[Upstream] [PATCH] arm64: dts: freescale: imx93-phycore-som: Delay the phy reset by a gpio

[Primoz Fiser]

Hi Christoph,

On 20. 05. 25 09:34, Christoph Stoidner wrote:
> According to the datasheet the phy needs to be held in reset until the
> reference clock got stable. Even though no issue was observed, fix this
> as the software should always comply with the specification.
> 
> Fix this in the bootloader, as this is the point where the reference
> clock gets initialized and stable first.

I would remove this paragraph about the "Fix this in the bootloader..."

Doesn't patch apply to both the kernel and the bootloader FEC driver?

> 
> Use gpio4 23, which is connected to the phy reset pin. On the same pin
> RX_ER was used before, but this signal is optional and can be dropped.
> 
> Note: This comes into effect with the phyCOREs SOM hardware revision 4.
> In revisions before, this gpio is not connected, and the phy reset is
> managed with the global hardware reset circuit.
> 
> Signed-off-by: Christoph Stoidner <c.stoidner at phytec.de>
> ---
>  arch/arm64/boot/dts/freescale/imx93-phycore-som.dtsi | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/freescale/imx93-phycore-som.dtsi b/arch/arm64/boot/dts/freescale/imx93-phycore-som.dtsi
> index 88c2657b50e6..f8e2f3f3baa8 100644
> --- a/arch/arm64/boot/dts/freescale/imx93-phycore-som.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx93-phycore-som.dtsi
> @@ -58,6 +58,9 @@ &fec {
>  				 <&clk IMX93_CLK_SYS_PLL_PFD1_DIV2>,
>  				 <&clk IMX93_CLK_SYS_PLL_PFD1_DIV2>;
>  	assigned-clock-rates = <100000000>, <50000000>, <50000000>;
> +	phy-reset-gpios = <&gpio4 23 GPIO_ACTIVE_HIGH>;
> +	phy-reset-duration = <1>;
> +	phy-reset-post-delay = <0>;
>  	status = "okay";
>  
>  	mdio: mdio {
> @@ -91,14 +94,16 @@ pinctrl_fec: fecgrp {
>  		fsl,pins = <
>  			MX93_PAD_ENET2_MDC__ENET1_MDC			0x50e
>  			MX93_PAD_ENET2_MDIO__ENET1_MDIO			0x502
> -			MX93_PAD_ENET2_RD0__ENET1_RGMII_RD0		0x57e
> -			MX93_PAD_ENET2_RD1__ENET1_RGMII_RD1		0x57e
> -			MX93_PAD_ENET2_RXC__ENET1_RX_ER			0x5fe
> +			/* the three pins below are connected to PHYs straps,
> +			 * that is what the pull-up/down setting is for. */

I would remove this comment and maybe move it to the commit msg why are
you changing the PD/PU configuration.

Anyway, if you decide to keep it, you need to fix the following warning:

WARNING: Block comments use a trailing */ on a separate line
#46: FILE: arch/arm64/boot/dts/freescale/imx93-phycore-som.dtsi:98:
+                        * that is what the pull-up/down setting is for. */

BR,
Primoz

> +			MX93_PAD_ENET2_RD0__ENET1_RGMII_RD0		0x37e
> +			MX93_PAD_ENET2_RD1__ENET1_RGMII_RD1		0x37e
>  			MX93_PAD_ENET2_RX_CTL__ENET1_RGMII_RX_CTL	0x57e
>  			MX93_PAD_ENET2_TD0__ENET1_RGMII_TD0		0x50e
>  			MX93_PAD_ENET2_TD1__ENET1_RGMII_TD1		0x50e
>  			MX93_PAD_ENET2_TX_CTL__ENET1_RGMII_TX_CTL	0x50e
>  			MX93_PAD_ENET2_TD2__ENET1_TX_CLK		0x4000050e
> +			MX93_PAD_ENET2_RXC__GPIO4_IO23			0x51e
>  		>;
>  	};
>  

-- 
Primoz Fiser
phone: +386-41-390-545
email: primoz.fiser at norik.com
--
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