[PATCH] drivers: base: Check all compatible strings for modalias match

[Trent Piepho]

When attempting a modalias match in device_match_of_modalias(), only the
first string in the compatible property, which is a list of strings, was
used.

A modalias (which is a bit of a misnomer in Barebox) match is used when
a driver does not have an of_compatible match table, e.g. the at24
driver.  The compatible string after the comma is matched against the
driver's id table.

Extend modalias match to try all strings in from the OF node's
compatible property.  This will cause a compatible like
"rohm,br24g04-3", "atmel,24c04" to match against the "24c04" ID in the
at24 driver.  Or "isil,isl12057", "dallas,ds1337" will match the ds1307
driver's table, which doesn't know about isl12057 in Barebox.

Signed-off-by: Trent Piepho <tpiepho at gmail.com>
---
 drivers/base/bus.c | 27 +++++++++------------------
 1 file changed, 9 insertions(+), 18 deletions(-)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 1038d20a1..aac5b69f3 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -75,7 +75,7 @@ int device_match_of_modalias(struct device_d *dev, struct driver_d *drv)
 {
 	const struct platform_device_id *id = drv->id_table;
 	const char *of_modalias = NULL, *p;
-	int cplen;
+	const struct property *prop;
 	const char *compat;
 
 	if (!device_match(dev, drv))
@@ -84,25 +84,16 @@ int device_match_of_modalias(struct device_d *dev, struct driver_d *drv)
 	if (!id || !IS_ENABLED(CONFIG_OFDEVICE) || !dev->device_node)
 		return -1;
 
-	compat = of_get_property(dev->device_node, "compatible", &cplen);
-	if (!compat)
-		return -1;
-
-	p = strchr(compat, ',');
-	of_modalias = p ? p + 1 : compat;
-
-	while (id->name) {
-		if (!strcmp(id->name, dev->name)) {
-			dev->id_entry = id;
-			return 0;
-		}
+	of_property_for_each_string(dev->device_node, "compatible", prop, compat) {
+		p = strchr(compat, ',');
+		of_modalias = p ? p + 1 : compat;
 
-		if (of_modalias && !strcmp(id->name, of_modalias)) {
-			dev->id_entry = id;
-			return 0;
+		for (id = drv->id_table; id->name; id++) {
+			if (!strcmp(id->name, dev->name) || !strcmp(id->name, of_modalias)) {
+				dev->id_entry = id;
+				return 0;
+			}
 		}
-
-		id++;
 	}
 
 	return -1;
-- 
2.26.2