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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.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21#include <linux/errno.h>
22#include <linux/slab.h>
23#include <linux/kernel.h>
24#include <linux/list.h>
25#include <linux/string.h>
26#include <linux/device.h>
27
28#include <linux/usb/ch9.h>
29#include <linux/usb/gadget.h>
30
31
32/**
33 * usb_descriptor_fillbuf - fill buffer with descriptors
34 * @buf: Buffer to be filled
35 * @buflen: Size of buf
36 * @src: Array of descriptor pointers, terminated by null pointer.
37 *
38 * Copies descriptors into the buffer, returning the length or a
39 * negative error code if they can't all be copied. Useful when
40 * assembling descriptors for an associated set of interfaces used
41 * as part of configuring a composite device; or in other cases where
42 * sets of descriptors need to be marshaled.
43 */
44int
45usb_descriptor_fillbuf(void *buf, unsigned buflen,
46 const struct usb_descriptor_header **src)
47{
48 u8 *dest = buf;
49
50 if (!src)
51 return -EINVAL;
52
53 /* fill buffer from src[] until null descriptor ptr */
54 for (; NULL != *src; src++) {
55 unsigned len = (*src)->bLength;
56
57 if (len > buflen)
58 return -EINVAL;
59 memcpy(dest, *src, len);
60 buflen -= len;
61 dest += len;
62 }
63 return dest - (u8 *)buf;
64}
65
66
67/**
68 * usb_gadget_config_buf - builts a complete configuration descriptor
69 * @config: Header for the descriptor, including characteristics such
70 * as power requirements and number of interfaces.
71 * @desc: Null-terminated vector of pointers to the descriptors (interface,
72 * endpoint, etc) defining all functions in this device configuration.
73 * @buf: Buffer for the resulting configuration descriptor.
74 * @length: Length of buffer. If this is not big enough to hold the
75 * entire configuration descriptor, an error code will be returned.
76 *
77 * This copies descriptors into the response buffer, building a descriptor
78 * for that configuration. It returns the buffer length or a negative
79 * status code. The config.wTotalLength field is set to match the length
80 * of the result, but other descriptor fields (including power usage and
81 * interface count) must be set by the caller.
82 *
83 * Gadget drivers could use this when constructing a config descriptor
84 * in response to USB_REQ_GET_DESCRIPTOR. They will need to patch the
85 * resulting bDescriptorType value if USB_DT_OTHER_SPEED_CONFIG is needed.
86 */
87int usb_gadget_config_buf(
88 const struct usb_config_descriptor *config,
89 void *buf,
90 unsigned length,
91 const struct usb_descriptor_header **desc
92)
93{
94 struct usb_config_descriptor *cp = buf;
95 int len;
96
97 /* config descriptor first */
98 if (length < USB_DT_CONFIG_SIZE || !desc)
99 return -EINVAL;
100 *cp = *config;
101
102 /* then interface/endpoint/class/vendor/... */
103 len = usb_descriptor_fillbuf(USB_DT_CONFIG_SIZE + (u8*)buf,
104 length - USB_DT_CONFIG_SIZE, desc);
105 if (len < 0)
106 return len;
107 len += USB_DT_CONFIG_SIZE;
108 if (len > 0xffff)
109 return -EINVAL;
110
111 /* patch up the config descriptor */
112 cp->bLength = USB_DT_CONFIG_SIZE;
113 cp->bDescriptorType = USB_DT_CONFIG;
114 cp->wTotalLength = cpu_to_le16(len);
115 cp->bmAttributes |= USB_CONFIG_ATT_ONE;
116 return len;
117}
118
119/**
120 * usb_copy_descriptors - copy a vector of USB descriptors
121 * @src: null-terminated vector to copy
122 * Context: initialization code, which may sleep
123 *
124 * This makes a copy of a vector of USB descriptors. Its primary use
125 * is to support usb_function objects which can have multiple copies,
126 * each needing different descriptors. Functions may have static
127 * tables of descriptors, which are used as templates and customized
128 * with identifiers (for interfaces, strings, endpoints, and more)
129 * as needed by a given function instance.
130 */
131struct usb_descriptor_header **
132usb_copy_descriptors(struct usb_descriptor_header **src)
133{
134 struct usb_descriptor_header **tmp;
135 unsigned bytes;
136 unsigned n_desc;
137 void *mem;
138 struct usb_descriptor_header **ret;
139
140 /* count descriptors and their sizes; then add vector size */
141 for (bytes = 0, n_desc = 0, tmp = src; *tmp; tmp++, n_desc++)
142 bytes += (*tmp)->bLength;
143 bytes += (n_desc + 1) * sizeof(*tmp);
144
145 mem = kmalloc(bytes, GFP_KERNEL);
146 if (!mem)
147 return NULL;
148
149 /* fill in pointers starting at "tmp",
150 * to descriptors copied starting at "mem";
151 * and return "ret"
152 */
153 tmp = mem;
154 ret = mem;
155 mem += (n_desc + 1) * sizeof(*tmp);
156 while (*src) {
157 memcpy(mem, *src, (*src)->bLength);
158 *tmp = mem;
159 tmp++;
160 mem += (*src)->bLength;
161 src++;
162 }
163 *tmp = NULL;
164
165 return ret;
166}
167
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.
10 */
11
12#include <linux/errno.h>
13#include <linux/slab.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/list.h>
17#include <linux/string.h>
18#include <linux/device.h>
19
20#include <linux/usb/ch9.h>
21#include <linux/usb/gadget.h>
22#include <linux/usb/composite.h>
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 */
36int
37usb_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 */
46 for (; NULL != *src; src++) {
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}
57EXPORT_SYMBOL_GPL(usb_descriptor_fillbuf);
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 */
79int 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;
92 *cp = *config;
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}
110EXPORT_SYMBOL_GPL(usb_gadget_config_buf);
111
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 */
124struct usb_descriptor_header **
125usb_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}
160EXPORT_SYMBOL_GPL(usb_copy_descriptors);
161
162int 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;
185err:
186 usb_free_all_descriptors(f);
187 return -ENOMEM;
188}
189EXPORT_SYMBOL_GPL(usb_assign_descriptors);
190
191void 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}
197EXPORT_SYMBOL_GPL(usb_free_all_descriptors);