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From: Lars-Peter Clausen <lars@metafoo.de>
To: Wolfram Sang <wsa@kernel.org>
Cc: Michal Simek <michal.simek@amd.com>,
	Shubhrajyoti Datta <Shubhrajyoti.datta@amd.com>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	linux-i2c@vger.kernel.org, devicetree@vger.kernel.org,
	Lars-Peter Clausen <lars@metafoo.de>,
	Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Subject: [PATCH v2 1/2] dt-bindings: i2c: cadence: Document `resets` property
Date: Thu,  6 Apr 2023 08:48:33 -0700	[thread overview]
Message-ID: <20230406154834.171577-1-lars@metafoo.de> (raw)

The Cadence I2C controller has an external reset that needs to be
de-asserted before the I2C controller can be accessed.

Document the `resets` devicetree property that can be used to describe how
the reset signal is connected.

While the reset signal will always be present in hardware the devicetree
property is kept optional for backwards compatibility with existing systems
that do not specify the reset property and where the reset signal might not
be controlled by operating system.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
Changes since v1:
	* Add `resets` property to example
---
 Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml b/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml
index 9187015d9702..cb24d7b3221c 100644
--- a/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml
+++ b/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml
@@ -24,6 +24,9 @@ properties:
   clocks:
     minItems: 1
 
+  resets:
+    maxItems: 1
+
   interrupts:
     maxItems: 1
 
@@ -59,6 +62,7 @@ examples:
     i2c@e0004000 {
         compatible = "cdns,i2c-r1p10";
         clocks = <&clkc 38>;
+        resets = <&rstc 288>;
         interrupts = <GIC_SPI 25 IRQ_TYPE_LEVEL_HIGH>;
         reg = <0xe0004000 0x1000>;
         clock-frequency = <400000>;
-- 
2.30.2


             reply	other threads:[~2023-04-06 15:49 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-06 15:48 Lars-Peter Clausen [this message]
2023-04-06 15:48 ` [PATCH v2 2/2] i2c: cadence: Add reset controller support Lars-Peter Clausen
2023-04-13 10:22   ` Michal Simek
2023-04-13 16:44   ` Wolfram Sang
2023-04-13 10:20 ` [PATCH v2 1/2] dt-bindings: i2c: cadence: Document `resets` property Michal Simek
2023-04-13 16:44 ` Wolfram Sang

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