diff options
| author | Bjorn Andersson <bjorn.andersson@linaro.org> | 2017-10-11 07:08:54 +0200 |
|---|---|---|
| committer | Andy Gross <andy.gross@linaro.org> | 2017-10-22 12:06:33 +0200 |
| commit | eb297bc716ec2cb3147e6e99002e37058c65cba3 (patch) | |
| tree | 680bcfbebfe7be6feab741dea7d3c41108330dbc | |
| parent | of/platform: Generalize /reserved-memory handling (diff) | |
| download | linux-eb297bc716ec2cb3147e6e99002e37058c65cba3.tar.xz linux-eb297bc716ec2cb3147e6e99002e37058c65cba3.zip | |
of: reserved_mem: Accessor for acquiring reserved_mem
In some cases drivers referencing a reserved-memory region might want to
remap the entire region, but when defining the reserved-memory by "size"
the client driver has no means to know the associated base address of
the reserved memory region.
This patch adds an accessor for such drivers to acquire a handle to
their associated reserved-memory for this purpose.
A complicating factor for the implementation is that the reserved_mem
objects are created from the flattened DeviceTree, as such we can't
use the device_node address for comparison. Fortunately the name of the
node will be used as "name" of the reserved_mem and will be used when
building the full_name, so we can compare the "name" with the basename
of the full_name to find the match.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>
| -rw-r--r-- | drivers/of/of_reserved_mem.c | 26 | ||||
| -rw-r--r-- | include/linux/of_reserved_mem.h | 5 |
2 files changed, 31 insertions, 0 deletions
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c index d507c3569a88..b108c7a1f74c 100644 --- a/drivers/of/of_reserved_mem.c +++ b/drivers/of/of_reserved_mem.c @@ -397,3 +397,29 @@ void of_reserved_mem_device_release(struct device *dev) rmem->ops->device_release(rmem, dev); } EXPORT_SYMBOL_GPL(of_reserved_mem_device_release); + +/** + * of_reserved_mem_lookup() - acquire reserved_mem from a device node + * @np: node pointer of the desired reserved-memory region + * + * This function allows drivers to acquire a reference to the reserved_mem + * struct based on a device node handle. + * + * Returns a reserved_mem reference, or NULL on error. + */ +struct reserved_mem *of_reserved_mem_lookup(struct device_node *np) +{ + const char *name; + int i; + + if (!np->full_name) + return NULL; + + name = kbasename(np->full_name); + for (i = 0; i < reserved_mem_count; i++) + if (!strcmp(reserved_mem[i].name, name)) + return &reserved_mem[i]; + + return NULL; +} +EXPORT_SYMBOL_GPL(of_reserved_mem_lookup); diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h index f8e1992d6423..c58f780104f9 100644 --- a/include/linux/of_reserved_mem.h +++ b/include/linux/of_reserved_mem.h @@ -44,6 +44,7 @@ int early_init_dt_alloc_reserved_memory_arch(phys_addr_t size, void fdt_init_reserved_mem(void); void fdt_reserved_mem_save_node(unsigned long node, const char *uname, phys_addr_t base, phys_addr_t size); +struct reserved_mem *of_reserved_mem_lookup(struct device_node *np); #else static inline int of_reserved_mem_device_init_by_idx(struct device *dev, struct device_node *np, int idx) @@ -55,6 +56,10 @@ static inline void of_reserved_mem_device_release(struct device *pdev) { } static inline void fdt_init_reserved_mem(void) { } static inline void fdt_reserved_mem_save_node(unsigned long node, const char *uname, phys_addr_t base, phys_addr_t size) { } +static inline struct reserved_mem *of_reserved_mem_lookup(struct device_node *np) +{ + return NULL; +} #endif /** |