arch/mips/cpu/xburst/timer.c

   1 /*
   2  *  Copyright (c) 2006
   3  *  Ingenic Semiconductor, <jlwei@ingenic.cn>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <config.h>
   9 #include <common.h>
  10 #include <asm/io.h>
  11
  12 #include <asm/jz4740.h>
  13
  14 #define TIMER_CHAN  0
  15 #define TIMER_FDATA 0xffff  /* Timer full data value */
  16
  17 DECLARE_GLOBAL_DATA_PTR;
  18
  19 static struct jz4740_tcu *tcu = (struct jz4740_tcu *)JZ4740_TCU_BASE;
  20
  21 void reset_timer_masked(void)
  22 {
  23         /* reset time */
  24         gd->arch.lastinc = readl(&tcu->tcnt0);
  25         gd->arch.tbl = 0;
  26 }
  27
  28 ulong get_timer_masked(void)
  29 {
  30         ulong now = readl(&tcu->tcnt0);
  31
  32         if (gd->arch.lastinc <= now)
  33                 gd->arch.tbl += now - gd->arch.lastinc; /* normal mode */
  34         else {
  35                 /* we have an overflow ... */
  36                 gd->arch.tbl += TIMER_FDATA + now - gd->arch.lastinc;
  37         }
  38
  39         gd->arch.lastinc = now;
  40
  41         return gd->arch.tbl;
  42 }
  43
  44 void udelay_masked(unsigned long usec)
  45 {
  46         ulong tmo;
  47         ulong endtime;
  48         signed long diff;
  49
  50         /* normalize */
  51         if (usec >= 1000) {
  52                 tmo = usec / 1000;
  53                 tmo *= CONFIG_SYS_HZ;
  54                 tmo /= 1000;
  55         } else {
  56                 if (usec > 1) {
  57                         tmo = usec * CONFIG_SYS_HZ;
  58                         tmo /= 1000*1000;
  59                 } else
  60                         tmo = 1;
  61         }
  62
  63         endtime = get_timer_masked() + tmo;
  64
  65         do {
  66                 ulong now = get_timer_masked();
  67                 diff = endtime - now;
  68         } while (diff >= 0);
  69 }
  70
  71 int timer_init(void)
  72 {
  73         writel(TCU_TCSR_PRESCALE256 | TCU_TCSR_EXT_EN, &tcu->tcsr0);
  74
  75         writel(0, &tcu->tcnt0);
  76         writel(0, &tcu->tdhr0);
  77         writel(TIMER_FDATA, &tcu->tdfr0);
  78
  79         /* mask irqs */
  80         writel((1 << TIMER_CHAN) | (1 << (TIMER_CHAN + 16)), &tcu->tmsr);
  81         writel(1 << TIMER_CHAN, &tcu->tscr); /* enable timer clock */
  82         writeb(1 << TIMER_CHAN, &tcu->tesr); /* start counting up */
  83
  84         gd->arch.lastinc = 0;
  85         gd->arch.tbl = 0;
  86
  87         return 0;
  88 }
  89
  90 void reset_timer(void)
  91 {
  92         reset_timer_masked();
  93 }
  94
  95 ulong get_timer(ulong base)
  96 {
  97         return get_timer_masked() - base;
  98 }
  99
 100 void set_timer(ulong t)
 101 {
 102         gd->arch.tbl = t;
 103 }
 104
 105 void __udelay(unsigned long usec)
 106 {
 107         ulong tmo, tmp;
 108
 109         /* normalize */
 110         if (usec >= 1000) {
 111                 tmo = usec / 1000;
 112                 tmo *= CONFIG_SYS_HZ;
 113                 tmo /= 1000;
 114         } else {
 115                 if (usec >= 1) {
 116                         tmo = usec * CONFIG_SYS_HZ;
 117                         tmo /= 1000 * 1000;
 118                 } else
 119                         tmo = 1;
 120         }
 121
 122         /* check for rollover during this delay */
 123         tmp = get_timer(0);
 124         if ((tmp + tmo) < tmp)
 125                 reset_timer_masked();  /* timer would roll over */
 126         else
 127                 tmo += tmp;
 128
 129         while (get_timer_masked() < tmo)
 130                 ;
 131 }
 132
 133 /*
 134  * This function is derived from PowerPC code (read timebase as long long).
 135  * On MIPS it just returns the timer value.
 136  */
 137 unsigned long long get_ticks(void)
 138 {
 139         return get_timer(0);
 140 }
 141
 142 /*
 143  * This function is derived from PowerPC code (timebase clock frequency).
 144  * On MIPS it returns the number of timer ticks per second.
 145  */
 146 ulong get_tbclk(void)
 147 {
 148         return CONFIG_SYS_HZ;
 149 }