Exporting hps gpio pin to device tree | LTC2308

Hi everyone,

I'm trying to make ltc2308 driver work on de1soc board. Main issue for me is CONVST pin.

LTC2308 works fine for me on NIOS processor (FPGA side), but I need to implement it on hps side, as device in Linux.

I have exported SPI from HPS and connected them to ADC pins.

Vhdl code:

ADC_CS_n : out std_logic;
ADC_DIN : out std_logic;
ADC_DOUT : in std_logic;
ADC_SCLK : out std_logic;

hps_0_spim0_txd => ADC_DIN,
hps_0_spim0_rxd => ADC_DOUT,
hps_0_spim0_ss_in_n => '1',
hps_0_spim0_ss_0_n => ADC_CS_n,

hps_0_spim0_sclk_out_clk => ADC_SCLK,

Problem is, i don't know how to see exported gpio pin in device tree so I can assign it as conversion-start pin in device tree node of ltc2308.

Also, I tried to add PIO component and assign it to GPIO header, to make it work like it was done on this example: github link

Result is given in attachments, it's just zeroed. Like the CONVST pin isn't working right.