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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// SPDX-License-Identifier: GPL-2.0+
2/*
3 * usb/gadget/config.c -- simplify building config descriptors
4 *
5 * Copyright (C) 2003 David Brownell
6 */
7
8#include <linux/errno.h>
9#include <linux/slab.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/list.h>
13#include <linux/string.h>
14#include <linux/device.h>
15
16#include <linux/usb/ch9.h>
17#include <linux/usb/gadget.h>
18#include <linux/usb/composite.h>
19#include <linux/usb/otg.h>
20
21/**
22 * usb_descriptor_fillbuf - fill buffer with descriptors
23 * @buf: Buffer to be filled
24 * @buflen: Size of buf
25 * @src: Array of descriptor pointers, terminated by null pointer.
26 *
27 * Copies descriptors into the buffer, returning the length or a
28 * negative error code if they can't all be copied. Useful when
29 * assembling descriptors for an associated set of interfaces used
30 * as part of configuring a composite device; or in other cases where
31 * sets of descriptors need to be marshaled.
32 */
33int
34usb_descriptor_fillbuf(void *buf, unsigned buflen,
35 const struct usb_descriptor_header **src)
36{
37 u8 *dest = buf;
38
39 if (!src)
40 return -EINVAL;
41
42 /* fill buffer from src[] until null descriptor ptr */
43 for (; NULL != *src; src++) {
44 unsigned len = (*src)->bLength;
45
46 if (len > buflen)
47 return -EINVAL;
48 memcpy(dest, *src, len);
49 buflen -= len;
50 dest += len;
51 }
52 return dest - (u8 *)buf;
53}
54EXPORT_SYMBOL_GPL(usb_descriptor_fillbuf);
55
56/**
57 * usb_gadget_config_buf - builts a complete configuration descriptor
58 * @config: Header for the descriptor, including characteristics such
59 * as power requirements and number of interfaces.
60 * @desc: Null-terminated vector of pointers to the descriptors (interface,
61 * endpoint, etc) defining all functions in this device configuration.
62 * @buf: Buffer for the resulting configuration descriptor.
63 * @length: Length of buffer. If this is not big enough to hold the
64 * entire configuration descriptor, an error code will be returned.
65 *
66 * This copies descriptors into the response buffer, building a descriptor
67 * for that configuration. It returns the buffer length or a negative
68 * status code. The config.wTotalLength field is set to match the length
69 * of the result, but other descriptor fields (including power usage and
70 * interface count) must be set by the caller.
71 *
72 * Gadget drivers could use this when constructing a config descriptor
73 * in response to USB_REQ_GET_DESCRIPTOR. They will need to patch the
74 * resulting bDescriptorType value if USB_DT_OTHER_SPEED_CONFIG is needed.
75 */
76int usb_gadget_config_buf(
77 const struct usb_config_descriptor *config,
78 void *buf,
79 unsigned length,
80 const struct usb_descriptor_header **desc
81)
82{
83 struct usb_config_descriptor *cp = buf;
84 int len;
85
86 /* config descriptor first */
87 if (length < USB_DT_CONFIG_SIZE || !desc)
88 return -EINVAL;
89 *cp = *config;
90
91 /* then interface/endpoint/class/vendor/... */
92 len = usb_descriptor_fillbuf(USB_DT_CONFIG_SIZE + (u8 *)buf,
93 length - USB_DT_CONFIG_SIZE, desc);
94 if (len < 0)
95 return len;
96 len += USB_DT_CONFIG_SIZE;
97 if (len > 0xffff)
98 return -EINVAL;
99
100 /* patch up the config descriptor */
101 cp->bLength = USB_DT_CONFIG_SIZE;
102 cp->bDescriptorType = USB_DT_CONFIG;
103 cp->wTotalLength = cpu_to_le16(len);
104 cp->bmAttributes |= USB_CONFIG_ATT_ONE;
105 return len;
106}
107EXPORT_SYMBOL_GPL(usb_gadget_config_buf);
108
109/**
110 * usb_copy_descriptors - copy a vector of USB descriptors
111 * @src: null-terminated vector to copy
112 * Context: initialization code, which may sleep
113 *
114 * This makes a copy of a vector of USB descriptors. Its primary use
115 * is to support usb_function objects which can have multiple copies,
116 * each needing different descriptors. Functions may have static
117 * tables of descriptors, which are used as templates and customized
118 * with identifiers (for interfaces, strings, endpoints, and more)
119 * as needed by a given function instance.
120 */
121struct usb_descriptor_header **
122usb_copy_descriptors(struct usb_descriptor_header **src)
123{
124 struct usb_descriptor_header **tmp;
125 unsigned bytes;
126 unsigned n_desc;
127 void *mem;
128 struct usb_descriptor_header **ret;
129
130 /* count descriptors and their sizes; then add vector size */
131 for (bytes = 0, n_desc = 0, tmp = src; *tmp; tmp++, n_desc++)
132 bytes += (*tmp)->bLength;
133 bytes += (n_desc + 1) * sizeof(*tmp);
134
135 mem = kmalloc(bytes, GFP_KERNEL);
136 if (!mem)
137 return NULL;
138
139 /* fill in pointers starting at "tmp",
140 * to descriptors copied starting at "mem";
141 * and return "ret"
142 */
143 tmp = mem;
144 ret = mem;
145 mem += (n_desc + 1) * sizeof(*tmp);
146 while (*src) {
147 memcpy(mem, *src, (*src)->bLength);
148 *tmp = mem;
149 tmp++;
150 mem += (*src)->bLength;
151 src++;
152 }
153 *tmp = NULL;
154
155 return ret;
156}
157EXPORT_SYMBOL_GPL(usb_copy_descriptors);
158
159int usb_assign_descriptors(struct usb_function *f,
160 struct usb_descriptor_header **fs,
161 struct usb_descriptor_header **hs,
162 struct usb_descriptor_header **ss,
163 struct usb_descriptor_header **ssp)
164{
165 /* super-speed-plus descriptor falls back to super-speed one,
166 * if such a descriptor was provided, thus avoiding a NULL
167 * pointer dereference if a 5gbps capable gadget is used with
168 * a 10gbps capable config (device port + cable + host port)
169 */
170 if (!ssp)
171 ssp = ss;
172
173 if (fs) {
174 f->fs_descriptors = usb_copy_descriptors(fs);
175 if (!f->fs_descriptors)
176 goto err;
177 }
178 if (hs) {
179 f->hs_descriptors = usb_copy_descriptors(hs);
180 if (!f->hs_descriptors)
181 goto err;
182 }
183 if (ss) {
184 f->ss_descriptors = usb_copy_descriptors(ss);
185 if (!f->ss_descriptors)
186 goto err;
187 }
188 if (ssp) {
189 f->ssp_descriptors = usb_copy_descriptors(ssp);
190 if (!f->ssp_descriptors)
191 goto err;
192 }
193 return 0;
194err:
195 usb_free_all_descriptors(f);
196 return -ENOMEM;
197}
198EXPORT_SYMBOL_GPL(usb_assign_descriptors);
199
200void usb_free_all_descriptors(struct usb_function *f)
201{
202 usb_free_descriptors(f->fs_descriptors);
203 f->fs_descriptors = NULL;
204 usb_free_descriptors(f->hs_descriptors);
205 f->hs_descriptors = NULL;
206 usb_free_descriptors(f->ss_descriptors);
207 f->ss_descriptors = NULL;
208 usb_free_descriptors(f->ssp_descriptors);
209 f->ssp_descriptors = NULL;
210}
211EXPORT_SYMBOL_GPL(usb_free_all_descriptors);
212
213struct usb_descriptor_header *usb_otg_descriptor_alloc(
214 struct usb_gadget *gadget)
215{
216 struct usb_descriptor_header *otg_desc;
217 unsigned length = 0;
218
219 if (gadget->otg_caps && (gadget->otg_caps->otg_rev >= 0x0200))
220 length = sizeof(struct usb_otg20_descriptor);
221 else
222 length = sizeof(struct usb_otg_descriptor);
223
224 otg_desc = kzalloc(length, GFP_KERNEL);
225 return otg_desc;
226}
227EXPORT_SYMBOL_GPL(usb_otg_descriptor_alloc);
228
229int usb_otg_descriptor_init(struct usb_gadget *gadget,
230 struct usb_descriptor_header *otg_desc)
231{
232 struct usb_otg_descriptor *otg1x_desc;
233 struct usb_otg20_descriptor *otg20_desc;
234 struct usb_otg_caps *otg_caps = gadget->otg_caps;
235 u8 otg_attributes = 0;
236
237 if (!otg_desc)
238 return -EINVAL;
239
240 if (otg_caps && otg_caps->otg_rev) {
241 if (otg_caps->hnp_support)
242 otg_attributes |= USB_OTG_HNP;
243 if (otg_caps->srp_support)
244 otg_attributes |= USB_OTG_SRP;
245 if (otg_caps->adp_support && (otg_caps->otg_rev >= 0x0200))
246 otg_attributes |= USB_OTG_ADP;
247 } else {
248 otg_attributes = USB_OTG_SRP | USB_OTG_HNP;
249 }
250
251 if (otg_caps && (otg_caps->otg_rev >= 0x0200)) {
252 otg20_desc = (struct usb_otg20_descriptor *)otg_desc;
253 otg20_desc->bLength = sizeof(struct usb_otg20_descriptor);
254 otg20_desc->bDescriptorType = USB_DT_OTG;
255 otg20_desc->bmAttributes = otg_attributes;
256 otg20_desc->bcdOTG = cpu_to_le16(otg_caps->otg_rev);
257 } else {
258 otg1x_desc = (struct usb_otg_descriptor *)otg_desc;
259 otg1x_desc->bLength = sizeof(struct usb_otg_descriptor);
260 otg1x_desc->bDescriptorType = USB_DT_OTG;
261 otg1x_desc->bmAttributes = otg_attributes;
262 }
263
264 return 0;
265}
266EXPORT_SYMBOL_GPL(usb_otg_descriptor_init);