[PATCH v2] of: match by compatible property first

[Thierry Reding]

When matching devices against an OF device ID table, the first string of
the compatible property that is listed in the table should match,
regardless of its position in the table.

Cc: Grant Likely <grant.likely at secretlab.ca>
Cc: Rob Herring <rob.herring at calxeda.com>
Cc: devicetree-discuss at lists.ozlabs.org
Signed-off-by: Thierry Reding <thierry.reding at avionic-design.de>

---
Changes in v2:
- don't export of_match_compat() function

 drivers/of/base.c |   30 ++++++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 91c1fb4..7cd5e8a 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -511,6 +511,22 @@ out:
 }
 EXPORT_SYMBOL(of_find_node_with_property);
 
+static const struct of_device_id *of_match_compat(const struct of_device_id *matches,
+						  const char *compat)
+{
+	while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
+		const char *cp = matches->compatible;
+		int len = strlen(cp);
+
+		if (len > 0 && of_compat_cmp(compat, cp, len) == 0)
+			return matches;
+
+		matches++;
+	}
+
+	return NULL;
+}
+
 /**
  * of_match_node - Tell if an device_node has a matching of_match structure
  *	@matches:	array of of device match structures to search in
@@ -521,9 +537,18 @@ EXPORT_SYMBOL(of_find_node_with_property);
 const struct of_device_id *of_match_node(const struct of_device_id *matches,
 					 const struct device_node *node)
 {
+	struct property *prop;
+	const char *cp;
+
 	if (!matches)
 		return NULL;
 
+	of_property_for_each_string(node, "compatible", prop, cp) {
+		const struct of_device_id *match = of_match_compat(matches, cp);
+		if (match)
+			return match;
+	}
+
 	while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
 		int match = 1;
 		if (matches->name[0])
@@ -532,10 +557,7 @@ const struct of_device_id *of_match_node(const struct of_device_id *matches,
 		if (matches->type[0])
 			match &= node->type
 				&& !strcmp(matches->type, node->type);
-		if (matches->compatible[0])
-			match &= of_device_is_compatible(node,
-						matches->compatible);
-		if (match)
+		if (match && !matches->compatible[0])
 			return matches;
 		matches++;
 	}
-- 
1.7.10.4