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 <init.h>
  11 #include <log.h>
  12 #include <time.h>
  13 #include <asm/microblaze_timer.h>
  14 #include <asm/microblaze_intc.h>
  15 #include <linux/delay.h>
  16
  17 DECLARE_GLOBAL_DATA_PTR;
  18
  19 volatile int timestamp = 0;
  20 microblaze_timer_t *tmr;
  21
  22 ulong get_timer (ulong base)
  23 {
  24         if (tmr)
  25                 return timestamp - base;
  26         return timestamp++ - base;
  27 }
  28
  29 void __udelay(unsigned long usec)
  30 {
  31         u32 i;
  32
  33         if (tmr) {
  34                 i = get_timer(0);
  35                 while ((get_timer(0) - i) < (usec / 1000))
  36                         ;
  37         }
  38 }
  39
  40 #ifndef CONFIG_SPL_BUILD
  41 static void timer_isr(void *arg)
  42 {
  43         timestamp++;
  44         tmr->control = tmr->control | TIMER_INTERRUPT;
  45 }
  46
  47 int timer_init (void)
  48 {
  49         int irq = -1;
  50         u32 preload = 0;
  51         u32 ret = 0;
  52         const void *blob = gd->fdt_blob;
  53         int node = 0;
  54         u32 cell[2];
  55
  56         debug("TIMER: Initialization\n");
  57
  58         /* Do not init before relocation */
  59         if (!(gd->flags & GD_FLG_RELOC))
  60                 return 0;
  61
  62         node = fdt_node_offset_by_compatible(blob, node,
  63                                 "xlnx,xps-timer-1.00.a");
  64         if (node != -1) {
  65                 fdt_addr_t base = fdtdec_get_addr(blob, node, "reg");
  66                 if (base == FDT_ADDR_T_NONE)
  67                         return -1;
  68
  69                 debug("TIMER: Base addr %lx\n", base);
  70                 tmr = (microblaze_timer_t *)base;
  71
  72                 ret = fdtdec_get_int_array(blob, node, "interrupts",
  73                                             cell, ARRAY_SIZE(cell));
  74                 if (ret)
  75                         return ret;
  76
  77                 irq = cell[0];
  78                 debug("TIMER: IRQ %x\n", irq);
  79
  80                 preload = fdtdec_get_int(blob, node, "clock-frequency", 0);
  81                 preload /= CONFIG_SYS_HZ;
  82         } else {
  83                 return node;
  84         }
  85
  86         if (tmr && preload && irq >= 0) {
  87                 tmr->loadreg = preload;
  88                 tmr->control = TIMER_INTERRUPT | TIMER_RESET;
  89                 tmr->control = TIMER_ENABLE | TIMER_ENABLE_INTR |\
  90                                         TIMER_RELOAD | TIMER_DOWN_COUNT;
  91                 timestamp = 0;
  92                 ret = install_interrupt_handler (irq, timer_isr, (void *)tmr);
  93                 if (ret)
  94                         tmr = NULL;
  95         }
  96         /* No problem if timer is not found/initialized */
  97         return 0;
  98 }
  99 #else
 100 int timer_init(void)
 101 {
 102         return 0;
 103 }
 104 #endif
 105
 106 /*
 107  * This function is derived from PowerPC code (read timebase as long long).
 108  * On Microblaze it just returns the timer value.
 109  */
 110 unsigned long long get_ticks(void)
 111 {
 112         return get_timer(0);
 113 }
 114
 115 /*
 116  * This function is derived from PowerPC code (timebase clock frequency).
 117  * On Microblaze it returns the number of timer ticks per second.
 118  */
 119 ulong get_tbclk(void)
 120 {
 121         return CONFIG_SYS_HZ;
 122 }