[PATCH 1/2] lib: devres: add a helper function for ioremap_wc

From: Abhilash Kesavan
Date: Wed Dec 10 2014 - 21:58:42 EST


Implement a resource managed writecombine ioremap function.

Signed-off-by: Abhilash Kesavan <a.kesavan@xxxxxxxxxxx>
---
Documentation/driver-model/devres.txt | 1 +
include/linux/io.h | 2 ++
lib/devres.c | 28 ++++++++++++++++++++++++++++
3 files changed, 31 insertions(+)

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index b5ab416..0f80cee 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -274,6 +274,7 @@ 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 fa02e55..42b33f0 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 0f1dd2e..e8e1738 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
--
1.7.9.5

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