[PATCH 1/3] of: reserved_mem: Add functions to parse "memory-region"

[Jonathan Cameron]

On Mon, 17 Mar 2025 18:24:21 -0500
"Rob Herring (Arm)" <robh at kernel.org> wrote:

> Drivers with "memory-region" properties currently have to do their own
> parsing of "memory-region" properties. The result is all the drivers
> have similar patterns of a call to parse "memory-region" and then get
> the region's address and size. As this is a standard property, it should
> have common functions for drivers to use. Add new functions to count the
> number of regions and retrieve the region's address as a resource.
> 
> Signed-off-by: Rob Herring (Arm) <robh at kernel.org>
> ---
>  drivers/of/of_reserved_mem.c    | 77 +++++++++++++++++++++++++++++++++
>  include/linux/of_reserved_mem.h | 26 +++++++++++
>  2 files changed, 103 insertions(+)
> 
> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> index 75e819f66a56..fd50038dff76 100644
> --- a/drivers/of/of_reserved_mem.c
> +++ b/drivers/of/of_reserved_mem.c
> @@ -12,6 +12,7 @@
>  #define pr_fmt(fmt)	"OF: reserved mem: " fmt
>  
>  #include <linux/err.h>
> +#include <linux/ioport.h>
>  #include <linux/libfdt.h>
>  #include <linux/of.h>
>  #include <linux/of_fdt.h>
> @@ -740,3 +741,79 @@ struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
>  	return NULL;
>  }
>  EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);
> +
> +/**
> + * of_reserved_mem_region_to_resource() - Get a reserved memory region as a resource
> + * @np:		node containing 'memory-region' property
> + * @idx:	index of 'memory-region' property to lookup
> + * @res:	Pointer to a struct resource to fill in with reserved region
> + *
> + * This function allows drivers to lookup a node's 'memory-region' property
> + * entries by index and return a struct resource for the entry.
> + *
> + * Returns 0 on success with @res filled in. Returns -ENODEV if 'memory-region'
> + * is missing or unavailable, -EINVAL for any other error.
> + */
> +int of_reserved_mem_region_to_resource(const struct device_node *np, unsigned int idx, struct resource *res)

Maybe wrap?
 
> +{