/*
   * Copyright (C) 2016 Stefan Roese <sr@denx.de>
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #include <common.h>
  #include <asm/io.h>
  #include <asm/pnp_def.h>
  
  #define WINBOND_ENTRY_KEY	0x87
  #define WINBOND_EXIT_KEY	0xaa
  
  /* Enable configuration: pass entry key '0x87' into index port dev twice */
  static void pnp_enter_conf_state(u16 dev)
  {
  	u16 port = dev >> 8;
  
  	outb(WINBOND_ENTRY_KEY, port);
  	outb(WINBOND_ENTRY_KEY, port);
  }
  
  /* Disable configuration: pass exit key '0xAA' into index port dev */
  static void pnp_exit_conf_state(u16 dev)
  {
  	u16 port = dev >> 8;
  
  	outb(WINBOND_EXIT_KEY, port);
  }
  
  /* Bring up early serial debugging output before the RAM is initialized */
  void winbond_enable_serial(uint dev, uint iobase, uint irq)
  {
  	pnp_enter_conf_state(dev);
  	pnp_set_logical_device(dev);
  	pnp_set_enable(dev, 0);
  	pnp_set_iobase(dev, PNP_IDX_IO0, iobase);
  	pnp_set_irq(dev, PNP_IDX_IRQ0, irq);
  	pnp_set_enable(dev, 1);
  	pnp_exit_conf_state(dev);
  }