Messages in this thread Patch in this message |  | | From | Marek Vasut <> | | Subject | [PATCH 05/11] arm64: dts: renesas: condor-common: Specify ethernet PHY reset timings | | Date | Tue, 5 May 2026 05:42:46 +0200 |
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The KSZ9031RNX reference manual [1] DS00002096H page 60 FIGURE 7-7: POWER-UP/POWER-DOWN/RESET TIMING Note 2 states, that after the de-assertion of reset, wait a minimum of 100 us before starting programming on the MIIM (MDC/MDIO) interface. Set DT property reset-deassert-us to three times that, 300 us, to provide ample time between reset deassertion and MDIO access.
The KSZ9031RNX reference manual [1] DS00002096H page 60 TABLE 7-7: POWER-UP/POWER-DOWN/RESET TIMING PARAMETERS row tSR Stable supply voltages to de-assertion of reset is at minimum 10 ms. Set DT property reset-assert-us to 10ms because the KSZ9031RNX 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/KSZ9031MNX-Data-Sheet-DS00002096.pdf
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org> --- Cc: Conor Dooley <conor+dt@kernel.org> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Krzysztof Kozlowski <krzk+dt@kernel.org> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: Rob Herring <robh@kernel.org> Cc: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org --- arch/arm64/boot/dts/renesas/condor-common.dtsi | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/arm64/boot/dts/renesas/condor-common.dtsi b/arch/arm64/boot/dts/renesas/condor-common.dtsi index 6b22cc0b05b19..9d55509b00b15 100644 --- a/arch/arm64/boot/dts/renesas/condor-common.dtsi +++ b/arch/arm64/boot/dts/renesas/condor-common.dtsi @@ -168,6 +168,8 @@ phy0: ethernet-phy@0 { reg = <0>; interrupts-extended = <&gpio4 23 IRQ_TYPE_LEVEL_LOW>; reset-gpios = <&gpio4 22 GPIO_ACTIVE_LOW>; + reset-assert-us = <10000>; + reset-deassert-us = <300>; }; }; -- 2.53.0
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