A call to of_iomap does not request the memory region.
This patch adds the function of_io_request_and_map which requests
the memory region before mapping it.
Signed-off-by: Matthias Brugger <matthias....@gmail.com>
Suggested-by: Thomas Gleixner <t...@linutronix.de>
Suggested-by: Rob Herring <r...@kernel.org>
---
drivers/of/address.c | 36 ++++++++++++++++++++++++++++++++++++
include/linux/io.h | 2 ++
include/linux/of_address.h | 11 +++++++++++
lib/devres.c | 2 --
4 files changed, 49 insertions(+), 2 deletions(-)
diff --git a/drivers/of/address.c b/drivers/of/address.c
index 5edfcb0..e371825 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -702,6 +702,42 @@ void __iomem *of_iomap(struct device_node *np, int index)
}
EXPORT_SYMBOL(of_iomap);
+/*
+ * of_io_request_and_map - Requests a resource and maps the memory mapped IO
+ * for a given device_node
+ * @device: the device whose io range will be mapped
+ * @index: index of the io range
+ * @name: name of the resource
+ *
+ * Returns a pointer to the requested and mapped memory or an ERR_PTR() encoded
+ * error code on failure. Usage example:
+ *
+ * base = of_io_request_and_map(node, 0, "foo");
+ * if (IS_ERR(base))
+ * return PTR_ERR(base);
+ */
+void __iomem *of_io_request_and_map(struct device_node *np, int index,
+ char *name)
+{
+ struct resource res;
+ void __iomem *mem;
+
+ if (of_address_to_resource(np, index, &res))
+ return IOMEM_ERR_PTR(-EINVAL);
+
+ if (!request_mem_region(res.start, resource_size(&res), name))
+ return IOMEM_ERR_PTR(-EBUSY);
+
+ mem = ioremap(res.start, resource_size(&res));
+ if (!mem) {
+ release_mem_region(res.start, resource_size(&res));
+ return IOMEM_ERR_PTR(-ENOMEM);
+ }
+
+ return mem;
+}
+EXPORT_SYMBOL(of_io_request_and_map);
+
/**
* of_dma_get_range - Get DMA range info
* @np: device node to get DMA range info
diff --git a/include/linux/io.h b/include/linux/io.h
index b76e6e5..d5fc9b8 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -58,6 +58,8 @@ static inline void devm_ioport_unmap(struct device *dev, void
__iomem *addr)
}
#endif
+#define IOMEM_ERR_PTR(err) (__force void __iomem *)ERR_PTR(err)
+
void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
unsigned long size);
void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index c13b878..fb7b722 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h
@@ -109,7 +109,12 @@ static inline bool of_dma_is_coherent(struct device_node
*np)
extern int of_address_to_resource(struct device_node *dev, int index,
struct resource *r);
void __iomem *of_iomap(struct device_node *node, int index);
+void __iomem *of_io_request_and_map(struct device_node *device,
+ int index, char *name);
#else
+
+#include <linux/io.h>
+
static inline int of_address_to_resource(struct device_node *dev, int index,
struct resource *r)
{
@@ -120,6 +125,12 @@ static inline void __iomem *of_iomap(struct device_node
*device, int index)
{
return NULL;
}
+
+static inline void __iomem *of_io_request_and_map(struct device_node *device,
+ int index, char *name)
+{
+ return IOMEM_ERR_PTR(-EINVAL);
+}
#endif
#if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_PCI)
diff --git a/lib/devres.c b/lib/devres.c
index f562bf6..bb63248 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -86,8 +86,6 @@ void devm_iounmap(struct device *dev, void __iomem *addr)
}
EXPORT_SYMBOL(devm_iounmap);
-#define IOMEM_ERR_PTR(err) (__force void __iomem *)ERR_PTR(err)
-
/**
* devm_ioremap_resource() - check, request region, and ioremap resource
* @dev: generic device to handle the resource for
--
1.7.9.5
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