drivers/misc/winbond_w83627.c

   1 /*
   2  * Copyright (C) 2016 Stefan Roese <sr@denx.de>
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <asm/io.h>
   9 #include <asm/pnp_def.h>
  10
  11 #define WINBOND_ENTRY_KEY       0x87
  12 #define WINBOND_EXIT_KEY        0xaa
  13
  14 /* Enable configuration: pass entry key '0x87' into index port dev twice */
  15 static void pnp_enter_conf_state(u16 dev)
  16 {
  17         u16 port = dev >> 8;
  18
  19         outb(WINBOND_ENTRY_KEY, port);
  20         outb(WINBOND_ENTRY_KEY, port);
  21 }
  22
  23 /* Disable configuration: pass exit key '0xAA' into index port dev */
  24 static void pnp_exit_conf_state(u16 dev)
  25 {
  26         u16 port = dev >> 8;
  27
  28         outb(WINBOND_EXIT_KEY, port);
  29 }
  30
  31 /* Bring up early serial debugging output before the RAM is initialized */
  32 void winbond_enable_serial(uint dev, uint iobase, uint irq)
  33 {
  34         pnp_enter_conf_state(dev);
  35         pnp_set_logical_device(dev);
  36         pnp_set_enable(dev, 0);
  37         pnp_set_iobase(dev, PNP_IDX_IO0, iobase);
  38         pnp_set_irq(dev, PNP_IDX_IRQ0, irq);
  39         pnp_set_enable(dev, 1);
  40         pnp_exit_conf_state(dev);
  41 }