This is a kernel driver for sound on Macs with Cirrus 8409 HDA chips. Sound output is now reasonably complete and integrated with Linux. Sound input still needs work.
It will play audio through Internal speakers or headphones.
The primary audio should be set to Analogue Stereo Output in the Settings Audio dialog.
Sound recording from internal mike and headset mike is not yet fully interfaced with Linux user side.
The recorded sound level is very low but this is the sound level as returned in OSX. Amplification will be required eg using something like PulseEffects.
The hardware device sound format is limited to 2/4 channel 44.1 kHz S24_LE S32_LE. As long as use the default device volume control, other formats, frequencies work.
NOTA BENE: The direct hardware device (hw:0,0) and plughw:0,0 device have NO volume control so will be VERY loud!
Currently this works with MAX98706, SSM3515 and TAS5764L amplifiers. It will NOT work with other amplifiers as each amplifier requires specific programming.
Power down/sleep completely unknown and untested. At the moment everything is permanently powered on.
The Apple speaker setup is 4 speakers as a left tweeter, left woofer, right tweeter and right woofer so this is actually a classic HiFi stereo (ie 2 channel) speaker system. (These names are listed in the layout files under AppleHDA.kext/Contents/Resources).
The channel order for Linux has been modified to left tweeter, right tweeter and left woofer, right woofer as this fits in with the Linux way much better.
The driver also has been modified to duplicate a stereo sound source onto the second stereo channel so all speakers are driven (this essentially replicates the snd_hda_multi_out_analog_prepare function).
This will not sound the same as Apple (which is known to be using specific digital filter effects in CoreAudio).
To create a more Apple-like sound requires creating eg an Alsa pseudo device to channel duplicate a stereo sound and apply different digital filters to the tweeter and woofer channels.
NOTE. My primary testing kernel is now Ubuntu LTS 22.04 5.15.
The following installation setup provided by leifliddy.
fedora package install
dnf install wget make gcc kernel-devel
ubuntu package install
apt install wget make gcc linux-headers-generic
arch package install
pacman -S wget make gcc linux-headers
void package install
xbps-install -S wget make gcc linux-headers
build driver
git clone https://github.com/davidjo/snd_hda_macbookpro.git
cd snd_hda_macbookpro/
#run the following command as root or with sudo
./install.cirrus.driver.sh
reboot