text: /*
   * Copyright 2008-2011, IBM Corporation
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version
   * 2 of the License, or (at your option) any later version.
   */
  
  #include <linux/kernel.h>
  #include <linux/of.h>
  #include <linux/io.h>
  
  #include "wsp.h"
  
  /*
   * The UART connection to the H8 is over ttyS1 which is just a 16550.
   * We assume that FW has it setup right and no one messes with it.
   */
  
  
  static u8 __iomem *h8;
  
  #define RBR 0		/* Receiver Buffer Register */
  #define THR 0		/* Transmitter Holding Register */
  #define LSR 5		/* Line Status Register */
  #define LSR_DR 0x01	/* LSR value for Data-Ready */
  #define LSR_THRE 0x20	/* LSR value for Transmitter-Holding-Register-Empty */
  static void wsp_h8_putc(int c)
  {
  	u8 lsr;
  
  	do {
  		lsr = readb(h8 + LSR);
  	} while ((lsr & LSR_THRE) != LSR_THRE);
  	writeb(c, h8 + THR);
  }
  
  static int wsp_h8_getc(void)
  {
  	u8 lsr;
  
  	do {
  		lsr = readb(h8 + LSR);
  	} while ((lsr & LSR_DR) != LSR_DR);
  
  	return readb(h8 + RBR);
  }
  
  static void wsp_h8_puts(const char *s, int sz)
  {
  	int i;
  
  	for (i = 0; i < sz; i++) {
  		wsp_h8_putc(s[i]);
  
  		/* no flow control so wait for echo */
  		wsp_h8_getc();
  	}
  	wsp_h8_putc('\r');
  	wsp_h8_putc('\n');
  }
  
  static void wsp_h8_terminal_cmd(const char *cmd, int sz)
  {
  	hard_irq_disable();
  	wsp_h8_puts(cmd, sz);
  	/* should never return, but just in case */
  	for (;;)
  		continue;
  }
  
  
  void wsp_h8_restart(char *cmd)
  {
  	static const char restart[] = "warm-reset";
  
  	(void)cmd;
  	wsp_h8_terminal_cmd(restart, sizeof(restart) - 1);
  }
  
  void wsp_h8_power_off(void)
  {
  	static const char off[] = "power-off";
  
  	wsp_h8_terminal_cmd(off, sizeof(off) - 1);
  }
  
  static void __iomem *wsp_h8_getaddr(void)
  {
  	struct device_node *aliases;
  	struct device_node *uart;
  	struct property *path;
  	void __iomem *va = NULL;
  
  	/*
  	 * there is nothing in the devtree to tell us which is mapped
  	 * to the H8, but se know it is the second serial port.
  	 */
  
  	aliases = of_find_node_by_path("/aliases");
  	if (aliases == NULL)
  		return NULL;
  
  	path = of_find_property(aliases, "serial1", NULL);
  	if (path == NULL)
  		goto out;
  
  	uart = of_find_node_by_path(path->value);
  	if (uart == NULL)
  		goto out;
  
  	va = of_iomap(uart, 0);
  
  	/* remove it so no one messes with it */
  	of_detach_node(uart);
  	of_node_put(uart);
  
  out:
  	of_node_put(aliases);
  
  	return va;
  }
  
  void __init wsp_setup_h8(void)
  {
  	h8 = wsp_h8_getaddr();
  
  	/* Devtree change? lets hard map it anyway */
  	if (h8 == NULL) {
  		pr_warn("UART to H8 could not be found");
  		h8 = ioremap(0xffc0008000ULL, 0x100);
  	}
  }
  