name: CI

on:
  push:
    branches:
      - main
  pull_request:
    branches:
      - main
  workflow_dispatch:

permissions:
  contents: read

concurrency:
  group: ci-${{ github.ref }}
  cancel-in-progress: true

env:
  I2C_TREE: https://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux.git
  SPARSE_REPOSITORY: https://git.kernel.org/pub/scm/devel/sparse/sparse.git
  SPARSE_COMMIT: 00c4b8e75cbf92003bc4a695a223045092b173f3

jobs:
  out-of-tree:
    name: Out-of-tree (${{ matrix.compiler }})
    runs-on: ubuntu-latest
    timeout-minutes: 30
    strategy:
      fail-fast: false
      matrix:
        include:
          - compiler: gcc
            make_args: ""
          - compiler: clang
            make_args: LLVM=1

    steps:
      - uses: actions/checkout@v4

      - name: Install build dependencies
        run: |
          sudo apt-get update
          sudo apt-get install -y build-essential clang llvm linux-headers-$(uname -r)

      # A stock kernel has no pci_mmcfg_read_config() yet, so this exercises
      # the compat/ shim path. The in-tree job below covers the real thing.
      - name: Build module
        run: make W=1 KCFLAGS=-W ${{ matrix.make_args }}

      - name: Run checkpatch
        if: matrix.compiler == 'gcc'
        run: make checkpatch

      - name: Check shell scripts
        if: matrix.compiler == 'gcc'
        run: |
          sudo apt-get install -y shellcheck
          bash -n test-smoke.sh
          for f in tools/*.sh; do bash -n "$f"; done
          shellcheck -S warning test-smoke.sh tools/*.sh

      - name: Upload artifact
        if: matrix.compiler == 'gcc'
        uses: actions/upload-artifact@v4
        with:
          name: i2c-imc-skylake-${{ github.ref_name }}
          path: i2c-imc-skylake.ko
          if-no-files-found: error

  in-tree:
    name: Current i2c-host integration (2-patch series)
    runs-on: ubuntu-latest
    timeout-minutes: 45

    steps:
      - uses: actions/checkout@v4

      - name: Install kernel build dependencies
        run: |
          sudo apt-get update
          sudo apt-get install -y bc bison build-essential clang flex libelf-dev libssl-dev llvm

      - name: Build pinned Sparse
        run: |
          git clone --filter=blob:none "$SPARSE_REPOSITORY" sparse
          git -C sparse checkout "$SPARSE_COMMIT"
          make -C sparse -j"$(nproc)"
          echo "$PWD/sparse" >> "$GITHUB_PATH"

      - name: Prepare current maintainer tree
        run: |
          git clone --depth=1 --branch i2c/i2c-host "$I2C_TREE" linux-i2c
          # Patch 1/2: the PCI/x86 accessor the driver depends on. If this
          # stops applying, the tracked copy is stale and must be refreshed
          # from the kernel tree - that is a real failure, not CI noise.
          git -C linux-i2c apply --verbose \
            ../docs/submission/0001-pci-mmcfg-accessor.patch
          # Patch 2/2: the driver itself.
          cp i2c-imc-skylake.c linux-i2c/drivers/i2c/busses/
          cat docs/submission/Kconfig.kernel >> linux-i2c/drivers/i2c/busses/Kconfig
          printf '%s\n' 'obj-$(CONFIG_I2C_IMC_SKYLAKE) += i2c-imc-skylake.o' \
            >> linux-i2c/drivers/i2c/busses/Makefile
          git -C linux-i2c rev-parse HEAD

      - name: Configure kernel
        working-directory: linux-i2c
        run: |
          make O=../linux-out x86_64_defconfig
          scripts/config --file ../linux-out/.config --enable I2C --module I2C_IMC_SKYLAKE
          make O=../linux-out olddefconfig
          grep '^CONFIG_I2C_IMC_SKYLAKE=m' ../linux-out/.config
          grep '^CONFIG_PCI_MMCONFIG=y' ../linux-out/.config

      - name: Build the series in-tree
        working-directory: linux-i2c
        run: |
          make O=../linux-out W=1 \
            drivers/pci/access.o \
            arch/x86/pci/mmconfig-shared.o \
            drivers/i2c/busses/i2c-imc-skylake.o

      - name: Build arm64 COMPILE_TEST with Clang
        working-directory: linux-i2c
        run: |
          make O=../linux-out-arm64 ARCH=arm64 LLVM=1 defconfig
          scripts/config --file ../linux-out-arm64/.config \
            --enable COMPILE_TEST --enable PCI --enable I2C \
            --module I2C_IMC_SKYLAKE
          make O=../linux-out-arm64 ARCH=arm64 LLVM=1 olddefconfig
          grep '^CONFIG_I2C_IMC_SKYLAKE=m' ../linux-out-arm64/.config
          make O=../linux-out-arm64 ARCH=arm64 LLVM=1 W=1 \
            drivers/pci/access.o \
            drivers/i2c/busses/i2c-imc-skylake.o

      - name: Run Sparse in-tree
        working-directory: linux-i2c
        run: |
          make O=../linux-out C=2 CF=-D__CHECK_ENDIAN__ \
            drivers/pci/access.o \
            arch/x86/pci/mmconfig-shared.o \
            drivers/i2c/busses/i2c-imc-skylake.o

      - name: Run current-tree checkpatch
        working-directory: linux-i2c
        run: |
          scripts/checkpatch.pl --strict --no-tree -f \
            drivers/i2c/busses/i2c-imc-skylake.c
          scripts/checkpatch.pl --strict \
            ../docs/submission/0001-pci-mmcfg-accessor.patch

      - name: Build the documentation
        working-directory: linux-i2c
        run: |
          sudo apt-get install -y python3-sphinx python3-sphinx-rtd-theme
          cp ../docs/submission/i2c-imc-skylake.rst Documentation/i2c/busses/
          sed -i 's|^   i2c-i801$|   i2c-i801\n   i2c-imc-skylake|' \
            Documentation/i2c/busses/index.rst
          grep -q i2c-imc-skylake Documentation/i2c/busses/index.rst
          make O=../linux-out htmldocs SPHINXDIRS=i2c 2>&1 | tee doc.log | tail -20
          ! grep -Ei 'WARNING|ERROR' doc.log