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of: Provide a function to request and map memory

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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>
This commit is contained in:
Matthias Brugger
2014-07-18 11:36:39 +02:00
committed by Daniel Lezcano
parent 7e1391876c
commit efd342fb00
4 changed files with 49 additions and 2 deletions
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36
drivers/of/address.c
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@@ -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