iBasso DX50/DX90: User selectable USB mode.

Depends on http://gerrit.rockbox.org/r/#/c/1043/.

This patch adds a new setting in Settings -> General -> System: USB Mode.

Usable in Quickscreen and Shortcuts.

Possible settings are:
- Mass Storage: The default, on USB connect export the internal and external
drives as usual. Rockbox will exit gracefully in this case, since the internal
drive (/mnt/sdcard) is exported as mass storage device and Android prevents
Rockbox from continued execution.
- Charge Only: USB charge only, do not export the internal and external drives.
This will not close Rockbox.
- ADB: Enable the Android Debug Bridge. This will not close Rockbox.

Charge only and ADB are actually the same, since it is not yet established if
charge only is doable without adb and major hooks into Android.

German translation provided.

This may be genric for Android based devices but is only enabled
for iBasso Devices. Other maintainers may choose do adopt this.

Change-Id: I616247c29946c6595ebcf8f0c14b2410c9f0498b

1 files changed, 2 insertions, 0 deletions

diff --git a/apps/settings.c b/apps/settings.c
index be7b7c30e6..a0e20839ed 100644
--- a/apps/settings.c
+++ b/apps/settings.c
@@ -107,6 +107,7 @@ struct system_status global_status;
 
 #if defined(DX50) || defined(DX90)
 #include "governor-ibasso.h"
+#include "usb-ibasso.h"
 #endif
 
 
@@ -1088,6 +1089,7 @@ void settings_apply(bool read_disk)
 
 #if defined(DX50) || defined(DX90)
     ibasso_set_governor(global_settings.governor);
+    ibasso_set_usb_mode(global_settings.usb_mode);
 #endif
 
     /* This should stay last */