net: stmmac: dwmac-loongson: Add DT-less GMAC PCI-device support

The Loongson GMAC driver currently supports the network controllers
installed on the LS2K1000 SoC and LS7A1000 chipset, for which the GMAC
devices are required to be defined in the platform device tree source.
But Loongson machines may have UEFI (implies ACPI) or PMON/UBOOT
(implies FDT) as the system bootloaders. In order to have both system
configurations support let's extend the driver functionality with the
case of having the Loongson GMAC probed on the PCI bus with no device
tree node defined for it. That requires to make the device DT-node
optional, to rely on the IRQ line detected by the PCI core and to
have the MDIO bus ID calculated using the PCIe Domain+BDF numbers.

In order to have the device probe() and remove() methods less
complicated let's move the DT- and ACPI-specific code to the
respective sub-functions.
Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Signed-off-by: Yinggang Gu <guyinggang@loongson.cn>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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

@@ -12,11 +12,15 @@
 #define PCI_DEVICE_ID_LOONGSON_GMAC	0x7a03
 
 struct stmmac_pci_info {
-	int (*setup)(struct plat_stmmacenet_data *plat);
+	int (*setup)(struct pci_dev *pdev, struct plat_stmmacenet_data *plat);
 };
 
-static void loongson_default_data(struct plat_stmmacenet_data *plat)
+static void loongson_default_data(struct pci_dev *pdev,
+				  struct plat_stmmacenet_data *plat)
 {
+	/* Get bus_id, this can be overwritten later */
+	plat->bus_id = pci_dev_id(pdev);
+
 	plat->clk_csr = 2;	/* clk_csr_i = 20-35MHz & MDC = clk_csr_i/16 */
 	plat->has_gmac = 1;
 	plat->force_sf_dma_mode = 1;
@@ -49,9 +53,10 @@ static void loongson_default_data(struct plat_stmmacenet_data *plat)
 	plat->dma_cfg->pblx8 = true;
 }
 
-static int loongson_gmac_data(struct plat_stmmacenet_data *plat)
+static int loongson_gmac_data(struct pci_dev *pdev,
+			      struct plat_stmmacenet_data *plat)
 {
-	loongson_default_data(plat);
+	loongson_default_data(pdev, plat);
 
 	plat->tx_queues_to_use = 1;
 	plat->rx_queues_to_use = 1;
@@ -65,20 +70,85 @@ static struct stmmac_pci_info loongson_gmac_pci_info = {
 	.setup = loongson_gmac_data,
 };
 
+static int loongson_dwmac_dt_config(struct pci_dev *pdev,
+				    struct plat_stmmacenet_data *plat,
+				    struct stmmac_resources *res)
+{
+	struct device_node *np = dev_of_node(&pdev->dev);
+	int ret;
+
+	plat->mdio_node = of_get_child_by_name(np, "mdio");
+	if (plat->mdio_node) {
+		dev_info(&pdev->dev, "Found MDIO subnode\n");
+		plat->mdio_bus_data->needs_reset = true;
+	}
+
+	ret = of_alias_get_id(np, "ethernet");
+	if (ret >= 0)
+		plat->bus_id = ret;
+
+	res->irq = of_irq_get_byname(np, "macirq");
+	if (res->irq < 0) {
+		dev_err(&pdev->dev, "IRQ macirq not found\n");
+		ret = -ENODEV;
+		goto err_put_node;
+	}
+
+	res->wol_irq = of_irq_get_byname(np, "eth_wake_irq");
+	if (res->wol_irq < 0) {
+		dev_info(&pdev->dev,
+			 "IRQ eth_wake_irq not found, using macirq\n");
+		res->wol_irq = res->irq;
+	}
+
+	res->lpi_irq = of_irq_get_byname(np, "eth_lpi");
+	if (res->lpi_irq < 0) {
+		dev_err(&pdev->dev, "IRQ eth_lpi not found\n");
+		ret = -ENODEV;
+		goto err_put_node;
+	}
+
+	ret = device_get_phy_mode(&pdev->dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "phy_mode not found\n");
+		ret = -ENODEV;
+		goto err_put_node;
+	}
+
+	plat->phy_interface = ret;
+
+	return 0;
+
+err_put_node:
+	of_node_put(plat->mdio_node);
+
+	return ret;
+}
+
+static void loongson_dwmac_dt_clear(struct pci_dev *pdev,
+				    struct plat_stmmacenet_data *plat)
+{
+	of_node_put(plat->mdio_node);
+}
+
+static int loongson_dwmac_acpi_config(struct pci_dev *pdev,
+				      struct plat_stmmacenet_data *plat,
+				      struct stmmac_resources *res)
+{
+	if (!pdev->irq)
+		return -EINVAL;
+
+	res->irq = pdev->irq;
+
+	return 0;
+}
+
 static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct plat_stmmacenet_data *plat;
 	struct stmmac_pci_info *info;
 	struct stmmac_resources res;
-	struct device_node *np;
-	int ret, i, phy_mode;
-
-	np = dev_of_node(&pdev->dev);
-
-	if (!np) {
-		pr_info("dwmac_loongson_pci: No OF node\n");
-		return -ENODEV;
-	}
+	int ret, i;
 
 	plat = devm_kzalloc(&pdev->dev, sizeof(*plat), GFP_KERNEL);
 	if (!plat)
@@ -90,25 +160,19 @@ static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id
 	if (!plat->mdio_bus_data)
 		return -ENOMEM;
 
-	plat->mdio_node = of_get_child_by_name(np, "mdio");
-	if (plat->mdio_node) {
-		dev_info(&pdev->dev, "Found MDIO subnode\n");
-		plat->mdio_bus_data->needs_reset = true;
-	}
-
 	plat->dma_cfg = devm_kzalloc(&pdev->dev, sizeof(*plat->dma_cfg), GFP_KERNEL);
-	if (!plat->dma_cfg) {
-		ret = -ENOMEM;
-		goto err_put_node;
-	}
+	if (!plat->dma_cfg)
+		return -ENOMEM;
 
 	/* Enable pci device */
 	ret = pci_enable_device(pdev);
 	if (ret) {
 		dev_err(&pdev->dev, "%s: ERROR: failed to enable device\n", __func__);
-		goto err_put_node;
+		return ret;
 	}
 
+	pci_set_master(pdev);
+
 	/* Get the base address of device */
 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
 		if (pci_resource_len(pdev, i) == 0)
@@ -119,59 +183,32 @@ static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id
 		break;
 	}
 
-	plat->bus_id = of_alias_get_id(np, "ethernet");
-	if (plat->bus_id < 0)
-		plat->bus_id = pci_dev_id(pdev);
-
-	phy_mode = device_get_phy_mode(&pdev->dev);
-	if (phy_mode < 0) {
-		dev_err(&pdev->dev, "phy_mode not found\n");
-		ret = phy_mode;
-		goto err_disable_device;
-	}
-
-	plat->phy_interface = phy_mode;
-
-	pci_set_master(pdev);
-
 	memset(&res, 0, sizeof(res));
 	res.addr = pcim_iomap_table(pdev)[0];
 
 	info = (struct stmmac_pci_info *)id->driver_data;
-	ret = info->setup(plat);
+	ret = info->setup(pdev, plat);
 	if (ret)
 		goto err_disable_device;
 
-	res.irq = of_irq_get_byname(np, "macirq");
-	if (res.irq < 0) {
-		dev_err(&pdev->dev, "IRQ macirq not found\n");
-		ret = -ENODEV;
-		goto err_disable_device;
-	}
-
-	res.wol_irq = of_irq_get_byname(np, "eth_wake_irq");
-	if (res.wol_irq < 0) {
-		dev_info(&pdev->dev, "IRQ eth_wake_irq not found, using macirq\n");
-		res.wol_irq = res.irq;
-	}
-
-	res.lpi_irq = of_irq_get_byname(np, "eth_lpi");
-	if (res.lpi_irq < 0) {
-		dev_err(&pdev->dev, "IRQ eth_lpi not found\n");
-		ret = -ENODEV;
+	if (dev_of_node(&pdev->dev))
+		ret = loongson_dwmac_dt_config(pdev, plat, &res);
+	else
+		ret = loongson_dwmac_acpi_config(pdev, plat, &res);
+	if (ret)
 		goto err_disable_device;
-	}
 
 	ret = stmmac_dvr_probe(&pdev->dev, plat, &res);
 	if (ret)
-		goto err_disable_device;
+		goto err_plat_clear;
 
-	return ret;
+	return 0;
 
+err_plat_clear:
+	if (dev_of_node(&pdev->dev))
+		loongson_dwmac_dt_clear(pdev, plat);
 err_disable_device:
 	pci_disable_device(pdev);
-err_put_node:
-	of_node_put(plat->mdio_node);
 	return ret;
 }
 
@@ -181,9 +218,11 @@ static void loongson_dwmac_remove(struct pci_dev *pdev)
 	struct stmmac_priv *priv = netdev_priv(ndev);
 	int i;
 
-	of_node_put(priv->plat->mdio_node);
 	stmmac_dvr_remove(&pdev->dev);
 
+	if (dev_of_node(&pdev->dev))
+		loongson_dwmac_dt_clear(pdev, priv->plat);
+
 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
 		if (pci_resource_len(pdev, i) == 0)
 			continue;