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From: Stefan Wahren <wahrenst@gmx.net>
To: Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Shawn Guo <shawnguo@kernel.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Fabio Estevam <festevam@gmail.com>
Cc: kernel@pengutronix.de, imx@lists.linux.dev,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	Stefan Wahren <wahrenst@gmx.net>
Subject: [PATCH 2/2] ARM: dts: imx6ull-tarragon: Reduce SPI clock for QCA7000
Date: Tue, 16 Apr 2024 21:06:59 +0200	[thread overview]
Message-ID: <20240416190659.15430-3-wahrenst@gmx.net> (raw)
In-Reply-To: <20240416190659.15430-1-wahrenst@gmx.net>

Our hardware department recently informed us that, according to
the specification, the QCA7000 should be operated with a
maximum SPI clock frequency of 12 MHz. Even if it appears to work
at a higher frequency, we should not take any risks here. A short
performance test showed no measurable loss of speed.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
---
 arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-master.dts  | 4 ++--
 arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slave.dts   | 2 +-
 arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slavext.dts | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-master.dts b/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-master.dts
index 67007ce383e3..f9bbd589b66d 100644
--- a/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-master.dts
+++ b/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-master.dts
@@ -45,7 +45,7 @@ &pinctrl_qca700x_cp_rst
 		interrupts = <19 IRQ_TYPE_EDGE_RISING>;
 		spi-cpha;
 		spi-cpol;
-		spi-max-frequency = <16000000>;
+		spi-max-frequency = <12000000>;
 	};
 };

@@ -63,7 +63,7 @@ &pinctrl_qca700x_mains_rst
 		interrupts = <9 IRQ_TYPE_EDGE_RISING>;
 		spi-cpha;
 		spi-cpol;
-		spi-max-frequency = <16000000>;
+		spi-max-frequency = <12000000>;
 	};
 };

diff --git a/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slave.dts b/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slave.dts
index cee223b5f8e1..ef06619d7c86 100644
--- a/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slave.dts
+++ b/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slave.dts
@@ -23,7 +23,7 @@ &pinctrl_qca700x_cp_rst
 		interrupts = <19 IRQ_TYPE_EDGE_RISING>;
 		spi-cpha;
 		spi-cpol;
-		spi-max-frequency = <16000000>;
+		spi-max-frequency = <12000000>;
 	};
 };

diff --git a/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slavext.dts b/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slavext.dts
index 7fd53b7a4372..83db65bf630f 100644
--- a/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slavext.dts
+++ b/arch/arm/boot/dts/nxp/imx/imx6ull-tarragon-slavext.dts
@@ -45,7 +45,7 @@ &pinctrl_qca700x_cp_rst
 		interrupts = <19 IRQ_TYPE_EDGE_RISING>;
 		spi-cpha;
 		spi-cpol;
-		spi-max-frequency = <16000000>;
+		spi-max-frequency = <12000000>;
 	};
 };

--
2.34.1


  parent reply	other threads:[~2024-04-16 19:08 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-16 19:06 [PATCH 0/2] ARM: dts: imx6ull-tarragon: Minor changes Stefan Wahren
2024-04-16 19:06 ` [PATCH 1/2] ARM: dts: imx6ull-tarragon: fix USB over-current polarity Stefan Wahren
2024-04-16 19:06 ` Stefan Wahren [this message]
2024-04-17  3:00   ` [PATCH 2/2] ARM: dts: imx6ull-tarragon: Reduce SPI clock for QCA7000 Fabio Estevam
2024-04-17 10:44     ` Stefan Wahren
2024-04-25  6:21 ` [PATCH 0/2] ARM: dts: imx6ull-tarragon: Minor changes Shawn Guo

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