[PATCH] ARM: dts: stm32: Keep MDIO bus in AF across suspend DH STM32MP13xx DHCOR DHSBC board

[Alexandre TORGUE]

Hi Marek

On 6/29/24 22:28, Marek Vasut wrote:
> The RTL8211F PHY gets confused when the MDIO bus lines get switched
> to ANALOG during suspend/resume cycle. Keep the MDIO and MDC lines
> in AF during suspend/resume to avoid confusing the PHY. The PHY can
> be brought out of the confused state by restarting auto-negotiation
> too, but that seems like an odd workaround and shouldn't be in the
> PHY driver.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> ---
> Cc: Alexandre Torgue <alexandre.torgue at foss.st.com>
> Cc: Christophe Roullier <christophe.roullier at foss.st.com>
> Cc: Conor Dooley <conor+dt at kernel.org>
> Cc: Krzysztof Kozlowski <krzk+dt at kernel.org>
> Cc: Maxime Coquelin <mcoquelin.stm32 at gmail.com>
> Cc: Rob Herring <robh at kernel.org>
> Cc: devicetree at vger.kernel.org
> Cc: kernel at dh-electronics.com
> Cc: linux-arm-kernel at lists.infradead.org
> Cc: linux-stm32 at st-md-mailman.stormreply.com
> ---
>   arch/arm/boot/dts/st/stm32mp13-pinctrl.dtsi | 20 ++++++++++++++++----
>   1 file changed, 16 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm/boot/dts/st/stm32mp13-pinctrl.dtsi b/arch/arm/boot/dts/st/stm32mp13-pinctrl.dtsi
> index d3deec602ae7a..e6c0dceee9866 100644
> --- a/arch/arm/boot/dts/st/stm32mp13-pinctrl.dtsi
> +++ b/arch/arm/boot/dts/st/stm32mp13-pinctrl.dtsi
> @@ -88,14 +88,20 @@ pins2 {
>   
>   	eth1_rgmii_sleep_pins_a: eth1-rgmii-sleep-0 {
>   		pins1 {
> +			pinmux = <STM32_PINMUX('A', 2, AF11)>, /* ETH_MDIO */
> +				 <STM32_PINMUX('G', 2, AF11)>; /* ETH_MDC */
> +			bias-disable;
> +			drive-push-pull;
> +			slew-rate = <2>;
> +		};
> +
> +		pins2 {
>   			pinmux = <STM32_PINMUX('G', 13, ANALOG)>, /* ETH_RGMII_TXD0 */
>   				 <STM32_PINMUX('G', 14, ANALOG)>, /* ETH_RGMII_TXD1 */
>   				 <STM32_PINMUX('C', 2, ANALOG)>, /* ETH_RGMII_TXD2 */
>   				 <STM32_PINMUX('E', 5, ANALOG)>, /* ETH_RGMII_TXD3 */
>   				 <STM32_PINMUX('B', 11, ANALOG)>, /* ETH_RGMII_TX_CTL */
>   				 <STM32_PINMUX('C', 1, ANALOG)>, /* ETH_RGMII_GTX_CLK */
> -				 <STM32_PINMUX('A', 2, ANALOG)>, /* ETH_MDIO */
> -				 <STM32_PINMUX('G', 2, ANALOG)>, /* ETH_MDC */
>   				 <STM32_PINMUX('C', 4, ANALOG)>, /* ETH_RGMII_RXD0 */
>   				 <STM32_PINMUX('C', 5, ANALOG)>, /* ETH_RGMII_RXD1 */
>   				 <STM32_PINMUX('B', 0, ANALOG)>, /* ETH_RGMII_RXD1 */
> @@ -169,14 +175,20 @@ pins2 {
>   
>   	eth2_rgmii_sleep_pins_a: eth2-rgmii-sleep-0 {
>   		pins1 {
> +			pinmux = <STM32_PINMUX('B', 6, ANALOG)>, /* ETH_MDIO */
> +				 <STM32_PINMUX('G', 5, ANALOG)>; /* ETH_MDC */

Why don't you put PB6 and PG5 in AF for the sleep config as for ETH1 ?

> +			bias-disable;
> +			drive-push-pull;
> +			slew-rate = <2>;
> +		};
> +
> +		pins2 {
>   			pinmux = <STM32_PINMUX('F', 7, ANALOG)>, /* ETH_RGMII_TXD0 */
>   				 <STM32_PINMUX('G', 11, ANALOG)>, /* ETH_RGMII_TXD1 */
>   				 <STM32_PINMUX('G', 1, ANALOG)>, /* ETH_RGMII_TXD2 */
>   				 <STM32_PINMUX('E', 6, ANALOG)>, /* ETH_RGMII_TXD3 */
>   				 <STM32_PINMUX('F', 6, ANALOG)>, /* ETH_RGMII_TX_CTL */
>   				 <STM32_PINMUX('G', 3, ANALOG)>, /* ETH_RGMII_GTX_CLK */
> -				 <STM32_PINMUX('B', 6, ANALOG)>, /* ETH_MDIO */
> -				 <STM32_PINMUX('G', 5, ANALOG)>, /* ETH_MDC */
>   				 <STM32_PINMUX('F', 4, ANALOG)>, /* ETH_RGMII_RXD0 */
>   				 <STM32_PINMUX('E', 2, ANALOG)>, /* ETH_RGMII_RXD1 */
>   				 <STM32_PINMUX('H', 6, ANALOG)>, /* ETH_RGMII_RXD2 */