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/mach/time.h>
  24 #include <asm/smp_twd.h>
  25
  26 void __init shmobile_setup_delay(unsigned int max_cpu_core_mhz,
  27                                  unsigned int mult, unsigned int div)
  28 {
  29         /* calculate a worst-case loops-per-jiffy value
  30          * based on maximum cpu core mhz setting and the
  31          * __delay() implementation in arch/arm/lib/delay.S
  32          *
  33          * this will result in a longer delay than expected
  34          * when the cpu core runs on lower frequencies.
  35          */
  36
  37         unsigned int value = (1000000 * mult) / (HZ * div);
  38
  39         if (!preset_lpj)
  40                 preset_lpj = max_cpu_core_mhz * value;
  41 }
  42
  43 static void __init shmobile_late_time_init(void)
  44 {
  45         /*
  46          * Make sure all compiled-in early timers register themselves.
  47          *
  48          * Run probe() for two "earlytimer" devices, these will be the
  49          * clockevents and clocksource devices respectively. In the event
  50          * that only a clockevents device is available, we -ENODEV on the
  51          * clocksource and the jiffies clocksource is used transparently
  52          * instead. No error handling is necessary here.
  53          */
  54         early_platform_driver_register_all("earlytimer");
  55         early_platform_driver_probe("earlytimer", 2, 0);
  56 }
  57
  58 void __init shmobile_earlytimer_init(void)
  59 {
  60         late_time_init = shmobile_late_time_init;
  61 }
  62
  63 static void __init shmobile_timer_init(void)
  64 {
  65 }
  66
  67 struct sys_timer shmobile_timer = {
  68         .init           = shmobile_timer_init,
  69 };