Re: [PATCH 7/7] arm64: dts: renesas: r8a779md: Add support for R-Car M3Le R8A779MD Geist

Geert Uytterhoeven
2026-05-04T09:25:08Z

Hi Marek,

On Sun, 3 May 2026 at 04:50, Marek Vasut <marek.vasut@mailbox.org> wrote:
> On 4/29/26 3:59 PM, Geert Uytterhoeven wrote:
> >> +&avb {
> >> + pinctrl-0 = <&avb_pins>;
> >> + pinctrl-names = "default";
> >> + phy-handle = <&phy0>;
> >> + tx-internal-delay-ps = <2000>;
> >> + status = "okay";
> >> +
> >> + phy0: ethernet-phy@0 {
> >
> > compatible = "ethernet-phy-id0022.1622";
> >
> >> + rxc-skew-ps = <1500>;
> >> + reg = <0>;
> >> + interrupt-parent = <&gpio2>;
> >> + interrupts = <11 IRQ_TYPE_LEVEL_LOW>;
> >
> > interrupts-extended = <&gpio2 11 IRQ_TYPE_LEVEL_LOW>;
> >
> >> + reset-gpios = <&gpio2 10 GPIO_ACTIVE_LOW>;
> >> + reset-assert-us = <100>;
> >> + reset-deassert-us = <100>;
> >
> > Do we need these two? We don't have them in e.g.
> > arch/arm64/boot/dts/renesas/salvator-common.dtsi
>
> I believe we should add them, the KSZ9031 PHY does require 100us delay
> after reset is deasserted and before MDIO access is possible:
>
> https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/DataSheets/KSZ9031RNX-Data-Sheet-DS00002117.pdf
>
> FIGURE 7-5: POWER-UP/POWER-DOWN/RESET TIMING
>
> "
> Note 2: After the de-assertion of reset, wait a minimum of 100 µs before
> starting programming on the MIIM (MDC/MDIO)
> interface
> "

OK. So please add it to the other boards, too.

> [...]
>
> >> + pwm2_pins: pwm2 {
> >> + groups = "pwm2_a";
> >> + function = "pwm2";
> >> + };
> >
> > What is pwm2 used for?
>
> The signal is accessible on the EXIO connector D (LBSC) .
> It is up to user to use the pin for their purposes.

Usually we do not enable support for random user wirings on EXIO connectors.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds