| Message ID | 20180622043134.18238-2-benh@kernel.crashing.org |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | fsi: Fixes and Coldfire coprocessor offload | expand |
On Fri, Jun 22, 2018 at 6:31 AM Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote: > 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> Ugh I just feel I have seen homecooked solutions to this problem a few times :/ I wonder if it is easy to find these cases and replace them with this neat function... Thanks for doing this. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Yours, Linus Walleij
On Fri, Jun 29, 2018 at 12:14 PM, Linus Walleij <linus.walleij@linaro.org> wrote: > I wonder if it is easy to find these cases and replace them with > this neat function... Would be reasonable easy by using coccinelle.
On Fri, 2018-06-29 at 23:27 +0300, Andy Shevchenko wrote: > On Fri, Jun 29, 2018 at 12:14 PM, Linus Walleij > <linus.walleij@linaro.org> wrote: > > > I wonder if it is easy to find these cases and replace them with > > this neat function... > > Would be reasonable easy by using coccinelle. For the obvious ones yes. A lot of the existing users of of_iomap however don't do the request_region, and while they probably should and should use the new accessor, this can't be done blindly without testing, because there are many old things around that have broken memory region tracking and that will fail.. I plan to do a sweep through some of my old powermac/powerpc stuff one of these days and do some conversions. Cheers, Ben.
diff --git a/include/linux/device.h b/include/linux/device.h index 477956990f5e..96249d790374 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -688,6 +688,10 @@ 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 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
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> --- include/linux/device.h | 4 ++++ lib/devres.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+)