[PATCH 2/2] arm: dts: renesas: armadillo800eva: Specify ethernet PHY reset timings

[Geert Uytterhoeven]

On Tue, 14 Jul 2026 at 15:03, Marek Vasut
<marek.vasut+renesas at mailbox.org> wrote:
> The LAN8710Ai reference manual [1] DS00002164C page 61 FIGURE 5-3:
> POWER-ON NRST & CONFIGURATION STRAP TIMING does not indicate how
> long should the system wait after deassertion of the PHY reset and
> before start of communication with the PHY via MDIO. Opt for 300 us
> which should cover every timing option, including the 16 us delay
> required for MDIO to switch to 25 MHz listed in Note: in Chapter
> 3.8.5 RESETS.
>
> The LAN8710Ai reference manual [1] DS00002164C page 61 TABLE 5-8:
> POWER-ON NRST & CONFIGURATION STRAP TIMING VALUES row tSR Stable
> supply voltages to reset high is at minimum 10 ms. Set DT property
> reset-assert-us to 25ms because the LAN8710Ai RM does not explicitly
> spell out how long the reset has to be asserted, but this at least
> covers the worst case scenario.
>
> [1] https://ww1.microchip.com/downloads/aemDocuments/documents/UNG/ProductDocuments/DataSheets/LAN8710A-LAN8710Ai-Data-Sheet-DS00002164.pdf
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>

Reviewed-by: Geert Uytterhoeven <geert+renesas at glider.be>
i.e. will queue in renesas-devel for v7.4.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at 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