diff options
Diffstat (limited to 'Demos/Host/Incomplete/AudioInputHost/ConfigDescriptor.c')
| -rw-r--r-- | Demos/Host/Incomplete/AudioInputHost/ConfigDescriptor.c | 59 |
1 files changed, 48 insertions, 11 deletions
diff --git a/Demos/Host/Incomplete/AudioInputHost/ConfigDescriptor.c b/Demos/Host/Incomplete/AudioInputHost/ConfigDescriptor.c index d0ca91a08..5dcd602ac 100644 --- a/Demos/Host/Incomplete/AudioInputHost/ConfigDescriptor.c +++ b/Demos/Host/Incomplete/AudioInputHost/ConfigDescriptor.c @@ -37,10 +37,24 @@ #include "ConfigDescriptor.h"
+/** Index of the currently used Audio Streaming Interface within the device. */
uint8_t StreamingInterfaceIndex = 0;
+
+/** Alternative Setting of the currently used Audio Streaming Interface within the device. */
uint8_t StreamingInterfaceAltSetting = 0;
+
+/** Address of the streaming audio endpoint currently in use within the device. */
uint8_t StreamingEndpointAddress = 0;
+
+/** Reads and processes an attached device's descriptors, to determine compatibility and pipe configurations. This
+ * routine will read in the entire configuration descriptor, and configure the hosts pipes to correctly communicate
+ * with compatible devices.
+ *
+ * This routine searches for a Streaming Audio interface descriptor containing a valid Isochronous audio endpoint.
+ *
+ * \return An error code from the \ref RNDISHost_GetConfigDescriptorDataCodes_t enum.
+ */
uint8_t ProcessConfigurationDescriptor(void)
{
uint8_t ConfigDescriptorData[512];
@@ -66,12 +80,17 @@ uint8_t ProcessConfigurationDescriptor(void) while (!(DataINEndpoint))
{
+ /* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
if (!(AudioControlInterface) ||
USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
DComp_NextAudioInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
{
- if (!(AudioControlInterface))
+ /* Check if we haven't found an Audio Control interface yet, or if we have run out of related Audio Streaming interfaces */
+ if (!(AudioControlInterface) ||
+ USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+ DComp_NextAudioStreamInterface) != DESCRIPTOR_SEARCH_COMP_Found)
{
+ /* Find a new Audio Control interface if the current one doesn't contain a compatible streaming interface */
if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
DComp_NextAudioControlInterface) != DESCRIPTOR_SEARCH_COMP_Found)
{
@@ -81,20 +100,14 @@ uint8_t ProcessConfigurationDescriptor(void) /* Save the interface in case we need to refer back to it later */
AudioControlInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
- }
-
- if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
- DComp_NextAudioStreamInterface) != DESCRIPTOR_SEARCH_COMP_Found)
- {
+
+ /* Find the next Audio Streaming interface within that Audio Control interface */
if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
- DComp_NextAudioControlInterface) != DESCRIPTOR_SEARCH_COMP_Found)
+ DComp_NextAudioStreamInterface) != DESCRIPTOR_SEARCH_COMP_Found)
{
/* Descriptor not found, error out */
return NoCompatibleInterfaceFound;
}
-
- /* Save the interface in case we need to refer back to it later */
- AudioControlInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
}
/* Save the interface in case we need to refer back to it later */
@@ -124,6 +137,14 @@ uint8_t ProcessConfigurationDescriptor(void) return SuccessfulConfigRead;
}
+/** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
+ * configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
+ * descriptor processing if an incompatible descriptor configuration is found.
+ *
+ * This comparator searches for the next Interface descriptor of the correct Audio Control Class, Subclass and Protocol values.
+ *
+ * \return A value from the DSEARCH_Return_ErrorCodes_t enum
+ */
uint8_t DComp_NextAudioControlInterface(void* CurrentDescriptor)
{
USB_Descriptor_Header_t* Header = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Header_t);
@@ -143,6 +164,14 @@ uint8_t DComp_NextAudioControlInterface(void* CurrentDescriptor) return DESCRIPTOR_SEARCH_NotFound;
}
+/** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
+ * configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
+ * descriptor processing if an incompatible descriptor configuration is found.
+ *
+ * This comparator searches for the next Interface descriptor of the correct Audio Streaming Class, Subclass and Protocol values.
+ *
+ * \return A value from the DSEARCH_Return_ErrorCodes_t enum
+ */
uint8_t DComp_NextAudioStreamInterface(void* CurrentDescriptor)
{
USB_Descriptor_Header_t* Header = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Header_t);
@@ -162,6 +191,15 @@ uint8_t DComp_NextAudioStreamInterface(void* CurrentDescriptor) return DESCRIPTOR_SEARCH_NotFound;
}
+/** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
+ * configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
+ * descriptor processing if an incompatible descriptor configuration is found.
+ *
+ * This comparator searches for the next Isochronous Endpoint descriptor within the current interface, aborting the
+ * search if another interface descriptor is found before the next endpoint.
+ *
+ * \return A value from the DSEARCH_Return_ErrorCodes_t enum
+ */
uint8_t DComp_NextAudioInterfaceDataEndpoint(void* CurrentDescriptor)
{
USB_Descriptor_Header_t* Header = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Header_t);
@@ -180,4 +218,3 @@ uint8_t DComp_NextAudioInterfaceDataEndpoint(void* CurrentDescriptor) return DESCRIPTOR_SEARCH_NotFound;
}
-
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