usb: hcd: Remove USB phy if needed

This adds remove_phy flag to the HCD structure. If the flag is
set and if hcd->phy is valid, the phy is shutdown and released
whenever usb_add_hcd fails or usb_hcd_remove is called.
This can be used by the HCD drivers to auto-remove
the external USB phy when it is no longer needed.

Signed-off-by: Valentine Barshak <valentine.barshak@cogentembedded.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/hcd.c

@@ -44,6 +44,7 @@
 
 #include <linux/usb.h>
 #include <linux/usb/hcd.h>
+#include <linux/usb/phy.h>
 
 #include "usb.h"
 
@@ -2603,7 +2604,7 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	 */
 	if ((retval = hcd_buffer_create(hcd)) != 0) {
 		dev_dbg(hcd->self.controller, "pool alloc failed\n");
-		return retval;
+		goto err_remove_phy;
 	}
 
 	if ((retval = usb_register_bus(&hcd->self)) < 0)
@@ -2734,6 +2735,12 @@ err_allocate_root_hub:
 	usb_deregister_bus(&hcd->self);
 err_register_bus:
 	hcd_buffer_destroy(hcd);
+err_remove_phy:
+	if (hcd->remove_phy && hcd->phy) {
+		usb_phy_shutdown(hcd->phy);
+		usb_put_phy(hcd->phy);
+		hcd->phy = NULL;
+	}
 	return retval;
 }
 EXPORT_SYMBOL_GPL(usb_add_hcd);
@@ -2806,6 +2813,11 @@ void usb_remove_hcd(struct usb_hcd *hcd)
 	usb_put_dev(hcd->self.root_hub);
 	usb_deregister_bus(&hcd->self);
 	hcd_buffer_destroy(hcd);
+	if (hcd->remove_phy && hcd->phy) {
+		usb_phy_shutdown(hcd->phy);
+		usb_put_phy(hcd->phy);
+		hcd->phy = NULL;
+	}
 }
 EXPORT_SYMBOL_GPL(usb_remove_hcd);
 

include/linux/usb/hcd.h

@@ -134,6 +134,7 @@ struct usb_hcd {
 	unsigned		rh_registered:1;/* is root hub registered? */
 	unsigned		rh_pollable:1;	/* may we poll the root hub? */
 	unsigned		msix_enabled:1;	/* driver has MSI-X enabled? */
+	unsigned		remove_phy:1;	/* auto-remove USB phy */
 
 	/* The next flag is a stopgap, to be removed when all the HCDs
 	 * support the new root-hub polling mechanism. */