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
  13 static struct pit_reg *cur_pit = (struct pit_reg *)PIT_BASE_ADDR;
  14
  15 DECLARE_GLOBAL_DATA_PTR;
  16
  17 #define TIMER_LOAD_VAL  0xffffffff
  18
  19 static 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
  27 static 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
  35 int 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
  49 unsigned 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
  61 ulong get_timer_masked(void)
  62 {
  63         return tick_to_time(get_ticks());
  64 }
  65
  66 ulong get_timer(ulong base)
  67 {
  68         return get_timer_masked() - base;
  69 }
  70
  71 /* delay x useconds AND preserve advance timstamp value */
  72 void __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  */
  87 ulong get_tbclk(void)
  88 {
  89         return mxc_get_clock(MXC_IPG_CLK);
  90 }