arch/arm/mach-shmobile/timer.c

   1 /*
   2  * SH-Mobile Timer
   3  *
   4  * Copyright (C) 2010  Magnus Damm
   5  * Copyright (C) 2002 - 2009  Paul Mundt
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; version 2 of the License.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  */
  21 #include <linux/platform_device.h>
  22 #include <linux/delay.h>
  23 #include <asm/arch_timer.h>
  24 #include <asm/mach/time.h>
  25 #include <asm/smp_twd.h>
  26
  27 void __init shmobile_setup_delay(unsigned int max_cpu_core_mhz,
  28                                  unsigned int mult, unsigned int div)
  29 {
  30         /* calculate a worst-case loops-per-jiffy value
  31          * based on maximum cpu core mhz setting and the
  32          * __delay() implementation in arch/arm/lib/delay.S
  33          *
  34          * this will result in a longer delay than expected
  35          * when the cpu core runs on lower frequencies.
  36          */
  37
  38         unsigned int value = (1000000 * mult) / (HZ * div);
  39
  40         if (!preset_lpj)
  41                 preset_lpj = max_cpu_core_mhz * value;
  42 }
  43
  44 static void __init shmobile_late_time_init(void)
  45 {
  46         /*
  47          * Make sure all compiled-in early timers register themselves.
  48          *
  49          * Run probe() for two "earlytimer" devices, these will be the
  50          * clockevents and clocksource devices respectively. In the event
  51          * that only a clockevents device is available, we -ENODEV on the
  52          * clocksource and the jiffies clocksource is used transparently
  53          * instead. No error handling is necessary here.
  54          */
  55         early_platform_driver_register_all("earlytimer");
  56         early_platform_driver_probe("earlytimer", 2, 0);
  57 }
  58
  59 void __init shmobile_earlytimer_init(void)
  60 {
  61         late_time_init = shmobile_late_time_init;
  62 }
  63
  64 void __init shmobile_timer_init(void)
  65 {
  66         arch_timer_of_register();
  67         arch_timer_sched_clock_init();
  68 }