Introducing Targets iBasso DX50 & iBasso DX90

The port to for this two targets has been entirely developped by Ilia Sergachev (alias Il or xzcc). His source
can be found at https://bitbucket.org/isergachev/rockbox . The few necesary modifications for the DX90 port
was done by headwhacker form head-fi.org. Unfortunately i could not try out the final state of the DX90 port.
The port is hosted on android (without java) as standalone app. The official Firmware is required to run this port.
Ilia did modify the source files for the "android" target in the rockbox source to make the DX port work. The work I did
was to separate the code for DX50 (&DX90) from the android target.
On this Target Ilia used source from tinyalsa from AOSP. I did not touch that part of the code because I do not understand it.
What else I changed from Ilias sources besides the separation from the target "android":
* removed a dirty hack to keep backlight off
* changed value battery meter to voltage battery meter
* made all plugins compile (named target as "standalone") and added keymaps
* i added the graphics for the manual but did not do anything else for the manual yet
* minor optimizations

known bugs:
* timers are slowed donw when playback is active (tinyalsa related?)
* some minor bugs

Things to do:
* The main prolem will be how to install the app correctly. A guy called DOC2008 added a CWM (by androtab.info) to the
  official firmware and Ilia made a CWM installation script and a dualboot selector (rbutils/ibassoboot, build with
  ndk-build). We will have to find a way to install rockbox in a proper way without breaking any copyrights.
  Maybe ADB is an option but it is not enable with OF by default. Patching the OF is probably the way to go.
* All the wiki and manual

to build:
needed: android ndk installed, android sdk installed with additional build-tools 19.1.0 installed

./tools/configure
select iBasso DX50 or iBasso DX90
make -j apk

the content of rockbox.zip/.rockbox needs to be copied to /system/rockbox/app_rockbox/rockbox/ (rockbox app not needed)
the content of libs/armeabi to /system/rockbox/lib/ (rockbox app needed)

The boot selector is needed as /system/bin/MangoPlayer and the iBasso app as /system/bin/MangoPlayer_original. There
is also the "vold" file. The one from OF does not work with DX50 rockbox (DX90 works!?), the one from Ilia is necessary.

Until we have found a proper way to install it, it can only be installed following the instructions of Ilia on his
bitbucket page, using the CWM-OF and his installation script package.

Change-Id: Ic4faaf84824c162aabcc08e492cee6e0068719d0
Reviewed-on: http://gerrit.rockbox.org/941
Tested: Chiwen Chang <rock1104.tw@yahoo.com.tw>
Reviewed-by: Michael Giacomelli <giac2000@hotmail.com>

1 files changed, 364 insertions, 0 deletions

diff --git a/firmware/target/hosted/android/dx50/pcm-dx50.c b/firmware/target/hosted/android/dx50/pcm-dx50.c
new file mode 100644
index 0000000000..e7695873a0
--- /dev/null
+++ b/firmware/target/hosted/android/dx50/pcm-dx50.c
@@ -0,0 +1,364 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2010 Thomas Martitz
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+
+/*
+ * Based, but heavily modified, on the example given at
+ * http://www.alsa-project.org/alsa-doc/alsa-lib/_2test_2pcm_8c-example.html
+ *
+ * This driver uses the so-called unsafe async callback method and hardcoded device
+ * names. It fails when the audio device is busy by other apps.
+ *
+ * To make the async callback safer, an alternative stack is installed, since
+ * it's run from a signal hanlder (which otherwise uses the user stack). If
+ * tick tasks are run from a signal handler too, please install
+ * an alternative stack for it too.
+ *
+ * TODO: Rewrite this to do it properly with multithreading
+ *
+ * Alternatively, a version using polling in a tick task is provided. While
+ * supposedly safer, it appears to use more CPU (however I didn't measure it
+ * accurately, only looked at htop). At least, in this mode the "default"
+ * device works which doesnt break with other apps running.
+ */
+
+
+#include "autoconf.h"
+
+#include <stdlib.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <errno.h>
+#include "tinyalsa/asoundlib.h"
+#include "tinyalsa/asound.h"
+#include "system.h"
+#include "debug.h"
+#include "kernel.h"
+
+#include "pcm.h"
+#include "pcm-internal.h"
+#include "pcm_mixer.h"
+#include "pcm_sampr.h"
+#include "audiohw.h"
+
+#include <pthread.h>
+#include <signal.h>
+
+static const snd_pcm_format_t format = PCM_FORMAT_S16_LE;    /* sample format */
+static const int channels = 2;                                /* count of channels */
+static unsigned int rate = 44100;                       /* stream rate */
+
+typedef struct pcm snd_pcm_t;
+static snd_pcm_t *handle;
+struct pcm_config config;
+
+static snd_pcm_sframes_t period_size = 512;  /* if set to >= 1024, all timers become even slower */
+static char *frames;
+
+static const void  *pcm_data = 0;
+static size_t       pcm_size = 0;
+
+static int recursion;
+
+static int set_hwparams(snd_pcm_t *handle)
+{
+    int err;
+    if (!frames)
+        frames = malloc(pcm_frames_to_bytes(handle, pcm_get_buffer_size(handle)));
+    err = 0; /* success */
+    return err;
+}
+
+
+/* copy pcm samples to a spare buffer, suitable for snd_pcm_writei() */
+static bool fill_frames(void)
+{
+   size_t copy_n, frames_left = period_size;
+   bool new_buffer = false;
+
+   while (frames_left > 0)
+   {
+       if (!pcm_size)
+       {
+           new_buffer = true;
+           if (!pcm_play_dma_complete_callback(PCM_DMAST_OK, &pcm_data,
+                                               &pcm_size))
+           {
+               return false;
+           }
+       }
+       copy_n = MIN((size_t)pcm_size, pcm_frames_to_bytes(handle, frames_left));
+       memcpy(&frames[pcm_frames_to_bytes(handle, period_size-frames_left)], pcm_data, copy_n);
+
+       pcm_data += copy_n;
+       pcm_size -= copy_n;
+       frames_left -= pcm_bytes_to_frames(handle, copy_n);
+
+       if (new_buffer)
+       {
+           new_buffer = false;
+           pcm_play_dma_status_callback(PCM_DMAST_STARTED);
+       }
+   }
+    return true;
+}
+
+
+static void pcm_tick(void)
+{
+   if (fill_frames())
+   {
+       if (pcm_write(handle, frames, pcm_frames_to_bytes(handle, period_size))) {
+            printf("Error playing sample\n");
+            return;//break;
+       }
+
+   }
+   else
+   {
+       DEBUGF("%s: No Data.\n", __func__);
+       return;//break;
+   }
+}
+
+static int async_rw(snd_pcm_t *handle)
+{
+   int err;
+   snd_pcm_sframes_t sample_size;
+   char *samples;
+
+   /* fill buffer with silence to initiate playback without noisy click */
+   sample_size = pcm_frames_to_bytes(handle, pcm_get_buffer_size(handle)); 
+   samples = malloc(sample_size);
+
+   memset(samples, 0, sample_size);
+
+   err = pcm_write(handle, samples, sample_size);
+   free(samples);
+
+   if (err != 0)
+   {
+           DEBUGF("Initial write error: %d\n", err);
+           return err;
+   }
+   if (pcm_state(handle) == PCM_STATE_PREPARED)
+   {
+           err = pcm_start(handle);
+           if (err < 0)
+           {
+               DEBUGF("Start error: %d\n", err);
+               return err;
+           }
+   }
+    return 0;
+}
+
+void cleanup(void)
+{
+    free(frames);
+    frames = NULL;
+    pcm_close(handle);
+}
+
+void pcm_play_dma_init(void)
+{
+    config.channels = channels;
+    config.rate = rate;
+    config.period_size = period_size;
+    config.period_count = 4;
+    config.format = format;
+    config.start_threshold = 0;
+    config.stop_threshold = 0;
+    config.silence_threshold = 0;
+
+
+   handle = pcm_open(0, 0, PCM_OUT, &config);
+   if (!handle || !pcm_is_ready(handle)) {
+       printf("Unable to open PCM device: %s\n", pcm_get_error(handle));
+       return;
+   }
+
+    pcm_dma_apply_settings();
+
+    tick_add_task(pcm_tick);
+
+    atexit(cleanup);
+    return;
+}
+
+
+void pcm_play_lock(void)
+{
+    if (recursion++ == 0)
+        tick_remove_task(pcm_tick);
+}
+
+void pcm_play_unlock(void)
+{
+    if (--recursion == 0)
+        tick_add_task(pcm_tick);
+}
+
+static void pcm_dma_apply_settings_nolock(void)
+{
+    set_hwparams(handle);
+}
+
+void pcm_dma_apply_settings(void)
+{
+    pcm_play_lock();
+    pcm_dma_apply_settings_nolock();
+    pcm_play_unlock();
+}
+
+
+void pcm_play_dma_pause(bool pause)
+{
+    (void)pause;
+}
+
+
+void pcm_play_dma_stop(void)
+{
+    pcm_stop(handle);
+}
+
+void pcm_play_dma_start(const void *addr, size_t size)
+{
+#if defined(DX50) || defined(DX90)
+   /* headphone output relay: if this is done at startup already, a loud click is audible on headphones. Here, some time later,
+      the output caps are charged a bit and the click is much softer  */
+   system("/system/bin/muteopen");
+#endif
+    pcm_dma_apply_settings_nolock();
+
+    pcm_data = addr;
+    pcm_size = size;
+
+   while (1)
+   {
+       snd_pcm_state_t state = pcm_state(handle);
+       switch (state)
+       {
+           case PCM_STATE_RUNNING:
+               return;
+           case PCM_STATE_XRUN:
+           {
+               printf("No handler for STATE_XRUN!\n");
+               continue;
+           }
+           case PCM_STATE_PREPARED:
+           {   /* prepared state, we need to fill the buffer with silence before
+                * starting */
+               int err = async_rw(handle);
+               if (err < 0)
+                   printf("Start error: %d\n", err);
+               return;
+           }
+           case PCM_STATE_PAUSED:
+           {   /* paused, simply resume */
+               pcm_play_dma_pause(0);
+               return;
+           }
+           case PCM_STATE_DRAINING:
+               /* run until drained */
+               continue;
+           default:
+               DEBUGF("Unhandled state: %d\n", state);
+               return;
+       }
+   }
+}
+
+size_t pcm_get_bytes_waiting(void)
+{
+    return pcm_size;
+}
+
+const void * pcm_play_dma_get_peak_buffer(int *count)
+{
+    uintptr_t addr = (uintptr_t)pcm_data;
+    *count = pcm_size / 4;
+    return (void *)((addr + 3) & ~3);
+}
+
+void pcm_play_dma_postinit(void)
+{
+   return;
+}
+
+void pcm_set_mixer_volume(int volume)
+{
+#if defined(DX50) || defined(DX90)
+    /* -990 to 0 -> 0 to 255 */
+    int val = (volume+990)*255/990;
+#if defined(DX50)
+    FILE *f = fopen("/dev/codec_volume", "w");
+#else /* DX90 */
+    FILE *f = fopen("/sys/class/codec/es9018_volume", "w");
+#endif  /* DX50 */
+    fprintf(f, "%d", val);
+    fclose(f);
+#else
+    (void)volume;
+#endif /* DX50 || DX90 */
+}
+
+#ifdef HAVE_RECORDING
+void pcm_rec_lock(void)
+{
+}
+
+void pcm_rec_unlock(void)
+{
+}
+
+void pcm_rec_dma_init(void)
+{
+}
+
+void pcm_rec_dma_close(void)
+{
+}
+
+void pcm_rec_dma_start(void *start, size_t size)
+{
+    (void)start;
+    (void)size;
+}
+
+void pcm_rec_dma_stop(void)
+{
+}
+
+const void * pcm_rec_dma_get_peak_buffer(void)
+{
+    return NULL;
+}
+
+void audiohw_set_recvol(int left, int right, int type)
+{
+    (void)left;
+    (void)right;
+    (void)type;
+}
+
+#endif /* HAVE_RECORDING */