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Date: Wed, 8 May 2024 16:02:52 +0300
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Subject: Re: [PATCH 1/3] arm64: dts: ti: k3-j722s: Add support for SERDES0
To: Ravi Gunasekaran <r-gunasekaran@ti.com>, nm@ti.com, vigneshr@ti.com
Cc: kristo@kernel.org, robh@kernel.org, krzk+dt@kernel.org,
 conor+dt@kernel.org, srk@ti.com, linux-arm-kernel@lists.infradead.org,
 devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20240429120932.11456-1-r-gunasekaran@ti.com>
 <20240429120932.11456-2-r-gunasekaran@ti.com>
 <41047a89-2787-422f-a643-3e2d850da6dd@kernel.org>
 <588e4d0a-78c6-553f-3c40-0d248f4c92f9@ti.com>
Content-Language: en-US
From: Roger Quadros <rogerq@kernel.org>
In-Reply-To: <588e4d0a-78c6-553f-3c40-0d248f4c92f9@ti.com>
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On 08/05/2024 15:34, Ravi Gunasekaran wrote:
> 
> 
> On 5/8/24 5:29 PM, Roger Quadros wrote:
>>
>>
>> On 29/04/2024 15:09, Ravi Gunasekaran wrote:
>>> Add SERDES0 and its wrapper description to support USB3
>>> and SGMII interfaces.
>>>
>>> Signed-off-by: Ravi Gunasekaran <r-gunasekaran@ti.com>
>>> ---
>>>  arch/arm64/boot/dts/ti/k3-j722s.dtsi | 54 ++++++++++++++++++++++++++++
>>>  1 file changed, 54 insertions(+)
>>>
>>> diff --git a/arch/arm64/boot/dts/ti/k3-j722s.dtsi b/arch/arm64/boot/dts/ti/k3-j722s.dtsi
>>> index c75744edb143..beba5a3ea6cc 100644
>>> --- a/arch/arm64/boot/dts/ti/k3-j722s.dtsi
>>> +++ b/arch/arm64/boot/dts/ti/k3-j722s.dtsi
>>> @@ -9,6 +9,7 @@
>>>  #include <dt-bindings/interrupt-controller/irq.h>
>>>  #include <dt-bindings/interrupt-controller/arm-gic.h>
>>>  #include <dt-bindings/soc/ti,sci_pm_domain.h>
>>> +#include <dt-bindings/phy/phy-ti.h>
>>>  
>>>  #include "k3-am62p5.dtsi"
>>>  
>>> @@ -75,6 +76,50 @@
>>>  			 <0x00 0x78000000 0x00 0x78000000 0x00 0x00008000>,
>>>  			 <0x00 0x78100000 0x00 0x78100000 0x00 0x00008000>;
>>>  	};
>>> +
>>> +	serdes_refclk: clock-cmnrefclk {
>>
>> What could be the generic name here?
>>
> 
> How about phy-clk or serdes-clk?
> I searched for "fixed-clock" and wide range of naming conventions is followed.

We shouldn't encode the clock function in the name. How about just clk-<n> ?
where <n> is an integer starting from 0 for such fixed-clocks on the platform?

e.g. from arch/arm64/boot/dts/ti/k3-am62p5-sk.dts

        tlv320_mclk: clk-0 {
                #clock-cells = <0>;
                compatible = "fixed-clock";
                clock-frequency = <12288000>;
        };

> 
>>> +		compatible = "fixed-clock";
>>> +		#clock-cells = <0>;
>>> +		clock-frequency = <0>;
>>> +	};
>>> +
>>> +	serdes_wiz0: wiz@f000000 {
>>
>> Should generic name be phy?
> 
> Since serdes is used for both USB and PCIe,
> I can go with "phy".
> 
>>
>>> +		compatible = "ti,am64-wiz-10g";
>>> +		ranges = <0x0f000000 0x0 0x0f000000 0x00010000>;
>>> +		#address-cells = <1>;
>>> +		#size-cells = <1>;
>>> +		power-domains = <&k3_pds 279 TI_SCI_PD_EXCLUSIVE>;
>>> +		clocks = <&k3_clks 279 0>, <&k3_clks 279 1>, <&serdes_refclk>;
>>> +		clock-names = "fck", "core_ref_clk", "ext_ref_clk";
>>> +		num-lanes = <1>;
>>> +		#reset-cells = <1>;
>>> +		#clock-cells = <1>;
>>> +
>>> +		assigned-clocks = <&k3_clks 279 1>;
>>> +		assigned-clock-parents = <&k3_clks 279 5>;
>>> +
>>> +		serdes0: serdes@f000000 {
>>
>> here too?
> 
> I could use "phy" here as well. 
> https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/qcom/sa8775p.dtsi#L1853
> https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/renesas/r8a779f0.dtsi#L563
> 
>>
>>> +			compatible = "ti,j721e-serdes-10g";
> 
> [...]
> 
>>
> 

-- 
cheers,
-roger