arch/arm/cpu/pxa/timer.c

   1 /*
   2  * (C) Copyright 2002
   3  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   4  * Marius Groeger <mgroeger@sysgo.de>
   5  *
   6  * (C) Copyright 2002
   7  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   8  * Alex Zuepke <azu@sysgo.de>
   9  *
  10  * See file CREDITS for list of people who contributed to this
  11  * project.
  12  *
  13  * This program is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU General Public License as
  15  * published by the Free Software Foundation; either version 2 of
  16  * the License, or (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  26  * MA 02111-1307 USA
  27  */
  28
  29 #include <common.h>
  30 #include <asm/arch/pxa-regs.h>
  31 #include <div64.h>
  32
  33 #ifdef CONFIG_USE_IRQ
  34 #error: interrupts not implemented yet
  35 #endif
  36
  37 #if defined(CONFIG_PXA27X) || defined(CONFIG_CPU_MONAHANS)
  38 #define TIMER_FREQ_HZ 3250000
  39 #elif defined(CONFIG_PXA250)
  40 #define TIMER_FREQ_HZ 3686400
  41 #else
  42 #error "Timer frequency unknown - please config PXA CPU type"
  43 #endif
  44
  45 static inline unsigned long long tick_to_time(unsigned long long tick)
  46 {
  47         tick *= CONFIG_SYS_HZ;
  48         do_div(tick, TIMER_FREQ_HZ);
  49         return tick;
  50 }
  51
  52 static inline unsigned long long us_to_tick(unsigned long long us)
  53 {
  54         us = us * TIMER_FREQ_HZ + 999999;
  55         do_div(us, 1000000);
  56         return us;
  57 }
  58
  59 int timer_init (void)
  60 {
  61         reset_timer();
  62
  63         return 0;
  64 }
  65
  66 void reset_timer (void)
  67 {
  68         reset_timer_masked ();
  69 }
  70
  71 ulong get_timer (ulong base)
  72 {
  73         return get_timer_masked () - base;
  74 }
  75
  76 void set_timer (ulong t)
  77 {
  78         /* nop */
  79 }
  80
  81 void __udelay (unsigned long usec)
  82 {
  83         udelay_masked (usec);
  84 }
  85
  86
  87 void reset_timer_masked (void)
  88 {
  89         OSCR = 0;
  90 }
  91
  92 ulong get_timer_masked (void)
  93 {
  94         return tick_to_time(get_ticks());
  95 }
  96
  97 void udelay_masked (unsigned long usec)
  98 {
  99         unsigned long long tmp;
 100         ulong tmo;
 101
 102         tmo = us_to_tick(usec);
 103         tmp = get_ticks() + tmo;        /* get current timestamp */
 104
 105         while (get_ticks() < tmp)       /* loop till event */
 106                  /*NOP*/;
 107
 108 }
 109
 110 /*
 111  * This function is derived from PowerPC code (read timebase as long long).
 112  * On ARM it just returns the timer value.
 113  */
 114 unsigned long long get_ticks(void)
 115 {
 116         return OSCR;
 117 }
 118
 119 /*
 120  * This function is derived from PowerPC code (timebase clock frequency).
 121  * On ARM it returns the number of timer ticks per second.
 122  */
 123 ulong get_tbclk (void)
 124 {
 125         ulong tbclk;
 126         tbclk = TIMER_FREQ_HZ;
 127         return tbclk;
 128 }