text: /*
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/delay.h>
  #include <linux/gpio.h>
  #include <linux/io.h>
  #include <asm/proc-fns.h>
  #include <asm/system_misc.h>
  
  #include <mach/regs-ost.h>
  #include <mach/reset.h>
  #include <mach/smemc.h>
  
  unsigned int reset_status;
  EXPORT_SYMBOL(reset_status);
  
  static void do_hw_reset(void);
  
  static int reset_gpio = -1;
  
  int init_gpio_reset(int gpio, int output, int level)
  {
  	int rc;
  
  	rc = gpio_request(gpio, "reset generator");
  	if (rc) {
  		printk(KERN_ERR "Can't request reset_gpio\n");
  		goto out;
  	}
  
  	if (output)
  		rc = gpio_direction_output(gpio, level);
  	else
  		rc = gpio_direction_input(gpio);
  	if (rc) {
  		printk(KERN_ERR "Can't configure reset_gpio\n");
  		gpio_free(gpio);
  		goto out;
  	}
  
  out:
  	if (!rc)
  		reset_gpio = gpio;
  
  	return rc;
  }
  
  /*
   * Trigger GPIO reset.
   * This covers various types of logic connecting gpio pin
   * to RESET pins (nRESET or GPIO_RESET):
   */
  static void do_gpio_reset(void)
  {
  	BUG_ON(reset_gpio == -1);
  
  	/* drive it low */
  	gpio_direction_output(reset_gpio, 0);
  	mdelay(2);
  	/* rising edge or drive high */
  	gpio_set_value(reset_gpio, 1);
  	mdelay(2);
  	/* falling edge */
  	gpio_set_value(reset_gpio, 0);
  
  	/* give it some time */
  	mdelay(10);
  
  	WARN_ON(1);
  	/* fallback */
  	do_hw_reset();
  }
  
  static void do_hw_reset(void)
  {
  	/* Initialize the watchdog and let it fire */
  	writel_relaxed(OWER_WME, OWER);
  	writel_relaxed(OSSR_M3, OSSR);
  	/* ... in 100 ms */
  	writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3);
  	/*
  	 * SDRAM hangs on watchdog reset on Marvell PXA270 (erratum 71)
  	 * we put SDRAM into self-refresh to prevent that
  	 */
  	while (1)
  		writel_relaxed(MDREFR_SLFRSH, MDREFR);
  }
  
  void pxa_restart(char mode, const char *cmd)
  {
  	local_irq_disable();
  	local_fiq_disable();
  
  	clear_reset_status(RESET_STATUS_ALL);
  
  	switch (mode) {
  	case 's':
  		/* Jump into ROM at address 0 */
  		soft_restart(0);
  		break;
  	case 'g':
  		do_gpio_reset();
  		break;
  	case 'h':
  	default:
  		do_hw_reset();
  		break;
  	}
  }
  