From:   Sam Protsenko <semen.protsenko@linaro.org>
To:     Rob Herring <robh+dt@kernel.org>
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Masahiro Yamada <masahiroy@kernel.org>,
        David Virag <virag.david003@gmail.com>,
        Jaewon Kim <jaewon02.kim@samsung.com>,
        linux-samsung-soc@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] dt-bindings: Only show unique unit address warning for enabled nodes
Date:   Fri,  3 Dec 2021 20:35:17 +0200
Message-Id: <20211203183517.11390-1-semen.protsenko@linaro.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

There are valid cases when two nodes can have the same address. For
example, in Exynos SoCs there is USI IP-core, which might be configured
to provide UART, SPI or I2C block, all of which having the same base
register address. But only one can be enabled at a time. That looks like
this:

    usi@138200c0 {
        serial@13820000 {
            status = "okay";
        };

        i2c@13820000 {
            status = "disabled";
        };
    };

When running "make dt_binding_check", it reports next warning:

    Warning (unique_unit_address):
    /example-0/usi@138200c0/serial@13820000:
    duplicate unit-address (also used in node
    /example-0/usi@138200c0/i2c@13820000)

Disable "unique_unit_address" in DTC_FLAGS to suppress warnings like
that, but enable "unique_unit_address_if_enabled" warning, so that dtc
still reports a warning when two enabled nodes are having the same
address.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reported-by: Rob Herring <robh@kernel.org>
Suggested-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/Makefile | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/Makefile b/Documentation/devicetree/bindings/Makefile
index c9abfbe3f0aa..41c555181b6f 100644
--- a/Documentation/devicetree/bindings/Makefile
+++ b/Documentation/devicetree/bindings/Makefile
@@ -65,7 +65,9 @@ DT_DOCS = $(patsubst $(srctree)/%,%,$(shell $(find_all_cmd)))
 override DTC_FLAGS := \
 	-Wno-avoid_unnecessary_addr_size \
 	-Wno-graph_child_address \
-	-Wno-interrupt_provider
+	-Wno-interrupt_provider \
+	-Wno-unique_unit_address \
+	-Wunique_unit_address_if_enabled
 
 # Disable undocumented compatible checks until warning free
 override DT_CHECKER_FLAGS ?=
-- 
2.30.2