[PATCH v2 1/3] driver core: platform: Add the helper function devm_platform_get_and_ioremap_resource_byname()

[Cai Huoqing <caihuoqing@baidu.com>]

Since provide the helper function devm_platform_ioremap_resource_byname()
which is wrap platform_get_resource_byname() and devm_ioremap_resource().
But sometimes, many drivers still need to use the resource variables
obtained by platform_get_resource(). In these cases, provide this helper
function devm_platform_get_and_ioremap_resource_byname().

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
---
v1->v2: Resend this patch as part of a patch series that uses
	the new function. 

 drivers/base/platform.c         | 30 ++++++++++++++++++++++++++----
 include/linux/platform_device.h |  3 +++
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 652531f67135..34bb581338d9 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -124,6 +124,31 @@ void __iomem *devm_platform_ioremap_resource(struct platform_device *pdev,
 }
 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource);
 
+/**
+ * devm_platform_get_and_ioremap_resource_byname - call devm_ioremap_resource() for a
+ *						   platform device and get resource
+ *
+ * @pdev: platform device to use both for memory resource lookup as well as
+ *        resource management
+ * @name: name of the resource
+ * @res: optional output parameter to store a pointer to the obtained resource.
+ *
+ * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
+ * on failure.
+ */
+void __iomem *
+devm_platform_get_and_ioremap_resource_byname(struct platform_device *pdev,
+					      const char *name, struct resource **res)
+{
+	struct resource *r;
+
+	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
+	if (res)
+		*res = r;
+	return devm_ioremap_resource(&pdev->dev, r);
+}
+EXPORT_SYMBOL_GPL(devm_platform_get_and_ioremap_resource_byname);
+
 /**
  * devm_platform_ioremap_resource_byname - call devm_ioremap_resource for
  *					   a platform device, retrieve the
@@ -140,10 +165,7 @@ void __iomem *
 devm_platform_ioremap_resource_byname(struct platform_device *pdev,
 				      const char *name)
 {
-	struct resource *res;
-
-	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
-	return devm_ioremap_resource(&pdev->dev, res);
+	return devm_platform_get_and_ioremap_resource_byname(pdev, name, NULL);
 }
 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource_byname);
 #endif /* CONFIG_HAS_IOMEM */
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 7c96f169d274..50eb1a5b503a 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -66,6 +66,9 @@ extern void __iomem *
 devm_platform_ioremap_resource(struct platform_device *pdev,
 			       unsigned int index);
 extern void __iomem *
+devm_platform_get_and_ioremap_resource_byname(struct platform_device *pdev,
+					      const char *name, struct resource **res);
+extern void __iomem *
 devm_platform_ioremap_resource_byname(struct platform_device *pdev,
 				      const char *name);
 extern int platform_get_irq(struct platform_device *, unsigned int);
-- 
2.25.1