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Commit d5e83827 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt
Browse files

devres: Add devm_of_iomap() 



There are still quite a few cases where a device might want
to get to a different node of the device-tree, obtain the
resources and map them.

We have of_iomap() and of_io_request_and_map() but they both
have shortcomings, such as not returning the size of the
resource found (which can be useful) and not being "managed".

This adds a devm_of_iomap() that provides all of these and
should probably replace uses of the above in most drivers.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: default avatarJoel Stanley <joel@jms.id.au>
parent d5e748ff

include/linux/device.h

+4 −0
Original line number Diff line number Diff line
@@ -696,6 +696,10 @@ extern void devm_free_pages(struct device *dev, unsigned long addr); 


void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);



void __iomem *devm_of_iomap(struct device *dev,

			    struct device_node *node, int index,

			    resource_size_t *size);



/* allows to add/remove a custom action to devres stack */

int devm_add_action(struct device *dev, void (*action)(void *), void *data);

void devm_remove_action(struct device *dev, void (*action)(void *), void *data);

lib/devres.c

+36 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
#include <linux/io.h>

#include <linux/gfp.h>

#include <linux/export.h>

#include <linux/of_address.h>



enum devm_ioremap_type {

	DEVM_IOREMAP = 0,
@@ -162,6 +163,41 @@ void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res) 
}

EXPORT_SYMBOL(devm_ioremap_resource);



/*

 * devm_of_iomap - Requests a resource and maps the memory mapped IO

 *		   for a given device_node managed by a given device

 *

 * Checks that a resource is a valid memory region, requests the memory

 * region and ioremaps it. All operations are managed and will be undone

 * on driver detach of the device.

 *

 * This is to be used when a device requests/maps resources described

 * by other device tree nodes (children or otherwise).

 *

 * @dev:	The device "managing" the resource

 * @node:       The device-tree node where the resource resides

 * @index:	index of the MMIO range in the "reg" property

 * @size:	Returns the size of the resource (pass NULL if not needed)

 * Returns a pointer to the requested and mapped memory or an ERR_PTR() encoded

 * error code on failure. Usage example:

 *

 *	base = devm_of_iomap(&pdev->dev, node, 0, NULL);

 *	if (IS_ERR(base))

 *		return PTR_ERR(base);

 */

void __iomem *devm_of_iomap(struct device *dev, struct device_node *node, int index,

			    resource_size_t *size)

{

	struct resource res;



	if (of_address_to_resource(node, index, &res))

		return IOMEM_ERR_PTR(-EINVAL);

	if (size)

		*size = resource_size(&res);

	return devm_ioremap_resource(dev, &res);

}

EXPORT_SYMBOL(devm_of_iomap);



#ifdef CONFIG_HAS_IOPORT_MAP

/*

 * Generic iomap devres