====== Testing the Linux Kernel driver for the Lattice iCE40 FPGA ======

Demonstration and testing of the new Linux Kernel driver for the Lattice iCE40 FPGA with sigrok, including an introduction to device-tree and driver development.

* [[https://odysee.com/@OpenTechLab:f/otl-002-ice40-linux-kernel-driver:5|odysee]] * [[https://www.youtube.com/watch?v=nIEB1VAGUcs|YouTube]] * [[https://peertube.social/videos/watch/80e5c173-093d-4e5a-981b-1bc0b98f4f2a|peertube.social]]

===== IceStorm FPGA Synthesis Tool-Chain ===== [[http://www.clifford.at/icestorm/]] ===== Patches ===== - [[https://patchwork.kernel.org/patch/9479207/|of: Add vendor prefix for Lattice Semiconductor]] - [[https://patchwork.kernel.org/patch/9479209/|Documentation: Add binding document for Lattice iCE40 FPGA manager]] - [[https://patchwork.kernel.org/patch/9479211/|fpga: Add support for Lattice iCE40 FPGAs]] ===== Device Tree ===== [[https://github.com/raspberrypi/linux/blob/rpi-4.4.y/arch/arm/boot/dts/bcm2708-rpi-b.dts|Raspberry Pi Device Tree]] ==== Overlay ====


/dts-v1/;
/plugin/;

/ {
  compatible="brcm,bcm2708";

  fragment@0 {
    target = <&spi0>;
    __overlay__ {
      status = "okay";

      spidev@0 {
        status = "disabled";
      };

      spidev@1 {
        status = "disabled";
      };
    };
  };

  fragment@1 {
    target = <&spi0>;

    __overlay__ {
      /* needed to avoid dtc warning */
      #address-cells = <1>;
      #size-cells = <0>;

      ice40: ice40@0 {
        compatible = "lattice,ice40-fpga-mgr";
	reg = <0>;
        spi-max-frequency = <10000000>;
        cdone-gpios = <&gpio 24 0>;
	reset-gpios = <&gpio 22 1>;
      };
    };
  };

};

==== Test Firmware ==== === Makefile ===


outdir=_out/
src=

synthesize: $(outdir)counter.bin

$(outdir)counter.bin: counter.v counter.pcf $(src)
	mkdir -p $(outdir)
	yosys -q -p "synth_ice40 -blif $(outdir)counter.blif" counter.v $(src)
	arachne-pnr -d 8k -p counter.pcf $(outdir)counter.blif -o $(outdir)counter.txt
	icepack $(outdir)counter.txt $(outdir)counter.bin

.PHONY: synthesize

=== counter.v ===


module top(input ref_12mhz, output test1, output test2, output [7:0] leds);

	reg [23:0] counter = 0;
	always @(posedge ref_12mhz) counter <= counter + 1;

	assign leds[0:7] = counter[16:23];

	assign test1 = counter[4];
	assign test2 = !counter[4];

endmodule

=== counter.pcf ===


set_io ref_12mhz J3

set_io test1     M1
set_io test2     M2

set_io leds[0]   B5
set_io leds[1]   B4
set_io leds[2]   A2
set_io leds[3]   A1
set_io leds[4]   C5
set_io leds[5]   C4
set_io leds[6]   B3
set_io leds[7]   C3

===== Credits ===== * Intro Music: [[http://freemusicarchive.org/music/Logan_Takahashi/Live_at_WFMU_on_Champ_Sound_with_DJ_Guy_4282016/|Logan Takashi - Orb-O]] (CC-BY-NC-ND). ===== Around the Web ===== * [[https://hackaday.com/2017/04/13/lattice-ice40-fpga-configured-by-linux-kernel/|HackADay Article]]