Similar to UAC1 spec, UAC2 feature unit descriptor
has variable size.
Current audio-v2 feature unit descriptor structure
is used for parsing descriptors, but can't be used
to define your own descriptor.
Add a new macro similar to what audio v1 already has.
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>
---
include/linux/usb/audio-v2.h | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/include/linux/usb/audio-v2.h b/include/linux/usb/audio-v2.h
index ead8c9a..8fc2abd 100644
--- a/include/linux/usb/audio-v2.h
+++ b/include/linux/usb/audio-v2.h
@@ -156,6 +156,20 @@ struct uac2_feature_unit_descriptor {
__u8 bmaControls[]; /* variable length */
} __attribute__((packed));
+#define UAC2_DT_FEATURE_UNIT_SIZE(ch) (6 + ((ch) + 1) * 4)
+
+/* As above, but more useful for defining your own descriptors: */
+#define DECLARE_UAC2_FEATURE_UNIT_DESCRIPTOR(ch) \
+struct uac2_feature_unit_descriptor_##ch { \
+ __u8 bLength; \
+ __u8 bDescriptorType; \
+ __u8 bDescriptorSubtype; \
+ __u8 bUnitID; \
+ __u8 bSourceID; \
+ __le32 bmaControls[ch + 1]; \
+ __u8 iFeature; \
+} __packed
+
/* 4.7.2.10 Effect Unit Descriptor */
struct uac2_effect_unit_descriptor {
--
1.9.1
