[PATCH v2 4/5] drivers: platform: provide devm_platform_ioremap_resource_wc()

[Bartosz Golaszewski <brgl@bgdev.pl>]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Provide a write-combined variant of devm_platform_ioremap_resource().

While at it: in order not to duplicate code - pass the resource
retrieved by platform_get_resource() directly to the appropriate
devm_ioremap_resource() variant.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 .../driver-api/driver-model/devres.rst        |  1 +
 drivers/base/platform.c                       | 27 +++++++++++++++----
 include/linux/platform_device.h               |  3 +++
 3 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index e605bb9df6e1..480b78ca3871 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -318,6 +318,7 @@ IOMAP
   devm_ioremap_resource() : checks resource, requests memory region, ioremaps
   devm_ioremap_resource_wc()
   devm_platform_ioremap_resource() : calls devm_ioremap_resource() for platform device
+  devm_platform_ioremap_resource_wc()
   devm_iounmap()
   pcim_iomap()
   pcim_iomap_regions()	: do request_region() and iomap() on multiple BARs
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index b6c6c7d97d5b..8fdf3eb23bda 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -60,6 +60,7 @@ struct resource *platform_get_resource(struct platform_device *dev,
 }
 EXPORT_SYMBOL_GPL(platform_get_resource);
 
+#ifdef CONFIG_HAS_IOMEM
 /**
  * devm_platform_ioremap_resource - call devm_ioremap_resource() for a platform
  *				    device
@@ -68,16 +69,32 @@ EXPORT_SYMBOL_GPL(platform_get_resource);
  *        resource management
  * @index: resource index
  */
-#ifdef CONFIG_HAS_IOMEM
 void __iomem *devm_platform_ioremap_resource(struct platform_device *pdev,
 					     unsigned int index)
 {
-	struct resource *res;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
-	return devm_ioremap_resource(&pdev->dev, res);
+	return devm_ioremap_resource(&pdev->dev,
+				     platform_get_resource(pdev,
+							   IORESOURCE_MEM,
+							   index));
 }
 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource);
+
+/**
+ * devm_platform_ioremap_resource_wc - write-combined variant of
+ *                                     devm_platform_ioremap_resource()
+ *
+ * @pdev: platform device to use both for memory resource lookup as well as
+ *        resource management
+ * @index: resource index
+ */
+void __iomem *devm_platform_ioremap_resource_wc(struct platform_device *pdev,
+						unsigned int index)
+{
+	return devm_ioremap_resource_wc(&pdev->dev,
+					platform_get_resource(pdev,
+							      IORESOURCE_MEM,
+							      index));
+}
 #endif /* CONFIG_HAS_IOMEM */
 
 static int __platform_get_irq(struct platform_device *dev, unsigned int num)
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 1b5cec067533..83930790c701 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -57,6 +57,9 @@ platform_find_device_by_driver(struct device *start,
 extern void __iomem *
 devm_platform_ioremap_resource(struct platform_device *pdev,
 			       unsigned int index);
+extern void __iomem *
+devm_platform_ioremap_resource_wc(struct platform_device *pdev,
+				  unsigned int index);
 extern int platform_get_irq(struct platform_device *, unsigned int);
 extern int platform_get_irq_optional(struct platform_device *, unsigned int);
 extern int platform_irq_count(struct platform_device *);
-- 
2.23.0