Re: [PATCH net-next 2/3] net: dsa: lantiq: allow arbitrary MII registers

[Vladimir Oltean]

On Tue, Jan 13, 2026 at 03:25:16AM +0000, Daniel Golle wrote:
> The Lantiq GSWIP and MaxLinear GSW1xx drivers are currently relying on a
> hard-coded mapping of MII ports to their respective MII_CFG and MII_PCDU
> registers and only allow applying an offset to the port index.
> 
> While this is sufficient for the currently supported hardware, the very
> similar Intel GSW150 (aka. Lantiq PEB7084) cannot be described using
> this arrangement.
> 
> Introduce two arrays to specify the MII_CFG and MII_PCDU registers for
> each port, replacing the current bitmap used to safeguard MII ports as
> well as the port index offset.
> 
> Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
> ---
> diff --git a/drivers/net/dsa/lantiq/lantiq_gswip.h b/drivers/net/dsa/lantiq/lantiq_gswip.h
> index 8fc4c7cc5283a..b87a68a1b3b67 100644
> --- a/drivers/net/dsa/lantiq/lantiq_gswip.h
> +++ b/drivers/net/dsa/lantiq/lantiq_gswip.h
> @@ -253,8 +253,8 @@ struct gswip_pce_microcode {
>  struct gswip_hw_info {
>  	int max_ports;
>  	unsigned int allowed_cpu_ports;
> -	unsigned int mii_ports;
> -	int mii_port_reg_offset;
> +	s16 mii_cfg[8];
> +	s16 mii_pcdu[8];

Why [8] and not [7] (the larger of GSW150_PORTS and GSW1XX_PORTS)?
I would prefer to see a macro holding the largest port count of the
supported switches, and the "7" also expressed as that value - 1.

>  	bool supports_2500m;
>  	const struct gswip_pce_microcode (*pce_microcode)[];
>  	size_t pce_microcode_size;