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Date:   Tue, 19 Apr 2022 09:05:22 +0530
From:   Vinod Koul <vkoul@kernel.org>
To:     Manivannan Sadhasivam <mani@kernel.org>
Cc:     Bjorn Andersson <bjorn.andersson@linaro.org>,
        linux-arm-msm@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzk+dt@kernel.org>,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] arm64: dts: qcom: db845c: Add support for MCP2517FD
Message-ID: <Yl4t+gaIvPvL2O0/@matsya>
References: <20220418125841.1409738-1-vkoul@kernel.org>
 <20220418134241.GA161722@thinkpad>
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On 18-04-22, 19:12, Manivannan Sadhasivam wrote:
> On Mon, Apr 18, 2022 at 06:28:41PM +0530, Vinod Koul wrote:
> > Add support for onboard MCP2517FD SPI CAN transceiver attached to
> > SPI0 of RB3.
> > 
> > Signed-off-by: Vinod Koul <vkoul@kernel.org>
> > ---
> >  arch/arm64/boot/dts/qcom/sdm845-db845c.dts | 23 ++++++++++++++++++++++
> >  1 file changed, 23 insertions(+)
> > 
> > diff --git a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts
> > index 28fe45c5d516..5179f8ddb060 100644
> > --- a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts
> > +++ b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts
> > @@ -28,6 +28,13 @@ chosen {
> >  		stdout-path = "serial0:115200n8";
> >  	};
> >  
> > +	/* Fixed crystal oscillator dedicated to MCP2517FD */
> > +	clk40M: can_clock {
> > +		compatible = "fixed-clock";
> > +		#clock-cells = <0>;
> > +		clock-frequency = <40000000>;
> > +	};
> > +
> >  	dc12v: dc12v-regulator {
> >  		compatible = "regulator-fixed";
> >  		regulator-name = "DC12V";
> > @@ -746,6 +753,22 @@ codec {
> >  	};
> >  };
> >  
> > +&spi0 {
> > +	/* On Low speed expansion */
> 
> Only SPI2 is exposed on the LS header. This one is dedicated to CAN controller.

ok

> 
> > +	status = "okay";
> 
> No chip select? Since CAN controller may operate at higher frequencies, it
> makes sense to increase the drive strength of the pins.

Okay will add and send v2

-- 
~Vinod