2 * usb/gadget/config.c -- simplify building config descriptors
4 * Copyright (C) 2003 David Brownell
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.
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>
20 #include <linux/usb/ch9.h>
21 #include <linux/usb/gadget.h>
22 #include <linux/usb/composite.h>
23 #include <linux/usb/otg.h>
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.
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.
38 usb_descriptor_fillbuf(void *buf, unsigned buflen,
39 const struct usb_descriptor_header **src)
46 /* fill buffer from src[] until null descriptor ptr */
47 for (; NULL != *src; src++) {
48 unsigned len = (*src)->bLength;
52 memcpy(dest, *src, len);
56 return dest - (u8 *)buf;
58 EXPORT_SYMBOL_GPL(usb_descriptor_fillbuf);
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.
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.
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.
80 int usb_gadget_config_buf(
81 const struct usb_config_descriptor *config,
84 const struct usb_descriptor_header **desc
87 struct usb_config_descriptor *cp = buf;
90 /* config descriptor first */
91 if (length < USB_DT_CONFIG_SIZE || !desc)
95 /* then interface/endpoint/class/vendor/... */
96 len = usb_descriptor_fillbuf(USB_DT_CONFIG_SIZE + (u8 *)buf,
97 length - USB_DT_CONFIG_SIZE, desc);
100 len += USB_DT_CONFIG_SIZE;
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;
111 EXPORT_SYMBOL_GPL(usb_gadget_config_buf);
114 * usb_copy_descriptors - copy a vector of USB descriptors
115 * @src: null-terminated vector to copy
116 * Context: initialization code, which may sleep
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.
125 struct usb_descriptor_header **
126 usb_copy_descriptors(struct usb_descriptor_header **src)
128 struct usb_descriptor_header **tmp;
132 struct usb_descriptor_header **ret;
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);
139 mem = kmalloc(bytes, GFP_KERNEL);
143 /* fill in pointers starting at "tmp",
144 * to descriptors copied starting at "mem";
149 mem += (n_desc + 1) * sizeof(*tmp);
151 memcpy(mem, *src, (*src)->bLength);
154 mem += (*src)->bLength;
161 EXPORT_SYMBOL_GPL(usb_copy_descriptors);
163 int 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)
169 struct usb_gadget *g = f->config->cdev->gadget;
171 /* super-speed-plus descriptor falls back to super-speed one,
172 * if such a descriptor was provided, thus avoiding a NULL
173 * pointer dereference if a 5gbps capable gadget is used with
174 * a 10gbps capable config (device port + cable + host port)
180 f->fs_descriptors = usb_copy_descriptors(fs);
181 if (!f->fs_descriptors)
184 if (hs && gadget_is_dualspeed(g)) {
185 f->hs_descriptors = usb_copy_descriptors(hs);
186 if (!f->hs_descriptors)
189 if (ss && gadget_is_superspeed(g)) {
190 f->ss_descriptors = usb_copy_descriptors(ss);
191 if (!f->ss_descriptors)
194 if (ssp && gadget_is_superspeed_plus(g)) {
195 f->ssp_descriptors = usb_copy_descriptors(ssp);
196 if (!f->ssp_descriptors)
201 usb_free_all_descriptors(f);
204 EXPORT_SYMBOL_GPL(usb_assign_descriptors);
206 void usb_free_all_descriptors(struct usb_function *f)
208 usb_free_descriptors(f->fs_descriptors);
209 f->fs_descriptors = NULL;
210 usb_free_descriptors(f->hs_descriptors);
211 f->hs_descriptors = NULL;
212 usb_free_descriptors(f->ss_descriptors);
213 f->ss_descriptors = NULL;
214 usb_free_descriptors(f->ssp_descriptors);
215 f->ssp_descriptors = NULL;
217 EXPORT_SYMBOL_GPL(usb_free_all_descriptors);
219 struct usb_descriptor_header *usb_otg_descriptor_alloc(
220 struct usb_gadget *gadget)
222 struct usb_descriptor_header *otg_desc;
225 if (gadget->otg_caps && (gadget->otg_caps->otg_rev >= 0x0200))
226 length = sizeof(struct usb_otg20_descriptor);
228 length = sizeof(struct usb_otg_descriptor);
230 otg_desc = kzalloc(length, GFP_KERNEL);
233 EXPORT_SYMBOL_GPL(usb_otg_descriptor_alloc);
235 int usb_otg_descriptor_init(struct usb_gadget *gadget,
236 struct usb_descriptor_header *otg_desc)
238 struct usb_otg_descriptor *otg1x_desc;
239 struct usb_otg20_descriptor *otg20_desc;
240 struct usb_otg_caps *otg_caps = gadget->otg_caps;
241 u8 otg_attributes = 0;
246 if (otg_caps && otg_caps->otg_rev) {
247 if (otg_caps->hnp_support)
248 otg_attributes |= USB_OTG_HNP;
249 if (otg_caps->srp_support)
250 otg_attributes |= USB_OTG_SRP;
251 if (otg_caps->adp_support && (otg_caps->otg_rev >= 0x0200))
252 otg_attributes |= USB_OTG_ADP;
254 otg_attributes = USB_OTG_SRP | USB_OTG_HNP;
257 if (otg_caps && (otg_caps->otg_rev >= 0x0200)) {
258 otg20_desc = (struct usb_otg20_descriptor *)otg_desc;
259 otg20_desc->bLength = sizeof(struct usb_otg20_descriptor);
260 otg20_desc->bDescriptorType = USB_DT_OTG;
261 otg20_desc->bmAttributes = otg_attributes;
262 otg20_desc->bcdOTG = cpu_to_le16(otg_caps->otg_rev);
264 otg1x_desc = (struct usb_otg_descriptor *)otg_desc;
265 otg1x_desc->bLength = sizeof(struct usb_otg_descriptor);
266 otg1x_desc->bDescriptorType = USB_DT_OTG;
267 otg1x_desc->bmAttributes = otg_attributes;
272 EXPORT_SYMBOL_GPL(usb_otg_descriptor_init);