usb: gadget: net2280: fix use of GPEP in both directions

USB3380 enhanced mode allows GPEP to be used in both IN and OUT
directions. However, IN and OUT endpoints must use same USB endpoint
address (bEndpointAddress). Fix this by setting the ep_cfg.ep_number
during initialization and keep it in net2280_enable()
Tested-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/udc/net2280.c

@@ -144,7 +144,9 @@ net2280_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
 {
 	struct net2280		*dev;
 	struct net2280_ep	*ep;
-	u32			max, tmp;
+	u32			max;
+	u32 tmp = 0;
+	u32 type;
 	unsigned long		flags;
 	static const u32 ep_key[9] = { 1, 0, 1, 0, 1, 1, 0, 1, 0 };
 	int ret = 0;
@@ -200,15 +202,29 @@ net2280_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
 
 	/* set type, direction, address; reset fifo counters */
 	writel(BIT(FIFO_FLUSH), &ep->regs->ep_stat);
-	tmp = (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
-	if (tmp == USB_ENDPOINT_XFER_INT) {
+
+	if ((dev->quirks & PLX_SUPERSPEED) && dev->enhanced_mode) {
+		tmp = readl(&ep->cfg->ep_cfg);
+		/* If USB ep number doesn't match hardware ep number */
+		if ((tmp & 0xf) != usb_endpoint_num(desc)) {
+			ret = -EINVAL;
+			spin_unlock_irqrestore(&dev->lock, flags);
+			goto print_err;
+		}
+		if (ep->is_in)
+			tmp &= ~USB3380_EP_CFG_MASK_IN;
+		else
+			tmp &= ~USB3380_EP_CFG_MASK_OUT;
+	}
+	type = (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
+	if (type == USB_ENDPOINT_XFER_INT) {
 		/* erratum 0105 workaround prevents hs NYET */
 		if (dev->chiprev == 0100 &&
 				dev->gadget.speed == USB_SPEED_HIGH &&
 				!(desc->bEndpointAddress & USB_DIR_IN))
 			writel(BIT(CLEAR_NAK_OUT_PACKETS_MODE),
 				&ep->regs->ep_rsp);
-	} else if (tmp == USB_ENDPOINT_XFER_BULK) {
+	} else if (type == USB_ENDPOINT_XFER_BULK) {
 		/* catch some particularly blatant driver bugs */
 		if ((dev->gadget.speed == USB_SPEED_SUPER && max != 1024) ||
 		    (dev->gadget.speed == USB_SPEED_HIGH && max != 512) ||
@@ -218,10 +234,10 @@ net2280_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
 			goto print_err;
 		}
 	}
-	ep->is_iso = (tmp == USB_ENDPOINT_XFER_ISOC);
+	ep->is_iso = (type == USB_ENDPOINT_XFER_ISOC);
 	/* Enable this endpoint */
 	if (dev->quirks & PLX_LEGACY) {
-		tmp <<= ENDPOINT_TYPE;
+		tmp |= type << ENDPOINT_TYPE;
 		tmp |= desc->bEndpointAddress;
 		/* default full fifo lines */
 		tmp |= (4 << ENDPOINT_BYTE_COUNT);
@@ -230,15 +246,16 @@ net2280_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
 	} else {
 		/* In Legacy mode, only OUT endpoints are used */
 		if (dev->enhanced_mode && ep->is_in) {
-			tmp <<= IN_ENDPOINT_TYPE;
+			tmp |= type << IN_ENDPOINT_TYPE;
 			tmp |= BIT(IN_ENDPOINT_ENABLE);
 		} else {
-			tmp <<= OUT_ENDPOINT_TYPE;
+			tmp |= type << OUT_ENDPOINT_TYPE;
 			tmp |= BIT(OUT_ENDPOINT_ENABLE);
 			tmp |= (ep->is_in << ENDPOINT_DIRECTION);
 		}
 
 		tmp |= (4 << ENDPOINT_BYTE_COUNT);
+		if (!dev->enhanced_mode)
 			tmp |= usb_endpoint_num(desc);
 		tmp |= (ep->ep.maxburst << MAX_BURST_SIZE);
 	}
@@ -2074,6 +2091,12 @@ static void usb_reinit_338x(struct net2280 *dev)
 
 		if (dev->enhanced_mode) {
 			ep->cfg = &dev->epregs[ne[i]];
+			/*
+			 * Set USB endpoint number, hardware allows same number
+			 * in both directions.
+			 */
+			 if (i > 0 && i < 5)
+				writel(ne[i], &ep->cfg->ep_cfg);
 			ep->regs = (struct net2280_ep_regs __iomem *)
 				(((void __iomem *)&dev->epregs[ne[i]]) +
 				ep_reg_addr[i]);

include/linux/usb/usb338x.h

@@ -43,6 +43,10 @@
 #define     IN_ENDPOINT_TYPE                    12
 #define     OUT_ENDPOINT_ENABLE                 10
 #define     OUT_ENDPOINT_TYPE                    8
+#define USB3380_EP_CFG_MASK_IN ((0x3 << IN_ENDPOINT_TYPE) | \
+				BIT(IN_ENDPOINT_ENABLE))
+#define USB3380_EP_CFG_MASK_OUT ((0x3 << OUT_ENDPOINT_TYPE) | \
+				BIT(OUT_ENDPOINT_ENABLE))
 
 struct usb338x_usb_ext_regs {
 	u32     usbclass;