From 80d62ecfaaf699bb3550681a12ec0745c87153c1 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 5 Jun 2018 13:21:26 +1000 Subject: [PATCH] UPSTREAM: 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 Reviewed-by: Linus Walleij Reviewed-by: Joel Stanley (cherry picked from commit d5e838275c80aeb96d4c0b81442a851dfef2e948) Change-Id: I5d68c3e23637c5e83e5f2bed3a1aa2c654d7d6a1 Signed-off-by: Jeffy Chen --- include/linux/device.h | 4 ++++ lib/devres.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/include/linux/device.h b/include/linux/device.h index b304ca6f90d8..5f9fa7fb2088 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -679,6 +679,10 @@ 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); diff --git a/lib/devres.c b/lib/devres.c index 8c85672639d3..12ab4eb241c5 100644 --- a/lib/devres.c +++ b/lib/devres.c @@ -3,6 +3,7 @@ #include #include #include +#include void devm_ioremap_release(struct device *dev, void *res) { @@ -163,6 +164,41 @@ 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