audio: add extremely basic routing

The configuration is derived from the default and speaker on
configurations from the configs/tiny_hw.xml file in the
replicant-6.0 branch of the device_samsung_i9300[1].

This should be sufficient for testing the audio as it routes
it to the speaker and never changes route.

This will be improved in subsequent commits as only having the
ability to use the speaker and leaving them on all the time
doesn't really make the device usable.

The audio_hw.c part was inspired from the audio_hw.c and audio_hw.h
files in the device_amlogic_yukawa repository[2] at the following
commit:
    7252a5cd25ced5badee99e7377fb678394c943a8
    7252a5c Snap for 6453963 from b70ebf49d8bc1f162601b8cb627edfc7a689b67a to rvc-release

References:
-----------
[1]https://git.replicant.us/replicant/device_samsung_i9300.git
[2]https://android.googlesource.com/device/amlogic/yukawa

Thanks to Joonas Kylmälä who found that some boards were using
a mixer_paths.xml configuration file. With that information I
was able to find the libaudioroute library and an example xml
file.

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>

4 files changed, 193 insertions, 1 deletions

diff --git a/audio/Android.mk b/audio/Android.mk
index afa804f..cfe9ec9 100644
--- a/audio/Android.mk
+++ b/audio/Android.mk
@@ -29,11 +29,12 @@ LOCAL_MODULE_PATH_64 := $(TARGET_OUT_VENDOR)/lib64/hw
 LOCAL_VENDOR_MODULE := true
 
 LOCAL_SRC_FILES := audio_hw.c
-LOCAL_SHARED_LIBRARIES := liblog libcutils libtinyalsa
+LOCAL_SHARED_LIBRARIES := liblog libcutils libtinyalsa libaudioroute
 LOCAL_CFLAGS := -Wno-unused-parameter
 LOCAL_C_INCLUDES += \
         external/tinyalsa/include \
         external/expat/lib \
+        $(call include-path-for, audio-route) \
         system/media/audio_utils/include \
         system/media/audio_effects/include
 
diff --git a/audio/audio_hw.c b/audio/audio_hw.c
index d601ea8..7be7178 100644
--- a/audio/audio_hw.c
+++ b/audio/audio_hw.c
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#define MIXER_XML_PATH "/vendor/etc/mixer_paths.xml"
+
 #define LOG_TAG "audio_hw_dragonboard"
 //#define LOG_NDEBUG 0
 
@@ -33,6 +35,7 @@
 #include <system/audio.h>
 #include <hardware/audio.h>
 
+#include <audio_route/audio_route.h>
 #include <sound/asound.h>
 #include <tinyalsa/asoundlib.h>
 #include <audio_utils/resampler.h>
@@ -69,6 +72,8 @@ struct alsa_audio_device {
     int devices;
     struct alsa_stream_in *active_input;
     struct alsa_stream_out *active_output;
+    struct audio_route *audio_route;
+    struct mixer *mixer;
     bool mic_mute;
 };
 
@@ -671,6 +676,35 @@ static int adev_open(const hw_module_t* module, const char* name,
 
     *device = &adev->hw_device.common;
 
+    /* TODO: Ideally we should use Alsa UCM instead of libaudioroute
+     * because with Alsa UCM:
+     * - We can share the work with GNU/Linux. For instance we
+     *   might have automatic support for the PinePhone and our
+     *   work would benefit GNU/Linux distributions as well.
+     * - It opens the door to generic images: With Alsa UCM, we
+     *   don't need build time configuration anymore: we could
+     *   ship a single audio library and Alsa UCM would take care
+     *   of the routing and abstract away the device specific part
+     *   for us. If we code that ourselves, it will probably not
+     *   be as fine grained nor as good as Alsa UCM.
+     * - It can be experimented with without even recompiling, this
+     *   could make porting Replicant to new devices much less time
+     * consuming and way easier.
+     */
+    adev->mixer = mixer_open(CARD_OUT);
+
+    if (!adev->mixer) {
+        ALOGE("Unable to open the mixer, aborting.");
+        return -EINVAL;
+    }
+
+    /* Set default audio route */
+    adev->audio_route = audio_route_init(CARD_OUT, MIXER_XML_PATH);
+    if (!adev->audio_route) {
+        ALOGE("%s: Failed to init audio route controls, aborting.", __func__);
+        return -EINVAL;
+    }
+
     return 0;
 }
 
diff --git a/audio/mixer_paths.xml b/audio/mixer_paths.xml
new file mode 100644
index 0000000..7932fec
--- /dev/null
+++ b/audio/mixer_paths.xml
@@ -0,0 +1,151 @@
+<?xml version="1.0" encoding="ISO-8859-1"?>
+<mixer>
+	<!--
+	    +==========+
+	    | Defaults |
+	    +==========+
+	-->
+
+	<!-- do not change the adc & dac source of AIF2 -->
+	<ctl name="AIF2DACL Source" value="0" />
+	<ctl name="AIF2DACR Source" value="0" />
+	<ctl name="AIF2ADCL Source" value="0" />
+	<ctl name="AIF2ADCR Source" value="1" />
+
+	<!-- AIF1->DAC1 -->
+	<ctl name="DAC1 Switch" value="1" />
+
+	<!-- general -->
+	<ctl name="IN1L ZC Switch" value="0" />
+	<ctl name="IN1R ZC Switch" value="0" />
+	<ctl name="IN2L ZC Switch" value="0" />
+	<ctl name="IN2R ZC Switch" value="0" />
+	<ctl name="Output ZC Switch" value="0" />
+	<ctl name="Speaker ZC Switch" value="0" />
+	<ctl name="Headphone ZC Switch" value="0" />
+
+	<!-- AIF1->DAC1 -->
+	<ctl name="DAC1L Mixer AIF1.1 Switch" value="1" />
+	<ctl name="DAC1R Mixer AIF1.1 Switch" value="1" />
+	<ctl name="DAC1 Switch" value="1" />
+
+	<!-- ADC->AIF2 -->
+	<ctl name="AIF2DAC2L Mixer Left Sidetone Switch" value="1" />
+	<ctl name="AIF2DAC2L Mixer Right Sidetone Switch" value="0" />
+	<ctl name="AIF2DAC2R Mixer Left Sidetone Switch" value="0" />
+	<ctl name="AIF2DAC2R Mixer Right Sidetone Switch" value="1" />
+	<ctl name="DAC2 Left Sidetone Volume" value="12" />
+	<ctl name="DAC2 Right Sidetone Volume" value="12" />
+	<ctl name="DAC2 Switch" value="1" />
+
+	<!-- DAC1->HP -->
+	<ctl name="Left Headphone Mux" value="Mixer" />
+	<ctl name="Right Headphone Mux" value="Mixer" />
+
+	<!-- DAC1->SPKL/R->SPKL/R Boost->SPK -->
+	<ctl name="SPKL DAC1 Switch" value="1" />
+	<ctl name="SPKR DAC1 Switch" value="1" />
+	<ctl name="SPKL Boost SPKL Switch" value="1" />
+	<ctl name="SPKL Boost SPKR Switch" value="1" />
+	<ctl name="SPKR Boost SPKL Switch" value="0" />
+	<ctl name="SPKR Boost SPKR Switch" value="1" />
+	<ctl name="Speaker Mixer Volume" value="3" />
+
+	<!-- DAC->Output mixer->Earpiece -->
+	<ctl name="Left Output Mixer DAC Switch" value="1" />
+	<ctl name="Right Output Mixer DAC Switch" value="1" />
+	<ctl name="Earpiece Mixer Left Output Switch" value="1" />
+	<ctl name="Earpiece Mixer Right Output Switch" value="1" />
+	<ctl name="Earpiece Switch" value="1" />
+
+	<!-- LINEOUT -->
+	<ctl name="LINEOUT2N Mixer Left Output Switch" value="1" />
+	<ctl name="LINEOUT2P Mixer Right Output Switch" value="1" />
+	<ctl name="LINEOUT1N Mixer Right Output Switch" value="1" />
+	<ctl name="LINEOUT1P Mixer Left Output Switch" value="1" />
+
+	<!-- Input mixer->ADC->AIF1.1 -->
+	<ctl name="AIF1ADC1L Mixer ADC/DMIC Switch" value="1" />
+	<ctl name="AIF1ADC1R Mixer ADC/DMIC Switch" value="1" />
+
+	<!-- Main Mic->IN1LP/N->Input Mixer with +30dB at mixer -->
+	<ctl name="IN1L PGA IN1LP Switch" value="1" />
+	<ctl name="IN1L PGA IN1LN Switch" value="1" />
+	<ctl name="MIXINL IN1L Volume" value="1" />
+	<ctl name="IN1L Switch" value="1" />
+
+	<!-- Sub Mic->IN1RP/N->Input Mixer with +30dB at mixer -->
+	<ctl name="IN1R PGA IN1RP Switch" value="1" />
+	<ctl name="IN1R PGA IN1RN Switch" value="1" />
+	<ctl name="MIXINR IN1R Volume" value="1" />
+	<ctl name="IN1R Switch" value="1" />
+
+	<!-- FM Radio->IN2RP/N->Input Mixer with +30dB at mixer -->
+	<ctl name="IN2R PGA IN2RP Switch" value="1" />
+	<ctl name="IN2R PGA IN2RN Switch" value="1" />
+	<ctl name="MIXINR IN2R Volume" value="1" />
+	<ctl name="IN2R Switch" value="1" />
+
+	<!-- Ear Mic->IN2LP/N->Input Mixer with +30dB at mixer -->
+	<ctl name="IN2L PGA IN2LP Switch" value="1" />
+	<ctl name="IN2L PGA IN2LN Switch" value="1" />
+	<ctl name="MIXINL IN2L Volume" value="1" />
+	<ctl name="IN2L Switch" value="1" />
+
+	<!-- Input mixer->ADC->AIF1 -->
+	<ctl name="AIF1ADC1L Mixer ADC/DMIC Switch" value="1" />
+	<ctl name="AIF1ADC1R Mixer ADC/DMIC Switch" value="1" />
+	<ctl name="ADCL Mux" value="ADC" />
+
+	<!-- HPF on to take out some bounce -->
+	<ctl name="Sidetone HPF Switch" value="0" />
+
+	<!-- Work around core issue -->
+	<ctl name="ADCL Mux" value="DMIC" />
+	<ctl name="ADCL Mux" value="ADC" />
+	<ctl name="ADCR Mux" value="DMIC" />
+	<ctl name="ADCR Mux" value="ADC" />
+
+	<!-- AIF2ADCDAT to AIF3ADC mux -->
+	<ctl name="AIF3ADC Mux" value="1" />
+
+	<!-- Default all outputs off -->
+	<ctl name="HP Switch" value="0" />
+	<!-- <ctl name="SPK Switch" value="0" /> -->
+	<ctl name="RCV Switch" value="0" />
+	<ctl name="LINE Switch" value="0" />
+	<ctl name="HDMI Switch" value="0" />
+
+	<!-- Default all inputs off -->
+	<ctl name="Main Mic Switch" value="0" />
+	<ctl name="Sub Mic Switch" value="0" />
+	<ctl name="Headset Mic Switch" value="0" />
+	<ctl name="FM In Switch" value="0" />
+
+	<!-- EQ Switches -->
+	<ctl name="AIF1DAC1 EQ Switch" value="1" />
+	<ctl name="AIF1DAC1 EQ1 Volume" value="9" />
+	<ctl name="AIF1DAC1 EQ2 Volume" value="7" />
+	<ctl name="AIF1DAC1 EQ3 Volume" value="10" />
+	<ctl name="AIF1DAC1 EQ4 Volume" value="13" />
+	<ctl name="AIF1DAC1 EQ5 Volume" value="12" />
+
+	<!--
+	    +============+
+	    | Speaker on |
+	    +============+
+	-->
+
+        <ctl name="SPK Switch" value="1" />
+        <ctl name="AIF1DAC1 Volume" value="96" />
+        <ctl name="AIF1 Boost Volume" value="0" />
+        <ctl name="DAC1 Volume" value="96" />
+        <ctl name="Left Output Mixer DAC Volume" value="7" />
+        <ctl name="Right Output Mixer DAC Volume" value="7" />
+        <ctl name="SPKL DAC1 Volume" value="1" />
+        <ctl name="SPKR DAC1 Volume" value="1" />
+        <ctl name="Speaker Mixer Volume" value="3" />
+        <ctl name="Speaker Boost Volume" value="4" />
+        <ctl name="Speaker Volume" value="57" />
+
+      </mixer>
diff --git a/midas.mk b/midas.mk
index 6514cb0..aaba6ef 100644
--- a/midas.mk
+++ b/midas.mk
@@ -37,6 +37,12 @@ PRODUCT_PACKAGES +=  android.hardware.soundtrigger@2.2-impl
 # HAL for handling audio frames
 PRODUCT_PACKAGES += audio.primary.exynos4
 
+# Hal for handling alsa controls, for instance the switch between speakers and
+# headphones.
+PRODUCT_PACKAGES += libaudioroute
+PRODUCT_COPY_FILES += \
+    $(LOCAL_PATH)/audio/mixer_paths.xml:$(TARGET_COPY_OUT_VENDOR)/etc/mixer_paths.xml
+
 # We do need debug utilities on the target to enable users to be able to give
 # certain information without needing to recompile an image. In addition it
 # makes experimenting with audio easier.