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From:   Dylan Hung <dylan_hung@aspeedtech.com>
To:     <robh+dt@kernel.org>, <joel@jms.id.au>, <andrew@aj.id.au>,
        <andrew@lunn.ch>, <hkallweit1@gmail.com>, <linux@armlinux.org.uk>,
        <davem@davemloft.net>, <kuba@kernel.org>, <pabeni@redhat.com>,
        <p.zabel@pengutronix.de>, <devicetree@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-aspeed@lists.ozlabs.org>, <linux-kernel@vger.kernel.org>,
        <netdev@vger.kernel.org>, <krzk+dt@kernel.org>
CC:     <BMC-SW@aspeedtech.com>, Krzysztof Kozlowski <krzk@kernel.org>
Subject: [PATCH v5 1/3] dt-bindings: net: add reset property for aspeed, ast2600-mdio binding
Date:   Wed, 13 Apr 2022 20:10:35 +0800
Message-ID: <20220413121037.23748-2-dylan_hung@aspeedtech.com>
In-Reply-To: <20220413121037.23748-1-dylan_hung@aspeedtech.com>
References: <20220413121037.23748-1-dylan_hung@aspeedtech.com>
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The AST2600 MDIO bus controller has a reset control bit and must be
deasserted before manipulating the MDIO controller. By default, the
hardware asserts the reset so the driver only need to deassert it.

Regarding to the old DT blobs which don't have reset property in them,
the reset deassertion is usually done by the bootloader so the reset
property is optional to work with them.

Signed-off-by: Dylan Hung <dylan_hung@aspeedtech.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 .../devicetree/bindings/net/aspeed,ast2600-mdio.yaml        | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/aspeed,ast2600-mdio.yaml b/Documentation/devicetree/bindings/net/aspeed,ast2600-mdio.yaml
index 1c88820cbcdf..f81eda8cb0a5 100644
--- a/Documentation/devicetree/bindings/net/aspeed,ast2600-mdio.yaml
+++ b/Documentation/devicetree/bindings/net/aspeed,ast2600-mdio.yaml
@@ -20,10 +20,14 @@ allOf:
 properties:
   compatible:
     const: aspeed,ast2600-mdio
+
   reg:
     maxItems: 1
     description: The register range of the MDIO controller instance
 
+  resets:
+    maxItems: 1
+
 required:
   - compatible
   - reg
@@ -34,11 +38,13 @@ unevaluatedProperties: false
 
 examples:
   - |
+    #include <dt-bindings/clock/ast2600-clock.h>
     mdio0: mdio@1e650000 {
             compatible = "aspeed,ast2600-mdio";
             reg = <0x1e650000 0x8>;
             #address-cells = <1>;
             #size-cells = <0>;
+            resets = <&syscon ASPEED_RESET_MII>;
 
             ethphy0: ethernet-phy@0 {
                     compatible = "ethernet-phy-ieee802.3-c22";
-- 
2.25.1