[PATCH] usb: dwc3: gadget: Fix match_ep callback for NXP UUU tool

[Marek Vasut <marex@denx.de>]

The UUU tool excepts the interrupt-in endpoint to be ep1in, otherwise
it crashes. This is a result of the previous hard-coded EP setup in
drivers/usb/gadget/epautoconf.c which did special-case EP allocation
for SPL builds, and which was since converted to this callback, but
without the special-case EP allocation in SPL part.

This reinstates the SPL part in an isolated manner, only for NXP iMX
SoCs, only for SPL builds, and only for the ep1in interrupt-in endpoint.

Fixes: 1918b8010c32 ("usb: dwc3: gadget: Convert epautoconf workaround to match_ep callback")
Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Lukasz Majewski <lukma@denx.de>
Cc: Marek Vasut <marex@denx.de>
Cc: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Cc: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Cc: Tom Rini <trini@konsulko.com>
Cc: u-boot@lists.denx.de
---
NOTE: This should go into master as a bugfix.
---
 drivers/usb/dwc3/gadget.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index e5a383407a2..477ecd02098 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1631,8 +1631,25 @@ usb_ep *dwc3_gadget_match_ep(struct usb_gadget *gadget,
 		return dwc3_find_ep(gadget, "ep1in");
 	if (usb_endpoint_is_bulk_out(desc))
 		return dwc3_find_ep(gadget, "ep2out");
-	if (usb_endpoint_is_int_in(desc))
+	if (usb_endpoint_is_int_in(desc)) {
+		/*
+		 * Special workaround for NXP UUU tool in SPL.
+		 *
+		 * The tool excepts the interrupt-in endpoint to be ep1in,
+		 * otherwise it crashes. This is a result of the previous
+		 * hard-coded EP setup in drivers/usb/gadget/epautoconf.c
+		 * which did special-case EP allocation for SPL builds,
+		 * and which was since converted to this callback, but
+		 * without the special-case EP allocation in SPL part.
+		 *
+		 * This reinstates the SPL part in an isolated manner,
+		 * only for NXP iMX SoCs, only for SPL builds, and only
+		 * for the ep1in interrupt-in endpoint.
+		 */
+		if (IS_ENABLED(CONFIG_MACH_IMX) && IS_ENABLED(CONFIG_XPL_BUILD))
+			return dwc3_find_ep(gadget, "ep1in");
 		return dwc3_find_ep(gadget, "ep3in");
+	}
 
 	return NULL;
 }
-- 
2.47.2