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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
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#include <linux/usb/otg.h>
24
25/**
26 * usb_descriptor_fillbuf - fill buffer with descriptors
27 * @buf: Buffer to be filled
28 * @buflen: Size of buf
29 * @src: Array of descriptor pointers, terminated by null pointer.
30 *
31 * Copies descriptors into the buffer, returning the length or a
32 * negative error code if they can't all be copied. Useful when
33 * assembling descriptors for an associated set of interfaces used
34 * as part of configuring a composite device; or in other cases where
35 * sets of descriptors need to be marshaled.
36 */
37int
38usb_descriptor_fillbuf(void *buf, unsigned buflen,
39 const struct usb_descriptor_header **src)
40{
41 u8 *dest = buf;
42
43 if (!src)
44 return -EINVAL;
45
46 /* fill buffer from src[] until null descriptor ptr */
47 for (; NULL != *src; src++) {
48 unsigned len = (*src)->bLength;
49
50 if (len > buflen)
51 return -EINVAL;
52 memcpy(dest, *src, len);
53 buflen -= len;
54 dest += len;
55 }
56 return dest - (u8 *)buf;
57}
58EXPORT_SYMBOL_GPL(usb_descriptor_fillbuf);
59
60/**
61 * usb_gadget_config_buf - builts a complete configuration descriptor
62 * @config: Header for the descriptor, including characteristics such
63 * as power requirements and number of interfaces.
64 * @desc: Null-terminated vector of pointers to the descriptors (interface,
65 * endpoint, etc) defining all functions in this device configuration.
66 * @buf: Buffer for the resulting configuration descriptor.
67 * @length: Length of buffer. If this is not big enough to hold the
68 * entire configuration descriptor, an error code will be returned.
69 *
70 * This copies descriptors into the response buffer, building a descriptor
71 * for that configuration. It returns the buffer length or a negative
72 * status code. The config.wTotalLength field is set to match the length
73 * of the result, but other descriptor fields (including power usage and
74 * interface count) must be set by the caller.
75 *
76 * Gadget drivers could use this when constructing a config descriptor
77 * in response to USB_REQ_GET_DESCRIPTOR. They will need to patch the
78 * resulting bDescriptorType value if USB_DT_OTHER_SPEED_CONFIG is needed.
79 */
80int usb_gadget_config_buf(
81 const struct usb_config_descriptor *config,
82 void *buf,
83 unsigned length,
84 const struct usb_descriptor_header **desc
85)
86{
87 struct usb_config_descriptor *cp = buf;
88 int len;
89
90 /* config descriptor first */
91 if (length < USB_DT_CONFIG_SIZE || !desc)
92 return -EINVAL;
93 *cp = *config;
94
95 /* then interface/endpoint/class/vendor/... */
96 len = usb_descriptor_fillbuf(USB_DT_CONFIG_SIZE + (u8*)buf,
97 length - USB_DT_CONFIG_SIZE, desc);
98 if (len < 0)
99 return len;
100 len += USB_DT_CONFIG_SIZE;
101 if (len > 0xffff)
102 return -EINVAL;
103
104 /* patch up the config descriptor */
105 cp->bLength = USB_DT_CONFIG_SIZE;
106 cp->bDescriptorType = USB_DT_CONFIG;
107 cp->wTotalLength = cpu_to_le16(len);
108 cp->bmAttributes |= USB_CONFIG_ATT_ONE;
109 return len;
110}
111EXPORT_SYMBOL_GPL(usb_gadget_config_buf);
112
113/**
114 * usb_copy_descriptors - copy a vector of USB descriptors
115 * @src: null-terminated vector to copy
116 * Context: initialization code, which may sleep
117 *
118 * This makes a copy of a vector of USB descriptors. Its primary use
119 * is to support usb_function objects which can have multiple copies,
120 * each needing different descriptors. Functions may have static
121 * tables of descriptors, which are used as templates and customized
122 * with identifiers (for interfaces, strings, endpoints, and more)
123 * as needed by a given function instance.
124 */
125struct usb_descriptor_header **
126usb_copy_descriptors(struct usb_descriptor_header **src)
127{
128 struct usb_descriptor_header **tmp;
129 unsigned bytes;
130 unsigned n_desc;
131 void *mem;
132 struct usb_descriptor_header **ret;
133
134 /* count descriptors and their sizes; then add vector size */
135 for (bytes = 0, n_desc = 0, tmp = src; *tmp; tmp++, n_desc++)
136 bytes += (*tmp)->bLength;
137 bytes += (n_desc + 1) * sizeof(*tmp);
138
139 mem = kmalloc(bytes, GFP_KERNEL);
140 if (!mem)
141 return NULL;
142
143 /* fill in pointers starting at "tmp",
144 * to descriptors copied starting at "mem";
145 * and return "ret"
146 */
147 tmp = mem;
148 ret = mem;
149 mem += (n_desc + 1) * sizeof(*tmp);
150 while (*src) {
151 memcpy(mem, *src, (*src)->bLength);
152 *tmp = mem;
153 tmp++;
154 mem += (*src)->bLength;
155 src++;
156 }
157 *tmp = NULL;
158
159 return ret;
160}
161EXPORT_SYMBOL_GPL(usb_copy_descriptors);
162
163int usb_assign_descriptors(struct usb_function *f,
164 struct usb_descriptor_header **fs,
165 struct usb_descriptor_header **hs,
166 struct usb_descriptor_header **ss,
167 struct usb_descriptor_header **ssp)
168{
169 struct usb_gadget *g = f->config->cdev->gadget;
170
171 if (fs) {
172 f->fs_descriptors = usb_copy_descriptors(fs);
173 if (!f->fs_descriptors)
174 goto err;
175 }
176 if (hs && gadget_is_dualspeed(g)) {
177 f->hs_descriptors = usb_copy_descriptors(hs);
178 if (!f->hs_descriptors)
179 goto err;
180 }
181 if (ss && gadget_is_superspeed(g)) {
182 f->ss_descriptors = usb_copy_descriptors(ss);
183 if (!f->ss_descriptors)
184 goto err;
185 }
186 if (ssp && gadget_is_superspeed_plus(g)) {
187 f->ssp_descriptors = usb_copy_descriptors(ssp);
188 if (!f->ssp_descriptors)
189 goto err;
190 }
191 return 0;
192err:
193 usb_free_all_descriptors(f);
194 return -ENOMEM;
195}
196EXPORT_SYMBOL_GPL(usb_assign_descriptors);
197
198void usb_free_all_descriptors(struct usb_function *f)
199{
200 usb_free_descriptors(f->fs_descriptors);
201 usb_free_descriptors(f->hs_descriptors);
202 usb_free_descriptors(f->ss_descriptors);
203 usb_free_descriptors(f->ssp_descriptors);
204}
205EXPORT_SYMBOL_GPL(usb_free_all_descriptors);
206
207struct usb_descriptor_header *usb_otg_descriptor_alloc(
208 struct usb_gadget *gadget)
209{
210 struct usb_descriptor_header *otg_desc;
211 unsigned length = 0;
212
213 if (gadget->otg_caps && (gadget->otg_caps->otg_rev >= 0x0200))
214 length = sizeof(struct usb_otg20_descriptor);
215 else
216 length = sizeof(struct usb_otg_descriptor);
217
218 otg_desc = kzalloc(length, GFP_KERNEL);
219 return otg_desc;
220}
221EXPORT_SYMBOL_GPL(usb_otg_descriptor_alloc);
222
223int usb_otg_descriptor_init(struct usb_gadget *gadget,
224 struct usb_descriptor_header *otg_desc)
225{
226 struct usb_otg_descriptor *otg1x_desc;
227 struct usb_otg20_descriptor *otg20_desc;
228 struct usb_otg_caps *otg_caps = gadget->otg_caps;
229 u8 otg_attributes = 0;
230
231 if (!otg_desc)
232 return -EINVAL;
233
234 if (otg_caps && otg_caps->otg_rev) {
235 if (otg_caps->hnp_support)
236 otg_attributes |= USB_OTG_HNP;
237 if (otg_caps->srp_support)
238 otg_attributes |= USB_OTG_SRP;
239 if (otg_caps->adp_support && (otg_caps->otg_rev >= 0x0200))
240 otg_attributes |= USB_OTG_ADP;
241 } else {
242 otg_attributes = USB_OTG_SRP | USB_OTG_HNP;
243 }
244
245 if (otg_caps && (otg_caps->otg_rev >= 0x0200)) {
246 otg20_desc = (struct usb_otg20_descriptor *)otg_desc;
247 otg20_desc->bLength = sizeof(struct usb_otg20_descriptor);
248 otg20_desc->bDescriptorType = USB_DT_OTG;
249 otg20_desc->bmAttributes = otg_attributes;
250 otg20_desc->bcdOTG = cpu_to_le16(otg_caps->otg_rev);
251 } else {
252 otg1x_desc = (struct usb_otg_descriptor *)otg_desc;
253 otg1x_desc->bLength = sizeof(struct usb_otg_descriptor);
254 otg1x_desc->bDescriptorType = USB_DT_OTG;
255 otg1x_desc->bmAttributes = otg_attributes;
256 }
257
258 return 0;
259}
260EXPORT_SYMBOL_GPL(usb_otg_descriptor_init);
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 struct usb_gadget *g = f->config->cdev->gadget;
166
167 /* super-speed-plus descriptor falls back to super-speed one,
168 * if such a descriptor was provided, thus avoiding a NULL
169 * pointer dereference if a 5gbps capable gadget is used with
170 * a 10gbps capable config (device port + cable + host port)
171 */
172 if (!ssp)
173 ssp = ss;
174
175 if (fs) {
176 f->fs_descriptors = usb_copy_descriptors(fs);
177 if (!f->fs_descriptors)
178 goto err;
179 }
180 if (hs && gadget_is_dualspeed(g)) {
181 f->hs_descriptors = usb_copy_descriptors(hs);
182 if (!f->hs_descriptors)
183 goto err;
184 }
185 if (ss && gadget_is_superspeed(g)) {
186 f->ss_descriptors = usb_copy_descriptors(ss);
187 if (!f->ss_descriptors)
188 goto err;
189 }
190 if (ssp && gadget_is_superspeed_plus(g)) {
191 f->ssp_descriptors = usb_copy_descriptors(ssp);
192 if (!f->ssp_descriptors)
193 goto err;
194 }
195 return 0;
196err:
197 usb_free_all_descriptors(f);
198 return -ENOMEM;
199}
200EXPORT_SYMBOL_GPL(usb_assign_descriptors);
201
202void usb_free_all_descriptors(struct usb_function *f)
203{
204 usb_free_descriptors(f->fs_descriptors);
205 f->fs_descriptors = NULL;
206 usb_free_descriptors(f->hs_descriptors);
207 f->hs_descriptors = NULL;
208 usb_free_descriptors(f->ss_descriptors);
209 f->ss_descriptors = NULL;
210 usb_free_descriptors(f->ssp_descriptors);
211 f->ssp_descriptors = NULL;
212}
213EXPORT_SYMBOL_GPL(usb_free_all_descriptors);
214
215struct usb_descriptor_header *usb_otg_descriptor_alloc(
216 struct usb_gadget *gadget)
217{
218 struct usb_descriptor_header *otg_desc;
219 unsigned length = 0;
220
221 if (gadget->otg_caps && (gadget->otg_caps->otg_rev >= 0x0200))
222 length = sizeof(struct usb_otg20_descriptor);
223 else
224 length = sizeof(struct usb_otg_descriptor);
225
226 otg_desc = kzalloc(length, GFP_KERNEL);
227 return otg_desc;
228}
229EXPORT_SYMBOL_GPL(usb_otg_descriptor_alloc);
230
231int usb_otg_descriptor_init(struct usb_gadget *gadget,
232 struct usb_descriptor_header *otg_desc)
233{
234 struct usb_otg_descriptor *otg1x_desc;
235 struct usb_otg20_descriptor *otg20_desc;
236 struct usb_otg_caps *otg_caps = gadget->otg_caps;
237 u8 otg_attributes = 0;
238
239 if (!otg_desc)
240 return -EINVAL;
241
242 if (otg_caps && otg_caps->otg_rev) {
243 if (otg_caps->hnp_support)
244 otg_attributes |= USB_OTG_HNP;
245 if (otg_caps->srp_support)
246 otg_attributes |= USB_OTG_SRP;
247 if (otg_caps->adp_support && (otg_caps->otg_rev >= 0x0200))
248 otg_attributes |= USB_OTG_ADP;
249 } else {
250 otg_attributes = USB_OTG_SRP | USB_OTG_HNP;
251 }
252
253 if (otg_caps && (otg_caps->otg_rev >= 0x0200)) {
254 otg20_desc = (struct usb_otg20_descriptor *)otg_desc;
255 otg20_desc->bLength = sizeof(struct usb_otg20_descriptor);
256 otg20_desc->bDescriptorType = USB_DT_OTG;
257 otg20_desc->bmAttributes = otg_attributes;
258 otg20_desc->bcdOTG = cpu_to_le16(otg_caps->otg_rev);
259 } else {
260 otg1x_desc = (struct usb_otg_descriptor *)otg_desc;
261 otg1x_desc->bLength = sizeof(struct usb_otg_descriptor);
262 otg1x_desc->bDescriptorType = USB_DT_OTG;
263 otg1x_desc->bmAttributes = otg_attributes;
264 }
265
266 return 0;
267}
268EXPORT_SYMBOL_GPL(usb_otg_descriptor_init);