net: stmmac: dwmac-socfpga: use pcs_init/pcs_exit

Use the newly introduced pcs_init() and pcs_exit() operations to
create and destroy the PCS instance at a more appropriate moment during
the driver lifecycle, thereby avoiding publishing a network device to
userspace that has not yet finished its PCS initialisation.

There are other similar issues with this driver which remain
unaddressed, but these are out of scope for this patch.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
[rgantois: removed second parameters of new callbacks]
Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
Reviewed-by: Hariprasad Kelam <hkelam@marvell.com>
Link: https://lore.kernel.org/r/20240513-rzn1-gmac1-v7-5-6acf58b5440d@bootlin.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c

@@ -379,6 +379,56 @@ static int socfpga_gen10_set_phy_mode(struct socfpga_dwmac *dwmac)
 	return 0;
 }
 
+static int socfpga_dwmac_pcs_init(struct stmmac_priv *priv)
+{
+	struct socfpga_dwmac *dwmac = priv->plat->bsp_priv;
+	struct regmap_config pcs_regmap_cfg = {
+		.reg_bits = 16,
+		.val_bits = 16,
+		.reg_shift = REGMAP_UPSHIFT(1),
+	};
+	struct mdio_regmap_config mrc;
+	struct regmap *pcs_regmap;
+	struct phylink_pcs *pcs;
+	struct mii_bus *pcs_bus;
+
+	if (!dwmac->tse_pcs_base)
+		return 0;
+
+	pcs_regmap = devm_regmap_init_mmio(priv->device, dwmac->tse_pcs_base,
+					   &pcs_regmap_cfg);
+	if (IS_ERR(pcs_regmap))
+		return PTR_ERR(pcs_regmap);
+
+	memset(&mrc, 0, sizeof(mrc));
+	mrc.regmap = pcs_regmap;
+	mrc.parent = priv->device;
+	mrc.valid_addr = 0x0;
+	mrc.autoscan = false;
+
+	/* Can't use ndev->name here because it will not have been initialised,
+	 * and in any case, the user can rename network interfaces at runtime.
+	 */
+	snprintf(mrc.name, MII_BUS_ID_SIZE, "%s-pcs-mii",
+		 dev_name(priv->device));
+	pcs_bus = devm_mdio_regmap_register(priv->device, &mrc);
+	if (IS_ERR(pcs_bus))
+		return PTR_ERR(pcs_bus);
+
+	pcs = lynx_pcs_create_mdiodev(pcs_bus, 0);
+	if (IS_ERR(pcs))
+		return PTR_ERR(pcs);
+
+	priv->hw->phylink_pcs = pcs;
+	return 0;
+}
+
+static void socfpga_dwmac_pcs_exit(struct stmmac_priv *priv)
+{
+	if (priv->hw->phylink_pcs)
+		lynx_pcs_destroy(priv->hw->phylink_pcs);
+}
+
 static int socfpga_dwmac_probe(struct platform_device *pdev)
 {
 	struct plat_stmmacenet_data *plat_dat;
@@ -426,6 +476,8 @@ static int socfpga_dwmac_probe(struct platform_device *pdev)
 	dwmac->ops = ops;
 	plat_dat->bsp_priv = dwmac;
 	plat_dat->fix_mac_speed = socfpga_dwmac_fix_mac_speed;
+	plat_dat->pcs_init = socfpga_dwmac_pcs_init;
+	plat_dat->pcs_exit = socfpga_dwmac_pcs_exit;
 
 	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
 	if (ret)
@@ -444,48 +496,6 @@ static int socfpga_dwmac_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_dvr_remove;
 
-	/* 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) {
-		struct regmap_config pcs_regmap_cfg;
-		struct mdio_regmap_config mrc;
-		struct regmap *pcs_regmap;
-		struct mii_bus *pcs_bus;
-
-		memset(&pcs_regmap_cfg, 0, sizeof(pcs_regmap_cfg));
-		memset(&mrc, 0, sizeof(mrc));
-
-		pcs_regmap_cfg.reg_bits = 16;
-		pcs_regmap_cfg.val_bits = 16;
-		pcs_regmap_cfg.reg_shift = REGMAP_UPSHIFT(1);
-
-		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;
-		mrc.parent = &pdev->dev;
-		mrc.valid_addr = 0x0;
-		mrc.autoscan = false;
-
-		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;
-		}
-
-		stpriv->hw->phylink_pcs = lynx_pcs_create_mdiodev(pcs_bus, 0);
-		if (IS_ERR(stpriv->hw->phylink_pcs)) {
-			ret = PTR_ERR(stpriv->hw->phylink_pcs);
-			goto err_dvr_remove;
-		}
-	}
-
 	return 0;
 
 err_dvr_remove:
@@ -494,17 +504,6 @@ static int socfpga_dwmac_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static void socfpga_dwmac_remove(struct platform_device *pdev)
-{
-	struct net_device *ndev = platform_get_drvdata(pdev);
-	struct stmmac_priv *priv = netdev_priv(ndev);
-	struct phylink_pcs *pcs = priv->hw->phylink_pcs;
-
-	stmmac_pltfr_remove(pdev);
-
-	lynx_pcs_destroy(pcs);
-}
-
 #ifdef CONFIG_PM_SLEEP
 static int socfpga_dwmac_resume(struct device *dev)
 {
@@ -576,7 +575,7 @@ MODULE_DEVICE_TABLE(of, socfpga_dwmac_match);
 
 static struct platform_driver socfpga_dwmac_driver = {
 	.probe  = socfpga_dwmac_probe,
-	.remove_new = socfpga_dwmac_remove,
+	.remove_new = stmmac_pltfr_remove,
 	.driver = {
 		.name           = "socfpga-dwmac",
 		.pm		= &socfpga_dwmac_pm_ops,