text: /*
   * (C) Copyright 2013
   * David Feng <fenghua@phytium.com.cn>
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #include <common.h>
  #include <command.h>
  #include <asm/system.h>
  
  DECLARE_GLOBAL_DATA_PTR;
  
  /*
   * Generic timer implementation of get_tbclk()
   */
  unsigned long get_tbclk(void)
  {
  	unsigned long cntfrq;
  	asm volatile("mrs %0, cntfrq_el0" : "=r" (cntfrq));
  	return cntfrq;
  }
  
  /*
   * Generic timer implementation of timer_read_counter()
   */
  unsigned long timer_read_counter(void)
  {
  	unsigned long cntpct;
  #ifdef CONFIG_SYS_FSL_ERRATUM_A008585
  	/* This erratum number needs to be confirmed to match ARM document */
  	unsigned long temp;
  #endif
  	isb();
  	asm volatile("mrs %0, cntpct_el0" : "=r" (cntpct));
  #ifdef CONFIG_SYS_FSL_ERRATUM_A008585
  	asm volatile("mrs %0, cntpct_el0" : "=r" (temp));
  	while (temp != cntpct) {
  		asm volatile("mrs %0, cntpct_el0" : "=r" (cntpct));
  		asm volatile("mrs %0, cntpct_el0" : "=r" (temp));
  	}
  #endif
  	return cntpct;
  }
  
  unsigned long long get_ticks(void)
  {
  	unsigned long ticks = timer_read_counter();
  
  	gd->arch.tbl = ticks;
  
  	return ticks;
  }
  
  unsigned long usec2ticks(unsigned long usec)
  {
  	ulong ticks;
  	if (usec < 1000)
  		ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
  	else
  		ticks = ((usec / 10) * (get_tbclk() / 100000));
  
  	return ticks;
  }
  