> |
9454a57a | 21 | #include <linux/usb/gadget.h> |
10287bae | 22 | #include <linux/usb/composite.h> |
1da177e4 LT |
23 | |
24 | /** | |
25 | * usb_descriptor_fillbuf - fill buffer with descriptors | |
26 | * @buf: Buffer to be filled | |
27 | * @buflen: Size of buf | |
28 | * @src: Array of descriptor pointers, terminated by null pointer. | |
29 | * | |
30 | * Copies descriptors into the buffer, returning the length or a | |
31 | * negative error code if they can't all be copied. Useful when | |
32 | * assembling descriptors for an associated set of interfaces used | |
33 | * as part of configuring a composite device; or in other cases where | |
34 | * sets of descriptors need to be marshaled. | |
35 | */ | |
36 | int | |
37 | usb_descriptor_fillbuf(void *buf, unsigned buflen, | |
38 | const struct usb_descriptor_header **src) | |
39 | { | |
40 | u8 *dest = buf; | |
41 | ||
42 | if (!src) | |
43 | return -EINVAL; | |
44 | ||
45 | /* fill buffer from src[] until null descriptor ptr */ | |
a9475226 | 46 | for (; NULL != *src; src++) { |
1da177e4 LT |
47 | unsigned len = (*src)->bLength; |
48 | ||
49 | if (len > buflen) | |
50 | return -EINVAL; | |
51 | memcpy(dest, *src, len); | |
52 | buflen -= len; | |
53 | dest += len; | |
54 | } | |
55 | return dest - (u8 *)buf; | |
56 | } | |
0ba16dea | 57 | EXPORT_SYMBOL_GPL(usb_descriptor_fillbuf); |
1da177e4 LT |
58 | |
59 | /** | |
60 | * usb_gadget_config_buf - builts a complete configuration descriptor | |
61 | * @config: Header for the descriptor, including characteristics such | |
62 | * as power requirements and number of interfaces. | |
63 | * @desc: Null-terminated vector of pointers to the descriptors (interface, | |
64 | * endpoint, etc) defining all functions in this device configuration. | |
65 | * @buf: Buffer for the resulting configuration descriptor. | |
66 | * @length: Length of buffer. If this is not big enough to hold the | |
67 | * entire configuration descriptor, an error code will be returned. | |
68 | * | |
69 | * This copies descriptors into the response buffer, building a descriptor | |
70 | * for that configuration. It returns the buffer length or a negative | |
71 | * status code. The config.wTotalLength field is set to match the length | |
72 | * of the result, but other descriptor fields (including power usage and | |
73 | * interface count) must be set by the caller. | |
74 | * | |
75 | * Gadget drivers could use this when constructing a config descriptor | |
76 | * in response to USB_REQ_GET_DESCRIPTOR. They will need to patch the | |
77 | * resulting bDescriptorType value if USB_DT_OTHER_SPEED_CONFIG is needed. | |
78 | */ | |
79 | int usb_gadget_config_buf( | |
80 | const struct usb_config_descriptor *config, | |
81 | void *buf, | |
82 | unsigned length, | |
83 | const struct usb_descriptor_header **desc | |
84 | ) | |
85 | { | |
86 | struct usb_config_descriptor *cp = buf; | |
87 | int len; | |
88 | ||
89 | /* config descriptor first */ | |
90 | if (length < USB_DT_CONFIG_SIZE || !desc) | |
91 | return -EINVAL; | |
a4c39c41 | 92 | *cp = *config; |
1da177e4 LT |
93 | |
94 | /* then interface/endpoint/class/vendor/... */ | |
95 | len = usb_descriptor_fillbuf(USB_DT_CONFIG_SIZE + (u8*)buf, | |
96 | length - USB_DT_CONFIG_SIZE, desc); | |
97 | if (len < 0) | |
98 | return len; | |
99 | len += USB_DT_CONFIG_SIZE; | |
100 | if (len > 0xffff) | |
101 | return -EINVAL; | |
102 | ||
103 | /* patch up the config descriptor */ | |
104 | cp->bLength = USB_DT_CONFIG_SIZE; | |
105 | cp->bDescriptorType = USB_DT_CONFIG; | |
106 | cp->wTotalLength = cpu_to_le16(len); | |
107 | cp->bmAttributes |= USB_CONFIG_ATT_ONE; | |
108 | return len; | |
109 | } | |
0ba16dea | 110 | EXPORT_SYMBOL_GPL(usb_gadget_config_buf); |
1da177e4 | 111 | |
a4c39c41 DB |
112 | /** |
113 | * usb_copy_descriptors - copy a vector of USB descriptors | |
114 | * @src: null-terminated vector to copy | |
115 | * Context: initialization code, which may sleep | |
116 | * | |
117 | * This makes a copy of a vector of USB descriptors. Its primary use | |
118 | * is to support usb_function objects which can have multiple copies, | |
119 | * each needing different descriptors. Functions may have static | |
120 | * tables of descriptors, which are used as templates and customized | |
121 | * with identifiers (for interfaces, strings, endpoints, and more) | |
122 | * as needed by a given function instance. | |
123 | */ | |
28824b18 | 124 | struct usb_descriptor_header ** |
a4c39c41 DB |
125 | usb_copy_descriptors(struct usb_descriptor_header **src) |
126 | { | |
127 | struct usb_descriptor_header **tmp; | |
128 | unsigned bytes; | |
129 | unsigned n_desc; | |
130 | void *mem; | |
131 | struct usb_descriptor_header **ret; | |
132 | ||
133 | /* count descriptors and their sizes; then add vector size */ | |
134 | for (bytes = 0, n_desc = 0, tmp = src; *tmp; tmp++, n_desc++) | |
135 | bytes += (*tmp)->bLength; | |
136 | bytes += (n_desc + 1) * sizeof(*tmp); | |
137 | ||
138 | mem = kmalloc(bytes, GFP_KERNEL); | |
139 | if (!mem) | |
140 | return NULL; | |
141 | ||
142 | /* fill in pointers starting at "tmp", | |
143 | * to descriptors copied starting at "mem"; | |
144 | * and return "ret" | |
145 | */ | |
146 | tmp = mem; | |
147 | ret = mem; | |
148 | mem += (n_desc + 1) * sizeof(*tmp); | |
149 | while (*src) { | |
150 | memcpy(mem, *src, (*src)->bLength); | |
151 | *tmp = mem; | |
152 | tmp++; | |
153 | mem += (*src)->bLength; | |
154 | src++; | |
155 | } | |
156 | *tmp = NULL; | |
157 | ||
158 | return ret; | |
159 | } | |
0ba16dea | 160 | EXPORT_SYMBOL_GPL(usb_copy_descriptors); |
10287bae SAS |
161 | |
162 | int usb_assign_descriptors(struct usb_function *f, | |
163 | struct usb_descriptor_header **fs, | |
164 | struct usb_descriptor_header **hs, | |
165 | struct usb_descriptor_header **ss) | |
166 | { | |
167 | struct usb_gadget *g = f->config->cdev->gadget; | |
168 | ||
169 | if (fs) { | |
170 | f->fs_descriptors = usb_copy_descriptors(fs); | |
171 | if (!f->fs_descriptors) | |
172 | goto err; | |
173 | } | |
174 | if (hs && gadget_is_dualspeed(g)) { | |
175 | f->hs_descriptors = usb_copy_descriptors(hs); | |
176 | if (!f->hs_descriptors) | |
177 | goto err; | |
178 | } | |
179 | if (ss && gadget_is_superspeed(g)) { | |
180 | f->ss_descriptors = usb_copy_descriptors(ss); | |
181 | if (!f->ss_descriptors) | |
182 | goto err; | |
183 | } | |
184 | return 0; | |
185 | err: | |
186 | usb_free_all_descriptors(f); | |
187 | return -ENOMEM; | |
188 | } | |
189 | EXPORT_SYMBOL_GPL(usb_assign_descriptors); | |
190 | ||
191 | void usb_free_all_descriptors(struct usb_function *f) | |
192 | { | |
193 | usb_free_descriptors(f->fs_descriptors); | |
194 | usb_free_descriptors(f->hs_descriptors); | |
195 | usb_free_descriptors(f->ss_descriptors); | |
196 | } | |
197 | EXPORT_SYMBOL_GPL(usb_free_all_descriptors); |