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

   1/*
   2 * Copyright 2013 Freescale Semiconductor, Inc.
   3 *
   4 * This program is free software; you can redistribute it and/or
   5 * modify it under the terms of the GNU General Public License as
   6 * published by the Free Software Foundation; either version 2 of
   7 * the License, or (at your option) any later version.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write to the Free Software
  16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  17 * MA 02111-1307 USA
  18 */
  19
  20#include <common.h>
  21#include <asm/io.h>
  22#include <div64.h>
  23#include <asm/arch/imx-regs.h>
  24#include <asm/arch/clock.h>
  25
  26static struct pit_reg *cur_pit = (struct pit_reg *)PIT_BASE_ADDR;
  27
  28DECLARE_GLOBAL_DATA_PTR;
  29
  30#define TIMER_LOAD_VAL  0xffffffff
  31
  32static inline unsigned long long tick_to_time(unsigned long long tick)
  33{
  34        tick *= CONFIG_SYS_HZ;
  35        do_div(tick, mxc_get_clock(MXC_IPG_CLK));
  36
  37        return tick;
  38}
  39
  40static inline unsigned long long us_to_tick(unsigned long long usec)
  41{
  42        usec = usec * mxc_get_clock(MXC_IPG_CLK)  + 999999;
  43        do_div(usec, 1000000);
  44
  45        return usec;
  46}
  47
  48int timer_init(void)
  49{
  50        __raw_writel(0, &cur_pit->mcr);
  51
  52        __raw_writel(TIMER_LOAD_VAL, &cur_pit->ldval1);
  53        __raw_writel(0, &cur_pit->tctrl1);
  54        __raw_writel(1, &cur_pit->tctrl1);
  55
  56        gd->arch.tbl = 0;
  57        gd->arch.tbu = 0;
  58
  59        return 0;
  60}
  61
  62unsigned long long get_ticks(void)
  63{
  64        ulong now = TIMER_LOAD_VAL - __raw_readl(&cur_pit->cval1);
  65
  66        /* increment tbu if tbl has rolled over */
  67        if (now < gd->arch.tbl)
  68                gd->arch.tbu++;
  69        gd->arch.tbl = now;
  70
  71        return (((unsigned long long)gd->arch.tbu) << 32) | gd->arch.tbl;
  72}
  73
  74ulong get_timer_masked(void)
  75{
  76        return tick_to_time(get_ticks());
  77}
  78
  79ulong get_timer(ulong base)
  80{
  81        return get_timer_masked() - base;
  82}
  83
  84/* delay x useconds AND preserve advance timstamp value */
  85void __udelay(unsigned long usec)
  86{
  87        unsigned long long start;
  88        ulong tmo;
  89
  90        start = get_ticks();                    /* get current timestamp */
  91        tmo = us_to_tick(usec);                 /* convert usecs to ticks */
  92        while ((get_ticks() - start) < tmo)
  93                ;                               /* loop till time has passed */
  94}
  95
  96/*
  97 * This function is derived from PowerPC code (timebase clock frequency).
  98 * On ARM it returns the number of timer ticks per second.
  99 */
 100ulong get_tbclk(void)
 101{
 102        return mxc_get_clock(MXC_IPG_CLK);
 103}
 104