diff --git a/include/fdtdec.h b/include/fdtdec.h index 2590d3071f..8b24deb767 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -40,6 +40,27 @@ struct fdt_memory { fdt_addr_t end; }; +/* + * Information about a resource. start is the first address of the resource + * and end is the last address (inclusive). The length of the resource will + * be equal to: end - start + 1. + */ +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__ where is the directory @@ -597,4 +618,35 @@ 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 prop_names name of the property containing the list of names + * @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 *prop_names, const char *name, + struct fdt_resource *res); + #endif diff --git a/lib/fdtdec.c b/lib/fdtdec.c index 06d4542029..b3c43be89d 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -708,4 +708,61 @@ int fdtdec_read_fmap_entry(const void *blob, int node, const char *name, return 0; } + +static u64 fdtdec_get_number(const fdt32_t *ptr, unsigned int cells) +{ + u64 number = 0; + + while (cells--) + number = (number << 32) | fdt32_to_cpu(*ptr++); + + return number; +} + +int fdt_get_resource(const void *fdt, int node, const char *property, + unsigned int index, struct fdt_resource *res) +{ + const fdt32_t *ptr, *end; + int na, ns, len, parent; + unsigned int i = 0; + + parent = fdt_parent_offset(fdt, node); + if (parent < 0) + return parent; + + na = fdt_address_cells(fdt, parent); + ns = fdt_size_cells(fdt, parent); + + ptr = fdt_getprop(fdt, node, property, &len); + if (!ptr) + return len; + + end = ptr + len / sizeof(*ptr); + + while (ptr + na + ns <= end) { + if (i == index) { + res->start = res->end = fdtdec_get_number(ptr, na); + res->end += fdtdec_get_number(&ptr[na], ns) - 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 *prop_names, const char *name, + struct fdt_resource *res) +{ + int index; + + index = fdt_find_string(fdt, node, prop_names, name); + if (index < 0) + return index; + + return fdt_get_resource(fdt, node, property, index, res); +} #endif