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kernel/linux-imx6_3.14.28/arch/arm/mach-shmobile/timer.c 1.95 KB
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  /*
   * SH-Mobile Timer
   *
   * Copyright (C) 2010  Magnus Damm
   * Copyright (C) 2002 - 2009  Paul Mundt
   *
   * 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; version 2 of the License.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   *
   */
  #include <linux/platform_device.h>
  #include <linux/clocksource.h>
  #include <linux/delay.h>
  
  void __init shmobile_setup_delay(unsigned int max_cpu_core_mhz,
  				 unsigned int mult, unsigned int div)
  {
  	/* calculate a worst-case loops-per-jiffy value
  	 * based on maximum cpu core mhz setting and the
  	 * __delay() implementation in arch/arm/lib/delay.S
  	 *
  	 * this will result in a longer delay than expected
  	 * when the cpu core runs on lower frequencies.
  	 */
  
  	unsigned int value = (1000000 * mult) / (HZ * div);
  
  	if (!preset_lpj)
  		preset_lpj = max_cpu_core_mhz * value;
  }
  
  static void __init shmobile_late_time_init(void)
  {
  	/*
  	 * Make sure all compiled-in early timers register themselves.
  	 *
  	 * Run probe() for two "earlytimer" devices, these will be the
  	 * clockevents and clocksource devices respectively. In the event
  	 * that only a clockevents device is available, we -ENODEV on the
  	 * clocksource and the jiffies clocksource is used transparently
  	 * instead. No error handling is necessary here.
  	 */
  	early_platform_driver_register_all("earlytimer");
  	early_platform_driver_probe("earlytimer", 2, 0);
  }
  
  void __init shmobile_earlytimer_init(void)
  {
  	late_time_init = shmobile_late_time_init;
  }