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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2018-06-05 06:21:26 +0300
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2018-07-23 08:22:39 +0300
commitd5e838275c80aeb96d4c0b81442a851dfef2e948 (patch)
treee315e83e62b5eab99f716f9cf20dd6813dd5256c /lib
parentd5e748ff2b996d83489ac76c072e8b99f9ecef13 (diff)
downloadlinux-d5e838275c80aeb96d4c0b81442a851dfef2e948.tar.xz
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: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Joel Stanley <joel@jms.id.au>
Diffstat (limited to 'lib')
-rw-r--r--lib/devres.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/lib/devres.c b/lib/devres.c
index 5bec1120b392..faccf1a037d0 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -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