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authorWolfram Sang <w.sang@pengutronix.de>2011-10-25 15:16:47 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2011-11-15 16:07:39 -0800
commit72f8c0bfa0de64c68ee59f40eb9b2683bffffbb0 (patch)
tree44fa0c66dbb41d9154e170d4d97455e5665a5f12 /lib
parent571806a9f70fc4a4c575ab796555dfb401c2dfc1 (diff)
lib: devres: add convenience function to remap a resource
Almost every platform_driver does the three steps get_resource, request_mem_region, ioremap. This does not only lead to a lot of code duplication, but also a huge number of similar error strings and inconsistent error codes on failure. So, introduce a helper function which simplifies remapping a resource and make it hard to do something wrong and add documentation for it. Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'lib')
-rw-r--r--lib/devres.c51
1 files changed, 51 insertions, 0 deletions
diff --git a/lib/devres.c b/lib/devres.c
index 78777aea5b3..4fbc09e6e9e 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -85,6 +85,57 @@ void devm_iounmap(struct device *dev, void __iomem *addr)
}
EXPORT_SYMBOL(devm_iounmap);
+/**
+ * devm_request_and_ioremap() - Check, request region, and ioremap resource
+ * @dev: Generic device to handle the resource for
+ * @res: resource to be handled
+ *
+ * Takes all necessary steps to ioremap a mem resource. Uses managed device, so
+ * everything is undone on driver detach. Checks arguments, so you can feed
+ * it the result from e.g. platform_get_resource() directly. Returns the
+ * remapped pointer or NULL on error. Usage example:
+ *
+ * res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ * base = devm_request_and_ioremap(&pdev->dev, res);
+ * if (!base)
+ * return -EADDRNOTAVAIL;
+ */
+void __iomem *devm_request_and_ioremap(struct device *dev,
+ struct resource *res)
+{
+ resource_size_t size;
+ const char *name;
+ void __iomem *dest_ptr;
+
+ BUG_ON(!dev);
+
+ if (!res || resource_type(res) != IORESOURCE_MEM) {
+ dev_err(dev, "invalid resource\n");
+ return NULL;
+ }
+
+ size = resource_size(res);
+ name = res->name ?: dev_name(dev);
+
+ if (!devm_request_mem_region(dev, res->start, size, name)) {
+ dev_err(dev, "can't request region for resource %pR\n", res);
+ return NULL;
+ }
+
+ if (res->flags & IORESOURCE_CACHEABLE)
+ dest_ptr = devm_ioremap(dev, res->start, size);
+ else
+ dest_ptr = devm_ioremap_nocache(dev, res->start, size);
+
+ if (!dest_ptr) {
+ dev_err(dev, "ioremap failed for resource %pR\n", res);
+ devm_release_mem_region(dev, res->start, size);
+ }
+
+ return dest_ptr;
+}
+EXPORT_SYMBOL(devm_request_and_ioremap);
+
#ifdef CONFIG_HAS_IOPORT
/*
* Generic iomap devres