RE: [PATCH v6 2/2] ARM: dts: at91: Adding SAMA5D3-EDS board

[Jerry.Ray]

>>>> 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@xxxxxxxxxxxxx>
>>>> ---
>>>> 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@xxxxxxxxxxxxx>  */ /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
>

I prefer names to be descriptive, but I suppose I can have the name generic and add a comment into the dts file.
However, the comment doesn't make it into the loaded device tree.  Would you be okay with "regulator-2-ldo"?

Regards,
Jerry.