usb: gadget: atmel: Add attach/detach support

Add controller attach/detach support by using
usb_gadget_ops.pullup() function.

Signed-off-by: Zixun LI <admin@hifiphile.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20240725153204.358925-7-admin@hifiphile.com
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
diff --git a/drivers/usb/gadget/atmel_usba_udc.c b/drivers/usb/gadget/atmel_usba_udc.c
index ea9ad75..a7b9644 100644
--- a/drivers/usb/gadget/atmel_usba_udc.c
+++ b/drivers/usb/gadget/atmel_usba_udc.c
@@ -506,10 +506,28 @@
 	return 0;
 }
 
+static int usba_udc_pullup(struct usb_gadget *gadget, int is_on)
+{
+	struct usba_udc *udc = to_usba_udc(gadget);
+	u32 ctrl;
+
+	ctrl = usba_readl(udc, CTRL);
+
+	if (is_on)
+		ctrl &= ~USBA_DETACH;
+	else
+		ctrl |= USBA_DETACH;
+
+	usba_writel(udc, CTRL, ctrl);
+
+	return 0;
+}
+
 static const struct usb_gadget_ops usba_udc_ops = {
 	.get_frame		= usba_udc_get_frame,
 	.wakeup			= usba_udc_wakeup,
 	.set_selfpowered	= usba_udc_set_selfpowered,
+	.pullup			= usba_udc_pullup,
 };
 
 static struct usb_endpoint_descriptor usba_ep0_desc = {