usb: dwc3: allocate gadget structure dynamically

The current code uses commit fac32347 ("usb: udc: allow adding
and removing the same gadget device") as the workaround to let
the gadget device is re-used, but it is not allowed from driver
core point. In this commit, we allocate gadget structure dynamically,
and free it at its release function. Since the gadget device's
driver_data has already occupied by usb_composite_dev structure, we have
to use gadget device's platform data to store dwc3 structure.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

drivers/usb/dwc3/core.h

@@ -1080,7 +1080,7 @@ struct dwc3 {
 	struct dwc3_event_buffer *ev_buf;
 	struct dwc3_ep		*eps[DWC3_ENDPOINTS_NUM];
 
-	struct usb_gadget	gadget;
+	struct usb_gadget	*gadget;
 	struct usb_gadget_driver *gadget_driver;
 
 	struct clk_bulk_data	*clks;

drivers/usb/dwc3/ep0.c

@@ -131,7 +131,7 @@ static int __dwc3_gadget_ep0_queue(struct dwc3_ep *dep,
 
 		direction = !dwc->ep0_expect_in;
 		dwc->delayed_status = false;
-		usb_gadget_set_state(&dwc->gadget, USB_STATE_CONFIGURED);
+		usb_gadget_set_state(dwc->gadget, USB_STATE_CONFIGURED);
 
 		if (dwc->ep0state == EP0_STATUS_PHASE)
 			__dwc3_ep0_do_control_status(dwc, dwc->eps[direction]);
@@ -325,7 +325,7 @@ static int dwc3_ep0_handle_status(struct dwc3 *dwc,
 		/*
 		 * LTM will be set once we know how to set this in HW.
 		 */
-		usb_status |= dwc->gadget.is_selfpowered;
+		usb_status |= dwc->gadget->is_selfpowered;
 
 		if ((dwc->speed == DWC3_DSTS_SUPERSPEED) ||
 		    (dwc->speed == DWC3_DSTS_SUPERSPEED_PLUS)) {
@@ -450,7 +450,7 @@ static int dwc3_ep0_handle_device(struct dwc3 *dwc,
 
 	wValue = le16_to_cpu(ctrl->wValue);
 	wIndex = le16_to_cpu(ctrl->wIndex);
-	state = dwc->gadget.state;
+	state = dwc->gadget->state;
 
 	switch (wValue) {
 	case USB_DEVICE_REMOTE_WAKEUP:
@@ -564,7 +564,7 @@ static int dwc3_ep0_handle_feature(struct dwc3 *dwc,
 
 static int dwc3_ep0_set_address(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
 {
-	enum usb_device_state state = dwc->gadget.state;
+	enum usb_device_state state = dwc->gadget->state;
 	u32 addr;
 	u32 reg;
 
@@ -585,9 +585,9 @@ static int dwc3_ep0_set_address(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
 	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
 
 	if (addr)
-		usb_gadget_set_state(&dwc->gadget, USB_STATE_ADDRESS);
+		usb_gadget_set_state(dwc->gadget, USB_STATE_ADDRESS);
 	else
-		usb_gadget_set_state(&dwc->gadget, USB_STATE_DEFAULT);
+		usb_gadget_set_state(dwc->gadget, USB_STATE_DEFAULT);
 
 	return 0;
 }
@@ -597,14 +597,14 @@ static int dwc3_ep0_delegate_req(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
 	int ret;
 
 	spin_unlock(&dwc->lock);
-	ret = dwc->gadget_driver->setup(&dwc->gadget, ctrl);
+	ret = dwc->gadget_driver->setup(dwc->gadget, ctrl);
 	spin_lock(&dwc->lock);
 	return ret;
 }
 
 static int dwc3_ep0_set_config(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
 {
-	enum usb_device_state state = dwc->gadget.state;
+	enum usb_device_state state = dwc->gadget->state;
 	u32 cfg;
 	int ret;
 	u32 reg;
@@ -627,7 +627,7 @@ static int dwc3_ep0_set_config(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
 			 * to change the state on the next usb_ep_queue()
 			 */
 			if (ret == 0)
-				usb_gadget_set_state(&dwc->gadget,
+				usb_gadget_set_state(dwc->gadget,
 						USB_STATE_CONFIGURED);
 
 			/*
@@ -646,7 +646,7 @@ static int dwc3_ep0_set_config(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
 	case USB_STATE_CONFIGURED:
 		ret = dwc3_ep0_delegate_req(dwc, ctrl);
 		if (!cfg && !ret)
-			usb_gadget_set_state(&dwc->gadget,
+			usb_gadget_set_state(dwc->gadget,
 					USB_STATE_ADDRESS);
 		break;
 	default:
@@ -702,7 +702,7 @@ static void dwc3_ep0_set_sel_cmpl(struct usb_ep *ep, struct usb_request *req)
 static int dwc3_ep0_set_sel(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
 {
 	struct dwc3_ep	*dep;
-	enum usb_device_state state = dwc->gadget.state;
+	enum usb_device_state state = dwc->gadget->state;
 	u16		wLength;
 
 	if (state == USB_STATE_DEFAULT)
@@ -746,7 +746,7 @@ static int dwc3_ep0_set_isoch_delay(struct dwc3 *dwc, struct usb_ctrlrequest *ct
 	if (wIndex || wLength)
 		return -EINVAL;
 
-	dwc->gadget.isoch_delay = wValue;
+	dwc->gadget->isoch_delay = wValue;
 
 	return 0;
 }
@@ -1118,7 +1118,7 @@ static void dwc3_ep0_xfernotready(struct dwc3 *dwc,
 			 */
 			if (!list_empty(&dep->pending_list)) {
 				dwc->delayed_status = false;
-				usb_gadget_set_state(&dwc->gadget,
+				usb_gadget_set_state(dwc->gadget,
 						     USB_STATE_CONFIGURED);
 				dwc3_ep0_do_control_status(dwc, event);
 			}

drivers/usb/dwc3/gadget.h

@@ -17,7 +17,7 @@
 
 struct dwc3;
 #define to_dwc3_ep(ep)		(container_of(ep, struct dwc3_ep, endpoint))
-#define gadget_to_dwc(g)	(container_of(g, struct dwc3, gadget))
+#define gadget_to_dwc(g)	(dev_get_platdata(&g->dev))
 
 /* DEPCFG parameter 1 */
 #define DWC3_DEPCFG_INT_NUM(n)		(((n) & 0x1f) << 0)