ALSA: usb-audio: Add support for Processing Units in UAC3

This patch adds support for the Processig Units defined in
the UAC3 spec. The main difference with the previous specs
is the lack of on/off switches in the controls for these
units and the addiction of the new Multi Function Processing
Unit.

The current version of the UAC3 spec doesn't define any
useful controls for the new Multi Function Processing Unit
so no control will get created once this unit is parsed.

Signed-off-by: Jorge Sanjuan <jorge.sanjuan@codethink.co.uk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 40 insertions, 9 deletions

diff --git a/include/uapi/linux/usb/audio.h b/include/uapi/linux/usb/audio.h
index 74e520fb944f..ddc5396800aa 100644
--- a/include/uapi/linux/usb/audio.h
+++ b/include/uapi/linux/usb/audio.h
@@ -390,33 +390,64 @@ static inline __u8 uac_processing_unit_iChannelNames(struct uac_processing_unit_
 static inline __u8 uac_processing_unit_bControlSize(struct uac_processing_unit_descriptor *desc,
                                                     int protocol)
 {
-        return (protocol == UAC_VERSION_1) ?
-                desc->baSourceID[desc->bNrInPins + 4] :
-                2; /* in UAC2, this value is constant */
+        switch (protocol) {
+        case UAC_VERSION_1:
+                return desc->baSourceID[desc->bNrInPins + 4];
+        case UAC_VERSION_2:
+                return 2; /* in UAC2, this value is constant */
+        case UAC_VERSION_3:
+                return 4; /* in UAC3, this value is constant */
+        default:
+                return 1;
+        }
 }
 
 static inline __u8 *uac_processing_unit_bmControls(struct uac_processing_unit_descriptor *desc,
                                                    int protocol)
 {
-        return (protocol == UAC_VERSION_1) ?
-                &desc->baSourceID[desc->bNrInPins + 5] :
-                &desc->baSourceID[desc->bNrInPins + 6];
+        switch (protocol) {
+        case UAC_VERSION_1:
+                return &desc->baSourceID[desc->bNrInPins + 5];
+        case UAC_VERSION_2:
+                return &desc->baSourceID[desc->bNrInPins + 6];
+        case UAC_VERSION_3:
+                return &desc->baSourceID[desc->bNrInPins + 2];
+        default:
+                return NULL;
+        }
 }
 
 static inline __u8 uac_processing_unit_iProcessing(struct uac_processing_unit_descriptor *desc,
                                                    int protocol)
 {
         __u8 control_size = uac_processing_unit_bControlSize(desc, protocol);
-        return *(uac_processing_unit_bmControls(desc, protocol)
-                        + control_size);
+
+        switch (protocol) {
+        case UAC_VERSION_1:
+        case UAC_VERSION_2:
+        default:
+                return *(uac_processing_unit_bmControls(desc, protocol)
+                         + control_size);
+        case UAC_VERSION_3:
+                return 0; /* UAC3 does not have this field */
+        }
 }
 
 static inline __u8 *uac_processing_unit_specific(struct uac_processing_unit_descriptor *desc,
                                                  int protocol)
 {
         __u8 control_size = uac_processing_unit_bControlSize(desc, protocol);
-        return uac_processing_unit_bmControls(desc, protocol)
+
+        switch (protocol) {
+        case UAC_VERSION_1:
+        case UAC_VERSION_2:
+        default:
+                return uac_processing_unit_bmControls(desc, protocol)
                         + control_size + 1;
+        case UAC_VERSION_3:
+                return uac_processing_unit_bmControls(desc, protocol)
+                        + control_size;
+        }
 }
 
 /* 4.5.2 Class-Specific AS Interface Descriptor */