From the reference design and documentation, I understood that the HDMI audio output is also supported in the reference design. So far I haven't gotten this to work, though the rest of the HDMI works fine.
There are two drivers available: "snd_soc_adv7511_hdmi" and "snd_soc_axi_spdif". Which is the one that does audio output over HDMI? They both claim to be the one in their descriptions.
It appears the CPU-to-codec link is missing, when I load the driver, I receive the following on dmesg output:
drm_kms_helper 28330 3 adi_axi_hdmi,drm_kms_cma_helper,adv7511, Live 0xbf00b000
Probably something I missed in the kernel config, but I cannot figure out what.
I got as far as building and loading the modules. Though the codec and the DAI are there, the driver isn't listed with ALSA.
I copied the changes to the DTS into mine, and merged the audio branch…
As for firmware loading, this is what happens when I plug in an USB wifi stick into the USB port. It loads the modules and firmware automatically:
usb 1-1: new high-speed USB device number 2 using xusbps-ehci
cfg80211: Calling CRDA to update world regulatory domain
usb 1-1: ath9k_htc: Firmware htc_9271.fw requested
usbcore: registered new interface driver ath9k_htc
usb 1-1: ath9k_htc: Transferred FW: htc_9271.fw, size: 51272
ath9k_htc 1-1:1.0: ath9k_htc: HTC initialized with 33 credits
ath9k_htc 1-1:1.0: ath9k_htc: FW Version: 1.3
ath: EEPROM regdomain: 0x809c
ath: EEPROM indicates we should expect a country code
ath: doing EEPROM country->regdmn map search
ath: country maps to regdmn code: 0x52
ath: Country alpha2 being used: CN
ath: Regpair used: 0x52
ieee80211 phy0: Atheros AR9271 Rev:1
Registered led device: ath9k_htc-phy0
If you need an mdev based image, you an simply use "mine", just build "my-image" from https://github.com/milosoftware/meta-zynq