/*
   * omap2-restart.c - code common to all OMAP2xxx machines.
   *
   * Copyright (C) 2012 Texas Instruments
   * Paul Walmsley
   *
   * 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/init.h>
  #include <linux/clk.h>
  #include <linux/io.h>
  
  #include "soc.h"
  #include "common.h"
  #include "prm2xxx.h"
  
  /*
   * reset_virt_prcm_set_ck, reset_sys_ck: pointers to the virt_prcm_set
   * clock and the sys_ck.  Used during the reset process
   */
  static struct clk *reset_virt_prcm_set_ck, *reset_sys_ck;
  
  /* Reboot handling */
  
  /**
   * omap2xxx_restart - Set DPLL to bypass mode for reboot to work
   *
   * Set the DPLL to bypass so that reboot completes successfully.  No
   * return value.
   */
  void omap2xxx_restart(enum reboot_mode mode, const char *cmd)
  {
  	u32 rate;
  
  	rate = clk_get_rate(reset_sys_ck);
  	clk_set_rate(reset_virt_prcm_set_ck, rate);
  
  	/* XXX Should save the cmd argument for use after the reboot */
  
  	omap2xxx_prm_dpll_reset(); /* never returns */
  	while (1);
  }
  
  /**
   * omap2xxx_common_look_up_clks_for_reset - look up clocks needed for restart
   *
   * Some clocks need to be looked up in advance for the SoC restart
   * operation to work - see omap2xxx_restart().  Returns -EINVAL upon
   * error or 0 upon success.
   */
  static int __init omap2xxx_common_look_up_clks_for_reset(void)
  {
  	reset_virt_prcm_set_ck = clk_get(NULL, "virt_prcm_set");
  	if (IS_ERR(reset_virt_prcm_set_ck))
  		return -EINVAL;
  
  	reset_sys_ck = clk_get(NULL, "sys_ck");
  	if (IS_ERR(reset_sys_ck))
  		return -EINVAL;
  
  	return 0;
  }
  omap_core_initcall(omap2xxx_common_look_up_clks_for_reset);