1 files changed, 78 insertions, 0 deletions

diff --git a/drivers/base/component.c b/drivers/base/component.c
index 891f0e38647c..8946dfee4768 100644
--- a/drivers/base/component.c
+++ b/drivers/base/component.c
@@ -14,6 +14,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/debugfs.h>
 
 struct component;
 
@@ -38,6 +39,7 @@ struct master {
         const struct component_master_ops *ops;
         struct device *dev;
         struct component_match *match;
+        struct dentry *dentry;
 };
 
 struct component {
@@ -53,6 +55,80 @@ static DEFINE_MUTEX(component_mutex);
 static LIST_HEAD(component_list);
 static LIST_HEAD(masters);
 
+#ifdef CONFIG_DEBUG_FS
+
+static struct dentry *component_debugfs_dir;
+
+static int component_devices_show(struct seq_file *s, void *data)
+{
+        struct master *m = s->private;
+        struct component_match *match = m->match;
+        size_t i;
+
+        mutex_lock(&component_mutex);
+        seq_printf(s, "%-40s %20s\n", "master name", "status");
+        seq_puts(s, "-------------------------------------------------------------\n");
+        seq_printf(s, "%-40s %20s\n\n",
+                   dev_name(m->dev), m->bound ? "bound" : "not bound");
+
+        seq_printf(s, "%-40s %20s\n", "device name", "status");
+        seq_puts(s, "-------------------------------------------------------------\n");
+        for (i = 0; i < match->num; i++) {
+                struct device *d = (struct device *)match->compare[i].data;
+
+                seq_printf(s, "%-40s %20s\n", dev_name(d),
+                           match->compare[i].component ?
+                           "registered" : "not registered");
+        }
+        mutex_unlock(&component_mutex);
+
+        return 0;
+}
+
+static int component_devices_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, component_devices_show, inode->i_private);
+}
+
+static const struct file_operations component_devices_fops = {
+        .open = component_devices_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .release = single_release,
+};
+
+static int __init component_debug_init(void)
+{
+        component_debugfs_dir = debugfs_create_dir("device_component", NULL);
+
+        return 0;
+}
+
+core_initcall(component_debug_init);
+
+static void component_master_debugfs_add(struct master *m)
+{
+        m->dentry = debugfs_create_file(dev_name(m->dev), 0444,
+                                        component_debugfs_dir,
+                                        m, &component_devices_fops);
+}
+
+static void component_master_debugfs_del(struct master *m)
+{
+        debugfs_remove(m->dentry);
+        m->dentry = NULL;
+}
+
+#else
+
+static void component_master_debugfs_add(struct master *m)
+{ }
+
+static void component_master_debugfs_del(struct master *m)
+{ }
+
+#endif
+
 static struct master *__master_find(struct device *dev,
         const struct component_master_ops *ops)
 {
@@ -287,6 +363,7 @@ static void free_master(struct master *master)
         struct component_match *match = master->match;
         int i;
 
+        component_master_debugfs_del(master);
         list_del(&master->node);
 
         if (match) {
@@ -320,6 +397,7 @@ int component_master_add_with_match(struct device *dev,
         master->ops = ops;
         master->match = match;
 
+        component_master_debugfs_add(master);
         /* Add to the list of available masters. */
         mutex_lock(&component_mutex);
         list_add(&master->node, &masters);