usb: gadget: f_sourcesink: eliminate abuse of ep->driver data

Since ep->driver_data is not used for endpoint claiming, neither for
enabled/disabled state storing, we can reduce number of places where
we read or modify it's value, as now it has no particular meaning for
function or framework logic.

In case of f_sourcesink we only need to store in ep->driver_data pointer
to struct f_sourcesink, as it's used in source_sink_complete() callback.
All other uses of ep->driver_data are now meaningless and can be safely
removed.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/function/f_sourcesink.c

@@ -311,13 +311,9 @@ static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
 {
 	int			value;
 
-	if (ep->driver_data) {
-		value = usb_ep_disable(ep);
-		if (value < 0)
-			DBG(cdev, "disable %s --> %d\n",
-					ep->name, value);
-		ep->driver_data = NULL;
-	}
+	value = usb_ep_disable(ep);
+	if (value < 0)
+		DBG(cdev, "disable %s --> %d\n", ep->name, value);
 }
 
 void disable_endpoints(struct usb_composite_dev *cdev,
@@ -355,12 +351,10 @@ sourcesink_bind(struct usb_configuration *c, struct usb_function *f)
 			f->name, cdev->gadget->name);
 		return -ENODEV;
 	}
-	ss->in_ep->driver_data = cdev;	/* claim */
 
 	ss->out_ep = usb_ep_autoconfig(cdev->gadget, &fs_sink_desc);
 	if (!ss->out_ep)
 		goto autoconf_fail;
-	ss->out_ep->driver_data = cdev;	/* claim */
 
 	/* sanity check the isoc module parameters */
 	if (isoc_interval < 1)
@@ -384,13 +378,10 @@ sourcesink_bind(struct usb_configuration *c, struct usb_function *f)
 	ss->iso_in_ep = usb_ep_autoconfig(cdev->gadget, &fs_iso_source_desc);
 	if (!ss->iso_in_ep)
 		goto no_iso;
-	ss->iso_in_ep->driver_data = cdev;	/* claim */
 
 	ss->iso_out_ep = usb_ep_autoconfig(cdev->gadget, &fs_iso_sink_desc);
-	if (ss->iso_out_ep) {
-		ss->iso_out_ep->driver_data = cdev;	/* claim */
-	} else {
-		ss->iso_in_ep->driver_data = NULL;
+	if (!ss->iso_out_ep) {
+		usb_ep_autoconfig_release(ss->iso_in_ep);
 		ss->iso_in_ep = NULL;
 no_iso:
 		/*
@@ -685,7 +676,6 @@ enable_source_sink(struct usb_composite_dev *cdev, struct f_sourcesink *ss,
 fail:
 		ep = ss->in_ep;
 		usb_ep_disable(ep);
-		ep->driver_data = NULL;
 		return result;
 	}
 
@@ -704,7 +694,6 @@ enable_source_sink(struct usb_composite_dev *cdev, struct f_sourcesink *ss,
 fail2:
 		ep = ss->out_ep;
 		usb_ep_disable(ep);
-		ep->driver_data = NULL;
 		goto fail;
 	}
 
@@ -726,10 +715,8 @@ enable_source_sink(struct usb_composite_dev *cdev, struct f_sourcesink *ss,
 		if (result < 0) {
 fail3:
 			ep = ss->iso_in_ep;
-			if (ep) {
+			if (ep)
 				usb_ep_disable(ep);
-				ep->driver_data = NULL;
-			}
 			goto fail2;
 		}
 	}
@@ -748,7 +735,6 @@ enable_source_sink(struct usb_composite_dev *cdev, struct f_sourcesink *ss,
 		result = source_sink_start_ep(ss, false, true, speed);
 		if (result < 0) {
 			usb_ep_disable(ep);
-			ep->driver_data = NULL;
 			goto fail3;
 		}
 	}
@@ -765,8 +751,7 @@ static int sourcesink_set_alt(struct usb_function *f,
 	struct f_sourcesink		*ss = func_to_ss(f);
 	struct usb_composite_dev	*cdev = f->config->cdev;
 
-	if (ss->in_ep->driver_data)
-		disable_source_sink(ss);
+	disable_source_sink(ss);
 	return enable_source_sink(cdev, ss, alt);
 }