Re: [PATCH v1] arm64: dts: imx8mm-verdin: update CAN clock to 40MHz - Marc Kleine-Budde

From: Marc Kleine-Budde <mkl@pengutronix.de>
To: Francesco Dolcini <francesco.dolcini@toradex.com>
Cc: Shawn Guo <shawnguo@kernel.org>,
	devicetree@vger.kernel.org,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Marcel Ziswiler <marcel.ziswiler@toradex.com>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	linux-kernel@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
	NXP Linux Team <linux-imx@nxp.com>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Andrejs Cainikovs <andrejs.cainikovs@toradex.com>,
	Fabio Estevam <festevam@gmail.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v1] arm64: dts: imx8mm-verdin: update CAN clock to 40MHz
Date: Tue, 21 Jun 2022 21:50:46 +0200	[thread overview]
Message-ID: <20220621195046.rnv66d2333wjmtow@pengutronix.de> (raw)
In-Reply-To: <20220621180749.GA22098@francesco-nb.int.toradex.com>

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On 21.06.2022 20:07:49, Francesco Dolcini wrote:
> Hello Shawn, just a ping on this.
> 
> Francesco
> 
> On Thu, May 12, 2022 at 12:40:19PM +0200, Andrejs Cainikovs wrote:
> > Update SPI CAN controller clock to match current hardware design.
> > 
> > Signed-off-by: Andrejs Cainikovs <andrejs.cainikovs@toradex.com>
> > ---
> >  arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi
> > index 0d84d29e70f1..d309bc0ab8f6 100644
> > --- a/arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi
> > +++ b/arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi
> > @@ -32,10 +32,10 @@ backlight: backlight {
> >  	};
> >  
> >  	/* Fixed clock dedicated to SPI CAN controller */
> > -	clk20m: oscillator {
> > +	clk40m: oscillator {
> >  		compatible = "fixed-clock";
> >  		#clock-cells = <0>;
> > -		clock-frequency = <20000000>;
> > +		clock-frequency = <40000000>;
> >  	};
> >  
> >  	gpio-keys {
> > @@ -194,7 +194,7 @@ &ecspi3 {
> >  
> >  	can1: can@0 {
> >  		compatible = "microchip,mcp251xfd";
> > -		clocks = <&clk20m>;
> > +		clocks = <&clk40m>;
> >  		interrupts-extended = <&gpio1 6 IRQ_TYPE_EDGE_FALLING>;

You don't want to use an edge triggered interrupt with the mcp251xfd
chip. You will be losing interrupts, better use IRQ_TYPE_LEVEL_LOW.

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
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