audio: simplify alt settings management

HiFiPhile · HiFiPhile · commit 8952838a265e · 2025-09-27T22:17:10.000+02:00
Signed-off-by: HiFiPhile &lt;admin@hifiphile.com&gt;
diff --git a/examples/device/audio_4_channel_mic/src/tusb_config.h b/examples/device/audio_4_channel_mic/src/tusb_config.h
@@ -107,7 +107,6 @@ extern "C" {
 
 #define CFG_TUD_AUDIO_FUNC_1_DESC_LEN                 TUD_AUDIO_MIC_FOUR_CH_DESC_LEN
 
-#define CFG_TUD_AUDIO_FUNC_1_N_AS_INT                 1
 #define CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ              64
 
 #define CFG_TUD_AUDIO_ENABLE_EP_IN                    1
diff --git a/examples/device/audio_4_channel_mic_freertos/src/tusb_config.h b/examples/device/audio_4_channel_mic_freertos/src/tusb_config.h
@@ -113,7 +113,6 @@ extern "C" {
 
 #define CFG_TUD_AUDIO_FUNC_1_DESC_LEN                 TUD_AUDIO_MIC_FOUR_CH_DESC_LEN
 
-#define CFG_TUD_AUDIO_FUNC_1_N_AS_INT                 1
 #define CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ              64
 
 #define CFG_TUD_AUDIO_ENABLE_EP_IN                    1
diff --git a/examples/device/audio_test/src/tusb_config.h b/examples/device/audio_test/src/tusb_config.h
@@ -109,7 +109,6 @@ extern "C" {
 #define CFG_TUD_AUDIO_FUNC_1_SAMPLE_RATE                              48000
 
 #define CFG_TUD_AUDIO_FUNC_1_DESC_LEN                                 TUD_AUDIO_MIC_ONE_CH_DESC_LEN
-#define CFG_TUD_AUDIO_FUNC_1_N_AS_INT                                 1                                       // Number of Standard AS Interface Descriptors (4.9.1) defined per audio function - this is required to be able to remember the current alternate settings of these interfaces - We restrict us here to have a constant number for all audio functions (which means this has to be the maximum number of AS interfaces an audio function has and a second audio function with less AS interfaces just wastes a few bytes)
 #define CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ                              64                                      // Size of control request buffer
 
 #define CFG_TUD_AUDIO_ENABLE_EP_IN                                    1
diff --git a/examples/device/audio_test_freertos/src/tusb_config.h b/examples/device/audio_test_freertos/src/tusb_config.h
@@ -115,7 +115,6 @@ extern "C" {
 #define CFG_TUD_AUDIO_FUNC_1_SAMPLE_RATE                              48000
 
 #define CFG_TUD_AUDIO_FUNC_1_DESC_LEN                                 TUD_AUDIO_MIC_ONE_CH_DESC_LEN
-#define CFG_TUD_AUDIO_FUNC_1_N_AS_INT                                 1                                       // Number of Standard AS Interface Descriptors (4.9.1) defined per audio function - this is required to be able to remember the current alternate settings of these interfaces - We restrict us here to have a constant number for all audio functions (which means this has to be the maximum number of AS interfaces an audio function has and a second audio function with less AS interfaces just wastes a few bytes)
 #define CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ                              64                                      // Size of control request buffer
 
 #define CFG_TUD_AUDIO_ENABLE_EP_IN                                    1
diff --git a/examples/device/audio_test_multi_rate/src/tusb_config.h b/examples/device/audio_test_multi_rate/src/tusb_config.h
@@ -123,7 +123,6 @@ extern "C" {
 // Have a look into audio_device.h for all configurations
 
 #define CFG_TUD_AUDIO_FUNC_1_DESC_LEN                                 TUD_AUDIO_MIC_ONE_CH_2_FORMAT_DESC_LEN
-#define CFG_TUD_AUDIO_FUNC_1_N_AS_INT                                 1                                       // Number of Standard AS Interface Descriptors (4.9.1) defined per audio function - this is required to be able to remember the current alternate settings of these interfaces - We restrict us here to have a constant number for all audio functions (which means this has to be the maximum number of AS interfaces an audio function has and a second audio function with less AS interfaces just wastes a few bytes)
 #define CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ                              64                                      // Size of control request buffer
 
 #define CFG_TUD_AUDIO_ENABLE_EP_IN                                    1
diff --git a/examples/device/cdc_uac2/src/tusb_config.h b/examples/device/cdc_uac2/src/tusb_config.h
@@ -157,9 +157,6 @@ extern "C" {
 #define CFG_TUD_AUDIO_FUNC_1_EP_OUT_SZ_MAX        TU_MAX(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_OUT, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_OUT) // Maximum EP IN size for all AS alternate settings used
 #define CFG_TUD_AUDIO_FUNC_1_EP_OUT_SW_BUF_SZ     (TUD_OPT_HIGH_SPEED ? 32 : 4) * CFG_TUD_AUDIO_FUNC_1_EP_OUT_SZ_MAX // Example read FIFO every 1ms, so it should be 8 times larger for HS device
 
-// Number of Standard AS Interface Descriptors (4.9.1) defined per audio function - this is required to be able to remember the current alternate settings of these interfaces - We restrict us here to have a constant number for all audio functions (which means this has to be the maximum number of AS interfaces an audio function has and a second audio function with less AS interfaces just wastes a few bytes)
-#define CFG_TUD_AUDIO_FUNC_1_N_AS_INT 	          2
-
 // Size of control request buffer
 #define CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ          64
 
diff --git a/examples/device/uac2_headset/src/tusb_config.h b/examples/device/uac2_headset/src/tusb_config.h
@@ -158,9 +158,6 @@ extern "C" {
 #define CFG_TUD_AUDIO_FUNC_1_EP_OUT_SZ_MAX        TU_MAX(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_EP_SZ_OUT, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_EP_SZ_OUT) // Maximum EP IN size for all AS alternate settings used
 #define CFG_TUD_AUDIO_FUNC_1_EP_OUT_SW_BUF_SZ     (TUD_OPT_HIGH_SPEED ? 32 : 4) * CFG_TUD_AUDIO_FUNC_1_EP_OUT_SZ_MAX // Example read FIFO every 1ms, so it should be 8 times larger for HS device
 
-// Number of Standard AS Interface Descriptors (4.9.1) defined per audio function - this is required to be able to remember the current alternate settings of these interfaces - We restrict us here to have a constant number for all audio functions (which means this has to be the maximum number of AS interfaces an audio function has and a second audio function with less AS interfaces just wastes a few bytes)
-#define CFG_TUD_AUDIO_FUNC_1_N_AS_INT 	          2
-
 // Size of control request buffer
 #define CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ	64
 
diff --git a/examples/device/uac2_speaker_fb/src/tusb_config.h b/examples/device/uac2_speaker_fb/src/tusb_config.h
@@ -130,7 +130,7 @@ extern "C" {
 
 #define CFG_TUD_AUDIO_FUNC_1_DESC_LEN                                TUD_AUDIO_SPEAKER_STEREO_FB_DESC_LEN
 
-// Enable if Full-Speed on OSX, also set feedback EP size to 3
+// Can be enabled with Full-Speed device on OSX, which forces feedback EP size to 3, in this case CFG_QUIRK_OS_GUESSING can be disabled
 #define CFG_TUD_AUDIO_ENABLE_FEEDBACK_FORMAT_CORRECTION              0
 
 // Audio format type I specifications
@@ -155,9 +155,6 @@ extern "C" {
 // Enable feedback EP
 #define CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP                             1
 
-// Number of Standard AS Interface Descriptors (4.9.1) defined per audio function - this is required to be able to remember the current alternate settings of these interfaces - We restrict us here to have a constant number for all audio functions (which means this has to be the maximum number of AS interfaces an audio function has and a second audio function with less AS interfaces just wastes a few bytes)
-#define CFG_TUD_AUDIO_FUNC_1_N_AS_INT 	                             1
-
 // Size of control request buffer
 #define CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ	                         64
 
diff --git a/src/class/audio/audio_device.c b/src/class/audio/audio_device.c
diff --git a/src/class/audio/audio_device.h b/src/class/audio/audio_device.h
