1 files changed, 53 insertions, 2 deletions

diff --git a/lib/devres.c b/lib/devres.c
index 7c0e953a7486..4fbc09e6e9e6 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -85,6 +85,57 @@ void devm_iounmap(struct device *dev, void __iomem *addr)
 }
 EXPORT_SYMBOL(devm_iounmap);
 
+/**
+ * devm_request_and_ioremap() - Check, request region, and ioremap resource
+ * @dev: Generic device to handle the resource for
+ * @res: resource to be handled
+ *
+ * Takes all necessary steps to ioremap a mem resource. Uses managed device, so
+ * everything is undone on driver detach. Checks arguments, so you can feed
+ * it the result from e.g. platform_get_resource() directly. Returns the
+ * remapped pointer or NULL on error. Usage example:
+ *
+ *      res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ *      base = devm_request_and_ioremap(&pdev->dev, res);
+ *      if (!base)
+ *              return -EADDRNOTAVAIL;
+ */
+void __iomem *devm_request_and_ioremap(struct device *dev,
+                        struct resource *res)
+{
+        resource_size_t size;
+        const char *name;
+        void __iomem *dest_ptr;
+
+        BUG_ON(!dev);
+
+        if (!res || resource_type(res) != IORESOURCE_MEM) {
+                dev_err(dev, "invalid resource\n");
+                return NULL;
+        }
+
+        size = resource_size(res);
+        name = res->name ?: dev_name(dev);
+
+        if (!devm_request_mem_region(dev, res->start, size, name)) {
+                dev_err(dev, "can't request region for resource %pR\n", res);
+                return NULL;
+        }
+
+        if (res->flags & IORESOURCE_CACHEABLE)
+                dest_ptr = devm_ioremap(dev, res->start, size);
+        else
+                dest_ptr = devm_ioremap_nocache(dev, res->start, size);
+
+        if (!dest_ptr) {
+                dev_err(dev, "ioremap failed for resource %pR\n", res);
+                devm_release_mem_region(dev, res->start, size);
+        }
+
+        return dest_ptr;
+}
+EXPORT_SYMBOL(devm_request_and_ioremap);
+
 #ifdef CONFIG_HAS_IOPORT
 /*
  * Generic iomap devres
@@ -348,5 +399,5 @@ void pcim_iounmap_regions(struct pci_dev *pdev, u16 mask)
         }
 }
 EXPORT_SYMBOL(pcim_iounmap_regions);
-#endif
-#endif
+#endif /* CONFIG_PCI */
+#endif /* CONFIG_HAS_IOPORT */