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authorMatthias Brugger <matthias.bgg@gmail.com>2014-07-18 11:36:39 +0200
committerDaniel Lezcano <daniel.lezcano@linaro.org>2014-07-23 12:02:30 +0200
commitefd342fb0031a17758571dce42e3f373d94e2fec (patch)
tree914578b4b0944ae5ca884e18ffe13cd223dccb14 /drivers/of
parent7e1391876c8f95df9241deb78fa98e799e7bb05e (diff)
of: Provide a function to request and map memory
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.bgg@gmail.com> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Suggested-by: Rob Herring <robh@kernel.org> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Diffstat (limited to 'drivers/of')
-rw-r--r--drivers/of/address.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/of/address.c b/drivers/of/address.c
index 5edfcb0da37d..e3718250d66e 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