[PATCH v2 BlueZ] android: Add initial Android Bluetooth Audio protocol API doc

[Luiz Augusto von Dentz <luiz.dentz@gmail.com>]

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This IPC is used to communicate Android BlueZ daemon and AudioFlinger
plugin.
---
v2: Rework IPC commands to match Android Audio HAL

 android/Makefile.am       |  3 +-
 android/audio-ipc-api.txt | 85 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 87 insertions(+), 1 deletion(-)
 create mode 100644 android/audio-ipc-api.txt

diff --git a/android/Makefile.am b/android/Makefile.am
index 79f30d7..ac00bb2 100644
--- a/android/Makefile.am
+++ b/android/Makefile.am
@@ -111,4 +111,5 @@ EXTRA_DIST += android/Android.mk android/hal-ipc-api.txt android/README \
 		android/pixit-gap.txt android/pixit-hid.txt \
 		android/pixit-opp.txt android/pixit-pan.txt \
 		android/pixit-pbap.txt android/pts-gap.txt android/pts-hid.txt \
-		android/pts-opp.txt android/pts-pbap.txt
+		android/pts-opp.txt android/pts-pbap.txt \
+		android/audio-ipc-api.txt
diff --git a/android/audio-ipc-api.txt b/android/audio-ipc-api.txt
new file mode 100644
index 0000000..e9a2136
--- /dev/null
+++ b/android/audio-ipc-api.txt
@@ -0,0 +1,85 @@
+Bluetooth Audio Plugin
+======================
+
+The audio plugin happen to be in a different socket but all the rules for
+HAL socket apply here as well, the abstract socket name is
+"\0bluez_audio_socket" (tentative):
+
+	.--Android--.                             .---Audio---.
+	|  daemon   |                             |   Plugin  |
+	|           |          Command            |           |
+	|           | <-------------------------- |           |
+	|           |                             |           |
+	|           | --------------------------> |           |
+	|           |          Response           |           |
+	|           |                             |           |
+	|           |                             |           |
+	|           |                             |           |
+	'-----------'                             '-----------'
+
+
+	Audio HAL                               Daemon
+	----------------------------------------------------
+
+	call dev->open()                    --> command 0x01
+	return dev->open()                  <-- response 0x01
+
+	call dev->open_output_stream()      --> command 0x03
+	return dev->open_output_stream()    <-- response 0x03
+
+	call stream_in->read()              --> command 0x05
+	return stream_in->read()            <-- response 0x05
+
+	call stream_in->common.standby()    --> command 0x06
+	return  stream_in->common.standby() <-- response 0x06
+
+	call dev->close_output_stream()     --> command 0x04
+	return dev->close_output_stream()   <-- response 0x04
+
+	call dev->close()                   --> command 0x02
+	return dev->close()                 <-- response 0x02
+
+Identifier: "audio" (BT_AUDIO_ID)
+
+	Opcode 0x00 - Error response
+
+		Response parameters: Status (1 octet)
+
+	Opcode 0x01 - Open Audio Endpoint commmand
+
+		Command parameters: Service UUID (16 octets)
+				    Codec ID (1 octets)
+				    Codec capabilities length (1 octets)
+				    Codec capabilities (variable)
+				    Number of codec presets (1 octets)
+				    Codec preset # length (1 octets)
+				    Codec preset # configuration (variable)
+				    ...
+		Response parameters: Endpoint ID (1 octets)
+
+	Opcode 0x02 - Close Audio Endpoint command
+
+		Command parameters: Endpoint ID (1 octets)
+		Response parameters: <none>
+
+	Opcode 0x03 - Open Stream command
+
+		Command parameters: Endpoint ID (1 octets)
+		Response parameters: Codec configuration length (1 octets)
+				     Codec configuration (1 octets)
+				     File descriptor (inline)
+
+	Opcode 0x04 - Close Stream command
+
+		Command parameters: Endpoint ID (1 octets)
+		Response parameters: <none>
+
+	Opcode 0x05 - Resume Stream command
+
+		Command parameters: Endpoint ID (1 octets)
+		Response parameters: <none>
+
+	Opcode 0x06 - Suspend Stream command
+
+		Command parameters: Endpoint ID (1 octets)
+		Response parameters: <none>
-- 
1.8.3.1