[delete]Is the linux SPI driver (/drivers/spi/spi-altera.c) suitable for the QSYS soft SPI IP (3 wire serial)?

Yes. The linux SPI driver(/drivers/spi/spi-altera.c) is suitable for the Qsys soft IP SPI(3 wire serial). 

We can connect the SPI(3 wire serial) to h2f_lw bridge and edit the dts as below:

   spi_0: spi@0x100020000 {
    compatible = "altr,spi-15.1", "altr,spi-1.0";
    reg = <0x00000001 0x00020000 0x00000020>;
    interrupt-parent = <&hps_0_arm_gic_0>;
    interrupts = <0 42 4>;
    clocks = <&clk_0>;
    #address-cells = <1>;
    #size-cells = <0>;
    bus-num = <0>;
    num-chipselect = <1>;
    status = "okay";
    
    spidev0_fpga: spidev@0 {
     compatible =  "rohm,dh2228fv";   /* appended from boardinfo */
     reg = <0>;  /* appended from boardinfo */
     spi-max-frequency = <2500000>;  /* appended from boardinfo */
    };//end spidev@0
   }; //end spi@0x100020000 (spi_0)