Re: [PATCH net-next v3 09/12] net: dsa: lantiq_gswip: add vendor property to setup MII refclk output

[Vladimir Oltean]

On Sun, Oct 26, 2025 at 11:47:21PM +0000, Daniel Golle wrote:
> Read boolean Device Tree property "maxlinear,rmii-refclk-out" and switch
> the RMII reference clock to be a clock output rather than an input if it
> is set.
> 
> Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
> ---
>  drivers/net/dsa/lantiq/lantiq_gswip_common.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/net/dsa/lantiq/lantiq_gswip_common.c b/drivers/net/dsa/lantiq/lantiq_gswip_common.c
> index 60a83093cd10..bf38ecc13f76 100644
> --- a/drivers/net/dsa/lantiq/lantiq_gswip_common.c
> +++ b/drivers/net/dsa/lantiq/lantiq_gswip_common.c
> @@ -1442,6 +1442,10 @@ static void gswip_phylink_mac_config(struct phylink_config *config,
>  		return;
>  	}
>  
> +	if (of_property_read_bool(dp->dn, "maxlinear,rmii-refclk-out") &&
> +	    !(miicfg & GSWIP_MII_CFG_MODE_RGMII))
> +		miicfg |= GSWIP_MII_CFG_RMII_CLK;
> +

What did you mean with the !(miicfg & GSWIP_MII_CFG_MODE_RGMII) test?
If the schema says "Only applicable for RMII mode.", what's the purpose
of this extra condition? For example, GSWIP_MII_CFG_MODE_GMII also has
the "GSWIP_MII_CFG_MODE_RGMII" bit (0x4) unset. Does this have any significance?

>  	gswip_mii_mask_cfg(priv,
>  			   GSWIP_MII_CFG_MODE_MASK | GSWIP_MII_CFG_RMII_CLK |
>  			   GSWIP_MII_CFG_RGMII_IBS | GSWIP_MII_CFG_LDCLKDIS,
> -- 
> 2.51.1