lib_m68k/time.c

   1 /*
   2  * (C) Copyright 2003 Josef Baumgartner <josef.baumgartner@telex.de>
   3  *
   4  * (C) Copyright 2000
   5  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   6  *
   7  * See file CREDITS for list of people who contributed to this
   8  * project.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation; either version 2 of
  13  * the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  23  * MA 02111-1307 USA
  24  */
  25
  26 #include <common.h>
  27
  28 #include <asm/timer.h>
  29 #include <asm/immap.h>
  30
  31 DECLARE_GLOBAL_DATA_PTR;
  32
  33 static ulong timestamp;
  34
  35 #if defined(CONFIG_MCFTMR)
  36 #ifndef CFG_UDELAY_BASE
  37 #       error   "uDelay base not defined!"
  38 #endif
  39
  40 #if !defined(CFG_TMR_BASE) || !defined(CFG_INTR_BASE) || !defined(CFG_TMRINTR_NO) || !defined(CFG_TMRINTR_MASK)
  41 #       error   "TMR_BASE, INTR_BASE, TMRINTR_NO or TMRINTR_MASk not defined!"
  42 #endif
  43 extern void dtimer_intr_setup(void);
  44
  45 void udelay(unsigned long usec)
  46 {
  47         volatile dtmr_t *timerp = (dtmr_t *) (CFG_UDELAY_BASE);
  48         uint start, now, tmp;
  49
  50         while (usec > 0) {
  51                 if (usec > 65000)
  52                         tmp = 65000;
  53                 else
  54                         tmp = usec;
  55                 usec = usec - tmp;
  56
  57                 /* Set up TIMER 3 as timebase clock */
  58                 timerp->tmr = DTIM_DTMR_RST_RST;
  59                 timerp->tcn = 0;
  60                 /* set period to 1 us */
  61                 timerp->tmr =
  62                     CFG_TIMER_PRESCALER | DTIM_DTMR_CLK_DIV1 | DTIM_DTMR_FRR |
  63                     DTIM_DTMR_RST_EN;
  64
  65                 start = now = timerp->tcn;
  66                 while (now < start + tmp)
  67                         now = timerp->tcn;
  68         }
  69 }
  70
  71 void dtimer_interrupt(void *not_used)
  72 {
  73         volatile dtmr_t *timerp = (dtmr_t *) (CFG_TMR_BASE);
  74
  75         /* check for timer interrupt asserted */
  76         if ((CFG_TMRPND_REG & CFG_TMRINTR_MASK) == CFG_TMRINTR_PEND) {
  77                 timerp->ter = (DTIM_DTER_CAP | DTIM_DTER_REF);
  78                 timestamp++;
  79                 return;
  80         }
  81 }
  82
  83 void timer_init(void)
  84 {
  85         volatile dtmr_t *timerp = (dtmr_t *) (CFG_TMR_BASE);
  86
  87         timestamp = 0;
  88
  89         timerp->tcn = 0;
  90         timerp->trr = 0;
  91
  92         /* Set up TIMER 4 as clock */
  93         timerp->tmr = DTIM_DTMR_RST_RST;
  94
  95         /* initialize and enable timer interrupt */
  96         irq_install_handler(CFG_TMRINTR_NO, dtimer_interrupt, 0);
  97
  98         timerp->tcn = 0;
  99         timerp->trr = 1000;     /* Interrupt every ms */
 100
 101         dtimer_intr_setup();
 102
 103         /* set a period of 1us, set timer mode to restart and enable timer and interrupt */
 104         timerp->tmr = CFG_TIMER_PRESCALER | DTIM_DTMR_CLK_DIV1 |
 105             DTIM_DTMR_FRR | DTIM_DTMR_ORRI | DTIM_DTMR_RST_EN;
 106 }
 107
 108 void reset_timer(void)
 109 {
 110         timestamp = 0;
 111 }
 112
 113 ulong get_timer(ulong base)
 114 {
 115         return (timestamp - base);
 116 }
 117
 118 void set_timer(ulong t)
 119 {
 120         timestamp = t;
 121 }
 122 #endif                          /* CONFIG_MCFTMR */
 123
 124 #if defined(CONFIG_MCFPIT)
 125 #if !defined(CFG_PIT_BASE)
 126 #       error   "CFG_PIT_BASE not defined!"
 127 #endif
 128
 129 static unsigned short lastinc;
 130
 131 void udelay(unsigned long usec)
 132 {
 133         volatile pit_t *timerp = (pit_t *) (CFG_UDELAY_BASE);
 134         uint tmp;
 135
 136         while (usec > 0) {
 137                 if (usec > 65000)
 138                         tmp = 65000;
 139                 else
 140                         tmp = usec;
 141                 usec = usec - tmp;
 142
 143                 /* Set up TIMER 3 as timebase clock */
 144                 timerp->pcsr = PIT_PCSR_OVW;
 145                 timerp->pmr = 0;
 146                 /* set period to 1 us */
 147                 timerp->pcsr |= PIT_PCSR_PRE(CFG_PIT_PRESCALE) | PIT_PCSR_EN;
 148
 149                 timerp->pmr = tmp;
 150                 while (timerp->pcntr > 0) ;
 151         }
 152 }
 153
 154 void timer_init(void)
 155 {
 156         volatile pit_t *timerp = (pit_t *) (CFG_PIT_BASE);
 157         timestamp = 0;
 158
 159         /* Set up TIMER 4 as poll clock */
 160         timerp->pcsr = PIT_PCSR_OVW;
 161         timerp->pmr = lastinc = 0;
 162         timerp->pcsr |= PIT_PCSR_PRE(CFG_PIT_PRESCALE) | PIT_PCSR_EN;
 163 }
 164
 165 void set_timer(ulong t)
 166 {
 167         volatile pit_t *timerp = (pit_t *) (CFG_PIT_BASE);
 168
 169         timestamp = 0;
 170         timerp->pmr = lastinc = 0;
 171 }
 172
 173 ulong get_timer(ulong base)
 174 {
 175         unsigned short now, diff;
 176         volatile pit_t *timerp = (pit_t *) (CFG_PIT_BASE);
 177
 178         now = timerp->pcntr;
 179         diff = -(now - lastinc);
 180
 181         timestamp += diff;
 182         lastinc = now;
 183         return timestamp - base;
 184 }
 185
 186 void wait_ticks(unsigned long ticks)
 187 {
 188         set_timer(0);
 189         while (get_timer(0) < ticks) ;
 190 }
 191 #endif                          /* CONFIG_MCFPIT */
 192
 193 /*
 194  * This function is derived from PowerPC code (read timebase as long long).
 195  * On M68K it just returns the timer value.
 196  */
 197 unsigned long long get_ticks(void)
 198 {
 199         return get_timer(0);
 200 }
 201
 202 /*
 203  * This function is derived from PowerPC code (timebase clock frequency).
 204  * On M68K it returns the number of timer ticks per second.
 205  */
 206 ulong get_tbclk(void)
 207 {
 208         ulong tbclk;
 209         tbclk = CFG_HZ;
 210         return tbclk;
 211 }