text: /*
   * Copyright (C) ST-Ericsson SA 2011
   *
   * License Terms: GNU General Public License v2
   * Author: Mattias Wallin <mattias.wallin@stericsson.com> for ST-Ericsson
   */
  #include <linux/io.h>
  #include <linux/errno.h>
  #include <linux/clksrc-dbx500-prcmu.h>
  #include <linux/of.h>
  #include <linux/of_address.h>
  
  #include <asm/smp_twd.h>
  
  #include <plat/mtu.h>
  
  #include <mach/setup.h>
  #include <mach/hardware.h>
  #include <mach/irqs.h>
  
  #ifdef CONFIG_HAVE_ARM_TWD
  static DEFINE_TWD_LOCAL_TIMER(u8500_twd_local_timer,
  			      U8500_TWD_BASE, IRQ_LOCALTIMER);
  
  static void __init ux500_twd_init(void)
  {
  	struct twd_local_timer *twd_local_timer;
  	int err;
  
  	/* Use this to switch local timer base if changed in new ASICs */
  	twd_local_timer = &u8500_twd_local_timer;
  
  	if (of_have_populated_dt())
  		twd_local_timer_of_register();
  	else {
  		err = twd_local_timer_register(twd_local_timer);
  		if (err)
  			pr_err("twd_local_timer_register failed %d\n", err);
  	}
  }
  #else
  #define ux500_twd_init()	do { } while(0)
  #endif
  
  const static struct of_device_id prcmu_timer_of_match[] __initconst = {
  	{ .compatible = "stericsson,db8500-prcmu-timer-4", },
  	{ },
  };
  
  static void __init ux500_timer_init(void)
  {
  	void __iomem *mtu_timer_base;
  	void __iomem *prcmu_timer_base;
  	void __iomem *tmp_base;
  	struct device_node *np;
  
  	if (cpu_is_u8500_family()) {
  		mtu_timer_base = __io_address(U8500_MTU0_BASE);
  		prcmu_timer_base = __io_address(U8500_PRCMU_TIMER_4_BASE);
  	} else {
  		ux500_unknown_soc();
  	}
  
  	/* TODO: Once MTU has been DT:ed place code above into else. */
  	if (of_have_populated_dt()) {
  #ifdef CONFIG_OF
  		np = of_find_matching_node(NULL, prcmu_timer_of_match);
  		if (!np)
  #endif
  			goto dt_fail;
  
  		tmp_base = of_iomap(np, 0);
  		if (!tmp_base)
  			goto dt_fail;
  
  		prcmu_timer_base = tmp_base;
  	}
  
  dt_fail:
  	/* Doing it the old fashioned way. */
  
  	/*
  	 * Here we register the timerblocks active in the system.
  	 * Localtimers (twd) is started when both cpu is up and running.
  	 * MTU register a clocksource, clockevent and sched_clock.
  	 * Since the MTU is located in the VAPE power domain
  	 * it will be cleared in sleep which makes it unsuitable.
  	 * We however need it as a timer tick (clockevent)
  	 * during boot to calibrate delay until twd is started.
  	 * RTC-RTT have problems as timer tick during boot since it is
  	 * depending on delay which is not yet calibrated. RTC-RTT is in the
  	 * always-on powerdomain and is used as clockevent instead of twd when
  	 * sleeping.
  	 * The PRCMU timer 4 register a clocksource and
  	 * sched_clock with higher rating then MTU since is always-on.
  	 *
  	 */
  
  	nmdk_timer_init(mtu_timer_base);
  	clksrc_dbx500_prcmu_init(prcmu_timer_base);
  	ux500_twd_init();
  }
  
  static void ux500_timer_reset(void)
  {
  	nmdk_clkevt_reset();
  	nmdk_clksrc_reset();
  }
  
  struct sys_timer ux500_timer = {
  	.init		= ux500_timer_init,
  	.resume		= ux500_timer_reset,
  };
  