LXR uboot/arch/arm/cpu/armv7/vf610/timer.c

   1/*
   2 * Copyright 2013 Freescale Semiconductor, Inc.
   3 *
   4 * SPDX-License-Identifier:     GPL-2.0+
   5 */
   6
   7#include <common.h>
   8#include <asm/io.h>
   9#include <div64.h>
  10#include <asm/arch/imx-regs.h>
  11#include <asm/arch/clock.h>
  12
  13static struct pit_reg *cur_pit = (struct pit_reg *)PIT_BASE_ADDR;
  14
  15DECLARE_GLOBAL_DATA_PTR;
  16
  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, mxc_get_clock(MXC_IPG_CLK));
  23
  24        return tick;
  25}
  26
  27static inline unsigned long long us_to_tick(unsigned long long usec)
  28{
  29        usec = usec * mxc_get_clock(MXC_IPG_CLK)  + 999999;
  30        do_div(usec, 1000000);
  31
  32        return usec;
  33}
  34
  35int timer_init(void)
  36{
  37        __raw_writel(0, &cur_pit->mcr);
  38
  39        __raw_writel(TIMER_LOAD_VAL, &cur_pit->ldval1);
  40        __raw_writel(0, &cur_pit->tctrl1);
  41        __raw_writel(1, &cur_pit->tctrl1);
  42
  43        gd->arch.tbl = 0;
  44        gd->arch.tbu = 0;
  45
  46        return 0;
  47}
  48
  49unsigned long long get_ticks(void)
  50{
  51        ulong now = TIMER_LOAD_VAL - __raw_readl(&cur_pit->cval1);
  52
  53        /* increment tbu if tbl has rolled over */
  54        if (now < gd->arch.tbl)
  55                gd->arch.tbu++;
  56        gd->arch.tbl = now;
  57
  58        return (((unsigned long long)gd->arch.tbu) << 32) | gd->arch.tbl;
  59}
  60
  61ulong get_timer_masked(void)
  62{
  63        return tick_to_time(get_ticks());
  64}
  65
  66ulong get_timer(ulong base)
  67{
  68        return get_timer_masked() - base;
  69}
  70
  71/* delay x useconds AND preserve advance timstamp value */
  72void __udelay(unsigned long usec)
  73{
  74        unsigned long long start;
  75        ulong tmo;
  76
  77        start = get_ticks();                    /* get current timestamp */
  78        tmo = us_to_tick(usec);                 /* convert usecs to ticks */
  79        while ((get_ticks() - start) < tmo)
  80                ;                               /* loop till time has passed */
  81}
  82
  83/*
  84 * This function is derived from PowerPC code (timebase clock frequency).
  85 * On ARM it returns the number of timer ticks per second.
  86 */
  87ulong get_tbclk(void)
  88{
  89        return mxc_get_clock(MXC_IPG_CLK);
  90}
  91