usb: gadget: move loopback's config descriptor out of f_loopback

f_loopback should only include the bare function but it also includes
the config descriptor. This patch moves the config descriptor into
zero.c, the only user of this function.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/f_loopback.c

@@ -185,6 +185,12 @@ loopback_bind(struct usb_configuration *c, struct usb_function *f)
 		return id;
 	loopback_intf.bInterfaceNumber = id;
 
+	id = usb_string_id(cdev);
+	if (id < 0)
+		return id;
+	strings_loopback[0].id = id;
+	loopback_intf.iInterface = id;
+
 	/* allocate endpoints */
 
 	loop->in_ep = usb_ep_autoconfig(cdev->gadget, &fs_loop_source_desc);
@@ -388,41 +394,3 @@ static int __init loopback_bind_config(struct usb_configuration *c)
 		kfree(loop);
 	return status;
 }
-
-static struct usb_configuration loopback_driver = {
-	.label		= "loopback",
-	.strings	= loopback_strings,
-	.bConfigurationValue = 2,
-	.bmAttributes	= USB_CONFIG_ATT_SELFPOWER,
-	/* .iConfiguration = DYNAMIC */
-};
-
-/**
- * loopback_add - add a loopback testing configuration to a device
- * @cdev: the device to support the loopback configuration
- */
-int __init loopback_add(struct usb_composite_dev *cdev, bool autoresume)
-{
-	int id;
-
-	/* allocate string ID(s) */
-	id = usb_string_id(cdev);
-	if (id < 0)
-		return id;
-	strings_loopback[0].id = id;
-
-	loopback_intf.iInterface = id;
-	loopback_driver.iConfiguration = id;
-
-	/* support autoresume for remote wakeup testing */
-	if (autoresume)
-		loopback_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
-
-	/* support OTG systems */
-	if (gadget_is_otg(cdev->gadget)) {
-		loopback_driver.descriptors = otg_desc;
-		loopback_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
-	}
-
-	return usb_add_config(cdev, &loopback_driver, loopback_bind_config);
-}

drivers/usb/gadget/g_zero.h

@@ -19,7 +19,4 @@ void disable_endpoints(struct usb_composite_dev *cdev,
 		struct usb_ep *in, struct usb_ep *out,
 		struct usb_ep *iso_in, struct usb_ep *iso_out);
 
-/* configuration-specific linkup */
-int loopback_add(struct usb_composite_dev *cdev, bool autoresume);
-
 #endif /* __G_ZERO_H */

drivers/usb/gadget/zero.c

@@ -140,12 +140,14 @@ const struct usb_descriptor_header *otg_desc[] = {
 static char serial[] = "0123456789.0123456789.0123456789";
 
 #define USB_GZERO_SS_DESC	(USB_GADGET_FIRST_AVAIL_IDX + 0)
+#define USB_GZERO_LB_DESC	(USB_GADGET_FIRST_AVAIL_IDX + 1)
 
 static struct usb_string strings_dev[] = {
 	[USB_GADGET_MANUFACTURER_IDX].s = "",
 	[USB_GADGET_PRODUCT_IDX].s = longname,
 	[USB_GADGET_SERIAL_IDX].s = serial,
 	[USB_GZERO_SS_DESC].s	= "source and sink data",
+	[USB_GZERO_LB_DESC].s	= "loop input to output",
 	{  }			/* end of list */
 };
 
@@ -254,6 +256,14 @@ static void zero_resume(struct usb_composite_dev *cdev)
 
 /*-------------------------------------------------------------------------*/
 
+static struct usb_configuration loopback_driver = {
+	.label          = "loopback",
+	.strings        = loopback_strings,
+	.bConfigurationValue = 2,
+	.bmAttributes   = USB_CONFIG_ATT_SELFPOWER,
+	/* .iConfiguration = DYNAMIC */
+};
+
 static struct usb_configuration sourcesink_driver = {
 	.label                  = "source/sink",
 	.strings                = sourcesink_strings,
@@ -281,29 +291,37 @@ static int __init zero_bind(struct usb_composite_dev *cdev)
 	setup_timer(&autoresume_timer, zero_autoresume, (unsigned long) cdev);
 
 	sourcesink_driver.iConfiguration = strings_dev[USB_GZERO_SS_DESC].id;
+	loopback_driver.iConfiguration = strings_dev[USB_GZERO_LB_DESC].id;
+
 	/* support autoresume for remote wakeup testing */
 	sourcesink_driver.bmAttributes &= ~USB_CONFIG_ATT_WAKEUP;
+	loopback_driver.bmAttributes &= ~USB_CONFIG_ATT_WAKEUP;
 	sourcesink_driver.descriptors = NULL;
-	if (autoresume)
+	loopback_driver.descriptors = NULL;
+	if (autoresume) {
 		sourcesink_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+		loopback_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+	}
 
 	/* support OTG systems */
 	if (gadget_is_otg(cdev->gadget)) {
 		sourcesink_driver.descriptors = otg_desc;
 		sourcesink_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+		loopback_driver.descriptors = otg_desc;
+		loopback_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 	}
 
 	/* Register primary, then secondary configuration.  Note that
 	 * SH3 only allows one config...
 	 */
 	if (loopdefault) {
-		loopback_add(cdev, autoresume != 0);
+		usb_add_config(cdev, &loopback_driver, loopback_bind_config);
 		usb_add_config(cdev, &sourcesink_driver,
 				sourcesink_bind_config);
 	} else {
 		usb_add_config(cdev, &sourcesink_driver,
 				sourcesink_bind_config);
-		loopback_add(cdev, autoresume != 0);
+		usb_add_config(cdev, &loopback_driver, loopback_bind_config);
 	}
 
 	usb_composite_overwrite_options(cdev, &coverwrite);