zmake: add verification that there are no duplicate GPIOs

Add a check that the final "named-gpios" node does not contain any
duplicate GPIO entries.

BUG=b:271135255
BRANCH=none
TEST=Build skyrim before and after CL:4297652. Verify error reported
when the duplicate GPIO is present and passes after duplicate entry
removed.

Change-Id: Ib89611f1c693456b9313b5df612dd783158806ce
Signed-off-by: Keith Short <keithshort@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/4307436
Reviewed-by: Abe Levkoy <alevkoy@chromium.org>

2 files changed, 111 insertions, 0 deletions

diff --git a/zephyr/zmake/zmake/named_gpios.py b/zephyr/zmake/zmake/named_gpios.py
new file mode 100644
index 0000000000..bc3133c809
--- /dev/null
+++ b/zephyr/zmake/zmake/named_gpios.py
@@ -0,0 +1,102 @@
+# Copyright 2023 The ChromiumOS Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Configure-time checks for the named-gpios node."""
+
+import importlib
+import logging
+import pickle
+import sys
+
+
+def verify_no_duplicates(zephyr_base, output_dir):
+    """Verify there are no duplicate GPIOs in the named-gpios node.
+
+    Args:
+        zephyr_base - pathlib.Path pointing to the Zephyr OS repository.
+        output_dir - pathlib.Path pointing to the output directory for the
+                     current build.
+
+    Returns:
+        True if no duplicates found.  Returns False otherwise.
+    """
+    logger = logging.getLogger()
+
+    zephyr_devicetree_path = (
+        zephyr_base / "scripts" / "dts" / "python-devicetree" / "src"
+    )
+
+    # Add Zephyr's python-devicetree into the source path
+    sys.path.insert(0, str(zephyr_devicetree_path))
+
+    edtlib_path = zephyr_devicetree_path / "devicetree" / "edtlib.py"
+    edt_pickle = output_dir / "zephyr" / "edt.pickle"
+
+    # The zmake tests don't provide a real Zephyr project, so skip these
+    # checks if the edtlib.py module cannot be found.
+    if not edtlib_path.is_file():
+        return True
+
+    # Dynamically import edtlib
+    spec = importlib.util.spec_from_file_location(edtlib_path.name, edtlib_path)
+    edtlib = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(edtlib)
+
+    try:
+        with open(edt_pickle, "rb") as edt_file:
+            edt = pickle.load(edt_file)
+    except edtlib.DTError as err:
+        logger.error("devicetree error: %s", err)
+
+    # Dictionary of GPIO controllers, indexed by the GPIO controller nodelabel
+    gpio_ctrls = dict()
+    duplicates = 0
+    count = 0
+    named_gpios = edt.get_node("/named-gpios")
+    for node in named_gpios.children.values():
+        if "gpios" not in node.props:
+            continue
+
+        gpios = node.props["gpios"].val
+        count += 1
+
+        # edtlib converts a "-gpios" style property to a list of of
+        # ControllerAndData objects.  However, the named-gpios node only
+        # supports a single GPIO per child, so no need to iterate over
+        # the list.
+        gpio = gpios[0]
+        gpio_pin = gpio.data["pin"]
+
+        # Note that EDT stores the node name (not a nodelabel) in the
+        # Node.name property.  Use the nodelabel, if available as the
+        # key for gpio_ctrls.
+        if gpio.controller.labels[0] is not None:
+            nodelabel = gpio.controller.labels[0]
+        else:
+            nodelabel = gpio.controller.name
+
+        if not nodelabel in gpio_ctrls:
+            # Create a dictionary at each GPIO controller
+            gpio_ctrls[nodelabel] = dict()
+
+        if gpio_pin in gpio_ctrls[nodelabel]:
+            logger.error(
+                "Duplicate GPIOs found at nodes: %s and %s",
+                gpio_ctrls[nodelabel][gpio_pin],
+                node.name,
+            )
+            duplicates += 1
+        else:
+            # Store the node name for the new pin
+            gpio_ctrls[nodelabel][gpio_pin] = node.name
+
+    if duplicates:
+        logger.error("%d duplicate GPIOs found in %s", duplicates, edt_pickle)
+    else:
+        logger.info("Verified %d GPIOs, no duplicates found", count)
+
+    if duplicates != 0:
+        return False
+
+    return True
diff --git a/zephyr/zmake/zmake/zmake.py b/zephyr/zmake/zmake/zmake.py
index f58b07eda1..1b02d5a2e8 100644
--- a/zephyr/zmake/zmake/zmake.py
+++ b/zephyr/zmake/zmake/zmake.py
@@ -21,6 +21,7 @@ import zmake.generate_readme
 import zmake.jobserver
 import zmake.modules
 import zmake.multiproc
+import zmake.named_gpios
 import zmake.project
 import zmake.util as util
 import zmake.version
@@ -690,6 +691,14 @@ class Zmake:
             if proc.wait():
                 raise OSError(get_process_failure_msg(proc))
             config_json_file.write_text(config_json)
+
+            # _configure_one_build uses shell semantics, so return
+            # a non-zero value if verify_no_duplicates fails.
+            if not zmake.named_gpios.verify_no_duplicates(
+                self.zephyr_base, output_dir
+            ):
+                return 1
+
             return 0
 
     def _build(