[PATCH] of_path: Make partition names work again

[Sascha Hauer]

The device-path "partname:<name>" mechanism is broken by:

75b6827 of_path: of_find_path() factor out device detection logic into separate function

This is because since said commit the device-path property is no longer
searched in the original device node anymore, but in the device node
of the device itself.

Fix this by passing the partition name directly to __of_find_path.

Originally it was intended to further extend the multi string property
device-path further with more elements, like for example a filename. It
turned out though that this is too complex and instead of further
extending the property we should instead create additional properties,
so this mechanism is removed with this patch.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
Cc: Marc Kleine-Budde <mkl at pengutronix.de>
---
 drivers/of/of_path.c | 125 ++++++++++++---------------------------------------
 1 file changed, 29 insertions(+), 96 deletions(-)

diff --git a/drivers/of/of_path.c b/drivers/of/of_path.c
index 6903905..35d3576 100644
--- a/drivers/of/of_path.c
+++ b/drivers/of/of_path.c
@@ -23,16 +23,6 @@
 
 #include <linux/mtd/mtd.h>
 
-struct of_path {
-	struct cdev *cdev;
-	struct device_d *dev;
-};
-
-struct of_path_type {
-	const char *name;
-	int (*parse)(struct of_path *op, const char *str);
-};
-
 struct device_d *of_find_device_by_node_path(const char *path)
 {
 	struct device_d *dev;
@@ -47,103 +37,34 @@ struct device_d *of_find_device_by_node_path(const char *path)
 	return NULL;
 }
 
-/**
- * of_path_type_partname - find a partition based on physical device and
- *                         partition name
- * @op: of_path context
- * @name: the partition name to find
- */
-static int of_path_type_partname(struct of_path *op, const char *name)
-{
-	if (!op->dev)
-		return -EINVAL;
-
-	op->cdev = device_find_partition(op->dev, name);
-	if (op->cdev) {
-		pr_debug("%s: found part '%s'\n", __func__, name);
-		return 0;
-	} else {
-		pr_debug("%s: cannot find part '%s'\n", __func__, name);
-		return -ENODEV;
-	}
-}
-
-static struct of_path_type of_path_types[] = {
-	{
-		.name = "partname",
-		.parse = of_path_type_partname,
-	},
-};
-
-static int of_path_parse_one(struct of_path *op, const char *str)
-{
-	int i, ret;
-	char *name, *desc;
-
-	pr_debug("parsing: %s\n", str);
-
-	name = xstrdup(str);
-	desc = strchr(name, ':');
-	if (!desc) {
-		free(name);
-		return -EINVAL;
-	}
-
-	*desc = 0;
-	desc++;
-
-	for (i = 0; i < ARRAY_SIZE(of_path_types); i++) {
-		if (!strcmp(of_path_types[i].name, name)) {
-			ret = of_path_types[i].parse(op, desc);
-			goto out;
-		}
-	}
-
-	ret = -EINVAL;
-out:
-	free(name);
-
-	return ret;
-}
-
-static int __of_find_path(struct device_node *node, const char *propname, char **outpath, unsigned flags)
+static int __of_find_path(struct device_node *node, const char *partname, char **outpath, unsigned flags)
 {
-	struct of_path op = {};
-	const char *str;
+	struct device_d *dev;
+	struct cdev *cdev;
 	bool add_bb = false;
-	int i, ret;
 
-	op.dev = of_find_device_by_node_path(node->full_name);
-	if (!op.dev) {
-		op.dev = of_find_device_by_node_path(node->parent->full_name);
-		if (!op.dev)
+	dev = of_find_device_by_node_path(node->full_name);
+	if (!dev) {
+		dev = of_find_device_by_node_path(node->parent->full_name);
+		if (!dev)
 			return -ENODEV;
 	}
 
-	device_detect(op.dev);
-
-	op.cdev = cdev_by_device_node(node);
+	device_detect(dev);
 
-	i = 1;
+	if (partname)
+		cdev = device_find_partition(dev, partname);
+	else
+		cdev = cdev_by_device_node(node);
 
-	while (propname) {
-		ret = of_property_read_string_index(node, propname, i++, &str);
-		if (ret)
-			break;
-
-		ret = of_path_parse_one(&op, str);
-		if (ret)
-			return ret;
-	}
-
-	if (!op.cdev)
+	if (!cdev)
 		return -ENOENT;
 
-	if ((flags & OF_FIND_PATH_FLAGS_BB) && op.cdev->mtd &&
-	    mtd_can_have_bb(op.cdev->mtd))
+	if ((flags & OF_FIND_PATH_FLAGS_BB) && cdev->mtd &&
+	    mtd_can_have_bb(cdev->mtd))
 		add_bb = true;
 
-	*outpath = asprintf("/dev/%s%s", op.cdev->name, add_bb ? ".bb" : "");
+	*outpath = asprintf("/dev/%s%s", cdev->name, add_bb ? ".bb" : "");
 
 	return 0;
 }
@@ -193,6 +114,8 @@ int of_find_path(struct device_node *node, const char *propname, char **outpath,
 {
 	struct device_node *rnode;
 	const char *path;
+	const char *partname = NULL;
+	char partnamestr[] = "partname:";
 
 	path = of_get_property(node, propname, NULL);
 	if (!path)
@@ -202,5 +125,15 @@ int of_find_path(struct device_node *node, const char *propname, char **outpath,
 	if (!rnode)
 		return -ENODEV;
 
-	return __of_find_path(rnode, propname, outpath, flags);
+	of_property_read_string_index(node, propname, 1, &partname);
+	if (partname) {
+		if (!strncmp(partname, partnamestr, sizeof(partnamestr) - 1)) {
+			partname += sizeof(partnamestr) - 1;
+		} else {
+			pr_err("Invalid device-path: %s\n", partname);
+			return -EINVAL;
+		}
+	}
+
+	return __of_find_path(rnode, partname, outpath, flags);
 }
-- 
2.6.4