[PATCH 1/2] ARM: dts: at91: sama7g5ek: use proper slew-rate settings for GMACs

From: Claudiu Beznea
Date: Wed Sep 15 2021 - 03:49:14 EST


Datasheet chapter "EMAC Timings" specifies that while in 3.3V domain
GMAC's MDIO pins should be configured with slew-rate enabled, while the
data + signaling pins should be configured with slew-rate disabled when
GMAC works in RGMII or RMII modes. The pin controller for SAMA7G5 sets
the slew-rate as enabled for all pins. Adapt the device tree to comply
with these.

Fixes: 7540629e2fc7 ("ARM: dts: at91: add sama7g5 SoC DT and sama7g5-ek")
Signed-off-by: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
---
arch/arm/boot/dts/at91-sama7g5ek.dts | 28 ++++++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/arch/arm/boot/dts/at91-sama7g5ek.dts b/arch/arm/boot/dts/at91-sama7g5ek.dts
index 8b13b031a167..0bed8207d498 100644
--- a/arch/arm/boot/dts/at91-sama7g5ek.dts
+++ b/arch/arm/boot/dts/at91-sama7g5ek.dts
@@ -353,7 +353,10 @@ &gmac0 {
#address-cells = <1>;
#size-cells = <0>;
pinctrl-names = "default";
- pinctrl-0 = <&pinctrl_gmac0_default &pinctrl_gmac0_txck_default &pinctrl_gmac0_phy_irq>;
+ pinctrl-0 = <&pinctrl_gmac0_default
+ &pinctrl_gmac0_mdio_default
+ &pinctrl_gmac0_txck_default
+ &pinctrl_gmac0_phy_irq>;
phy-mode = "rgmii-id";
status = "okay";

@@ -368,7 +371,9 @@ &gmac1 {
#address-cells = <1>;
#size-cells = <0>;
pinctrl-names = "default";
- pinctrl-0 = <&pinctrl_gmac1_default &pinctrl_gmac1_phy_irq>;
+ pinctrl-0 = <&pinctrl_gmac1_default
+ &pinctrl_gmac1_mdio_default
+ &pinctrl_gmac1_phy_irq>;
phy-mode = "rmii";
status = "okay";

@@ -423,14 +428,20 @@ pinctrl_gmac0_default: gmac0_default {
<PIN_PA15__G0_TXEN>,
<PIN_PA30__G0_RXCK>,
<PIN_PA18__G0_RXDV>,
- <PIN_PA22__G0_MDC>,
- <PIN_PA23__G0_MDIO>,
<PIN_PA25__G0_125CK>;
+ slew-rate = <0>;
+ bias-disable;
+ };
+
+ pinctrl_gmac0_mdio_default: gmac0_mdio_default {
+ pinmux = <PIN_PA22__G0_MDC>,
+ <PIN_PA23__G0_MDIO>;
bias-disable;
};

pinctrl_gmac0_txck_default: gmac0_txck_default {
pinmux = <PIN_PA24__G0_TXCK>;
+ slew-rate = <0>;
bias-pull-up;
};

@@ -447,8 +458,13 @@ pinctrl_gmac1_default: gmac1_default {
<PIN_PD25__G1_RX0>,
<PIN_PD26__G1_RX1>,
<PIN_PD27__G1_RXER>,
- <PIN_PD24__G1_RXDV>,
- <PIN_PD28__G1_MDC>,
+ <PIN_PD24__G1_RXDV>;
+ slew-rate = <0>;
+ bias-disable;
+ };
+
+ pinctrl_gmac1_mdio_default: gmac1_mdio_default {
+ pinmux = <PIN_PD28__G1_MDC>,
<PIN_PD29__G1_MDIO>;
bias-disable;
};
--
2.25.1