arch/microblaze/cpu/timer.c

   1 /*
   2  * (C) Copyright 2007 Michal Simek
   3  *
   4  * Michal  SIMEK <monstr@monstr.eu>
   5  *
   6  * SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 #include <common.h>
  10 #include <asm/microblaze_timer.h>
  11 #include <asm/microblaze_intc.h>
  12
  13 volatile int timestamp = 0;
  14 microblaze_timer_t *tmr;
  15
  16 ulong get_timer (ulong base)
  17 {
  18         if (tmr)
  19                 return timestamp - base;
  20         return timestamp++ - base;
  21 }
  22
  23 void __udelay(unsigned long usec)
  24 {
  25         u32 i;
  26
  27         if (tmr) {
  28                 i = get_timer(0);
  29                 while ((get_timer(0) - i) < (usec / 1000))
  30                         ;
  31         } else {
  32                 for (i = 0; i < (usec * XILINX_CLOCK_FREQ / 10000000); i++)
  33                         ;
  34         }
  35 }
  36
  37 static void timer_isr(void *arg)
  38 {
  39         timestamp++;
  40         tmr->control = tmr->control | TIMER_INTERRUPT;
  41 }
  42
  43 int timer_init (void)
  44 {
  45         int irq = -1;
  46         u32 preload = 0;
  47         u32 ret = 0;
  48
  49 #if defined(CONFIG_SYS_TIMER_0_ADDR) && defined(CONFIG_SYS_INTC_0_NUM)
  50         preload = XILINX_CLOCK_FREQ / CONFIG_SYS_HZ;
  51         irq = CONFIG_SYS_TIMER_0_IRQ;
  52         tmr = (microblaze_timer_t *) (CONFIG_SYS_TIMER_0_ADDR);
  53 #endif
  54
  55         if (tmr && preload && irq >= 0) {
  56                 tmr->loadreg = preload;
  57                 tmr->control = TIMER_INTERRUPT | TIMER_RESET;
  58                 tmr->control = TIMER_ENABLE | TIMER_ENABLE_INTR |\
  59                                         TIMER_RELOAD | TIMER_DOWN_COUNT;
  60                 timestamp = 0;
  61                 ret = install_interrupt_handler (irq, timer_isr, (void *)tmr);
  62                 if (ret)
  63                         tmr = NULL;
  64         }
  65
  66         /* No problem if timer is not found/initialized */
  67         return 0;
  68 }
  69
  70 /*
  71  * This function is derived from PowerPC code (read timebase as long long).
  72  * On Microblaze it just returns the timer value.
  73  */
  74 unsigned long long get_ticks(void)
  75 {
  76         return get_timer(0);
  77 }
  78
  79 /*
  80  * This function is derived from PowerPC code (timebase clock frequency).
  81  * On Microblaze it returns the number of timer ticks per second.
  82  */
  83 ulong get_tbclk(void)
  84 {
  85         return CONFIG_SYS_HZ;
  86 }