[PATCH v1 2/3] usb: dwc3: gadget: Add support for snps,reserved-endpoints property

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

The snps,reserved-endpoints property lists the reserved endpoints
that shouldn't be used for normal transfers. Add support for that
to the driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/usb/dwc3/gadget.c | 38 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 31a654c6f15b..3f806fb8b61c 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -3349,14 +3349,50 @@ static int dwc3_gadget_init_endpoint(struct dwc3 *dwc, u8 epnum)
 	return 0;
 }
 
+static int dwc3_gadget_parse_reserved_endpoints(struct dwc3 *dwc, u8 *eps, size_t count)
+{
+	const char *propname = "snps,reserved-endpoints";
+	int ret;
+
+	ret = device_property_count_u8(dwc->dev, propname);
+	if (ret < 0)
+		return 0;
+	if (ret == 0)
+		return 0;
+	if (ret > count) {
+		dev_err(dwc->dev, "too many entries in %s\n", propname);
+		return -EINVAL;
+	}
+
+	count = ret;
+	ret = device_property_read_u8_array(dwc->dev, propname, eps, count);
+	if (ret)
+		dev_err(dwc->dev, "failed to read %s\n", propname);
+
+	return ret;
+}
+
 static int dwc3_gadget_init_endpoints(struct dwc3 *dwc, u8 total)
 {
 	u8				epnum;
+	u8 eps[DWC3_ENDPOINTS_NUM];
+	u8 count, num;
+	int ret;
 
 	INIT_LIST_HEAD(&dwc->gadget->ep_list);
 
+	ret = dwc3_gadget_parse_reserved_endpoints(dwc, eps, ARRAY_SIZE(eps));
+	if (ret < 0)
+		return ret;
+	count = ret;
+
 	for (epnum = 0; epnum < total; epnum++) {
-		int			ret;
+		for (num = 0; num < count; num++) {
+			if (epnum == eps[num])
+				break;
+		}
+		if (num < count)
+			continue;
 
 		ret = dwc3_gadget_init_endpoint(dwc, epnum);
 		if (ret)
-- 
2.43.0.rc1.1336.g36b5255a03ac