Fix Initial Volume for Jabra

1 files changed, 175 insertions, 0 deletions

diff --git a/conf.d/project/alsa.d/README.md b/conf.d/project/alsa.d/README.md
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+
+Alsa Configuration is not complex, but it's heavy and every except intuitive. 
+
+In order to set your configuration move step by step. And verify at each new step that you did not introduce a regression.
+
+### Make sure your board is not taken by PulseAudio
+
+* Pavucontrol is your friend. Go in device configuration and switch to off the device you want to make available to ALSA.
+* Check for your device list with 'play -l'. Note that just after card number your get an alias for your sound card. 
+  it is simpler to use this alias, card number will change depending on plug/unplug of device when this alias name
+  is more stable (except for few stupid driver who use 'USB' as sound card name.
+* When your know your sound alias (eg:v1340 in mu case) you can test it with 'speaker-test -D v1340 -c2 -twav'. You may also
+  use sound card number with 'speaker-test -D hw:0 -c2 -twav'. Nevertheless as said previously this number is not stable.
+* you are now ready to write your $HOME/.asoundrc config
+
+Note that $HOME/.asoundrc is loaded within libasound client and not by Alsa kernel, this is the reason why you do not need
+to activate any control or restart a daemon for modifications to be taken in account.
+
+To use ALSA with AAAA and the controller you need to write 1 section in your ALSA config
+ 
+* Sound Card Mixer: Allows multiple audio stream to be played on the same sound card. If hardware support mixer, Alsa will use it. If  
+  not it will provide mixing by software.
+* Audio Role Volume: They provide independent volume for each audio role. For reference, we use Alsa softvolume, depending on 
+  your hardware you may have this directly avaliable from your sound card.
+* Authorised Audio PCM: those channel are designed for applications we do not trust and then enforce AAAA control check
+  before granting the access to a given channel. 
+
+### Sound Card Mixer
+
+```
+pcm.SoundCardMixer {
+    type dmix
+    ipc_key 1024
+    ipc_key_add_uid false
+    ipc_perm 0666   # mixing for all users
+
+    # Define target effective sound card (cannot be a plugin)
+    slave { pcm "hw:v1340" } #Jabra Solmate
+
+    # DMIX can only map two channels
+    bindings {
+        0 0
+        1 1
+    }
+}
+```
+
+Warning: if you have more than one Mixer each of them should have a unique ipc_key. You sound card alias move in the slave section.
+When this is done you may try your mixer with:
+
+```
+ speaker-test -D MyMixerPCM -c2 -twav
+```
+
+
+### Audio Role
+
+```
+pcm.NavigationRole {
+    type        softvol
+
+    # Point Slave on HOOK for policies control
+    slave.pcm   "SoundCardMixer"
+
+    # name should match with HAL but do not set card=xx
+    control.name    "Playback Navigation"
+
+}
+
+```
+
+The slave you point to your SoundCardMixer, and the control.name should be EXACTLY the same as the one defined in your HAL.
+
+
+WARNING: The control here  "Playback Navigation" is a user defined kernel control. It means that this kernel is created in
+kernel space, but that its action happen in user space. When create those control remains visible until you reset your
+sound card (eg: unplug USB), but they are save each time you reboot. It is recommended to start AAAA binder before testing
+your softvol audio role channel. If you do the opposite the control will be create by Alsa Plugin and this will not inherit
+of the default value you have in your HAL.
+
+When in place you should test it with:
+```
+ speaker-test -D NavigationRole -c2 -twav
+```
+
+IMPORTANT: control volume are attache to your physical hardware and not to intermediary level (Softvol or Mixer). To see the
+newly created channel you should use
+```
+  amixer -Dhw:v1340 controls | grep -i playback
+```
+
+## Authorised Audio PCM
+
+This PCM is supervised with the AAAA audio hook plugin. The pluging and will any application request on this PCM and will
+1st request an autorisation from AAAA controller to grant access for the client application. To do so, two things:
+* the plugin should be declared (only once)
+* you should declare as many authorized PCM as you need.
+
+### Plugin declaration
+
+```
+pcm_hook_type.MyHookPlugin {
+    install "AlsaInstallHook"
+    lib "/home/fulup/Workspace/AGL-AppFW/audio-bindings-dev/build/Alsa-Plugin/Alsa-Policy-Hook/policy_hook_cb.so"
+}
+
+```
+
+Lib is the path where to find AAAA Alsa hook plugin, install is the name of the init function it should not be changed.
+
+
+When your plugin is defined you may declare your authorised PCM. Those PCM like softvol will take a slave, typically a lower
+level of the audio role, or directly a mixer if your goal is to protect directly the Mixer. The AAAA Plugin hook take as
+
+```
+pcm.AuthorisedToNavigationOnly {
+    type hooks
+    slave.pcm "NavigationRole"
+    # Defined used hook sharelib and provide arguments/config to install func
+    hooks.0 {
+        type "MyHookPlugin"
+        hook_args {
+            verbose true # print few log messages (default false);
+
+            # Every Call should return OK in order PCM to open (default timeout 100ms)
+            uri   "ws://localhost:1234/api?token=audio-agent-token&uuid=audio-agent-session"
+            request {
+                # Request autorisation to write on navigation
+                RequestNavigation {
+                    api    "control"
+                    verb   "dispatch"
+	            query  "{'target':'navigation', 'args':{'device':'Jabra SOLEMATE v1.34.0'}}"
+                }
+            }
+            # map event reception to self generated signal
+            event {
+                pause  30
+                resume 31
+                stop   3
+            }
+        }
+    }
+}
+
+```
+
+ * The slave is the PCM that application will be transfer to if access to control is granted. 
+ * Request is a suite à control action that respond to AGL standard application framework API
+ * Event is the mapping of signal an appplication will receive in case AAAA controller push event to the audio application.
+
+When using AAAA controller, most action should be transfert to the controller that will take action to authorise/deny the access. 
+Nevertheless it is also possible to directly access a lower level (e.g. call alsa Use Case Manager). People may also have their
+own audio policy engine and request it directly from here.
+
+To test this last part your need to have a controller ready to respond to your request. Otherwise control will systematically
+be denied. When your AAAA controller is ready to serve your request you may check this with
+```  
+  amixer -Dhw:AuthorisedToMusicOnly controls | grep -i playback
+  amixer -Dhw:AuthorisedToNavigationOnly controls | grep -i playback
+```
+
+IMPORTANT: you need at least to audio role to really test this part. While you may assert with one channel that your flow
+to accept/deny application works. You need two simultaneous audio stream to really play with the control. Typically when playing
+music if you send a navigation message then the audio will be lower during the rendering of the navigation message.
+
+The action on how you lower an audio role when an other one with a higger level of priority come in place not defined at the
+plugin level, but in the AAAA controller, where the API control/dispatch?target=xxxxx will execute a set of actions corresponding
+the set/unset accept/deny of requested control.
+
+Remark: to understand what is happening it is a good idea to have an alxamixer option on the your soundcard
+```
+ amixer -Dhw:v1340
+```
+
+(!) Do not forget to replace 'hw:v1340' by what ever is the alias of your sound card.
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