From a4f740cf33f7f6c164bbde3c0cdbcc77b0c4997c Mon Sep 17 00:00:00 2001
From: Grant Likely <grant.likely@secretlab.ca>
Date: Sat, 30 Oct 2010 11:49:09 -0400
Subject: of/flattree: Add of_flat_dt_match() helper function

This patch adds of_flat_dt_match() which tests a node for
compatibility with a list of values and converts the relevant powerpc
platform code to use it.  This approach simplifies the board support
code a bit.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Reviewed-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
---
 drivers/of/fdt.c | 37 +++++++++++++++++++++++++++++++++++--
 1 file changed, 35 insertions(+), 2 deletions(-)

(limited to 'drivers/of')

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 8a90ee42071a..c787c3d95c60 100644
--- 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
-- 
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