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.
>>>>>

I am not at liberty to change this as both node name and label are defined in the sama5d3.dtsi source file.
If there is a way to override the label, please share the syntax as nothing I have tried is working.

>>>>>> +                     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"?
>
>You have the descriptive name in the regulator-name property, but ok, can be in node name as well.
>
>Best regards,
>Krzysztof
>

Regards,
Jerry.