of/flattree: Add of_flat_dt_match() helper function

[mv-sheeva.git] / drivers / of / fdt.c

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 8a90ee42071a784dfd14b6c5dabb75cd4481db9b..c787c3d95c600eb51955dcb4d2e64dca88d559ba 100644 (file)
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -78,19 +78,23 @@ void *of_fdt_get_property(struct boot_param_header *blob,
  * @blob: A device tree blob
  * @node: node to test
  * @compat: compatible string to compare with compatible list.
+ *
+ * On match, returns a non-zero value with smaller values returned for more
+ * specific compatible values.
  */
 int of_fdt_is_compatible(struct boot_param_header *blob,
                      unsigned long node, const char *compat)
 {
        const char *cp;
-       unsigned long cplen, l;
+       unsigned long cplen, l, score = 0;
 
        cp = of_fdt_get_property(blob, node, "compatible", &cplen);
        if (cp == NULL)
                return 0;
        while (cplen > 0) {
+               score++;
                if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
-                       return 1;
+                       return score;
                l = strlen(cp) + 1;
                cp += l;
                cplen -= l;
@@ -99,6 +103,27 @@ int of_fdt_is_compatible(struct boot_param_header *blob,
        return 0;
 }
 
+/**
+ * of_fdt_match - Return true if node matches a list of compatible values
+ */
+int of_fdt_match(struct boot_param_header *blob, unsigned long node,
+                 const char **compat)
+{
+       unsigned int tmp, score = 0;
+
+       if (!compat)
+               return 0;
+
+       while (*compat) {
+               tmp = of_fdt_is_compatible(blob, node, *compat);
+               if (tmp && (score == 0 || (tmp < score)))
+                       score = tmp;
+               compat++;
+       }
+
+       return score;
+}
+
 static void *unflatten_dt_alloc(unsigned long *mem, unsigned long size,
                                       unsigned long align)
 {
@@ -511,6 +536,14 @@ int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
        return of_fdt_is_compatible(initial_boot_params, node, compat);
 }
 
+/**
+ * of_flat_dt_match - Return true if node matches a list of compatible values
+ */
+int __init of_flat_dt_match(unsigned long node, const char **compat)
+{
+       return of_fdt_match(initial_boot_params, node, compat);
+}
+
 #ifdef CONFIG_BLK_DEV_INITRD
 /**
  * early_init_dt_check_for_initrd - Decode initrd location from flat tree