From 72f8c0bfa0de64c68ee59f40eb9b2683bffffbb0 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Tue, 25 Oct 2011 15:16:47 +0200 Subject: [PATCH] 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 Acked-by: Grant Likely Acked-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- Documentation/driver-model/devres.txt | 1 + include/linux/device.h | 3 ++ lib/devres.c | 51 +++++++++++++++++++++++++++ 3 files changed, 55 insertions(+) diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index d79aead9418b..10c64c8a13d4 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -262,6 +262,7 @@ IOMAP devm_ioremap() devm_ioremap_nocache() devm_iounmap() + devm_request_and_ioremap() : checks resource, requests region, ioremaps pcim_iomap() pcim_iounmap() pcim_iomap_table() : array of mapped addresses indexed by BAR diff --git a/include/linux/device.h b/include/linux/device.h index ffbcf95cd97d..c6335982774c 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -490,6 +490,9 @@ extern int devres_release_group(struct device *dev, void *id); extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp); extern void devm_kfree(struct device *dev, void *p); +void __iomem *devm_request_and_ioremap(struct device *dev, + struct resource *res); + struct device_dma_parameters { /* * a low level driver may set these to teach IOMMU code about diff --git a/lib/devres.c b/lib/devres.c index 78777aea5b34..4fbc09e6e9e6 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 -- GitLab