net: stmmac: dwmac-sun8i: Balance syscon (de)initialization

Previously, sun8i_dwmac_set_syscon was called from a chain of functions
in several different files:
    sun8i_dwmac_probe
      stmmac_dvr_probe
        stmmac_hw_init
          stmmac_hwif_init
            sun8i_dwmac_setup
              sun8i_dwmac_set_syscon
which made the lifetime of the syscon values hard to reason about. Part
of the problem is that there is no similar platform driver callback from
stmmac_dvr_remove. As a result, the driver unset the syscon value in
sun8i_dwmac_exit, but this leaves it uninitialized after a suspend/
resume cycle. It was also unset a second time (outside sun8i_dwmac_exit)
in the probe error path.

Move the init to the earliest available place in sun8i_dwmac_probe
(after stmmac_probe_config_dt, which initializes plat_dat), and the
deinit to the corresponding position in the cleanup order.

Since priv is not filled in until stmmac_dvr_probe, this requires
changing the sun8i_dwmac_set_syscon parameters to priv's two relevant
members.

Fixes: 9f93ac8d ("net-next: stmmac: Add dwmac-sun8i")
Fixes: 634db83b ("net: stmmac: dwmac-sun8i: Handle integrated/external MDIOs")
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c

@@ -898,22 +898,23 @@ static int sun8i_dwmac_register_mdio_mux(struct stmmac_priv *priv)
 	return ret;
 }
 
-static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
+static int sun8i_dwmac_set_syscon(struct device *dev,
+				  struct plat_stmmacenet_data *plat)
 {
-	struct sunxi_priv_data *gmac = priv->plat->bsp_priv;
-	struct device_node *node = priv->device->of_node;
+	struct sunxi_priv_data *gmac = plat->bsp_priv;
+	struct device_node *node = dev->of_node;
 	int ret;
 	u32 reg, val;
 
 	ret = regmap_field_read(gmac->regmap_field, &val);
 	if (ret) {
-		dev_err(priv->device, "Fail to read from regmap field.\n");
+		dev_err(dev, "Fail to read from regmap field.\n");
 		return ret;
 	}
 
 	reg = gmac->variant->default_syscon_value;
 	if (reg != val)
-		dev_warn(priv->device,
+		dev_warn(dev,
 			 "Current syscon value is not the default %x (expect %x)\n",
 			 val, reg);
 
@@ -926,9 +927,9 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
 		/* Force EPHY xtal frequency to 24MHz. */
 		reg |= H3_EPHY_CLK_SEL;
 
-		ret = of_mdio_parse_addr(priv->device, priv->plat->phy_node);
+		ret = of_mdio_parse_addr(dev, plat->phy_node);
 		if (ret < 0) {
-			dev_err(priv->device, "Could not parse MDIO addr\n");
+			dev_err(dev, "Could not parse MDIO addr\n");
 			return ret;
 		}
 		/* of_mdio_parse_addr returns a valid (0 ~ 31) PHY
@@ -944,17 +945,17 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
 
 	if (!of_property_read_u32(node, "allwinner,tx-delay-ps", &val)) {
 		if (val % 100) {
-			dev_err(priv->device, "tx-delay must be a multiple of 100\n");
+			dev_err(dev, "tx-delay must be a multiple of 100\n");
 			return -EINVAL;
 		}
 		val /= 100;
-		dev_dbg(priv->device, "set tx-delay to %x\n", val);
+		dev_dbg(dev, "set tx-delay to %x\n", val);
 		if (val <= gmac->variant->tx_delay_max) {
 			reg &= ~(gmac->variant->tx_delay_max <<
 				 SYSCON_ETXDC_SHIFT);
 			reg |= (val << SYSCON_ETXDC_SHIFT);
 		} else {
-			dev_err(priv->device, "Invalid TX clock delay: %d\n",
+			dev_err(dev, "Invalid TX clock delay: %d\n",
 				val);
 			return -EINVAL;
 		}
@@ -962,17 +963,17 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
 
 	if (!of_property_read_u32(node, "allwinner,rx-delay-ps", &val)) {
 		if (val % 100) {
-			dev_err(priv->device, "rx-delay must be a multiple of 100\n");
+			dev_err(dev, "rx-delay must be a multiple of 100\n");
 			return -EINVAL;
 		}
 		val /= 100;
-		dev_dbg(priv->device, "set rx-delay to %x\n", val);
+		dev_dbg(dev, "set rx-delay to %x\n", val);
 		if (val <= gmac->variant->rx_delay_max) {
 			reg &= ~(gmac->variant->rx_delay_max <<
 				 SYSCON_ERXDC_SHIFT);
 			reg |= (val << SYSCON_ERXDC_SHIFT);
 		} else {
-			dev_err(priv->device, "Invalid RX clock delay: %d\n",
+			dev_err(dev, "Invalid RX clock delay: %d\n",
 				val);
 			return -EINVAL;
 		}
@@ -983,7 +984,7 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
 	if (gmac->variant->support_rmii)
 		reg &= ~SYSCON_RMII_EN;
 
-	switch (priv->plat->interface) {
+	switch (plat->interface) {
 	case PHY_INTERFACE_MODE_MII:
 		/* default */
 		break;
@@ -997,8 +998,8 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
 		reg |= SYSCON_RMII_EN | SYSCON_ETCS_EXT_GMII;
 		break;
 	default:
-		dev_err(priv->device, "Unsupported interface mode: %s",
-			phy_modes(priv->plat->interface));
+		dev_err(dev, "Unsupported interface mode: %s",
+			phy_modes(plat->interface));
 		return -EINVAL;
 	}
 
@@ -1023,8 +1024,6 @@ static void sun8i_dwmac_exit(struct platform_device *pdev, void *priv)
 			sun8i_dwmac_unpower_internal_phy(gmac);
 	}
 
-	sun8i_dwmac_unset_syscon(gmac);
-
 	clk_disable_unprepare(gmac->tx_clk);
 
 	if (gmac->regulator)
@@ -1059,16 +1058,11 @@ static struct mac_device_info *sun8i_dwmac_setup(void *ppriv)
 {
 	struct mac_device_info *mac;
 	struct stmmac_priv *priv = ppriv;
-	int ret;
 
 	mac = devm_kzalloc(priv->device, sizeof(*mac), GFP_KERNEL);
 	if (!mac)
 		return NULL;
 
-	ret = sun8i_dwmac_set_syscon(priv);
-	if (ret)
-		return NULL;
-
 	mac->pcsr = priv->ioaddr;
 	mac->mac = &sun8i_dwmac_ops;
 	mac->dma = &sun8i_dwmac_dma_ops;
@@ -1224,10 +1218,14 @@ static int sun8i_dwmac_probe(struct platform_device *pdev)
 	plat_dat->exit = sun8i_dwmac_exit;
 	plat_dat->setup = sun8i_dwmac_setup;
 
-	ret = sun8i_dwmac_init(pdev, plat_dat->bsp_priv);
+	ret = sun8i_dwmac_set_syscon(&pdev->dev, plat_dat);
 	if (ret)
 		goto dwmac_deconfig;
 
+	ret = sun8i_dwmac_init(pdev, plat_dat->bsp_priv);
+	if (ret)
+		goto dwmac_syscon;
+
 	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
 	if (ret)
 		goto dwmac_exit;
@@ -1256,11 +1254,12 @@ static int sun8i_dwmac_probe(struct platform_device *pdev)
 dwmac_mux:
 	reset_control_put(gmac->rst_ephy);
 	clk_put(gmac->ephy_clk);
-	sun8i_dwmac_unset_syscon(gmac);
 dwmac_remove:
 	stmmac_dvr_remove(&pdev->dev);
 dwmac_exit:
 	sun8i_dwmac_exit(pdev, gmac);
+dwmac_syscon:
+	sun8i_dwmac_unset_syscon(gmac);
 dwmac_deconfig:
 	stmmac_remove_config_dt(pdev, plat_dat);
 
@@ -1281,6 +1280,7 @@ static int sun8i_dwmac_remove(struct platform_device *pdev)
 	}
 
 	stmmac_pltfr_remove(pdev);
+	sun8i_dwmac_unset_syscon(gmac);
 
 	return 0;
 }