blob: 5b338c5b689b67270e19d4097229bdce7e40f26c [file] [log] [blame]
#include <common.h>
#include <malloc.h>
#include <errno.h>
#include <usb/ch9.h>
* usb_descriptor_fillbuf - fill buffer with descriptors
* @buf: Buffer to be filled
* @buflen: Size of buf
* @src: Array of descriptor pointers, terminated by null pointer.
* Copies descriptors into the buffer, returning the length or a
* negative error code if they can't all be copied. Useful when
* assembling descriptors for an associated set of interfaces used
* as part of configuring a composite device; or in other cases where
* sets of descriptors need to be marshaled.
usb_descriptor_fillbuf(void *buf, unsigned buflen,
const struct usb_descriptor_header **src)
u8 *dest = buf;
if (!src)
return -EINVAL;
/* fill buffer from src[] until null descriptor ptr */
for (; NULL != *src; src++) {
unsigned len = (*src)->bLength;
if (len > buflen)
return -EINVAL;
memcpy(dest, *src, len);
buflen -= len;
dest += len;
return dest - (u8 *)buf;
* usb_copy_descriptors - copy a vector of USB descriptors
* @src: null-terminated vector to copy
* Context: initialization code, which may sleep
* This makes a copy of a vector of USB descriptors. Its primary use
* is to support usb_function objects which can have multiple copies,
* each needing different descriptors. Functions may have static
* tables of descriptors, which are used as templates and customized
* with identifiers (for interfaces, strings, endpoints, and more)
* as needed by a given function instance.
struct usb_descriptor_header **__init
usb_copy_descriptors(struct usb_descriptor_header **src)
struct usb_descriptor_header **tmp;
unsigned bytes;
unsigned n_desc;
void *mem;
struct usb_descriptor_header **ret;
/* count descriptors and their sizes; then add vector size */
for (bytes = 0, n_desc = 0, tmp = src; *tmp; tmp++, n_desc++)
bytes += (*tmp)->bLength;
bytes += (n_desc + 1) * sizeof(*tmp);
mem = kmalloc(bytes, GFP_KERNEL);
if (!mem)
return NULL;
/* fill in pointers starting at "tmp",
* to descriptors copied starting at "mem";
* and return "ret"
tmp = mem;
ret = mem;
mem += (n_desc + 1) * sizeof(*tmp);
while (*src) {
memcpy(mem, *src, (*src)->bLength);
*tmp = mem;
mem += (*src)->bLength;
*tmp = NULL;
return ret;
* usb_find_endpoint - find a copy of an endpoint descriptor
* @src: original vector of descriptors
* @copy: copy of @src
* @match: endpoint descriptor found in @src
* This returns the copy of the @match descriptor made for @copy. Its
* intended use is to help remembering the endpoint descriptor to use
* when enabling a given endpoint.
struct usb_endpoint_descriptor *__init
struct usb_descriptor_header **src,
struct usb_descriptor_header **copy,
struct usb_endpoint_descriptor *match
while (*src) {
if (*src == (void *) match)
return (void *)*copy;
return NULL;