GPIO protocol, Maaxboard support

.reuse/dep5

@@ -12,6 +12,7 @@ Files:
     examples/i2c_bus_scan/build.zig.zon
     examples/serial/build.zig.zon
     examples/timer/build.zig.zon
+    examples/gpio/build.zig.zon
     examples/blk/build.zig.zon
     examples/blk/basic_data.txt
     examples/blk/basic_data.h
@@ -42,6 +43,7 @@ Files:
     drivers/timer/bcm2835/config.json
     drivers/timer/apb_timer/config.json
     drivers/timer/rk3568/config.json
+    drivers/gpio/imx/config.json
 Copyright: UNSW
 License: BSD-2-Clause
 

build.zig

@@ -29,6 +29,11 @@ const DriverClass = struct {
         rk3568,
     };
 
+    const Gpio = enum {
+        imx,
+        meson,
+    };
+
     const Network = enum {
         imx,
         meson,
@@ -186,6 +191,35 @@ fn addTimerDriver(
     return driver;
 }
 
+fn addGpioDriver(
+    b: *std.Build,
+    gpio_config_include: LazyPath,
+    util: *std.Build.Step.Compile,
+    class: DriverClass.Gpio,
+    target: std.Build.ResolvedTarget,
+    optimize: std.builtin.OptimizeMode,
+) *std.Build.Step.Compile {
+    const driver = addPd(b, .{
+        .name = b.fmt("driver_gpio_{s}.elf", .{@tagName(class)}),
+        .root_module = b.createModule(.{
+            .target = target,
+            .optimize = optimize,
+            .strip = false,
+        }),
+    });
+    const source = b.fmt("drivers/gpio/{s}/gpio.c", .{@tagName(class)});
+    driver.addCSourceFile(.{
+        .file = b.path(source),
+    });
+    driver.addIncludePath(gpio_config_include);
+
+    driver.addIncludePath(b.path("include"));
+    driver.addIncludePath(b.path("include/microkit"));
+    driver.linkLibrary(util);
+
+    return driver;
+}
+
 fn addI2cDriverDevice(
     b: *std.Build,
     util: *std.Build.Step.Compile,
@@ -482,6 +516,13 @@ pub fn build(b: *std.Build) !void {
         // debug error if you do need a serial config but forgot to pass one in.
         const gpu_config_include = LazyPath{ .cwd_relative = gpu_config_include_option };
 
+        const gpio_config_include_option = b.option([]const u8, "gpio_config_include", "Include path to gpio config header") orelse "";
+
+        // TODO: So ideally this is part of the meta.py file
+        // for now we have a config file that defines which gpio/irq is assigned to
+        // all of the driver channels in the gpio driver.
+        const gpio_config_include = LazyPath{ .cwd_relative = gpio_config_include_option };
+
         // Util libraries
         const util = b.addLibrary(.{
             .name = "util",
@@ -698,6 +739,12 @@ pub fn build(b: *std.Build) !void {
         libi2c_raw.addIncludePath(libmicrokit_include);
         libi2c_raw.linkLibrary(util);
         b.installArtifact(libi2c_raw);
+        // Gpio drivers
+        inline for (std.meta.fields(DriverClass.Gpio)) |class| {
+            const driver = addGpioDriver(b, gpio_config_include, util, @enumFromInt(class.value), target, optimize);
+            driver.linkLibrary(util_putchar_debug);
+            b.installArtifact(driver);
+        }
 
         // I2C components
         const i2c_virt = addPd(b, .{

ci/examples/gpio.py

@@ -0,0 +1,39 @@
+#!/usr/bin/env python3
+# Copyright 2026, UNSW
+# SPDX-License-Identifier: BSD-2-Clause
+
+import asyncio
+from pathlib import Path
+import sys
+
+sys.path.insert(1, Path(__file__).parents[2].as_posix())
+
+from ci.lib.backends import *
+from ci.lib.runner import run_single_example, matrix_product
+from ci.common import TestConfig
+from ci import common, matrix
+
+TEST_MATRIX = matrix_product(
+    example=["gpio"],
+    board=matrix.EXAMPLES["gpio"]["boards_test"],
+    config=matrix.EXAMPLES["gpio"]["configs"],
+    build_system=matrix.EXAMPLES["gpio"]["build_systems"],
+)
+
+
+def backend_fn(test_config: TestConfig, loader_img: Path) -> HardwareBackend:
+    backend = common.backend_fn(test_config, loader_img)
+    return backend
+
+
+async def test(backend: HardwareBackend, test_config: TestConfig):
+    async with asyncio.timeout(60):
+        await wait_for_output(backend, b"           	 ... is present!\r\n")
+
+
+if __name__ == "__main__":
+    run_single_example(
+        test,
+        TEST_MATRIX,
+        backend_fn,
+    )

ci/matrix.py

@@ -3,6 +3,7 @@
 # SPDX-License-Identifier: BSD-2-Clause
 
 from __future__ import annotations
+
 from typing import TYPE_CHECKING, Any, Literal, TypedDict
 
 NO_OUTPUT_DEFAULT_TIMEOUT_S: int = 60
@@ -29,7 +30,7 @@
     "hifive_p550": dict(uboot_image_started=b"Starting kernel ..."),
 }
 
-EXAMPLES: dict[str, _ExampleMatrixType] = {
+EXAMPLES: dict[Literal[str], _ExampleMatrixType] = {
     "blk": {
         "configs": ["debug", "release"],
         "build_systems": ["make", "zig"],
@@ -89,6 +90,14 @@
             "star64",
         ],
     },
+    "gpio": {
+        "configs": ["debug", "release", "benchmark"],
+        "build_systems": ["make", "zig"],
+        "boards_build": [
+            "maaxboard",
+        ],
+        "boards_test": [],
+    },
     "serial": {
         "configs": ["debug", "release"],
         "build_systems": ["make", "zig"],

drivers/gpio/imx/config.json

@@ -0,0 +1,26 @@
+{
+    "compatible": [
+        "fsl,imx8mq-gpio",
+        "fsl,imx35-gpio"
+    ],
+    "resources": {
+        "regions": [
+            {
+                "name": "regs",
+                "perms": "rw",
+                "size": 65536,
+                "dt_index": 0
+            }
+        ],
+        "irqs": [
+            {
+                "dt_index": 0,
+                "channel_id": 60
+            },
+            {
+                "dt_index": 1,
+                "channel_id": 61
+            }
+        ]
+    }
+}