descriptor: Introduce interface association descriptors (IAD)

Types:
  struct libusb_interface_association_descriptor
  struct libusb_interface_association_descriptor_array

Accessor / cleanup functions:
  libusb_get_interface_association_descriptors
  libusb_get_active_interface_association_descriptors
  libusb_free_interface_association_descriptors

Signed-off-by: Ryan Metcalfe <ryan.metcalfe@novanta.com>
[Tormod: Fixed Doxygen comment]
Signed-off-by: Tormod Volden <debian.tormod@gmail.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/libusb/libusb.h b/libusb/libusb.h
index bc7ef16..0946a55 100644
--- a/libusb/libusb.h
+++ b/libusb/libusb.h
@@ -269,6 +269,10 @@ enum libusb_descriptor_type {
 	/** Endpoint descriptor. See libusb_endpoint_descriptor. */
 	LIBUSB_DT_ENDPOINT = 0x05,
 
+	/** Interface Association Descriptor.
+	* See libusb_interface_association_descriptor */
+	LIBUSB_DT_INTERFACE_ASSOCIATION = 0x0b,
+
 	/** BOS descriptor */
 	LIBUSB_DT_BOS = 0x0f,
 
@@ -633,6 +637,65 @@ struct libusb_endpoint_descriptor {
 };
 
 /** \ingroup libusb_desc
+ * A structure representing the standard USB interface association descriptor.
+ * This descriptor is documented in section 9.6.4 of the USB 3.0 specification.
+ * All multiple-byte fields are represented in host-endian format.
+ */
+struct libusb_interface_association_descriptor {
+	/** Size of this descriptor (in bytes) */
+	uint8_t  bLength;
+
+	/** Descriptor type. Will have value
+	* \ref libusb_descriptor_type::LIBUSB_DT_INTERFACE_ASSOCIATION
+	* LIBUSB_DT_INTERFACE_ASSOCIATION in this context. */
+	uint8_t  bDescriptorType;
+
+	/** Interface number of the first interface that is associated
+	* with this function */
+	uint8_t  bFirstInterface;
+
+	/** Number of contiguous interfaces that are associated with
+	* this function */
+	uint8_t  bInterfaceCount;
+
+	/** USB-IF class code for this function.
+	* A value of zero is not allowed in this descriptor.
+	* If this field is 0xff, the function class is vendor-specific.
+	* All other values are reserved for assignment by the USB-IF.
+	*/
+	uint8_t  bFunctionClass;
+
+	/** USB-IF subclass code for this function.
+	* If this field is not set to 0xff, all values are reserved
+	* for assignment by the USB-IF
+	*/
+	uint8_t  bFunctionSubClass;
+
+	/** USB-IF protocol code for this function.
+	* These codes are qualified by the values of the bFunctionClass
+	* and bFunctionSubClass fields.
+	*/
+	uint8_t  bFunctionProtocol;
+
+	/** Index of string descriptor describing this function */
+	uint8_t  iFunction;
+};
+
+/** \ingroup libusb_desc
+ * Structure containing an array of 0 or more interface association
+ * descriptors
+ */
+struct libusb_interface_association_descriptor_array {
+	/** Array of interface association descriptors. The size of this array
+	 * is determined by the length field.
+	 */
+	const struct libusb_interface_association_descriptor *iad;
+
+	/** Number of interface association descriptors contained. Read-only. */
+	int length;
+};
+
+/** \ingroup libusb_desc
  * A structure representing the standard USB interface descriptor. This
  * descriptor is documented in section 9.6.5 of the USB 3.0 specification.
  * All multiple-byte fields are represented in host-endian format.
@@ -1433,6 +1496,13 @@ int LIBUSB_CALL libusb_get_max_packet_size(libusb_device *dev,
 int LIBUSB_CALL libusb_get_max_iso_packet_size(libusb_device *dev,
 	unsigned char endpoint);
 
+int LIBUSB_CALL libusb_get_interface_association_descriptors(libusb_device *dev,
+	uint8_t config_index, struct libusb_interface_association_descriptor_array **iad_array);
+int LIBUSB_CALL libusb_get_active_interface_association_descriptors(libusb_device *dev,
+	struct libusb_interface_association_descriptor_array **iad_array);
+void LIBUSB_CALL libusb_free_interface_association_descriptors(
+	struct libusb_interface_association_descriptor_array *iad_array);
+
 int LIBUSB_CALL libusb_wrap_sys_device(libusb_context *ctx, intptr_t sys_dev, libusb_device_handle **dev_handle);
 int LIBUSB_CALL libusb_open(libusb_device *dev, libusb_device_handle **dev_handle);
 void LIBUSB_CALL libusb_close(libusb_device_handle *dev_handle);