usb: dwc3: ep0: push ep0state into xfernotready processing

We wait for the XferNotReady before we start the transfer and by then we
know ep0 state in which we supposed to be.
This is some cleanup work for the following patch in which we require to
know the ep0 state before the transfer completes.
While here, also change the argument to dwc3_ep0_do_control_status() so
we don't require the complete event structure but only the required
piece of information.

Inspired-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/ep0.c

@@ -53,9 +53,6 @@
 #include "gadget.h"
 #include "io.h"
 
-static void dwc3_ep0_inspect_setup(struct dwc3 *dwc,
-		const struct dwc3_event_depevt *event);
-
 static const char *dwc3_ep0_state_string(enum dwc3_ep0_state state)
 {
 	switch (state) {
@@ -639,7 +636,6 @@ static void dwc3_ep0_xfer_complete(struct dwc3 *dwc,
 static void dwc3_ep0_do_control_setup(struct dwc3 *dwc,
 		const struct dwc3_event_depevt *event)
 {
-	dwc->ep0state = EP0_SETUP_PHASE;
 	dwc3_ep0_out_start(dwc);
 }
 
@@ -651,7 +647,6 @@ static void dwc3_ep0_do_control_data(struct dwc3 *dwc,
 	int			ret;
 
 	dep = dwc->eps[0];
-	dwc->ep0state = EP0_DATA_PHASE;
 
 	if (list_empty(&dep->request_list)) {
 		dev_vdbg(dwc->dev, "pending request for EP0 Data phase\n");
@@ -665,7 +660,6 @@ static void dwc3_ep0_do_control_data(struct dwc3 *dwc,
 	req = next_request(&dep->request_list);
 	req->direction = !!event->endpoint_number;
 
-	dwc->ep0state = EP0_DATA_PHASE;
 	if (req->request.length == 0) {
 		ret = dwc3_ep0_start_trans(dwc, event->endpoint_number,
 				dwc->ctrl_req_addr, 0,
@@ -697,21 +691,23 @@ static void dwc3_ep0_do_control_data(struct dwc3 *dwc,
 	WARN_ON(ret < 0);
 }
 
-static void dwc3_ep0_do_control_status(struct dwc3 *dwc,
-		const struct dwc3_event_depevt *event)
+static int dwc3_ep0_start_control_status(struct dwc3_ep *dep)
 {
+	struct dwc3		*dwc = dep->dwc;
 	u32			type;
-	int			ret;
-
-	dwc->ep0state = EP0_STATUS_PHASE;
 
 	type = dwc->three_stage_setup ? DWC3_TRBCTL_CONTROL_STATUS3
 		: DWC3_TRBCTL_CONTROL_STATUS2;
 
-	ret = dwc3_ep0_start_trans(dwc, event->endpoint_number,
+	return dwc3_ep0_start_trans(dwc, dep->number,
 			dwc->ctrl_req_addr, 0, type);
+}
 
-	WARN_ON(ret < 0);
+static void dwc3_ep0_do_control_status(struct dwc3 *dwc, u32 epnum)
+{
+	struct dwc3_ep		*dep = dwc->eps[epnum];
+
+	WARN_ON(dwc3_ep0_start_control_status(dep));
 }
 
 static void dwc3_ep0_xfernotready(struct dwc3 *dwc,
@@ -755,12 +751,17 @@ static void dwc3_ep0_xfernotready(struct dwc3 *dwc,
 	switch (event->status) {
 	case DEPEVT_STATUS_CONTROL_SETUP:
 		dev_vdbg(dwc->dev, "Control Setup\n");
+
+		dwc->ep0state = EP0_SETUP_PHASE;
+
 		dwc3_ep0_do_control_setup(dwc, event);
 		break;
 
 	case DEPEVT_STATUS_CONTROL_DATA:
 		dev_vdbg(dwc->dev, "Control Data\n");
 
+		dwc->ep0state = EP0_DATA_PHASE;
+
 		if (dwc->ep0_next_event != DWC3_EP0_NRDY_DATA) {
 			dev_vdbg(dwc->dev, "Expected %d got %d\n",
 					dwc->ep0_next_event,
@@ -790,6 +791,8 @@ static void dwc3_ep0_xfernotready(struct dwc3 *dwc,
 	case DEPEVT_STATUS_CONTROL_STATUS:
 		dev_vdbg(dwc->dev, "Control Status\n");
 
+		dwc->ep0state = EP0_STATUS_PHASE;
+
 		if (dwc->ep0_next_event != DWC3_EP0_NRDY_STATUS) {
 			dev_vdbg(dwc->dev, "Expected %d got %d\n",
 					dwc->ep0_next_event,
@@ -798,7 +801,7 @@ static void dwc3_ep0_xfernotready(struct dwc3 *dwc,
 			dwc3_ep0_stall_and_restart(dwc);
 			return;
 		}
-		dwc3_ep0_do_control_status(dwc, event);
+		dwc3_ep0_do_control_status(dwc, event->endpoint_number);
 	}
 }