diff mbox series

[v2,1/4] usb: audio-v2: add ability to define feature unit descriptor

Message ID 20210711095351.16877-2-pavel.hofman@ivitera.com
State New
Headers show
Series usb: gadget: audio: add bi-directional volume and mute support | expand

Commit Message

Pavel Hofman July 11, 2021, 9:53 a.m. UTC 
From: Ruslan Bilovol <ruslan.bilovol@gmail.com>

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@gmail.com>
Signed-off-by: Pavel Hofman <pavel.hofman@ivitera.com>
---
 include/linux/usb/audio-v2.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
diff mbox series

Patch

diff --git a/include/linux/usb/audio-v2.h b/include/linux/usb/audio-v2.h
index ead8c9a47c6a..8fc2abd7aecb 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 {