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From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Fri, 13 Oct 2023 00:35:16 +0200
Subject: [PATCH 3/3] RFC: net: dsa: mv88e6xxx: Register mdio-external
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Message-Id: <20231013-marvell-88e6152-wan-led-v1-3-0712ba99857c@linaro.org>
References: <20231013-marvell-88e6152-wan-led-v1-0-0712ba99857c@linaro.org>
In-Reply-To: <20231013-marvell-88e6152-wan-led-v1-0-0712ba99857c@linaro.org>
To:     Andrew Lunn <andrew@lunn.ch>,
        Gregory Clement <gregory.clement@bootlin.com>,
        Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Russell King <linux@armlinux.org.uk>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>
Cc:     Christian Marangi <ansuelsmth@gmail.com>,
        linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        Linus Walleij <linus.walleij@linaro.org>
Precedence: bulk

Make it legal to have a subnode just named "mdio-external"
and have that be recognized immediately as the external
MDIO bus, register it and return. Only fallback to the
old method with a compatible in the external bus node
if this doesn't work.

This is the result of deprecating the old DT method
of providing a node "mdio1" with a compatible string.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/net/dsa/mv88e6xxx/chip.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 52a99d8bada0..05f6776885f6 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -3676,7 +3676,21 @@ static int mv88e6xxx_mdios_register(struct mv88e6xxx_chip *chip)
 	if (err)
 		return err;
 
-	/* Walk the device tree, and see if there are any other nodes
+	/* If the optional external bus is explicitly named as such,
+	 * just register it and be done with this.
+	 */
+	child = of_get_child_by_name(np, "mdio-external");
+	if (child) {
+		err = mv88e6xxx_mdio_register(chip, child, true);
+		of_node_put(child);
+		if (err)
+			return err;
+		return 0;
+	}
+
+	/* Deprecated binding with compatible:
+	 *
+	 * Walk the device tree, and see if there are any other nodes
 	 * which say they are compatible with the external mdio
 	 * bus.
 	 */

-- 
2.41.0