Hello Rob,
On 4/23/25 21:42, Rob Herring (Arm) 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.
>
> Reviewed-by: Daniel Baluta <daniel.bal...@nxp.com>
> Signed-off-by: Rob Herring (Arm) <r...@kernel.org>
> ---
> v2:
> - Wrap function parameters
> ---
> drivers/of/of_reserved_mem.c | 80
> +++++++++++++++++++++++++++++++++++++++++
> include/linux/of_reserved_mem.h | 26 ++++++++++++++
> 2 files changed, 106 insertions(+)
>
> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> index ee2e31522d7e..f87915cce961 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 +741,82 @@ 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)
> +{
> + struct reserved_mem *rmem;
> +
> + if (!np)
> + return -EINVAL;
> +
> + struct device_node __free(device_node) *target = of_parse_phandle(np,
> "memory-region", idx);
> + if (!target || !of_device_is_available(target))
> + return -ENODEV;
> +
> + rmem = of_reserved_mem_lookup(target);
> + if (!rmem)
> + return -EINVAL;
> +
> + resource_set_range(res, rmem->base, rmem->size);
> + res->name = rmem->name;
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(of_reserved_mem_region_to_resource);
> +
> +/**
> + * of_reserved_mem_region_to_resource_byname() - Get a reserved memory
> region as a resource
> + * @np: node containing 'memory-region' property
> + * @name: name of 'memory-region' property entry 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 name 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.
of_property_match_string() can return some other error values.
Thanks,
Arnaud
> + */
> +int of_reserved_mem_region_to_resource_byname(const struct device_node *np,
> + const char *name,
> + struct resource *res)
> +{
> + int idx;
> +
> + if (!name)
> + return -EINVAL;
> +
> + idx = of_property_match_string(np, "memory-region-names", name);
> + if (idx < 0)
> + return idx;
> +
> + return of_reserved_mem_region_to_resource(np, idx, res);
> +}
> +EXPORT_SYMBOL_GPL(of_reserved_mem_region_to_resource_byname);
> +
> +/**
> + * of_reserved_mem_region_count() - Return the number of 'memory-region'
> entries
> + * @np: node containing 'memory-region' property
> + *
> + * This function allows drivers to retrieve the number of entries for a
> node's
> + * 'memory-region' property.
> + *
> + * Returns the number of entries on success, or negative error code on a
> + * malformed property.
> + */
> +int of_reserved_mem_region_count(const struct device_node *np)
> +{
> + return of_count_phandle_with_args(np, "memory-region", NULL);
> +}
> +EXPORT_SYMBOL_GPL(of_reserved_mem_region_count);
> diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
> index e338282da652..f573423359f4 100644
> --- a/include/linux/of_reserved_mem.h
> +++ b/include/linux/of_reserved_mem.h
> @@ -7,6 +7,7 @@
>
> struct of_phandle_args;
> struct reserved_mem_ops;
> +struct resource;
>
> struct reserved_mem {
> const char *name;
> @@ -39,6 +40,12 @@ int of_reserved_mem_device_init_by_name(struct device *dev,
> void of_reserved_mem_device_release(struct device *dev);
>
> struct reserved_mem *of_reserved_mem_lookup(struct device_node *np);
> +int of_reserved_mem_region_to_resource(const struct device_node *np,
> + unsigned int idx, struct resource *res);
> +int of_reserved_mem_region_to_resource_byname(const struct device_node *np,
> + const char *name, struct resource
> *res);
> +int of_reserved_mem_region_count(const struct device_node *np);
> +
> #else
>
> #define RESERVEDMEM_OF_DECLARE(name, compat, init) \
> @@ -63,6 +70,25 @@ static inline struct reserved_mem
> *of_reserved_mem_lookup(struct device_node *np
> {
> return NULL;
> }
> +
> +static inline int of_reserved_mem_region_to_resource(const struct
> device_node *np,
> + unsigned int idx,
> + struct resource *res)
> +{
> + return -ENOSYS;
> +}
> +
> +static inline int of_reserved_mem_region_to_resource_byname(const struct
> device_node *np,
> + const char *name,
> + struct resource
> *res)
> +{
> + return -ENOSYS;
> +}
> +
> +static inline int of_reserved_mem_region_count(const struct device_node *np)
> +{
> + return 0;
> +}
> #endif
>
> /**
>
