usb: add support for "grouped" interfaces and the Interface Association Descriptor

This is used for some devices that have multiple interfaces that form a logic
device. An example is Video Class, which has a Control interface and a
Streaming interface. There can be additional interfaces on the same (physical)
devices (e.g. a microphone), and Interface Association Descriptor handles this
case.

Signed-off-by: Brad Hards <bradh@frogmouth.net>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/hw/usb-desc.h b/hw/usb-desc.h
index ac734ab088..a612515c43 100644
--- a/hw/usb-desc.h
+++ b/hw/usb-desc.h
@@ -30,6 +30,24 @@ struct USBDescConfig {
     uint8_t                   bmAttributes;
     uint8_t                   bMaxPower;
 
+    /* grouped interfaces */
+    uint8_t                   nif_groups;
+    const USBDescIfaceAssoc   *if_groups;
+
+    /* "normal" interfaces */
+    uint8_t                   nif;
+    const USBDescIface        *ifs;
+};
+
+/* conceptually an Interface Association Descriptor, and releated interfaces */
+struct USBDescIfaceAssoc {
+    uint8_t                   bFirstInterface;
+    uint8_t                   bInterfaceCount;
+    uint8_t                   bFunctionClass;
+    uint8_t                   bFunctionSubClass;
+    uint8_t                   bFunctionProtocol;
+    uint8_t                   iFunction;
+
     uint8_t                   nif;
     const USBDescIface        *ifs;
 };
@@ -75,6 +93,8 @@ int usb_desc_device(const USBDescID *id, const USBDescDevice *dev,
 int usb_desc_device_qualifier(const USBDescDevice *dev,
                               uint8_t *dest, size_t len);
 int usb_desc_config(const USBDescConfig *conf, uint8_t *dest, size_t len);
+int usb_desc_iface_group(const USBDescIfaceAssoc *iad, uint8_t *dest,
+                         size_t len);
 int usb_desc_iface(const USBDescIface *iface, uint8_t *dest, size_t len);
 int usb_desc_endpoint(const USBDescEndpoint *ep, uint8_t *dest, size_t len);
 int usb_desc_other(const USBDescOther *desc, uint8_t *dest, size_t len);