nikkov

Thanks.
Actually everything's been done by a kind genius, mr. Zhang from the very Rockchip. He is a very responsive and caring person! I had only to slightly touch the simple-card-utils.c so the driver sets the clock accordingly to the sample rate (there was only fixed multiplier available OOB).
 
The docs, as I cited above, say nothing on whether clkin_i2s can be an input. Yes, it can, and even on the same pin. We don't even need to mod the code, everything's done in devicetree!
We just have to declare this clock in the DTS, and (in my case) set it as gpio-mux-clock, not a fixed one. This was my insane idea, I didn't believe it could work, but it did. The whole clock tree of this CPU looks beautifully logical, one can do miracles with it, once he catches the idea.
Finally we have a precious hi-end data source for a serious grade DAC. The difference from Sitara that I love is 6 cores, PCIE for m.2 SSD, MIPI for a nice display, and lots of nice peripheria.
 
So, the DTS:
+ osc45m: osc45m { + compatible = "fixed-clock"; + #clock-cells = <0>; + clock-frequency = <45158400>; + }; + + osc49m: osc49m { + compatible = "fixed-clock"; + #clock-cells = <0>; + clock-frequency = <49152000>; + }; + clkin_i2s: clkin_i2s { - compatible = "fixed-clock"; + compatible = "gpio-mux-clock"; #clock-cells = <0>; - clock-frequency = <12288000>; clock-output-names = "clkin_i2s"; + clocks = <&osc45m>, <&osc49m>; + select-gpios = <&gpio0 RK_PB6 GPIO_ACTIVE_HIGH>; };  

SPDIF may be enabled by simple overlay file with this content:
/dts-v1/; /plugin/; / { compatible = "friendlyelec,nanopi-neo3", "rockchip,rk3328"; fragment@0 { target = <&spdif_out>; __overlay__ { status = "okay"; }; }; }; compile and install:
sudo armbian-add-overlay spdif-out-enable.dts reboot and check:
nik@nanopineo3:~$ aplay -l **** List of PLAYBACK Hardware Devices **** card 0: I2S [I2S], device 0: ff010000.i2s-pcm5102a-hifi pcm5102a-hifi-0 [ff010000.i2s-pcm5102a-hifi pcm5102a-hifi-0] Subdevices: 1/1 Subdevice #0: subdevice #0 card 1: SPDIF [SPDIF], device 0: ff030000.spdif-dit-hifi dit-hifi-0 [ff030000.spdif-dit-hifi dit-hifi-0] Subdevices: 1/1 Subdevice #0: subdevice #0  

Not related to armbian, but I made some work with friendlyarm kernel 4.11.2 for support i2s driver for h3/h5 with support 16/24 bit master/slave mode i2s (link) and build Volumio image for nanopi neo (link). In future I want to get same in mainline kernel.

Not related to armbian, but I made some work with friendlyarm kernel 4.11.2 for support i2s driver for h3/h5 with support 16/24 bit master/slave mode i2s (link) and build Volumio image for nanopi neo (link). In future I want to get same in mainline kernel.