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authorMaciej Purski <m.purski@samsung.com>2017-12-01 14:23:16 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-12-18 16:51:11 +0100
commit59e73854b5fd1213fe90ae993d98c759786c3712 (patch)
tree7aeff8061dd2d355bb084d4279bf526ea265546b /drivers/base
parent0a006e864edc077451384bd28ac9be36e8d172e5 (diff)
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component: add debugfs support
Currently there is no information in any vfs about which devices a master component consists of, what makes debugging hard if one of the component devices fails to register. Add 'device_component' directory to debugfs. Create a new file for each component master, when it has been added. Remove it on a master deletion. Show a list of devices required by the given master and their status (registered or not). This provides an easy way to check, which device has failed to register if the given master device is not available in the system. Signed-off-by: Maciej Purski <m.purski@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/component.c78
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);