text: // SPDX-License-Identifier: GPL-2.0+
  /*
   * dfu.c -- dfu command
   *
   * Copyright (C) 2015
   * Lukasz Majewski <l.majewski@majess.pl>
   *
   * Copyright (C) 2012 Samsung Electronics
   * authors: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
   *	    Lukasz Majewski <l.majewski@samsung.com>
   */
  
  #include <common.h>
  #include <watchdog.h>
  #include <dfu.h>
  #include <console.h>
  #include <g_dnl.h>
  #include <usb.h>
  #include <net.h>
  
  int run_usb_dnl_gadget(int usbctrl_index, char *usb_dnl_gadget)
  {
  	bool dfu_reset = false;
  	int ret, i = 0;
  
  	ret = usb_gadget_initialize(usbctrl_index);
  	if (ret) {
  		pr_err("usb_gadget_initialize failed\n");
  		return CMD_RET_FAILURE;
  	}
  	g_dnl_clear_detach();
  	ret = g_dnl_register(usb_dnl_gadget);
  	if (ret) {
  		pr_err("g_dnl_register failed");
  		return CMD_RET_FAILURE;
  	}
  
  	while (1) {
  		if (g_dnl_detach()) {
  			/*
  			 * Check if USB bus reset is performed after detach,
  			 * which indicates that -R switch has been passed to
  			 * dfu-util. In this case reboot the device
  			 */
  			if (dfu_usb_get_reset()) {
  				dfu_reset = true;
  				goto exit;
  			}
  
  			/*
  			 * This extra number of usb_gadget_handle_interrupts()
  			 * calls is necessary to assure correct transmission
  			 * completion with dfu-util
  			 */
  			if (++i == 10000)
  				goto exit;
  		}
  
  		if (ctrlc())
  			goto exit;
  
  		if (dfu_get_defer_flush()) {
  			/*
  			 * Call to usb_gadget_handle_interrupts() is necessary
  			 * to act on ZLP OUT transaction from HOST PC after
  			 * transmitting the whole file.
  			 *
  			 * If this ZLP OUT packet is NAK'ed, the HOST libusb
  			 * function fails after timeout (by default it is set to
  			 * 5 seconds). In such situation the dfu-util program
  			 * exits with error message.
  			 */
  			usb_gadget_handle_interrupts(usbctrl_index);
  			ret = dfu_flush(dfu_get_defer_flush(), NULL, 0, 0);
  			dfu_set_defer_flush(NULL);
  			if (ret) {
  				pr_err("Deferred dfu_flush() failed!");
  				goto exit;
  			}
  		}
  
  		WATCHDOG_RESET();
  		usb_gadget_handle_interrupts(usbctrl_index);
  	}
  exit:
  	g_dnl_unregister();
  	usb_gadget_release(usbctrl_index);
  
  	if (dfu_reset)
  		do_reset(NULL, 0, 0, NULL);
  
  	g_dnl_clear_detach();
  
  	return ret;
  }
  