arch/microblaze/cpu/timer.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2007 Michal Simek
   4  *
   5  * Michal  SIMEK <monstr@monstr.eu>
   6  */
   7
   8 #include <common.h>
   9 #include <fdtdec.h>
  10 #include <time.h>
  11 #include <asm/microblaze_timer.h>
  12 #include <asm/microblaze_intc.h>
  13
  14 DECLARE_GLOBAL_DATA_PTR;
  15
  16 volatile int timestamp = 0;
  17 microblaze_timer_t *tmr;
  18
  19 ulong get_timer (ulong base)
  20 {
  21         if (tmr)
  22                 return timestamp - base;
  23         return timestamp++ - base;
  24 }
  25
  26 void __udelay(unsigned long usec)
  27 {
  28         u32 i;
  29
  30         if (tmr) {
  31                 i = get_timer(0);
  32                 while ((get_timer(0) - i) < (usec / 1000))
  33                         ;
  34         }
  35 }
  36
  37 #ifndef CONFIG_SPL_BUILD
  38 static void timer_isr(void *arg)
  39 {
  40         timestamp++;
  41         tmr->control = tmr->control | TIMER_INTERRUPT;
  42 }
  43
  44 int timer_init (void)
  45 {
  46         int irq = -1;
  47         u32 preload = 0;
  48         u32 ret = 0;
  49         const void *blob = gd->fdt_blob;
  50         int node = 0;
  51         u32 cell[2];
  52
  53         debug("TIMER: Initialization\n");
  54
  55         /* Do not init before relocation */
  56         if (!(gd->flags & GD_FLG_RELOC))
  57                 return 0;
  58
  59         node = fdt_node_offset_by_compatible(blob, node,
  60                                 "xlnx,xps-timer-1.00.a");
  61         if (node != -1) {
  62                 fdt_addr_t base = fdtdec_get_addr(blob, node, "reg");
  63                 if (base == FDT_ADDR_T_NONE)
  64                         return -1;
  65
  66                 debug("TIMER: Base addr %lx\n", base);
  67                 tmr = (microblaze_timer_t *)base;
  68
  69                 ret = fdtdec_get_int_array(blob, node, "interrupts",
  70                                             cell, ARRAY_SIZE(cell));
  71                 if (ret)
  72                         return ret;
  73
  74                 irq = cell[0];
  75                 debug("TIMER: IRQ %x\n", irq);
  76
  77                 preload = fdtdec_get_int(blob, node, "clock-frequency", 0);
  78                 preload /= CONFIG_SYS_HZ;
  79         } else {
  80                 return node;
  81         }
  82
  83         if (tmr && preload && irq >= 0) {
  84                 tmr->loadreg = preload;
  85                 tmr->control = TIMER_INTERRUPT | TIMER_RESET;
  86                 tmr->control = TIMER_ENABLE | TIMER_ENABLE_INTR |\
  87                                         TIMER_RELOAD | TIMER_DOWN_COUNT;
  88                 timestamp = 0;
  89                 ret = install_interrupt_handler (irq, timer_isr, (void *)tmr);
  90                 if (ret)
  91                         tmr = NULL;
  92         }
  93         /* No problem if timer is not found/initialized */
  94         return 0;
  95 }
  96 #else
  97 int timer_init(void)
  98 {
  99         return 0;
 100 }
 101 #endif
 102
 103 /*
 104  * This function is derived from PowerPC code (read timebase as long long).
 105  * On Microblaze it just returns the timer value.
 106  */
 107 unsigned long long get_ticks(void)
 108 {
 109         return get_timer(0);
 110 }
 111
 112 /*
 113  * This function is derived from PowerPC code (timebase clock frequency).
 114  * On Microblaze it returns the number of timer ticks per second.
 115  */
 116 ulong get_tbclk(void)
 117 {
 118         return CONFIG_SYS_HZ;
 119 }