audio: Move hosted audio "codec" drivers into their respective target dirs

They are nearly entirely generic wrappers around ALSA controls, unique
per target, and are ripe for further consolidation.

Change-Id: I05e4a450e3e89e03616906601c4f8fa46200dff5

firmware/target/hosted/fiio/fiiolinux_codec.c

@@ -0,0 +1,169 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ *
+ * Copyright (c) 2018 Marcin Bukat
+ * Copyright (c) 2019 Roman Stolyarov
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include "config.h"
+#include "audio.h"
+#include "audiohw.h"
+#include "system.h"
+#include "kernel.h"
+#include "panic.h"
+#include "sysfs.h"
+#include "alsa-controls.h"
+#include "pcm-alsa.h"
+#include <sys/ioctl.h>
+
+static int ak_hw = -1;
+
+static      int vol_sw[2] = {0};
+static long int vol_hw[2] = {0};
+
+static void hw_open(void)
+{
+    ak_hw = open("/dev/ak4376", O_RDWR);
+    if(ak_hw < 0)
+        panicf("Cannot open '/dev/ak4376'");
+
+    if(ioctl(ak_hw, 0x20003424, 0) < 0)
+    {
+        panicf("Call cmd AK4376_POWER_ON fail");
+    }
+}
+
+static void hw_close(void)
+{
+    if(ioctl(ak_hw, 0x20003425, 0) < 0)
+    {
+        panicf("Call cmd AK4376_POWER_OFF fail");
+    }
+    close(ak_hw);
+    ak_hw = -1;
+}
+
+void audiohw_preinit(void)
+{
+    alsa_controls_init("default");
+    hw_open();
+    // NOTE:
+    // Of the exported controls, only these do anything:
+    // 10 DACL Playback Volume
+    // 11 DACR Playback Volume
+    // 12 Low Mode Switch  (see table 25 in datasheet, not simple..)
+    audiohw_mute(false);
+}
+
+void audiohw_postinit(void)
+{
+}
+
+void audiohw_close(void)
+{
+    hw_close();
+    alsa_controls_close();
+}
+
+void audiohw_set_frequency(int fsel)
+{
+    (void)fsel;
+}
+
+static int muted = -1;
+
+void audiohw_set_volume(int vol_l, int vol_r)
+{
+    int vol[2];
+
+    if (ak_hw < 0)
+       return;
+
+    vol[0] = vol_l / 20;
+    vol[1] = vol_r / 20;
+
+    for (int i = 0; i < 2; i++)
+    {
+        if (vol[i] > -56)
+        {
+            if (vol[i] < -12)
+            {
+                vol_hw[i] = 1;
+                vol_sw[i] = vol[i] + 12;
+            }
+            else
+            {
+                vol_hw[i] = 25 - (-vol[i] * 2);
+                vol_sw[i] = 0;
+            }
+        }
+        else
+        {
+            // Mute
+            vol_hw[i] = 0;
+            vol_sw[i] = 0;
+        }
+    }
+
+    if (!muted) {
+       alsa_controls_set_ints("DACL Playback Volume", 1, &vol_hw[0]);
+       alsa_controls_set_ints("DACR Playback Volume", 1, &vol_hw[1]);
+       pcm_set_mixer_volume(vol_sw[0], vol_sw[1]);
+    }
+}
+
+void audiohw_mute(int mute)
+{
+    long int vol0 = 0;
+
+    if (ak_hw < 0 || muted == mute)
+       return;
+
+    muted = mute;
+
+    if(mute)
+    {
+        alsa_controls_set_ints("DACL Playback Volume", 1, &vol0);
+        alsa_controls_set_ints("DACR Playback Volume", 1, &vol0);
+        pcm_set_mixer_volume(0, 0);
+    }
+    else
+    {
+        alsa_controls_set_ints("DACL Playback Volume", 1, &vol_hw[0]);
+        alsa_controls_set_ints("DACR Playback Volume", 1, &vol_hw[1]);
+        pcm_set_mixer_volume(vol_sw[0], vol_sw[1]);
+    }
+}
+
+void audiohw_set_filter_roll_off(int value)
+{
+#if 0 //  defined(FIIO_M3K_LINUX)
+    if (ak_hw < 0)
+       return;
+
+    /* 0 = Sharp;
+       1 = Slow;
+       2 = Short Sharp
+       3 = Short Slow */
+    // AK4376 supports this but the control isn't wired into ALSA!
+    long int value_hw = value;
+    alsa_controls_set_ints("AK4376 Digital Filter", 1, &value_hw);
+#endif
+    (void)value;
+}

firmware/target/hosted/fiio/fiiolinux_codec.h

@@ -0,0 +1,12 @@
+#ifndef __FIIOLINUX_CODEC__
+#define __FIIOLINUX_CODEC__
+
+#define AUDIOHW_CAPS (FILTER_ROLL_OFF_CAP)
+#define AUDIOHW_HAVE_SHORT2_ROLL_OFF
+AUDIOHW_SETTING(VOLUME, "dB", 0, 1, -100,  0, -30)
+AUDIOHW_SETTING(FILTER_ROLL_OFF, "", 0, 1, 0, 4, 0)
+#endif
+
+#define AUDIOHW_MUTE_ON_STOP
+
+void audiohw_mute(int mute);