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

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright 2013 Freescale Semiconductor, Inc.
   4 */
   5
   6#include <common.h>
   7#include <init.h>
   8#include <time.h>
   9#include <asm/global_data.h>
  10#include <asm/io.h>
  11#include <div64.h>
  12#include <asm/arch/imx-regs.h>
  13#include <asm/arch/clock.h>
  14#include <linux/delay.h>
  15
  16static struct pit_reg *cur_pit = (struct pit_reg *)PIT_BASE_ADDR;
  17
  18DECLARE_GLOBAL_DATA_PTR;
  19
  20#define TIMER_LOAD_VAL  0xffffffff
  21
  22static inline unsigned long long tick_to_time(unsigned long long tick)
  23{
  24        tick *= CONFIG_SYS_HZ;
  25        do_div(tick, mxc_get_clock(MXC_IPG_CLK));
  26
  27        return tick;
  28}
  29
  30static inline unsigned long long us_to_tick(unsigned long long usec)
  31{
  32        usec = usec * mxc_get_clock(MXC_IPG_CLK)  + 999999;
  33        do_div(usec, 1000000);
  34
  35        return usec;
  36}
  37
  38int timer_init(void)
  39{
  40        __raw_writel(0, &cur_pit->mcr);
  41
  42        __raw_writel(TIMER_LOAD_VAL, &cur_pit->ldval1);
  43        __raw_writel(0, &cur_pit->tctrl1);
  44        __raw_writel(1, &cur_pit->tctrl1);
  45
  46        gd->arch.tbl = 0;
  47        gd->arch.tbu = 0;
  48
  49        return 0;
  50}
  51
  52unsigned long long get_ticks(void)
  53{
  54        ulong now = TIMER_LOAD_VAL - __raw_readl(&cur_pit->cval1);
  55
  56        /* increment tbu if tbl has rolled over */
  57        if (now < gd->arch.tbl)
  58                gd->arch.tbu++;
  59        gd->arch.tbl = now;
  60
  61        return (((unsigned long long)gd->arch.tbu) << 32) | gd->arch.tbl;
  62}
  63
  64ulong get_timer(ulong base)
  65{
  66        return tick_to_time(get_ticks()) - base;
  67}
  68
  69/* delay x useconds AND preserve advance timstamp value */
  70void __udelay(unsigned long usec)
  71{
  72        unsigned long long start;
  73        ulong tmo;
  74
  75        start = get_ticks();                    /* get current timestamp */
  76        tmo = us_to_tick(usec);                 /* convert usecs to ticks */
  77        while ((get_ticks() - start) < tmo)
  78                ;                               /* loop till time has passed */
  79}
  80
  81/*
  82 * This function is derived from PowerPC code (timebase clock frequency).
  83 * On ARM it returns the number of timer ticks per second.
  84 */
  85ulong get_tbclk(void)
  86{
  87        return mxc_get_clock(MXC_IPG_CLK);
  88}
  89