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authorKevin Hao <haokexin@gmail.com>2014-02-14 13:22:46 +0800
committerRob Herring <robh@kernel.org>2014-02-15 18:51:17 -0600
commit06b29e76a74b2373e6f8b5a7938b3630b9ae98b2 (patch)
treea9ad65687400206ef0b07f08af5237c977be7009
parent4e8ca6ee3a5d0e0f4c0cb32e43dc3d69e79e5a76 (diff)
of: search the best compatible match first in __of_match_node()dt-fixes-for-3.14
Currently, of_match_node compares each given match against all node's compatible strings with of_device_is_compatible. To achieve multiple compatible strings per node with ordering from specific to generic, this requires given matches to be ordered from specific to generic. For most of the drivers this is not true and also an alphabetical ordering is more sane there. Therefore, this patch introduces a function to match each of the node's compatible strings against all given compatible matches without type and name first, before checking the next compatible string. This implies that node's compatibles are ordered from specific to generic while given matches can be in any order. If we fail to find such a match entry, then fall-back to the old method in order to keep compatibility. Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> Signed-off-by: Kevin Hao <haokexin@gmail.com> Tested-by: Stephen Chivers <schivers@csc.com> Signed-off-by: Rob Herring <robh@kernel.org>
-rw-r--r--drivers/of/base.c43
1 files changed, 42 insertions, 1 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c
index ba195fb..10b5110 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -730,13 +730,49 @@ out:
}
EXPORT_SYMBOL(of_find_node_with_property);
+static const struct of_device_id *
+of_match_compatible(const struct of_device_id *matches,
+ const struct device_node *node)
+{
+ const char *cp;
+ int cplen, l;
+ const struct of_device_id *m;
+
+ cp = __of_get_property(node, "compatible", &cplen);
+ while (cp && (cplen > 0)) {
+ m = matches;
+ while (m->name[0] || m->type[0] || m->compatible[0]) {
+ /* Only match for the entries without type and name */
+ if (m->name[0] || m->type[0] ||
+ of_compat_cmp(m->compatible, cp,
+ strlen(m->compatible)))
+ m++;
+ else
+ return m;
+ }
+
+ /* Get node's next compatible string */
+ l = strlen(cp) + 1;
+ cp += l;
+ cplen -= l;
+ }
+
+ return NULL;
+}
+
static
const struct of_device_id *__of_match_node(const struct of_device_id *matches,
const struct device_node *node)
{
+ const struct of_device_id *m;
+
if (!matches)
return NULL;
+ m = of_match_compatible(matches, node);
+ if (m)
+ return m;
+
while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
int match = 1;
if (matches->name[0])
@@ -760,7 +796,12 @@ const struct of_device_id *__of_match_node(const struct of_device_id *matches,
* @matches: array of of device match structures to search in
* @node: the of device structure to match against
*
- * Low level utility function used by device matching.
+ * Low level utility function used by device matching. We have two ways
+ * of matching:
+ * - Try to find the best compatible match by comparing each compatible
+ * string of device node with all the given matches respectively.
+ * - If the above method failed, then try to match the compatible by using
+ * __of_device_is_compatible() besides the match in type and name.
*/
const struct of_device_id *of_match_node(const struct of_device_id *matches,
const struct device_node *node)