codec音频路由调试
Platform: RK3368
OS: Android 6.0
Kernel: 3.10.0
由于底层codec驱动都已实现相关ALSA相关 control，所以只需修改音频HAL中路由的配置即可实现麦克风输入的切换。源码位于hardware/rockchip/audio/tinyalsa_hal
查看当前音频路由：
$ logcat -s alsa_route
01-21 10:18:41.640 199 199 D alsa_route: Get route table for sound card0 RKES8316
使用amix命令查看所有mixer:
源码位于hardware/rockchip/audio/tinyalsa_hal/amix.c
# amix
Card:0
id iface dev sub idx num perms type name
1 MIXER 0 0 0 2 rw R INT32 HP Playback Volume: 0 0 { 0-0 }
2 MIXER 0 0 0 2 rw R INT32 HPMixer Gain: 0 0 { 0-7 }
3 MIXER 0 0 0 2 rw R INT32 DAC Playback Volume: 192 192 { 0-192 }
4 MIXER 0 0 0 1 rw BOOL Enable DAC Soft Ramp: ON { OFF=0, ON=1 }
5 MIXER 0 0 0 1 rw INT32 DAC Soft Ramp Rate: 0 { 0-4 }
6 MIXER 0 0 0 1 rw ENUM Playback Polarity: (0 Normal) { Normal=0, R Invert=1, L Invert=2, L + R Invert=3 }
7 MIXER 0 0 0 1 rw BOOL DAC Notch Filter: OFF { OFF=0, ON=1 }
8 MIXER 0 0 0 1 rw BOOL DAC Double Fs Mode: OFF { OFF=0, ON=1 }
9 MIXER 0 0 0 1 rw INT32 DAC Volume Control-LeR: 0 { 0-1 }
10 MIXER 0 0 0 1 rw INT32 DAC Stereo Enhancement: 0 { 0-7 }
11 MIXER 0 0 0 1 rw R BOOL MIC Boost: ON { OFF=0, ON=1 }
12 MIXER 0 0 0 1 rw R INT32 Input PGA: 6 { 0-8 }
13 MIXER 0 0 0 1 rw R INT32 ADC Capture Volume: 192 { 0-192 }
14 MIXER 0 0 0 1 rw BOOL ADC Soft Ramp: ON { OFF=0, ON=1 }
15 MIXER 0 0 0 1 rw ENUM Capture Polarity: (0 Normal) { Normal=0, Invert=1 }
16 MIXER 0 0 0 1 rw BOOL ADC Double FS Mode: OFF { OFF=0, ON=1 }
17 MIXER 0 0 0 1 rw INT32 ALC Capture Target Volume: 10 { 0-10 }
18 MIXER 0 0 0 1 rw INT32 ALC Capture Max PGA: 13 { 0-28 }
19 MIXER 0 0 0 1 rw INT32 ALC Capture Min PGA: 8 { 0-28 }
20 MIXER 0 0 0 1 rw ENUM ALC Capture Function: (1 On) { Off=0, On=1 }
21 MIXER 0 0 0 1 rw INT32 ALC Capture Hold Time: 0 { 0-10 }
22 MIXER 0 0 0 1 rw INT32 ALC Capture Decay Time: 0 { 0-10 }
23 MIXER 0 0 0 1 rw INT32 ALC Capture Attack Time: 5 { 0-10 }
24 MIXER 0 0 0 1 rw INT32 ALC Capture NG Threshold: 1 { 0-31 }
25 MIXER 0 0 0 1 rw ENUM ALC Capture NG Type: (1 Mute ADC Output) { Constant PGA Gain=0, Mute ADC Output=1 }
26 MIXER 0 0 0 1 rw BOOL ALC Capture NG Switch: ON { OFF=0, ON=1 }
27 MIXER 0 0 0 1 rw BOOL RLIN Switch: OFF { OFF=0, ON=1 }
28 MIXER 0 0 0 1 rw BOOL Right DAC Switch: OFF { OFF=0, ON=1 }
29 MIXER 0 0 0 1 rw BOOL LLIN Switch: OFF { OFF=0, ON=1 }
30 MIXER 0 0 0 1 rw BOOL Left DAC Switch: OFF { OFF=0, ON=1 }
31 MIXER 0 0 0 1 rw ENUM Right Hp mux: (0 lin1-rin1) { lin1-rin1=0, lin2-rin2=1, lin-rin with Boost=2, lin-rin with Boost and PGA=3 }
32 MIXER 0 0 0 1 rw ENUM Left Hp mux: (0 lin1-rin1) { lin1-rin1=0, lin2-rin2=1, lin-rin with Boost=2, lin-rin with Boost and PGA=3 }
33 MIXER 0 0 0 1 rw ENUM DAC SRC Mux: (0 LDATA TO LDAC, RDATA TO RDAC) { LDATA TO LDAC, RDATA TO RDAC=0, LDATA TO LDAC, LDATA TO RDAC=1, RDATA TO LDAC, RDATA TO RDAC=2, RDATA TO LDAC, LDATA TO RDAC=3 }
34 MIXER 0 0 0 1 rw ENUM Digital Mic Mux: (0 dmic disable) { dmic disable=0, dmic data at high level=1, dmic data at low level=2 }
35 MIXER 0 0 0 1 rw ENUM Differential Mux: (0 lin1-rin1) { lin1-rin1=0, lin2-rin2=1, lin1-rin1 with 20db Boost=2, lin2-rin2 with 20db Boost=3 }
使用amix配置control：
# 例如设置es8316麦克风左右输入
amix -c 0 "Differential Mux" 2
使用代码配置control：
hardware/rockchip/audio/tinyalsa_hal/tinyalsa_hal/codec_config/es8316_config.h
+const struct config_control es8316_main_mic_capture_controls[] = {
+ {
+ .ctl_name = "Differential Mux",
+ .int_val = {2},
+ },
+};
+