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