arch/sh/lib/time_sh2.c

   1 /*
   2  * Copyright (C) 2007,2008 Nobobuhiro Iwamatsu <iwamatsu@nigauri.org>
   3  * Copyright (C) 2008 Renesas Solutions Corp.
   4  *
   5  * (C) Copyright 2003
   6  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   7  *
   8  * See file CREDITS for list of people who contributed to this
   9  * project.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License as
  13  * published by the Free Software Foundation; either version 2 of
  14  * the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  24  * MA 02111-1307 USA
  25  */
  26
  27 #include <common.h>
  28 #include <asm/io.h>
  29 #include <asm/processor.h>
  30
  31 #define CMT_CMCSR_INIT  0x0001  /* PCLK/32 */
  32 #define CMT_CMCSR_CALIB 0x0000
  33 #define CMT_MAX_COUNTER (0xFFFFFFFF)
  34 #define CMT_TIMER_RESET (0xFFFF)
  35
  36 static vu_long cmt0_timer;
  37
  38 static void cmt_timer_start(unsigned int timer)
  39 {
  40         writew(readw(CMSTR) | 0x01, CMSTR);
  41 }
  42
  43 static void cmt_timer_stop(unsigned int timer)
  44 {
  45         writew(readw(CMSTR) & ~0x01, CMSTR);
  46 }
  47
  48 int timer_init(void)
  49 {
  50         cmt0_timer = 0;
  51         /* Divide clock by 32 */
  52         readw(CMCSR_0);
  53         writew(CMT_CMCSR_INIT, CMCSR_0);
  54
  55         /* User Device 0 only */
  56         cmt_timer_stop(0);
  57         writew(CMT_TIMER_RESET, CMCOR_0);
  58         cmt_timer_start(0);
  59
  60         return 0;
  61 }
  62
  63 unsigned long long get_ticks(void)
  64 {
  65         return cmt0_timer;
  66 }
  67
  68 static vu_long cmcnt = 0;
  69 static unsigned long get_usec (void)
  70 {
  71         ulong data = readw(CMCNT_0);
  72
  73         if (data >= cmcnt)
  74                 cmcnt = data - cmcnt;
  75         else
  76                 cmcnt = (CMT_TIMER_RESET - cmcnt) + data;
  77
  78         if ((cmt0_timer + cmcnt) > CMT_MAX_COUNTER)
  79                 cmt0_timer = ((cmt0_timer + cmcnt) - CMT_MAX_COUNTER);
  80         else
  81                 cmt0_timer += cmcnt;
  82
  83         cmcnt = data;
  84         return cmt0_timer;
  85 }
  86
  87 /* return msec */
  88 ulong get_timer(ulong base)
  89 {
  90         return (get_usec() / 1000) - base;
  91 }
  92
  93 void __udelay(unsigned long usec)
  94 {
  95         unsigned long end = get_usec() + usec;
  96
  97         while (get_usec() < end)
  98                 continue;
  99 }
 100
 101 unsigned long get_tbclk(void)
 102 {
 103         return CONFIG_SYS_HZ;
 104 }