[PATCH 4/9] arm: dts: renesas: porter: Specify ethernet PHY reset timings

[Marek Vasut]

The KSZ8041RNL reference manual [1] DS00002245C page 47 TABLE 7-10:
POWER-UP/RESET TIMING PARAMETERS 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 the same value as
used for KSZ9031RNX, which is 300 us.

The KSZ8041RNL reference manual [1] DS00002245C page 47 TABLE 7-10:
POWER-UP/RESET TIMING PARAMETERS row tSR Stable supply voltages to
reset high is at minimum 10 ms. Set the DT property reset-assert-us
to 10ms because the KSZ8041RNL 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/00002841D.pdf

Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
---
Cc: Conor Dooley <conor+dt at kernel.org>
Cc: Geert Uytterhoeven <geert+renesas at glider.be>
Cc: Krzysztof Kozlowski <krzk+dt at kernel.org>
Cc: Rob Herring <robh at kernel.org>
Cc: devicetree at vger.kernel.org
Cc: linux-kernel at vger.kernel.org
Cc: linux-renesas-soc at vger.kernel.org
---
 arch/arm/boot/dts/renesas/r8a7791-porter.dts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/boot/dts/renesas/r8a7791-porter.dts b/arch/arm/boot/dts/renesas/r8a7791-porter.dts
index 811e263452acd..05989da3be046 100644
--- a/arch/arm/boot/dts/renesas/r8a7791-porter.dts
+++ b/arch/arm/boot/dts/renesas/r8a7791-porter.dts
@@ -328,12 +328,14 @@ &ether {
 	phy1: ethernet-phy at 1 {
 		compatible = "ethernet-phy-id0022.1537";
 		reg = <1>;
 		interrupts-extended = <&irqc0 0 IRQ_TYPE_LEVEL_LOW>;
 		micrel,led-mode = <1>;
 		reset-gpios = <&gpio5 22 GPIO_ACTIVE_LOW>;
+		reset-assert-us = <10000>;
+		reset-deassert-us = <300>;
 	};
 };
 
 &sdhi0 {
 	pinctrl-0 = <&sdhi0_pins>;
 	pinctrl-names = "default";
-- 
2.53.0