usb: dwc3: gadget: re-factor USB2 test mode to a function

There are some situations were we might need to
enable USB Test Modes without having access to a
Host stack. In such situations we cannot rely
solely on USB Control Messages to enable test
features.

For those cases, we will also allow test mode
to be enabled via debugfs and this patch is a
preparation for that.
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/ep0.c

@@ -315,7 +315,6 @@ static int dwc3_ep0_handle_feature(struct dwc3 *dwc,
 	u32			recip;
 	u32			wValue;
 	u32			wIndex;
-	u32			reg;
 	int			ret;
 	u32			mode;
 
@@ -357,24 +356,12 @@ static int dwc3_ep0_handle_feature(struct dwc3 *dwc,
 				return -EINVAL;
 
 			mode = wIndex >> 8;
-			reg = dwc3_readl(dwc->regs, DWC3_DCTL);
-			reg &= ~DWC3_DCTL_TSTCTRL_MASK;
-
-			switch (mode) {
-			case TEST_J:
-			case TEST_K:
-			case TEST_SE0_NAK:
-			case TEST_PACKET:
-			case TEST_FORCE_EN:
-				reg |= mode << 1;
-				break;
-			default:
-				return -EINVAL;
+			ret = dwc3_gadget_set_test_mode(dwc, mode);
+			if (ret < 0) {
+				dev_dbg(dwc->dev, "Invalid Test #%d\n",
+						mode);
+				return ret;
 			}
-			dwc3_writel(dwc->regs, DWC3_DCTL, reg);
-			break;
-		default:
-			return -EINVAL;
 		}
 		break;
 

drivers/usb/dwc3/gadget.c

@@ -56,6 +56,39 @@
 
 #define	DMA_ADDR_INVALID	(~(dma_addr_t)0)
 
+/**
+ * dwc3_gadget_set_test_mode - Enables USB2 Test Modes
+ * @dwc: pointer to our context structure
+ * @mode: the mode to set (J, K SE0 NAK, Force Enable)
+ *
+ * Caller should take care of locking. This function will
+ * return 0 on success or -EINVAL if wrong Test Selector
+ * is passed
+ */
+int dwc3_gadget_set_test_mode(struct dwc3 *dwc, int mode)
+{
+	u32		reg;
+
+	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+	reg &= ~DWC3_DCTL_TSTCTRL_MASK;
+
+	switch (mode) {
+	case TEST_J:
+	case TEST_K:
+	case TEST_SE0_NAK:
+	case TEST_PACKET:
+	case TEST_FORCE_EN:
+		reg |= mode << 1;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+
+	return 0;
+}
+
 void dwc3_map_buffer_to_dma(struct dwc3_request *req)
 {
 	struct dwc3			*dwc = req->dep->dwc;

drivers/usb/dwc3/gadget.h

@@ -100,6 +100,8 @@ static inline void dwc3_gadget_move_request_queued(struct dwc3_request *req)
 void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
 		int status);
 
+int dwc3_gadget_set_test_mode(struct dwc3 *dwc, int mode);
+
 void dwc3_ep0_interrupt(struct dwc3 *dwc,
 		const struct dwc3_event_depevt *event);
 void dwc3_ep0_out_start(struct dwc3 *dwc);