Re: [PATCH 4/7] net: stmmac: dwmac-rk: Enable refout clock for RGMII

[Heiko Stübner]

Hi,

Am Mittwoch, 24. Juni 2026, 10:44:41 Mitteleuropäische Sommerzeit schrieb Yanan He:
> Some Rockchip GMAC integrations use clk_mac_refout as an external PHY
> reference clock even when the MAC is configured for RGMII.
> 
> RV1126 boards can route CLK_GMAC_ETHERNET_OUT to the external PHY as a
> 25 MHz reference clock. If the driver does not acquire and enable this
> clock in RGMII mode, the common clock framework may disable it as unused
> and the PHY can lose its reference clock.
> 
> Enable the refout clock handling for RGMII in addition to RMII.

the clock your referencing is not limited to your rv1126 but instead
present on most (all?) Rockchip SoCs.

And it is an input clock for the phy itself, so should be handled there.

See for example
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/rockchip/rk3588-tiger.dtsi#n313
as a reference.


Heiko

> Signed-off-by: Yanan He <grumpycat921013@xxxxxxxxx>
> ---
>  drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> index 8d7042e68926..f6fdc0c5b475 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> @@ -1112,7 +1112,8 @@ static int rk_gmac_clk_init(struct plat_stmmacenet_data *plat)
>  	bsp_priv->clk_enabled = false;
>  
>  	bsp_priv->num_clks = ARRAY_SIZE(rk_clocks);
> -	if (phy_iface == PHY_INTERFACE_MODE_RMII)
> +	if (phy_iface == PHY_INTERFACE_MODE_RMII ||
> +	    phy_iface == PHY_INTERFACE_MODE_RGMII)
>  		bsp_priv->num_clks += ARRAY_SIZE(rk_rmii_clocks);
>  
>  	bsp_priv->clks = devm_kcalloc(dev, bsp_priv->num_clks,
> @@ -1123,7 +1124,8 @@ static int rk_gmac_clk_init(struct plat_stmmacenet_data *plat)
>  	for (i = 0; i < ARRAY_SIZE(rk_clocks); i++)
>  		bsp_priv->clks[i].id = rk_clocks[i];
>  
> -	if (phy_iface == PHY_INTERFACE_MODE_RMII) {
> +	if (phy_iface == PHY_INTERFACE_MODE_RMII ||
> +	    phy_iface == PHY_INTERFACE_MODE_RGMII) {
>  		for (j = 0; j < ARRAY_SIZE(rk_rmii_clocks); j++)
>  			bsp_priv->clks[i++].id = rk_rmii_clocks[j];
>  	}
> 
>