[PATCH 04/21] ata: libahci_platform: Convert to using handy devm-ioremap methods

[Serge Semin <Sergey.Semin@baikalelectronics.ru>]

Currently the IOMEM AHCI registers space is mapped by means of the
two functions invocation: platform_get_resource() is used to get the very
first memory resource and devm_ioremap_resource() is called to remap that
resource. Device-managed kernel API provides a handy wrapper to perform
the same in single function call: devm_platform_ioremap_resource().

While at it seeing many AHCI platform drivers rely on having the AHCI CSR
space marked with "ahci" name let's first try to find and remap the CSR
IO-mem with that name and only if it fails fallback to getting the very
first registers space platform resource.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
---
 drivers/ata/libahci_platform.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
index 1bd2f1686239..8eabbb5f208c 100644
--- a/drivers/ata/libahci_platform.c
+++ b/drivers/ata/libahci_platform.c
@@ -404,11 +404,13 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev,
 
 	devres_add(dev, hpriv);
 
-	hpriv->mmio = devm_ioremap_resource(dev,
-			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
+	hpriv->mmio = devm_platform_ioremap_resource_byname(pdev, "ahci");
 	if (IS_ERR(hpriv->mmio)) {
-		rc = PTR_ERR(hpriv->mmio);
-		goto err_out;
+		hpriv->mmio = devm_platform_ioremap_resource(pdev, 0);
+		if (IS_ERR(hpriv->mmio)) {
+			rc = PTR_ERR(hpriv->mmio);
+			goto err_out;
+		}
 	}
 
 	for (i = 0; i < AHCI_MAX_CLKS; i++) {
-- 
2.35.1