ALSA: usb-audio: parse UAC2 endpoint descriptors correctly

UAC2 devices have their information about pitch control stored in a
different field. Parse it, and emulate the bits for a v1 device.

A new struct uac2_iso_endpoint_descriptor is added.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 16 insertions, 0 deletions

diff --git a/include/linux/usb/audio-v2.h b/include/linux/usb/audio-v2.h
index 2389f93a28b5..92f1d99f0f17 100644
--- a/include/linux/usb/audio-v2.h
+++ b/include/linux/usb/audio-v2.h
@@ -105,6 +105,22 @@ struct uac_as_header_descriptor_v2 {
         __u8 iChannelNames;
 } __attribute__((packed));
 
+/* 4.10.1.2 Class-Specific AS Isochronous Audio Data Endpoint Descriptor */
+
+struct uac2_iso_endpoint_descriptor {
+        __u8  bLength;                  /* in bytes: 8 */
+        __u8  bDescriptorType;          /* USB_DT_CS_ENDPOINT */
+        __u8  bDescriptorSubtype;       /* EP_GENERAL */
+        __u8  bmAttributes;
+        __u8  bmControls;
+        __u8  bLockDelayUnits;
+        __le16 wLockDelay;
+} __attribute__((packed));
+
+#define UAC2_CONTROL_PITCH              (3 << 0)
+#define UAC2_CONTROL_DATA_OVERRUN       (3 << 2)
+#define UAC2_CONTROL_DATA_UNDERRUN      (3 << 4)
+
 /* 6.1 Interrupt Data Message */
 
 #define UAC2_INTERRUPT_DATA_MSG_VENDOR  (1 << 0)