Revert "net: ethernet: bgmac: Use devm_platform_ioremap_resource_byname"

This reverts commit 3710e809.

Since idm_base and nicpm_base are still optional resources not present
on all platforms, this breaks the driver for everything except Northstar
2 (which has both).

The same change was already reverted once with 755f5738 ("net:
broadcom: fix a mistake about ioremap resource").

So let's do it again.

Fixes: 3710e809 ("net: ethernet: bgmac: Use devm_platform_ioremap_resource_byname")
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
[florian: Added comments to explain the resources are optional]
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220216184634.2032460-1-f.fainelli@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/bgmac-platform.c

@@ -172,6 +172,7 @@ static int bgmac_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
 	struct bgmac *bgmac;
+	struct resource *regs;
 	int ret;
 
 	bgmac = bgmac_alloc(&pdev->dev);
@@ -208,15 +209,23 @@ static int bgmac_probe(struct platform_device *pdev)
 	if (IS_ERR(bgmac->plat.base))
 		return PTR_ERR(bgmac->plat.base);
 
-	bgmac->plat.idm_base = devm_platform_ioremap_resource_byname(pdev, "idm_base");
+	/* The idm_base resource is optional for some platforms */
+	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "idm_base");
+	if (regs) {
+		bgmac->plat.idm_base = devm_ioremap_resource(&pdev->dev, regs);
 		if (IS_ERR(bgmac->plat.idm_base))
 			return PTR_ERR(bgmac->plat.idm_base);
-	else
 		bgmac->feature_flags &= ~BGMAC_FEAT_IDM_MASK;
+	}
 
-	bgmac->plat.nicpm_base = devm_platform_ioremap_resource_byname(pdev, "nicpm_base");
+	/* The nicpm_base resource is optional for some platforms */
+	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nicpm_base");
+	if (regs) {
+		bgmac->plat.nicpm_base = devm_ioremap_resource(&pdev->dev,
+							       regs);
 		if (IS_ERR(bgmac->plat.nicpm_base))
 			return PTR_ERR(bgmac->plat.nicpm_base);
+	}
 
 	bgmac->read = platform_bgmac_read;
 	bgmac->write = platform_bgmac_write;