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>

2 files changed, 27 insertions, 0 deletions

diff --git a/include/linux/usb/audio-v2.h b/include/linux/usb/audio-v2.h
index 0952231e6c3f..2389f93a28b5 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
diff --git a/include/linux/usb/audio.h b/include/linux/usb/audio.h
index 9fae6bdab338..c0ef18dc2da7 100644
--- a/include/linux/usb/audio.h
+++ b/include/linux/usb/audio.h
@@ -488,6 +488,21 @@ struct uac_iso_endpoint_descriptor {
 #define UAC_FU_BASS_BOOST       (1 << (UAC_BASS_BOOST_CONTROL - 1))
 #define UAC_FU_LOUDNESS         (1 << (UAC_LOUDNESS_CONTROL - 1))
 
+/* status word format (3.7.1.1) */
+
+#define UAC1_STATUS_TYPE_ORIG_MASK              0x0f
+#define UAC1_STATUS_TYPE_ORIG_AUDIO_CONTROL_IF  0x0
+#define UAC1_STATUS_TYPE_ORIG_AUDIO_STREAM_IF   0x1
+#define UAC1_STATUS_TYPE_ORIG_AUDIO_STREAM_EP   0x2
+
+#define UAC1_STATUS_TYPE_IRQ_PENDING            (1 << 7)
+#define UAC1_STATUS_TYPE_MEM_CHANGED            (1 << 6)
+
+struct uac1_status_word {
+        __u8 bStatusType;
+        __u8 bOriginator;
+} __attribute__((packed));
+
 #ifdef __KERNEL__
 
 struct usb_audio_control {