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Date:   Thu, 20 Dec 2018 14:22:47 -0600
From:   Rob Herring <robh@kernel.org>
To:     Joakim Zhang <qiangqing.zhang@nxp.com>
Cc:     "mkl@pengutronix.de" <mkl@pengutronix.de>,
        "linux-can@vger.kernel.org" <linux-can@vger.kernel.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        dl-linux-imx <linux-imx@nxp.com>,
        Aisheng Dong <aisheng.dong@nxp.com>
Subject: Re: [PATCH 1/2] Documentation: can: flexcan: add PE clock source
 property to device tree
Message-ID: <20181220202247.GA26362@bogus>
References: <20181213070537.25095-1-qiangqing.zhang@nxp.com>
 <20181213070537.25095-2-qiangqing.zhang@nxp.com>
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On Thu, Dec 13, 2018 at 07:07:57AM +0000, Joakim Zhang wrote:
> From: Dong Aisheng <aisheng.dong@nxp.com>
> 
> The FlexCAN controller can parse clock source property from DTS file to
> select PE clock source.
> 
> Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
> Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
> ---
>  Documentation/devicetree/bindings/net/can/fsl-flexcan.txt | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
> index bc77477c6878..a04168605998 100644
> --- a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
> +++ b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
> @@ -32,6 +32,13 @@ Optional properties:
>  		 ack_gpr is the gpr register offset of CAN stop acknowledge.
>  		 ack_bit is the bit offset of CAN stop acknowledge.
>  
> +- fsl,clk-source: Select the clock source to the CAN Protocol Engine (PE).
> +		  It's SoC Implementation dependent. Refer to RM for detailed

If SoC dependent, then it should be implied by the SoC specific 
compatible. Also, seems like you should add clock binding support here 
if you need more clock control.

> +		  definition. If this property is not set in device tree node
> +		  then driver selects clock source 1 by default.
> +		  0: clock source 0 (oscillator clock)
> +		  1: clock source 1 (peripheral clock)
> +
>  Example:
>  
>  	can@1c000 {
> @@ -40,4 +47,5 @@ Example:
>  		interrupts = <48 0x2>;
>  		interrupt-parent = <&mpic>;
>  		clock-frequency = <200000000>; // filled in by bootloader
> +		fsl,clk-source = <0>; // select clock source 0 for PE
>  	};
> -- 
> 2.17.1
>