USB: gadget: composite device-level suspend/resume hooks

Address one open question in the composite gadget framework:
Yes, we should have device-level suspend/resume callbacks
in addition to the function-level ones.  We have at least one
scenario (with gadget zero in OTG test mode) that's awkward
to handle without it.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 14 insertions, 2 deletions

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 40f1da77a006..59e85234fa0a 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1014,7 +1014,7 @@ composite_suspend(struct usb_gadget *gadget)
         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
         struct usb_function             *f;
 
-        /* REVISIT:  should we have config and device level
+        /* REVISIT:  should we have config level
          * suspend/resume callbacks?
          */
         DBG(cdev, "suspend\n");
@@ -1024,6 +1024,8 @@ composite_suspend(struct usb_gadget *gadget)
                                 f->suspend(f);
                 }
         }
+        if (composite->suspend)
+                composite->suspend(cdev);
 }
 
 static void
@@ -1032,10 +1034,12 @@ composite_resume(struct usb_gadget *gadget)
         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
         struct usb_function             *f;
 
-        /* REVISIT:  should we have config and device level
+        /* REVISIT:  should we have config level
          * suspend/resume callbacks?
          */
         DBG(cdev, "resume\n");
+        if (composite->resume)
+                composite->resume(cdev);
         if (cdev->config) {
                 list_for_each_entry(f, &cdev->config->functions, list) {
                         if (f->resume)
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index 935c380ffe47..acd7b0f06c8a 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -244,6 +244,10 @@ int usb_add_config(struct usb_composite_dev *,
  *      value; it should return zero on successful initialization.
  * @unbind: Reverses @bind(); called as a side effect of unregistering
  *      this driver.
+ * @suspend: Notifies when the host stops sending USB traffic,
+ *      after function notifications
+ * @resume: Notifies configuration when the host restarts USB traffic,
+ *      before function notifications
  *
  * Devices default to reporting self powered operation.  Devices which rely
  * on bus powered operation should report this in their @bind() method.
@@ -268,6 +272,10 @@ struct usb_composite_driver {
 
         int                     (*bind)(struct usb_composite_dev *);
         int                     (*unbind)(struct usb_composite_dev *);
+
+        /* global suspend hooks */
+        void                    (*suspend)(struct usb_composite_dev *);
+        void                    (*resume)(struct usb_composite_dev *);
 };
 
 extern int usb_composite_register(struct usb_composite_driver *);