LXR uboot/arch/arm/cpu/arm920t/a320/timer.c

   1/*
   2 * (C) Copyright 2009 Faraday Technology
   3 * Po-Yu Chuang <ratbert@faraday-tech.com>
   4 *
   5 * SPDX-License-Identifier:     GPL-2.0+
   6 */
   7
   8#include <common.h>
   9#include <div64.h>
  10#include <asm/io.h>
  11#include <faraday/ftpmu010.h>
  12#include <faraday/fttmr010.h>
  13
  14DECLARE_GLOBAL_DATA_PTR;
  15
  16#define TIMER_CLOCK     32768
  17#define TIMER_LOAD_VAL  0xffffffff
  18
  19static inline unsigned long long tick_to_time(unsigned long long tick)
  20{
  21        tick *= CONFIG_SYS_HZ;
  22        do_div(tick, gd->arch.timer_rate_hz);
  23
  24        return tick;
  25}
  26
  27static inline unsigned long long usec_to_tick(unsigned long long usec)
  28{
  29        usec *= gd->arch.timer_rate_hz;
  30        do_div(usec, 1000000);
  31
  32        return usec;
  33}
  34
  35int timer_init(void)
  36{
  37        struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
  38        unsigned int cr;
  39
  40        debug("%s()\n", __func__);
  41
  42        /* disable timers */
  43        writel(0, &tmr->cr);
  44
  45        /* use 32768Hz oscillator for RTC, WDT, TIMER */
  46        ftpmu010_32768osc_enable();
  47
  48        /* setup timer */
  49        writel(TIMER_LOAD_VAL, &tmr->timer3_load);
  50        writel(TIMER_LOAD_VAL, &tmr->timer3_counter);
  51        writel(0, &tmr->timer3_match1);
  52        writel(0, &tmr->timer3_match2);
  53
  54        /* we don't want timer to issue interrupts */
  55        writel(FTTMR010_TM3_MATCH1 |
  56               FTTMR010_TM3_MATCH2 |
  57               FTTMR010_TM3_OVERFLOW,
  58               &tmr->interrupt_mask);
  59
  60        cr = readl(&tmr->cr);
  61        cr |= FTTMR010_TM3_CLOCK;       /* use external clock */
  62        cr |= FTTMR010_TM3_ENABLE;
  63        writel(cr, &tmr->cr);
  64
  65        gd->arch.timer_rate_hz = TIMER_CLOCK;
  66        gd->arch.tbu = gd->arch.tbl = 0;
  67
  68        return 0;
  69}
  70
  71/*
  72 * Get the current 64 bit timer tick count
  73 */
  74unsigned long long get_ticks(void)
  75{
  76        struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
  77        ulong now = TIMER_LOAD_VAL - readl(&tmr->timer3_counter);
  78
  79        /* increment tbu if tbl has rolled over */
  80        if (now < gd->arch.tbl)
  81                gd->arch.tbu++;
  82        gd->arch.tbl = now;
  83        return (((unsigned long long)gd->arch.tbu) << 32) | gd->arch.tbl;
  84}
  85
  86void __udelay(unsigned long usec)
  87{
  88        unsigned long long start;
  89        ulong tmo;
  90
  91        start = get_ticks();            /* get current timestamp */
  92        tmo = usec_to_tick(usec);       /* convert usecs to ticks */
  93        while ((get_ticks() - start) < tmo)
  94                ;                       /* loop till time has passed */
  95}
  96
  97/*
  98 * get_timer(base) can be used to check for timeouts or
  99 * to measure elasped time relative to an event:
 100 *
 101 * ulong start_time = get_timer(0) sets start_time to the current
 102 * time value.
 103 * get_timer(start_time) returns the time elapsed since then.
 104 *
 105 * The time is used in CONFIG_SYS_HZ units!
 106 */
 107ulong get_timer(ulong base)
 108{
 109        return tick_to_time(get_ticks()) - base;
 110}
 111
 112/*
 113 * Return the number of timer ticks per second.
 114 */
 115ulong get_tbclk(void)
 116{
 117        return gd->arch.timer_rate_hz;
 118}
 119