usb: dwc3: ep0: simplify dwc3_ep0_handle_feature()

By extracting smaller functions from
dwc3_ep0_handle_feature(), it becomes far easier to
understand what's going on. Cleanup only, no
functional changes.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/ep0.c

@@ -371,126 +371,197 @@ static int dwc3_ep0_handle_status(struct dwc3 *dwc,
 	return __dwc3_gadget_ep0_queue(dep, &dwc->ep0_usb_req);
 }
 
-static int dwc3_ep0_handle_feature(struct dwc3 *dwc,
+static int dwc3_ep0_handle_u1(struct dwc3 *dwc, enum usb_device_state state,
+		int set)
+{
+	u32 reg;
+
+	if (state != USB_STATE_CONFIGURED)
+		return -EINVAL;
+	if ((dwc->speed != DWC3_DSTS_SUPERSPEED) &&
+			(dwc->speed != DWC3_DSTS_SUPERSPEED_PLUS))
+		return -EINVAL;
+
+	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+	if (set)
+		reg |= DWC3_DCTL_INITU1ENA;
+	else
+		reg &= ~DWC3_DCTL_INITU1ENA;
+	dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+
+	return 0;
+}
+
+static int dwc3_ep0_handle_u2(struct dwc3 *dwc, enum usb_device_state state,
+		int set)
+{
+	u32 reg;
+
+
+	if (state != USB_STATE_CONFIGURED)
+		return -EINVAL;
+	if ((dwc->speed != DWC3_DSTS_SUPERSPEED) &&
+			(dwc->speed != DWC3_DSTS_SUPERSPEED_PLUS))
+		return -EINVAL;
+
+	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+	if (set)
+		reg |= DWC3_DCTL_INITU2ENA;
+	else
+		reg &= ~DWC3_DCTL_INITU2ENA;
+	dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+
+	return 0;
+}
+
+static int dwc3_ep0_handle_test(struct dwc3 *dwc, enum usb_device_state state,
+		u32 wIndex, int set)
+{
+	if ((wIndex & 0xff) != 0)
+		return -EINVAL;
+	if (!set)
+		return -EINVAL;
+
+	switch (wIndex >> 8) {
+	case TEST_J:
+	case TEST_K:
+	case TEST_SE0_NAK:
+	case TEST_PACKET:
+	case TEST_FORCE_EN:
+		dwc->test_mode_nr = wIndex >> 8;
+		dwc->test_mode = true;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int dwc3_ep0_handle_device(struct dwc3 *dwc,
 		struct usb_ctrlrequest *ctrl, int set)
 {
-	struct dwc3_ep		*dep;
-	u32			recip;
+	enum usb_device_state	state;
 	u32			wValue;
 	u32			wIndex;
-	u32			reg;
-	int			ret;
-	enum usb_device_state	state;
+	int			ret = 0;
 
 	wValue = le16_to_cpu(ctrl->wValue);
 	wIndex = le16_to_cpu(ctrl->wIndex);
-	recip = ctrl->bRequestType & USB_RECIP_MASK;
 	state = dwc->gadget.state;
 
-	switch (recip) {
-	case USB_RECIP_DEVICE:
+	switch (wValue) {
+	case USB_DEVICE_REMOTE_WAKEUP:
+		break;
+	/*
+	 * 9.4.1 says only only for SS, in AddressState only for
+	 * default control pipe
+	 */
+	case USB_DEVICE_U1_ENABLE:
+		ret = dwc3_ep0_handle_u1(dwc, state, set);
+		break;
+	case USB_DEVICE_U2_ENABLE:
+		ret = dwc3_ep0_handle_u2(dwc, state, set);
+		break;
+	case USB_DEVICE_LTM_ENABLE:
+		ret = -EINVAL;
+		break;
+	case USB_DEVICE_TEST_MODE:
+		ret = dwc3_ep0_handle_test(dwc, state, wIndex, set);
+		break;
+	default:
+		ret = -EINVAL;
+	}
 
-		switch (wValue) {
-		case USB_DEVICE_REMOTE_WAKEUP:
-			break;
-		/*
-		 * 9.4.1 says only only for SS, in AddressState only for
-		 * default control pipe
-		 */
-		case USB_DEVICE_U1_ENABLE:
-			if (state != USB_STATE_CONFIGURED)
-				return -EINVAL;
-			if ((dwc->speed != DWC3_DSTS_SUPERSPEED) &&
-			    (dwc->speed != DWC3_DSTS_SUPERSPEED_PLUS))
-				return -EINVAL;
+	return ret;
+}
 
-			reg = dwc3_readl(dwc->regs, DWC3_DCTL);
-			if (set)
-				reg |= DWC3_DCTL_INITU1ENA;
-			else
-				reg &= ~DWC3_DCTL_INITU1ENA;
-			dwc3_writel(dwc->regs, DWC3_DCTL, reg);
-			break;
+static int dwc3_ep0_handle_intf(struct dwc3 *dwc,
+		struct usb_ctrlrequest *ctrl, int set)
+{
+	enum usb_device_state	state;
+	u32			wValue;
+	u32			wIndex;
+	int			ret = 0;
 
-		case USB_DEVICE_U2_ENABLE:
-			if (state != USB_STATE_CONFIGURED)
-				return -EINVAL;
-			if ((dwc->speed != DWC3_DSTS_SUPERSPEED) &&
-			    (dwc->speed != DWC3_DSTS_SUPERSPEED_PLUS))
-				return -EINVAL;
+	wValue = le16_to_cpu(ctrl->wValue);
+	wIndex = le16_to_cpu(ctrl->wIndex);
+	state = dwc->gadget.state;
 
-			reg = dwc3_readl(dwc->regs, DWC3_DCTL);
-			if (set)
-				reg |= DWC3_DCTL_INITU2ENA;
-			else
-				reg &= ~DWC3_DCTL_INITU2ENA;
-			dwc3_writel(dwc->regs, DWC3_DCTL, reg);
-			break;
+	switch (wValue) {
+	case USB_INTRF_FUNC_SUSPEND:
+		if (wIndex & USB_INTRF_FUNC_SUSPEND_LP)
+			/* XXX enable Low power suspend */
+			;
+		if (wIndex & USB_INTRF_FUNC_SUSPEND_RW)
+			/* XXX enable remote wakeup */
+			;
+		break;
+	default:
+		ret = -EINVAL;
+	}
 
-		case USB_DEVICE_LTM_ENABLE:
+	return ret;
+}
+
+static int dwc3_ep0_handle_endpoint(struct dwc3 *dwc,
+		struct usb_ctrlrequest *ctrl, int set)
+{
+	struct dwc3_ep		*dep;
+	enum usb_device_state	state;
+	u32			wValue;
+	u32			wIndex;
+	int			ret;
+
+	wValue = le16_to_cpu(ctrl->wValue);
+	wIndex = le16_to_cpu(ctrl->wIndex);
+	state = dwc->gadget.state;
+
+	switch (wValue) {
+	case USB_ENDPOINT_HALT:
+		dep = dwc3_wIndex_to_dep(dwc, ctrl->wIndex);
+		if (!dep)
 			return -EINVAL;
 
-		case USB_DEVICE_TEST_MODE:
-			if ((wIndex & 0xff) != 0)
-				return -EINVAL;
-			if (!set)
-				return -EINVAL;
-
-			switch (wIndex >> 8) {
-			case TEST_J:
-			case TEST_K:
-			case TEST_SE0_NAK:
-			case TEST_PACKET:
-			case TEST_FORCE_EN:
-				dwc->test_mode_nr = wIndex >> 8;
-				dwc->test_mode = true;
-				break;
-			default:
-				return -EINVAL;
-			}
+		if (set == 0 && (dep->flags & DWC3_EP_WEDGE))
 			break;
-		default:
+
+		ret = __dwc3_gadget_ep_set_halt(dep, set, true);
+		if (ret)
 			return -EINVAL;
-		}
 		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int dwc3_ep0_handle_feature(struct dwc3 *dwc,
+		struct usb_ctrlrequest *ctrl, int set)
+{
+	u32			recip;
+	int			ret;
+	enum usb_device_state	state;
+
+	recip = ctrl->bRequestType & USB_RECIP_MASK;
+	state = dwc->gadget.state;
 
+	switch (recip) {
+	case USB_RECIP_DEVICE:
+		ret = dwc3_ep0_handle_device(dwc, ctrl, set);
+		break;
 	case USB_RECIP_INTERFACE:
-		switch (wValue) {
-		case USB_INTRF_FUNC_SUSPEND:
-			if (wIndex & USB_INTRF_FUNC_SUSPEND_LP)
-				/* XXX enable Low power suspend */
-				;
-			if (wIndex & USB_INTRF_FUNC_SUSPEND_RW)
-				/* XXX enable remote wakeup */
-				;
-			break;
-		default:
-			return -EINVAL;
-		}
+		ret = dwc3_ep0_handle_intf(dwc, ctrl, set);
 		break;
-
 	case USB_RECIP_ENDPOINT:
-		switch (wValue) {
-		case USB_ENDPOINT_HALT:
-			dep = dwc3_wIndex_to_dep(dwc, ctrl->wIndex);
-			if (!dep)
-				return -EINVAL;
-			if (set == 0 && (dep->flags & DWC3_EP_WEDGE))
-				break;
-			ret = __dwc3_gadget_ep_set_halt(dep, set, true);
-			if (ret)
-				return -EINVAL;
-			break;
-		default:
-			return -EINVAL;
-		}
+		ret = dwc3_ep0_handle_endpoint(dwc, ctrl, set);
 		break;
-
 	default:
-		return -EINVAL;
+		ret = -EINVAL;
 	}
 
-	return 0;
+	return ret;
 }
 
 static int dwc3_ep0_set_address(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)