lib: devres: prepare devm_ioremap_resource() for more variants

We want to add the write-combined variant of devm_ioremap_resource().
Let's first implement __devm_ioremap_resource() which takes
an additional argument type. The types are the same as for
__devm_ioremap(). The existing devm_ioremap_resource() now simply
calls __devm_ioremap_resource() with regular DEVM_IOREMAP type.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20191022084318.22256-3-brgl@bgdev.pl
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/lib/devres.c b/lib/devres.c
index 6a0e9bd..a14c727 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -114,6 +114,37 @@
 }
 EXPORT_SYMBOL(devm_iounmap);
 
+static void __iomem *
+__devm_ioremap_resource(struct device *dev, const struct resource *res,
+			enum devm_ioremap_type type)
+{
+	resource_size_t size;
+	void __iomem *dest_ptr;
+
+	BUG_ON(!dev);
+
+	if (!res || resource_type(res) != IORESOURCE_MEM) {
+		dev_err(dev, "invalid resource\n");
+		return IOMEM_ERR_PTR(-EINVAL);
+	}
+
+	size = resource_size(res);
+
+	if (!devm_request_mem_region(dev, res->start, size, dev_name(dev))) {
+		dev_err(dev, "can't request region for resource %pR\n", res);
+		return IOMEM_ERR_PTR(-EBUSY);
+	}
+
+	dest_ptr = __devm_ioremap(dev, res->start, size, type);
+	if (!dest_ptr) {
+		dev_err(dev, "ioremap failed for resource %pR\n", res);
+		devm_release_mem_region(dev, res->start, size);
+		dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
+	}
+
+	return dest_ptr;
+}
+
 /**
  * devm_ioremap_resource() - check, request region, and ioremap resource
  * @dev: generic device to handle the resource for
@@ -134,31 +165,7 @@
 void __iomem *devm_ioremap_resource(struct device *dev,
 				    const struct resource *res)
 {
-	resource_size_t size;
-	void __iomem *dest_ptr;
-
-	BUG_ON(!dev);
-
-	if (!res || resource_type(res) != IORESOURCE_MEM) {
-		dev_err(dev, "invalid resource\n");
-		return IOMEM_ERR_PTR(-EINVAL);
-	}
-
-	size = resource_size(res);
-
-	if (!devm_request_mem_region(dev, res->start, size, dev_name(dev))) {
-		dev_err(dev, "can't request region for resource %pR\n", res);
-		return IOMEM_ERR_PTR(-EBUSY);
-	}
-
-	dest_ptr = devm_ioremap(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);
-		dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
-	}
-
-	return dest_ptr;
+	return __devm_ioremap_resource(dev, res, DEVM_IOREMAP);
 }
 EXPORT_SYMBOL(devm_ioremap_resource);