From 0ee203186d1adf98a04484ee9e601ca9714f0497 Mon Sep 17 00:00:00 2001
From: Sascha Hauer <s.hauer@pengutronix.de>
Date: Wed, 10 Jul 2013 08:49:46 +0200
Subject: [PATCH] cdev: add device_find_partition

device_find_partition allows to find a partition of a device with
a particular name.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 fs/devfs-core.c  | 27 +++++++++++++++++++++++++++
 include/driver.h |  1 +
 2 files changed, 28 insertions(+)

diff --git a/fs/devfs-core.c b/fs/devfs-core.c
index 816f244f1..a92d4347f 100644
--- a/fs/devfs-core.c
+++ b/fs/devfs-core.c
@@ -56,6 +56,33 @@ struct cdev *cdev_by_name(const char *filename)
 	return NULL;
 }
 
+/**
+ * device_find_partition - find a partition belonging to a physical device
+ *
+ * @dev: the device which should be searched for partitions
+ * @name: the partition name
+ */
+struct cdev *device_find_partition(struct device_d *dev, const char *name)
+{
+	struct cdev *cdev;
+	struct device_d *child;
+
+	list_for_each_entry(cdev, &dev->cdevs, devices_list) {
+		if (!cdev->partname)
+			continue;
+		if (!strcmp(cdev->partname, name))
+			return cdev;
+	}
+
+	device_for_each_child(dev, child) {
+		cdev = device_find_partition(child, name);
+		if (cdev)
+			return cdev;
+	}
+
+	return NULL;
+}
+
 int cdev_find_free_index(const char *basename)
 {
 	int i;
diff --git a/include/driver.h b/include/driver.h
index 7ac2eef84..f95c93cca 100644
--- a/include/driver.h
+++ b/include/driver.h
@@ -458,6 +458,7 @@ struct cdev {
 int devfs_create(struct cdev *);
 int devfs_remove(struct cdev *);
 int cdev_find_free_index(const char *);
+struct cdev *device_find_partition(struct device_d *dev, const char *name);
 struct cdev *cdev_by_name(const char *filename);
 struct cdev *cdev_open(const char *name, unsigned long flags);
 int cdev_do_open(struct cdev *, unsigned long flags);