dt: add property iteration helpers
This patch adds macros of_property_for_each_u32() and
of_property_for_each_string(), which iterate over an array of values
within a device-tree property. Usage is for example:
struct property *prop;
const __be32 *p;
u32 u;
of_property_for_each_u32(np, "propname", prop, p, u)
printk("U32 value: %x\n", u);
struct property *prop;
const char *s;
of_property_for_each_string(np, "propname", prop, s)
printk("String value: %s\n", s);
Based on work by Rob Herring <[email protected]>
Cc: Grant Likely <[email protected]>
Signed-off-by: Stephen Warren <[email protected]>
Acked-by: Rob Herring <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 5806449..d9bfd49 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1260,3 +1260,44 @@
return id;
}
EXPORT_SYMBOL_GPL(of_alias_get_id);
+
+const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
+ u32 *pu)
+{
+ const void *curv = cur;
+
+ if (!prop)
+ return NULL;
+
+ if (!cur) {
+ curv = prop->value;
+ goto out_val;
+ }
+
+ curv += sizeof(*cur);
+ if (curv >= prop->value + prop->length)
+ return NULL;
+
+out_val:
+ *pu = be32_to_cpup(curv);
+ return curv;
+}
+EXPORT_SYMBOL_GPL(of_prop_next_u32);
+
+const char *of_prop_next_string(struct property *prop, const char *cur)
+{
+ const void *curv = cur;
+
+ if (!prop)
+ return NULL;
+
+ if (!cur)
+ return prop->value;
+
+ curv += strlen(cur) + 1;
+ if (curv >= prop->value + prop->length)
+ return NULL;
+
+ return curv;
+}
+EXPORT_SYMBOL_GPL(of_prop_next_string);
