ata: libahci_platform: Convert to using platform devm-ioremap methods

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>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
index 32495ae..1e9e825 100644 (file)
--- a/drivers/ata/libahci_platform.c
+++ b/drivers/ata/libahci_platform.c
@@ -402,8 +402,14 @@ 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));
+       /*
+        * If the DT provided an "ahci" named resource, use it. Otherwise,
+        * fallback to using the default first resource for the device node.
+        */
+       if (platform_get_resource_byname(pdev, IORESOURCE_MEM, "ahci"))
+               hpriv->mmio = devm_platform_ioremap_resource_byname(pdev, "ahci");
+       else
+               hpriv->mmio = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(hpriv->mmio)) {
                rc = PTR_ERR(hpriv->mmio);
                goto err_out;