usb: gadget: udc: atmel: implement .pullup callback

Implement udc->pullup callback, so that udc_connect/disconnect work.
This is needed for composite gadget, as it assumes udc_disconnect()
actually works and calls its ->disconnect callback.
Acked-by: Cristian Birsan <cristian.birsan@microchip.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

drivers/usb/gadget/udc/atmel_usba_udc.c

@@ -1028,6 +1028,7 @@ usba_udc_set_selfpowered(struct usb_gadget *gadget, int is_selfpowered)
 	return 0;
 }
 
+static int atmel_usba_pullup(struct usb_gadget *gadget, int is_on);
 static int atmel_usba_start(struct usb_gadget *gadget,
 		struct usb_gadget_driver *driver);
 static int atmel_usba_stop(struct usb_gadget *gadget);
@@ -1101,6 +1102,7 @@ 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			= atmel_usba_pullup,
 	.udc_start		= atmel_usba_start,
 	.udc_stop		= atmel_usba_stop,
 	.match_ep		= atmel_usba_match_ep,
@@ -1957,6 +1959,24 @@ static irqreturn_t usba_vbus_irq_thread(int irq, void *devid)
 	return IRQ_HANDLED;
 }
 
+static int atmel_usba_pullup(struct usb_gadget *gadget, int is_on)
+{
+	struct usba_udc *udc = container_of(gadget, struct usba_udc, gadget);
+	unsigned long flags;
+	u32 ctrl;
+
+	spin_lock_irqsave(&udc->lock, flags);
+	ctrl = usba_readl(udc, CTRL);
+	if (is_on)
+		ctrl &= ~USBA_DETACH;
+	else
+		ctrl |= USBA_DETACH;
+	usba_writel(udc, CTRL, ctrl);
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return 0;
+}
+
 static int atmel_usba_start(struct usb_gadget *gadget,
 		struct usb_gadget_driver *driver)
 {