USB: move usb debugfs directory creation to the usb common core

The USB gadget subsystem wants to use the USB debugfs root directory, so
move it to the common "core" USB code so that it is properly initialized
and removed as needed.

In order to properly do this, we need to load the common code before the
usb core code, when everything is linked into the kernel, so reorder the
link order of the code.

Also as the usb common code has the possibility of the led trigger logic
to be merged into it, handle the build option properly by only having
one module init/exit function and have the common code initialize the
led trigger if needed.

Reported-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Tested-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 21 insertions, 0 deletions

diff --git a/drivers/usb/common/common.c b/drivers/usb/common/common.c
index 18f5dcf58b0d..1433260d99b4 100644
--- a/drivers/usb/common/common.c
+++ b/drivers/usb/common/common.c
@@ -15,6 +15,8 @@
 #include <linux/usb/of.h>
 #include <linux/usb/otg.h>
 #include <linux/of_platform.h>
+#include <linux/debugfs.h>
+#include "common.h"
 
 static const char *const ep_type_names[] = {
 	[USB_ENDPOINT_XFER_CONTROL] = "ctrl",
@@ -291,4 +293,23 @@ struct device *usb_of_get_companion_dev(struct device *dev)
 EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
 #endif
 
+struct dentry *usb_debug_root;
+EXPORT_SYMBOL_GPL(usb_debug_root);
+
+static int __init usb_common_init(void)
+{
+	usb_debug_root = debugfs_create_dir("usb", NULL);
+	ledtrig_usb_init();
+	return 0;
+}
+
+static void __exit usb_common_exit(void)
+{
+	ledtrig_usb_exit();
+	debugfs_remove_recursive(usb_debug_root);
+}
+
+subsys_initcall(usb_common_init);
+module_exit(usb_common_exit);
+
 MODULE_LICENSE("GPL");