/** Parses the given descriptor list via customized function.
* \param descriptor Pointer to the start of the whole descriptors list.
* \param totalLength Total size of descriptors in bytes.
* \param parseFunction Function to parse each descriptor scanned.
* Return 0 to continue parsing.
* \param parseArg Argument passed to parse function.
* \return Pointer to USBGenericDescriptor instance for next descriptor.
*/
USBGenericDescriptor *USBGenericDescriptor_Parse(
const USBGenericDescriptor *descriptor,
uint32_t totalLength,
USBDescriptorParseFunction parseFunction,
void *parseArg)
{
int32_t size = totalLength;
if (size == 0)
return 0;
/* Start parsing descriptors */
while (1) {
uint32_t parseRC = 0;
/* Parse current descriptor */
if (parseFunction)
parseRC = parseFunction((void *)descriptor, parseArg);
/* Get next descriptor */
size -= USBGenericDescriptor_GetLength(descriptor);
descriptor = USBGenericDescriptor_GetNextDescriptor(descriptor);
if (size) {
if (parseRC != 0)
return (USBGenericDescriptor *)descriptor;
} else
break;
}
/* No descriptors remaining */
return 0;
}
/** Parses the given Configuration descriptor (followed by relevant
* interface, endpoint and class-specific descriptors) into three arrays.
* *Each array must have its size equal or greater to the number of
* descriptors it stores plus one*. A null-value is inserted after the last
* descriptor of each type to indicate the array end.
*
* Note that if the pointer to an array is null (0), nothing is stored in
* it.
* \param configuration Pointer to the start of the whole Configuration
* descriptor.
* \param interfaces Pointer to the Interface descriptor array.
* \param endpoints Pointer to the Endpoint descriptor array.
* \param others Pointer to the class-specific descriptor array.
*/
void USBConfigurationDescriptor_Parse(
const USBConfigurationDescriptor *configuration,
USBInterfaceDescriptor **interfaces,
USBEndpointDescriptor **endpoints,
USBGenericDescriptor **others)
{
/* Get size of configuration to parse */
int size = USBConfigurationDescriptor_GetTotalLength(configuration);
size -= sizeof(USBConfigurationDescriptor);
/* Start parsing descriptors */
USBGenericDescriptor *descriptor = (USBGenericDescriptor *) configuration;
while (size > 0) {
/* Get next descriptor */
descriptor = USBGenericDescriptor_GetNextDescriptor(descriptor);
size -= USBGenericDescriptor_GetLength(descriptor);
/* Store descriptor in correponding array */
if (USBGenericDescriptor_GetType(descriptor)
== USBGenericDescriptor_INTERFACE) {
if (interfaces) {
*interfaces = (USBInterfaceDescriptor *) descriptor;
interfaces++;
}
}
else if (USBGenericDescriptor_GetType(descriptor)
== USBGenericDescriptor_ENDPOINT) {
if (endpoints) {
*endpoints = (USBEndpointDescriptor *) descriptor;
endpoints++;
}
}
else if (others) {
*others = descriptor;
others++;
}
}
/* Null-terminate arrays */
if (interfaces) {
*interfaces = 0;
}
if (endpoints) {
*endpoints = 0;
}
if (others) {
*others = 0;
}
}