[U-Boot] [PATCH 03/23] fdt: Add resource parsing functions

Thierry Reding
2014-08-18T07:16:16Z

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_ _<filename> where 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
--
2.0.4