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