Find a file
Michael McAllister dbd53ef8ae hibyr1: implement USB DAC
Implement the USB Audio Class DAC on the HiBy R1 and R3ProII, driven by
the usb_audio setting from the scaffolding patch: the host plays audio
over USB and the player's CS43131 renders it.

The vendor kernel provides a UAC gadget function "uac_sa" whose char
device /dev/uac_sa delivers the host's PCM: the isochronous OUT frames
are converted to left-justified S16-in-S32 stereo and queued in a kernel
ring, drained with a non-blocking read(). The data path lives in
usb-dac-hiby.c -- a pump thread drains /dev/uac_sa into a small
single-producer/single-consumer ring and the mixer callback hands that
PCM to the codec through the normal ALSA output path. No resampling is
needed because Rockbox clocks the codec at the host-negotiated rate.

The DAC is built on the existing configfs gadget and binds the UDC like
ADB, while usb_power_only keeps the USB thread out of the way. In charge
mode it is a standalone self-bound gadget. In adb mode it is composed
alongside adb on one gadget so the host gets a sound card and adb at
once; uac_sa must be the first-linked function (audio interfaces 0-1)
because the vendor function hard-codes its interface numbers.

The pump is hardware-only, so usb-dac-hiby.c is excluded from simulator
builds; the usb_audio_get_active() playback-interlock stub lives with the
scaffolding.

The R3ProII shares this hosted HiBy port and the same userspace gadget,
and the data path is codec-agnostic, so nothing here is R1-specific.
Only the R1 has been validated on-device.

Co-Authored-By: Claude Opus 4.8
Change-Id: I64c57ede27f411a2c61d41a7e0fa127b51a7b5b9
2026-07-22 15:22:46 -04:00
android chore: Get rid of *all* vestigal CVS '$Id:$' tags 2026-06-01 16:01:18 -04:00
apps hibyr1: add USB DAC scaffolding 2026-07-22 15:22:46 -04:00
backdrops Rockbox for the HiBy R3 Pro II/R1 2025-12-27 15:44:54 -05:00
bootloader [FixRed] sonybootloader has a glyphcache but no open_pathfmt 2026-06-09 02:01:29 -04:00
docs hibyr1: implement USB DAC 2026-07-22 15:22:46 -04:00
firmware hibyr1: implement USB DAC 2026-07-22 15:22:46 -04:00
fonts chore: Get rid of *all* vestigal CVS '$Id:$' tags 2026-06-01 16:01:18 -04:00
icons chore: Get rid of *all* vestigal CVS '$Id:$' tags 2026-06-01 16:01:18 -04:00
lib libspeex: Silence a spurious warning under Clang 2026-07-15 16:22:18 -04:00
manual FS#13938 - Line disappears after %Vf tag and %Vb tag 2026-06-30 13:55:03 -04:00
packaging chore: Get rid of *all* vestigal CVS '$Id:$' tags 2026-06-01 16:01:18 -04:00
tools echoplayer: enable plugins 2026-07-12 08:56:44 -04:00
uisimulator hibyr1: add USB DAC scaffolding 2026-07-22 15:22:46 -04:00
utils themeeditor: only add -Wsfinae-incomplete if compiler supports it 2026-07-19 11:17:05 +01:00
wps chore: Get rid of *all* vestigal CVS '$Id:$' tags 2026-06-01 16:01:18 -04:00
.gitattributes
.gitignore misc: Update gitignore to cover a bunch of utils/* binaries 2026-06-17 13:56:29 -04:00
.gitreview misc: Add a .gitreview file for better gerrit integration 2021-06-24 07:22:19 -04:00

               __________               __   ___.
     Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
     Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
     Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
     Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
                       \/            \/     \/    \/            \/

Build Your Own Rockbox

1. Clone 'rockbox' from git (or extract a downloaded archive).

   $ git clone git://git.rockbox.org/rockbox

     or

   $ tar xJf rockbox.tar.xz

2. Create a build directory, preferably in the same directory as the firmware/
   and apps/ directories. This is where all generated files will be written.

   $ cd rockbox
   $ mkdir build
   $ cd build

3. Make sure you have mips/m68k/arm-elf-gcc and siblings in the PATH. Make sure
   that you have 'perl' in your PATH too. Your gcc cross compiler needs to be
   a particular version depending on what player you are compiling for. These
   can be generated using the rockboxdev.sh script in the /tools/ folder of the
   source.

   $ which arm-elf-eabi-gcc
   $ which perl

4. In your build directory, run the 'tools/configure' script and enter what
   target you want to build for and if you want a debug version or not (and a
   few more questions). It'll prompt you. The debug version is for making a
   gdb version out of it. It is only useful if you run gdb towards your target
   Archos.

   $ ../tools/configure

5. *ploink*. Now you have got a Makefile generated for you.

6. Run 'make' and soon the necessary pieces from the firmware and the apps
   directories have been compiled, linked and scrambled for you.

   $ make
   $ make zip

7. unzip the rockbox.zip on your music player, reboot it and
   *smile*.

If you want to build for more than one target, just create several build
directories and create a setup for each target:

   $ mkdir build-fuzeplus
   $ cd build-fuzeplus
   $ ../tools/configure

   $ mkdir build-xduoox3
   $ cd build-xduoox3
   $ ../tools/configure

Questions anyone? Ask on the mailing list or on IRC. We'll be happy to help you!