PS SPI driver not working

[herbertp]

Both PS SPI buses seem to be unsupported/not detected properly.

After enabling both SPI master entries in the devicetree, the cadence spi driver does not detect or handle any of them and no SPI bus entries are created in /sys/bus/spi

spi0: spi@e0006000
spi1: spi@e0007000

[herbertp]

I think I figured this one out: the driver doesn't log anything when there is no client on the SPI bus so it very much looks like it doesn't recognize the devicetree entry.

Here is an entry which works and creates a userspace accessible device:

        spi0: spi@e0006000 { 
            compatible = "xlnx,zynq-spi-r1p6", "cdns,spi-r1p6";
            reg = <0xe0006000 0x1000>;
            status = "okay";
            interrupt-parent = <&intc>;
            interrupts = <0 26 4>;
            clocks = <&clkc 25>, <&clkc 34>;
            clock-names = "ref_clk", "pclk";
            num-cs = <4>;
            num-chip-select = <4>;
            is-decoded-cs = <0>;
            #address-cells = <1>;
            #size-cells = <0>;

            spidev@0 {
                compatible = "spidev";
                reg = <0>;
                spi-max-frequency = <25000000>;
                #address-cells = <1>;
                #size-cells = <0>;
            };
        };

We probably want to add this as examples to the devicetree.