From: Thierry Reding treding@nvidia.com
Add the fdt_get_resource() and fdt_get_named_resource() functions which can be used to parse resources (memory regions) from an FDT. A helper to compute the size of a region is also provided.
Signed-off-by: Thierry Reding treding@nvidia.com --- include/fdtdec.h | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ lib/fdtdec.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 91 insertions(+)
diff --git a/include/fdtdec.h b/include/fdtdec.h index 856e6cf766de..e9091eee6bae 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -40,6 +40,23 @@ struct fdt_memory { fdt_addr_t end; };
+/* information about a resource */ +struct fdt_resource { + fdt_addr_t start; + fdt_addr_t end; +}; + +/** + * Compute the size of a resource. + * + * @param res the resource to operate on + * @return the size of the resource + */ +static inline fdt_size_t fdt_resource_size(const struct fdt_resource *res) +{ + return res->end - res->start + 1; +} + /** * Compat types that we know about and for which we might have drivers. * Each is named COMPAT_<dir>_<filename> where <dir> is the directory @@ -583,4 +600,35 @@ struct fmap_entry { */ int fdtdec_read_fmap_entry(const void *blob, int node, const char *name, struct fmap_entry *entry); + +/** + * Obtain an indexed resource from a device property. + * + * @param fdt FDT blob + * @param node node to examine + * @param property name of the property to parse + * @param index index of the resource to retrieve + * @param res returns the resource + * @return 0 if ok, negative on error + */ +int fdt_get_resource(const void *fdt, int node, const char *property, + unsigned int index, struct fdt_resource *res); + +/** + * Obtain a named resource from a device property. + * + * Look up the index of the name in a list of strings and return the resource + * at that index. + * + * @param fdt FDT blob + * @param node node to examine + * @param property name of the property to parse + * @param names name of the property to obtain the match the name to + * @param name the name of the entry to look up + * @param res returns the resource + */ +int fdt_get_named_resource(const void *fdt, int node, const char *property, + const char *names, const char *name, + struct fdt_resource *res); + #endif diff --git a/lib/fdtdec.c b/lib/fdtdec.c index eb5aa20526fd..fbfae4a7cbaf 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -691,4 +691,47 @@ int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
return 0; } + +int fdt_get_resource(const void *fdt, int node, const char *property, + unsigned int index, struct fdt_resource *res) +{ + const fdt32_t *ptr, *end; + unsigned int i = 0; + int na, ns, len; + + na = fdt_n_addr_cells(fdt, node); + ns = fdt_n_size_cells(fdt, node); + + ptr = fdt_getprop(fdt, node, property, &len); + if (!ptr) + return len; + + end = ptr + len / 4; + + while (ptr + na + ns <= end) { + if (i == index) { + res->start = fdt_addr_to_cpu(*ptr); + res->end = res->start + fdt_size_to_cpu(ptr[na]) - 1; + return 0; + } + + ptr += na + ns; + i++; + } + + return -FDT_ERR_NOTFOUND; +} + +int fdt_get_named_resource(const void *fdt, int node, const char *property, + const char *names, const char *name, + struct fdt_resource *res) +{ + int index; + + index = fdt_get_string_index(fdt, node, names, name); + if (index < 0) + return index; + + return fdt_get_resource(fdt, node, property, index, res); +} #endif