Subject: Re: [PATCH net-next v3 4/4] net: stmmac: dwmac-sogfpga: use the lynx pcs driver

From: Simon Horman <[email-masked]>
Date: Fri, 26 May 2023 10:52:17 +0200

On Fri, May 26, 2023 at 09:42:52AM +0200, Maxime Chevallier wrote:
> dwmac_socfpga re-implements support for the TSE PCS, which is identical
> to the already existing TSE PCS, which in turn is the same as the Lynx
> PCS. Drop the existing TSE re-implemenation and use the Lynx PCS
> instead, relying on the regmap-mdio driver to translate MDIO accesses
> into mmio accesses.
> 
> Instead of extending xpcs, allow using a generic phylink_pcs, populated
> by lynx_pcs_create(), and use .mac_select_pcs() to return the relevant
> PCS to be used.
> 
> Signed-off-by: Maxime Chevallier <[email-masked]>
> ---
> V2->V3 : No changes
> V1->V2 : No changes
> 
>  drivers/net/ethernet/stmicro/stmmac/Kconfig   |   1 +
>  drivers/net/ethernet/stmicro/stmmac/Makefile  |   2 +-
>  .../ethernet/stmicro/stmmac/altr_tse_pcs.c    | 257 ------------------
>  .../ethernet/stmicro/stmmac/altr_tse_pcs.h    |  29 --
>  drivers/net/ethernet/stmicro/stmmac/common.h  |   1 +
>  .../ethernet/stmicro/stmmac/dwmac-socfpga.c   |  90 ++++--
>  .../net/ethernet/stmicro/stmmac/stmmac_main.c |  12 +-
>  7 files changed, 76 insertions(+), 316 deletions(-)

Another nice diffstat :)

...

> @@ -443,6 +454,35 @@ static int socfpga_dwmac_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto err_dvr_remove;
>  
> +	memset(&pcs_regmap_cfg, 0, sizeof(pcs_regmap_cfg));
> +	pcs_regmap_cfg.reg_bits = 16;
> +	pcs_regmap_cfg.val_bits = 16;
> +	pcs_regmap_cfg.reg_shift = REGMAP_UPSHIFT(1);
> +
> +	/* Create a regmap for the PCS so that it can be used by the PCS driver,
> +	 * if we have such a PCS
> +	 */
> +	if (dwmac->tse_pcs_base) {

nit: perhaps the scope of pcs_regmap and pcs_bus could be reduced to
     this block.

> +		pcs_regmap = devm_regmap_init_mmio(&pdev->dev, dwmac->tse_pcs_base,
> +						   &pcs_regmap_cfg);
> +		if (IS_ERR(pcs_regmap)) {
> +			ret = PTR_ERR(pcs_regmap);
> +			goto err_dvr_remove;
> +		}
> +
> +		mrc.regmap = pcs_regmap;
> +
> +		snprintf(mrc.name, MII_BUS_ID_SIZE, "%s-pcs-mii", ndev->name);
> +		pcs_bus = devm_mdio_regmap_register(&pdev->dev, &mrc);
> +		if (IS_ERR(pcs_bus)) {
> +			ret = PTR_ERR(pcs_bus);
> +			goto err_dvr_remove;
> +		}
> +
> +		dwmac->pcs_mdiodev = mdio_device_create(pcs_bus, 0);
> +		stpriv->hw->phylink_pcs = lynx_pcs_create(dwmac->pcs_mdiodev);
> +	}
> +
>  	return 0;
>  
>  err_dvr_remove:

...