USB: Allow skipping device resume during system resume

This allows xHC to remain in low power mode and not
resume the bus when system wide resume happens.
Controller comes out of low power mode only when usb
device issues a remote wakeup or if there is a host
initiated bus resume.

Change-Id: I96cdcb9e3642906b4afa08d9bde07e123d9b3977
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/usb.h b/include/linux/usb.h
index 440248ba4123..7e6e4665212f 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -395,6 +395,15 @@ struct usb_bus {
 	struct mon_bus *mon_bus;	/* non-null when associated */
 	int monitored;			/* non-zero when monitored */
 #endif
+	unsigned skip_resume:1;		/* All USB devices are brought into full
+					 * power state after system resume. It
+					 * is desirable for some buses to keep
+					 * their devices in suspend state even
+					 * after system resume. The devices
+					 * are resumed later when a remote
+					 * wakeup is detected or an interface
+					 * driver starts I/O.
+					 */
 };
 
 struct usb_dev_state;