ALSA: sound/usb: add preliminary support for UAC2 interrupts

For both UAC1 and UAC2, interrupt endpoint messages are now parsed with
structs rather that with anonymous buffer array accesses.

For UAC2, only CUR interrupt notifications are supported for now.

snd_usb_mixer_status_complete() was renamed to
snd_usb_mixer_interrupt().

Fixed one indentation flaw on the way.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/linux/usb/audio-v2.h b/include/linux/usb/audio-v2.h
index 0952231e6c3..2389f93a28b 100644
--- a/include/linux/usb/audio-v2.h
+++ b/include/linux/usb/audio-v2.h
@@ -105,6 +105,17 @@ struct uac_as_header_descriptor_v2 {
         __u8 iChannelNames;
 } __attribute__((packed));
 
+/* 6.1 Interrupt Data Message */
+
+#define UAC2_INTERRUPT_DATA_MSG_VENDOR  (1 << 0)
+#define UAC2_INTERRUPT_DATA_MSG_EP      (1 << 1)
+
+struct uac2_interrupt_data_msg {
+        __u8 bInfo;
+        __u8 bAttribute;
+        __le16 wValue;
+        __le16 wIndex;
+} __attribute__((packed));
 
 /* A.7 Audio Function Category Codes */
 #define UAC2_FUNCTION_SUBCLASS_UNDEFINED        0x00
@@ -153,6 +164,7 @@ struct uac_as_header_descriptor_v2 {
 /* A.14 Audio Class-Specific Request Codes */
 #define UAC2_CS_CUR                     0x01
 #define UAC2_CS_RANGE                   0x02
+#define UAC2_CS_MEM                     0x03
 
 /* A.15 Encoder Type Codes */
 #define UAC2_ENCODER_UNDEFINED          0x00