audio: expose generic Audio Control requests

Remove the narrow public Feature Unit request API while retaining managed mute and volume helpers. Expose validated Audio Control descriptors during enumeration and provide raw asynchronous and synchronous entity requests for advanced controls.

Signed-off-by: HiFiPHile <[email protected]>

1 files changed, 27 insertions, 34 deletions

diff --git a/src/class/audio/audio_host.h b/src/class/audio/audio_host.h
index 4807d376a..2e778c184 100644
--- a/src/class/audio/audio_host.h
+++ b/src/class/audio/audio_host.h
@@ -115,6 +115,14 @@ typedef struct {
   uint16_t res;
 } tuh_audio_volume_range_t;
 
+// Audio Control descriptors reported during enumeration. Descriptor pointers
+// are valid only for the duration of tuh_audio_descriptor_cb().
+typedef struct {
+  const tusb_desc_interface_t *desc_audio_control;
+  const uint8_t               *desc_cs_audio_control;
+  uint16_t                     desc_cs_audio_control_len;
+} tuh_audio_descriptor_cb_t;
+
 //--------------------------------------------------------------------+
 // Stream Enumeration
 //--------------------------------------------------------------------+
@@ -212,8 +220,6 @@ static inline uint32_t tuh_audio_config_frame_size(const tuh_audio_stream_config
 bool tuh_audio_mounted(uint8_t idx);
 // Get device address of Audio device
 uint8_t tuh_audio_get_dev_addr(uint8_t idx);
-// Get the Feature Unit ID associated with a stream (0 = none)
-uint8_t tuh_audio_get_feature_unit_id(uint8_t idx, uint8_t stream_idx);
 // True when the stream's Feature Unit supports master mute control.
 bool tuh_audio_mute_supported(uint8_t idx, uint8_t stream_idx);
 // Get the cached master volume range. Returns false when volume is unsupported.
@@ -223,22 +229,13 @@ bool tuh_audio_volume_range_get(uint8_t idx, uint8_t stream_idx, tuh_audio_volum
 // Control Request API
 //--------------------------------------------------------------------+
 
-// Set a Feature Unit control associated with an Audio stream. UAC2 supports
-// mute and volume through this low-level API; the other fixed-width selectors
-// below are UAC1-only.
-// Mute/bass/mid/treble/AGC/bass boost/loudness use one byte; volume/delay use two.
-// Graphic EQ and unknown selectors are unsupported.
-bool tuh_audio_feature_unit_set(uint8_t idx, uint8_t stream_idx, uint8_t control_selector, uint8_t channel,
-                                uint16_t value, tuh_xfer_cb_t complete_cb, uintptr_t user_data);
-
-// Get a Feature Unit control associated with an Audio stream. UAC2 supports
-// mute and volume through this low-level API; the other fixed-width selectors
-// below are UAC1-only.
-// The value is converted to host byte order before complete_cb is invoked.
-// Graphic EQ and unknown selectors are unsupported.
-// Only one Feature Unit operation may be in flight per device.
-bool tuh_audio_feature_unit_get(uint8_t idx, uint8_t stream_idx, uint8_t control_selector, uint8_t channel,
-                                uint16_t *value, tuh_xfer_cb_t complete_cb, uintptr_t user_data);
+// Submit a class-specific request to an entity on the Audio Control interface.
+// request is the protocol-specific UAC request code. buffer contains the raw
+// little-endian control payload. For an asynchronous transfer, buffer must
+// remain valid until complete_cb is invoked.
+bool tuh_audio_control_xfer(uint8_t idx, uint8_t entity_id, tusb_dir_t direction, uint8_t request,
+                            uint8_t control_selector, uint8_t channel, void *buffer, uint16_t length,
+                            tuh_xfer_cb_t complete_cb, uintptr_t user_data);
 
 // Master mute and volume controls. Capability and range information is cached
 // before tuh_audio_mount_cb() is invoked. Volume SET accepts
@@ -252,23 +249,12 @@ bool tuh_audio_volume_get(uint8_t idx, uint8_t stream_idx, int16_t *volume, tuh_
                           uintptr_t user_data);
 
 //--------------------------------------------------------------------+
-// Control Request Sync API
-// Each Function will make a USB control transfer request to/from device the function will block until request is
-// complete. The function will return the transfer request result
+// Synchronous control requests block until the transfer completes and return
+// its result. actual_len may be NULL when the received length is not needed.
 //--------------------------------------------------------------------+
-TU_ATTR_ALWAYS_INLINE static inline tusb_xfer_result_t tuh_audio_feature_unit_set_sync(uint8_t idx, uint8_t stream_idx,
-                                                                                       uint8_t  control_selector,
-                                                                                       uint8_t  channel,
-                                                                                       uint16_t value) {
-  TU_API_SYNC(tuh_audio_feature_unit_set, idx, stream_idx, control_selector, channel, value);
-}
-
-TU_ATTR_ALWAYS_INLINE static inline tusb_xfer_result_t tuh_audio_feature_unit_get_sync(uint8_t idx, uint8_t stream_idx,
-                                                                                       uint8_t   control_selector,
-                                                                                       uint8_t   channel,
-                                                                                       uint16_t *value) {
-  TU_API_SYNC(tuh_audio_feature_unit_get, idx, stream_idx, control_selector, channel, value);
-}
+tusb_xfer_result_t tuh_audio_control_xfer_sync(uint8_t idx, uint8_t entity_id, tusb_dir_t direction, uint8_t request,
+                                               uint8_t control_selector, uint8_t channel, void *buffer, uint16_t length,
+                                               uint32_t *actual_len);
 
 TU_ATTR_ALWAYS_INLINE static inline tusb_xfer_result_t tuh_audio_mute_set_sync(uint8_t idx, uint8_t stream_idx,
                                                                                bool mute) {
@@ -294,6 +280,13 @@ TU_ATTR_ALWAYS_INLINE static inline tusb_xfer_result_t tuh_audio_volume_get_sync
 // Callbacks (Weak is optional)
 //--------------------------------------------------------------------+
 
+// Invoked after the Audio Control and Streaming descriptors have been
+// validated during enumeration, before tuh_audio_mount_cb(). The interface is
+// not mounted yet and control requests must not be submitted from this
+// callback. Applications may inspect or copy descriptors needed for later raw
+// entity control requests.
+void tuh_audio_descriptor_cb(uint8_t idx, const tuh_audio_descriptor_cb_t *desc_cb_data);
+
 // Invoked when device with Audio interface is mounted
 void tuh_audio_mount_cb(uint8_t idx);