The YP-CP3 uses Wolfson WM8750. Headphones are wired on OUT2 and
a headphone amplifier enabled by GPIO F2, active high -
all RE from the original firmware.
The original firmware runs the codec as I2S master in its 12 MHz "USB
mode", fed a fixed 12 MHz MCLK, which puts 44.1 kHz at 44.118. Rockbox
instead makes the rk27xx the master and clocks the codec from the codec
PLL at exactly 256 fs (CODEC_SLAVE, as every other rk27xx target with an
external codec), so the codec's CLOCKING register is its normal-mode
256 fs setting at every rate. 96 kHz is left out: the WM8750 cannot take
it at 256 fs.
- config: HAVE_WM8750, CODEC_SLAVE, rates 8-48 kHz; the WM8750 has
hardware tone controls, so HAVE_SW_TONE_CONTROLS goes
- ypcp3/wmcodec-ypcp3.c: register writes over the rk27xx I2C driver
- wm8751.c: on the YP-CP3, power on and drive OUT2 instead of OUT1, set
the volume there, and switch the amplifier with the outputs
- english.lang: the YP-CP3 gets the bass/treble cutoff settings the
WM8750 brings
Tested on a YP-CP3: playback at 44.1 and 48 kHz on headphones, pitch and
volume correct.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Change-Id: I870038fb6a21a9c26b025e3df7c220fd925f49f6
a35f344eef