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Message-ID: <42c193c8-5edf-4b00-9f76-34b9cc947dc8@linaro.org>
Date:   Thu, 8 Sep 2022 16:19:44 +0200
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Subject: Re: [PATCH v6 2/2] ARM: dts: at91: Adding SAMA5D3-EDS board
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To:     Jerry.Ray@microchip.com, krzysztof.kozlowski+dt@linaro.org,
        robh+dt@kernel.org, Nicolas.Ferre@microchip.com,
        alexandre.belloni@bootlin.com, Claudiu.Beznea@microchip.com,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
References: <20220902192236.14862-1-jerry.ray@microchip.com>
 <20220902192236.14862-2-jerry.ray@microchip.com>
 <bc6f19f3-0825-7c9c-c11d-92474bb12375@linaro.org>
 <MWHPR11MB1693B3327E7061DB8DDB5577EF409@MWHPR11MB1693.namprd11.prod.outlook.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <MWHPR11MB1693B3327E7061DB8DDB5577EF409@MWHPR11MB1693.namprd11.prod.outlook.com>
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On 08/09/2022 15:58, Jerry.Ray@microchip.com wrote:
>> On 02/09/2022 21:22, Jerry Ray wrote:
>>> The SAMA5D3-EDS board is an Ethernet Development Platform allowing for 
>>> evaluating many Microchip ethernet switch and PHY products.  Various 
>>> daughter cards can connect up via an RGMII connector or an RMII connector.
>>>
>>> The EDS board is not intended for stand-alone use and has no ethernet 
>>> capabilities when no daughter board is connected.  As such, this 
>>> device tree is intended to be used with a DT overlay defining the add-on board.
>>> To better ensure consistency, some items are defined here as a form of 
>>> documentation so that all add-on overlays will use the same terms.
>>>
>>> Google search keywords: "Microchip SAMA5D3-EDS"
>>>
>>> Signed-off-by: Jerry Ray <jerry.ray@microchip.com>
>>> ---
>>> v5->v6:
>>>  - Replaced underscores in names where I can, improving naming.
>>> v4->v5:
>>>  - patch now applies to v6.0-rc2
>>> v3->v4:
>>>  - Fixed regulators as necessary to get the board to boot from SD Card.
>>> v2->v3:
>>>  - Alphabetized pinctrl entries.
>>>  - cleaned up a warning in the regulators section.
>>>  - License tweaked to 'OR MIT'
>>>  - Included Makefile change
>>> v1->v2:
>>>  - Modified the compatible field in the device tree to reflect Microchip
>>>    Ethernet Development System Board.
>>> ---
>>>  arch/arm/boot/dts/Makefile             |   1 +
>>>  arch/arm/boot/dts/at91-sama5d3_eds.dts | 309 
>>> +++++++++++++++++++++++++
>>>  2 files changed, 310 insertions(+)
>>>  create mode 100644 arch/arm/boot/dts/at91-sama5d3_eds.dts
>>>
>>> diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile 
>>> index 05d8aef6e5d2..e92e639a2dc3 100644
>>> --- a/arch/arm/boot/dts/Makefile
>>> +++ b/arch/arm/boot/dts/Makefile
>>> @@ -61,6 +61,7 @@ dtb-$(CONFIG_SOC_SAM_V7) += \
>>>       at91-sama5d2_icp.dtb \
>>>       at91-sama5d2_ptc_ek.dtb \
>>>       at91-sama5d2_xplained.dtb \
>>> +     at91-sama5d3_eds.dtb \
>>>       at91-sama5d3_ksz9477_evb.dtb \
>>>       at91-sama5d3_xplained.dtb \
>>>       at91-dvk_som60.dtb \
>>> diff --git a/arch/arm/boot/dts/at91-sama5d3_eds.dts 
>>> b/arch/arm/boot/dts/at91-sama5d3_eds.dts
>>> new file mode 100644
>>> index 000000000000..b4fe1c5f2997
>>> --- /dev/null
>>> +++ b/arch/arm/boot/dts/at91-sama5d3_eds.dts
>>> @@ -0,0 +1,309 @@
>>> +// SPDX-License-Identifier: GPL-2.0+ OR MIT
>>> +/*
>>> + * at91-sama5d3_eds.dts - Device Tree file for the SAMA5D3 Ethernet
>>> + *    Development System board.
>>> + *
>>> + * Copyright (C) 2022 Microchip Technology Inc. and its subsidiaries
>>> + *
>>> + * Author: Jerry Ray <jerry.ray@microchip.com>  */ /dts-v1/; #include 
>>> +"sama5d36.dtsi"
>>> +
>>> +/ {
>>> +     model = "SAMA5D3 Ethernet Development System";
>>> +     compatible = "microchip,sama5d3-eds", "atmel,sama5d36",
>>> +                  "atmel,sama5d3", "atmel,sama5";
>>> +
>>> +     chosen {
>>> +             stdout-path = "serial0:115200n8";
>>> +     };
>>> +
>>> +     clocks {
>>> +             slow_xtal {
>>
>> No underscores in node names. Override by label.
>>
>>> +                     clock-frequency = <32768>;
>>> +             };
>>> +
>>> +             main_xtal {
>>> +                     clock-frequency = <12000000>;
>>> +             };
>>> +     };
>>> +
>>> +     gpio {
>>> +             compatible = "gpio-keys";
>>> +
>>> +             pinctrl-names = "default";
>>> +             pinctrl-0 = <&pinctrl_key_gpio>;
>>> +
>>> +             button-3 {
>>> +                     label = "PB_USER";
>>> +                     gpios = <&pioE 29 GPIO_ACTIVE_LOW>;
>>> +                     linux,code = <0x104>;
>>> +                     wakeup-source;
>>> +             };
>>> +     };
>>> +
>>> +     memory@20000000 {
>>> +             reg = <0x20000000 0x10000000>;
>>> +     };
>>> +
>>> +     vcc_3v3_reg: buck-regulator-1 {
>>
>> Keep consistent prefix or suffix, so:
>> regulator-buck-1
>>
>>> +             compatible = "regulator-fixed";
>>> +             regulator-name = "VCC_3V3";
>>> +             regulator-min-microvolt = <3300000>;
>>> +             regulator-max-microvolt = <3300000>;
>>> +             regulator-always-on;
>>> +     };
>>> +
>>> +     vcc_2v5_reg: ldo-regulator-2 {
>>
>> regulator-ldo-1
>> (why numbering of LDO regulators starts from 2? keep some sense in this)
>>
>>
> 
> There are N regulators on the board, so they are numbered 1 thru N.
> Regulator 2 is regulator 2 whether it's a buck or LDO.

So if this is supposed to match board schematics (which is good idea),
then maybe just "regulator-2"? The point is to have same generic name
and customize either prefix or suffix, but not both.

Best regards,
Krzysztof