nuttx/audio: add fake audio driver.

The fake audio driver aims to easily simulate the functions of audio driver through reading and writing files.
With it, you can conveniently customize and define various capture or playback audio drivers for debugging or automated testing.

Signed-off-by: yaojingwei <yaojingwei@xiaomi.com>

arch/sim/src/sim/sim_initialize.c

@@ -26,6 +26,7 @@
 
 #include <nuttx/arch.h>
 #include <nuttx/audio/audio.h>
+#include <nuttx/audio/audio_fake.h>
 #include <nuttx/kthread.h>
 #include <nuttx/motor/foc/foc_dummy.h>
 #include <nuttx/mtd/mtd.h>
@@ -298,6 +299,12 @@ void up_initialize(void)
 
   audio_register("mixer", sim_audio_initialize(false, false));
 
+#ifdef CONFIG_AUDIO_FAKE
+  /* Register fake audio driver */
+
+  audio_fake_initialize();
+#endif
+
 #endif
 
 #ifdef CONFIG_SIM_USB_DEV

cmake/nuttx_mkconfig.cmake

@@ -69,6 +69,7 @@ set(DEQUOTELIST
     "CONFIG_TTY_LAUNCH_ENTRYPOINT" # Name of entry point from tty launch
     "CONFIG_TTY_LAUNCH_ARGS" # Argument list of entry point from tty launch
     "CONFIG_BOARD_MEMORY_RANGE" # Memory range for board
+    "CONFIG_FAKE_AUDIO_DEVICE_PARAMS" # Arguments for the fake audio device
     # NxWidgets/NxWM
     "CONFIG_NXWM_BACKGROUND_IMAGE" # Name of bitmap image class
     "CONFIG_NXWM_CALIBRATION_ICON" # Name of bitmap image class

drivers/audio/Kconfig

@@ -518,4 +518,52 @@ config AUDIO_DMA
 	depends on AUDIO
 	depends on DMA
 
+config AUDIO_FAKE
+	bool "Fake audio device"
+	default n
+	depends on AUDIO
+	---help---
+		A fake audio device driver to simplify testing of audio
+		capture and playback.
+
+if AUDIO_FAKE
+
+config FAKE_AUDIO_DEVICE_PARAMS
+	string "fake audio device params"
+	default ""
+	---help---
+		This is a params for fake audio device. The format like:
+		{dev_name, playback, sample_rates[4], channels, format[4], period_time, periods}.
+
+		- dev_name (string): pcm2c or pcm2p or others.
+		- playback (bool): true or false.
+		- sample_rates(uint32 array): {16000, 32000}.
+		- channels  (uint8, {min_chan, max_chan}): {1, 2}.
+		- format(uint8 array): {8,16,32}.
+		- period_time(uint32): 100, unit ms.
+		- periods    (uint32): 4, buffer cnt.
+		e.g:
+			{"pcm2c", false, {8000, 16000, 44100}, {1, 2}, {16}, 100, 4},
+			{"pcm2p", true, {8000, 16000, 44100}, {1, 2}, {16}, 100, 4},
+
+config FAKE_AUDIO_DATA_PATH
+	string "fake audio device data path"
+	default "/data/"
+	---help---
+		This dir is used to store the audio file for virtual capture or playback device.
+		The filename for capture device should comply with the format "devname_samplerate_channels_format.pcm".
+		e.g: pcm2c_16000_2_16.pcm.
+		The filename format of playback device is the same as capture device.
+		e.g: pcm2p_16000_2_16.pcm.
+
+config AUDIO_FAKE_MSG_PRIO
+	int "Fake audio device message priority"
+	default 1
+
+config AUDIO_FAKE_WORKER_STACKSIZE
+	int "Fake audio device worker thread stack size"
+	default 768
+
+endif # AUDIO_FAKE
+
 endif # DRIVERS_AUDIO

drivers/audio/Make.defs

@@ -87,6 +87,10 @@ ifeq ($(CONFIG_AUDIO_NULL),y)
 CSRCS += audio_null.c
 endif
 
+ifeq ($(CONFIG_AUDIO_FAKE),y)
+CSRCS += audio_fake.c
+endif
+
 ifeq ($(CONFIG_AUDIO_TONE),y)
 CSRCS += tone.c
 endif

include/nuttx/audio/audio_fake.h

@@ -0,0 +1,52 @@
+/****************************************************************************
+ * include/nuttx/audio/audio_fake.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_NUTTX_AUDIO_AUDIO_FAKE_H
+#define __INCLUDE_NUTTX_AUDIO_AUDIO_FAKE_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#ifdef CONFIG_AUDIO_FAKE
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+int audio_fake_initialize(void);
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* CONFIG_AUDIO_FAKE */
+#endif /* __INCLUDE_NUTTX_AUDIO_AUDIO_FAKE_H */

tools/cfgdefine.c

@@ -65,6 +65,7 @@ static const char *dequote_list[] =
   "CONFIG_TTY_LAUNCH_ENTRYPOINT",         /* Name of entry point from tty launch */
   "CONFIG_TTY_LAUNCH_ARGS",               /* Argument list of entry point from tty launch */
   "CONFIG_BOARD_MEMORY_RANGE",            /* Memory range for board */
+  "CONFIG_FAKE_AUDIO_DEVICE_PARAMS",      /* Arguments for the fake audio device */
 
   /* NxWidgets/NxWM */