Re: [PATCH v2 3/5] arm64: dts: freescale: add Ka-Ro Electronics tx8m-1610 COM

[Maud Spierings <maudspierings@gocontroll.com>]

On 10/28/25 13:15, Matti Vaittinen wrote:
> Hi Maud,
> 
> Thanks for the upstreaming work! :)
> 
> On 22/10/2025 10:22, Maud Spierings via B4 Relay wrote:
>> From: Maud Spierings <maudspierings@gocontroll.com>
>>
>> The Ka-Ro Electronics tx8m-1610 is a COM based on the imx8mm SOC. It has
>> 1 GB of ram and 4 GB of eMMC storage on board.
>>
>> Add it to enable boards based on this module
>>
>> Signed-off-by: Maud Spierings <maudspierings@gocontroll.com>
>> ---
>>   .../arm64/boot/dts/freescale/imx8mm-tx8m-1610.dtsi | 439 +++++++++++ 
>> ++++++++++
>>   1 file changed, 439 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-tx8m-1610.dtsi b/ 
>> arch/arm64/boot/dts/freescale/imx8mm-tx8m-1610.dtsi
>> new file mode 100644
>> index 0000000000000..46d3ad80942cc
>> --- /dev/null
>> +++ b/arch/arm64/boot/dts/freescale/imx8mm-tx8m-1610.dtsi
>> @@ -0,0 +1,439 @@
>> +// SPDX-License-Identifier: (GPL-2.0 OR MIT)
>> +/*
>> + * Copyright (C) 2021 Lothar Waßmann <LW@KARO-electronics.de>
>> + * 2025 Maud Spierings <maudspierings@gocontroll.com>
>> + */
>> +
>> +#include "imx8mm.dtsi"
>> +
> 
> // snip
> 
>> +    pmic: pmic@4b {
>> +        compatible = "rohm,bd71847";
>> +        reg = <0x4b>;
>> +        interrupt-parent = <&gpio1>;
>> +        interrupts = <3 IRQ_TYPE_LEVEL_LOW>;
>> +        pinctrl-0 = <&pinctrl_pmic>;
>> +        pinctrl-names = "default";
>> +        rohm,reset-snvs-powered;
>> +
>> +        regulators {
>> +            reg_vdd_soc: BUCK1 {
>> +                regulator-always-on;
>> +                regulator-boot-on;
>> +                regulator-max-microvolt = <900000>;
>> +                regulator-min-microvolt = <780000>;
>> +                regulator-name = "buck1";
>> +                regulator-ramp-delay = <1250>;
>> +            };
>> +
>> +            reg_vdd_arm: BUCK2 {
>> +                regulator-always-on;
>> +                regulator-boot-on;
>> +                regulator-max-microvolt = <950000>;
>> +                regulator-min-microvolt = <805000>;
>> +                regulator-name = "buck2";
>> +                regulator-ramp-delay = <1250>;
>> +                rohm,dvs-run-voltage = <950000>;
>> +                rohm,dvs-idle-voltage = <810000>;
>> +            };
>> +
>> +            reg_vdd_dram: BUCK3 {
>> +                regulator-always-on;
>> +                regulator-boot-on;
>> +                regulator-max-microvolt = <900000>;
>> +                regulator-min-microvolt = <805000>;
>> +                regulator-name = "buck3";
>> +            };
>> +
>> +            reg_vdd_3v3: BUCK4 {
>> +                regulator-always-on;
>> +                regulator-boot-on;
>> +                regulator-max-microvolt = <3300000>;
>> +                regulator-min-microvolt = <3300000>;
>> +                regulator-name = "buck4";
>> +            };
>> +
>> +            reg_vdd_1v8: BUCK5 {
>> +                regulator-always-on;
>> +                regulator-boot-on;
>> +                regulator-max-microvolt = <1950000>;
>> +                regulator-min-microvolt = <1700000>;
>> +                regulator-name = "buck5";
>> +            };
>> +
>> +            BUCK6 {
>> +                regulator-always-on;
>> +                regulator-boot-on;
>> +                /*
>> +                 * The default output voltage is 1.1V, bumped
>> +                 * to 1.35V in HW by a 499R/2.2K voltage divider in the
>> +                 * feedback path.
>> +                 */
> 
> Could/Should this be described using the:
> 'rohm,feedback-pull-up-r1-ohms' and
> 'rohm,feedback-pull-up-r2-ohms'? If I understand the comment correctly, 
> that might allow the driver to be able to use correctly scaled voltages.
> 
> https://elixir.bootlin.com/linux/v6.18-rc1/source/Documentation/ 
> devicetree/bindings/regulator/rohm,bd71837-regulator.yaml#L108
> 

Ah I didn't know those existed, should've checked the bindings in more 
detail, thanks for the hint!

I will have to investigate this carefully, since I don't have access to 
the actual design of the COM, so I don't know exactly what is there.

Kind regards,
Maud