lib: devres: add a helper function for ioremap_wc

Implement a resource managed writecombine ioremap function.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 31 insertions, 0 deletions

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index 6d1e8eeb5990..7fe7fd263aba 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -276,6 +276,7 @@ IOMAP
   devm_ioport_unmap()
   devm_ioremap()
   devm_ioremap_nocache()
+  devm_ioremap_wc()
   devm_ioremap_resource() : checks resource, requests memory region, ioremaps
   devm_iounmap()
   pcim_iomap()
diff --git a/include/linux/io.h b/include/linux/io.h
index fa02e55e5a2e..42b33f03d1df 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -64,6 +64,8 @@ void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
                            resource_size_t size);
 void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
                                    resource_size_t size);
+void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
+                                   resource_size_t size);
 void devm_iounmap(struct device *dev, void __iomem *addr);
 int check_signature(const volatile void __iomem *io_addr,
                         const unsigned char *signature, int length);
diff --git a/lib/devres.c b/lib/devres.c
index 0f1dd2e9d2c1..fbe2aac522e6 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -72,6 +72,34 @@ void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
 EXPORT_SYMBOL(devm_ioremap_nocache);
 
 /**
+ * devm_ioremap_wc - Managed ioremap_wc()
+ * @dev: Generic device to remap IO address for
+ * @offset: BUS offset to map
+ * @size: Size of map
+ *
+ * Managed ioremap_wc().  Map is automatically unmapped on driver detach.
+ */
+void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
+                              resource_size_t size)
+{
+        void __iomem **ptr, *addr;
+
+        ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
+        if (!ptr)
+                return NULL;
+
+        addr = ioremap_wc(offset, size);
+        if (addr) {
+                *ptr = addr;
+                devres_add(dev, ptr);
+        } else
+                devres_free(ptr);
+
+        return addr;
+}
+EXPORT_SYMBOL(devm_ioremap_wc);
+
+/**
  * devm_iounmap - Managed iounmap()
  * @dev: Generic device to unmap for
  * @addr: Address to unmap