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/global_data.h>
  14 #include <asm/microblaze_timer.h>
  15 #include <asm/microblaze_intc.h>
  16 #include <linux/delay.h>
  17
  18 DECLARE_GLOBAL_DATA_PTR;
  19
  20 volatile int timestamp = 0;
  21 microblaze_timer_t *tmr;
  22
  23 ulong get_timer (ulong base)
  24 {
  25         if (tmr)
  26                 return timestamp - base;
  27         return timestamp++ - base;
  28 }
  29
  30 void __udelay(unsigned long usec)
  31 {
  32         u32 i;
  33
  34         if (tmr) {
  35                 i = get_timer(0);
  36                 while ((get_timer(0) - i) < (usec / 1000))
  37                         ;
  38         }
  39 }
  40
  41 #ifndef CONFIG_SPL_BUILD
  42 static void timer_isr(void *arg)
  43 {
  44         timestamp++;
  45         tmr->control = tmr->control | TIMER_INTERRUPT;
  46 }
  47
  48 int timer_init (void)
  49 {
  50         int irq = -1;
  51         u32 preload = 0;
  52         u32 ret = 0;
  53         const void *blob = gd->fdt_blob;
  54         int node = 0;
  55         u32 cell[2];
  56
  57         debug("TIMER: Initialization\n");
  58
  59         /* Do not init before relocation */
  60         if (!(gd->flags & GD_FLG_RELOC))
  61                 return 0;
  62
  63         node = fdt_node_offset_by_compatible(blob, node,
  64                                 "xlnx,xps-timer-1.00.a");
  65         if (node != -1) {
  66                 fdt_addr_t base = fdtdec_get_addr(blob, node, "reg");
  67                 if (base == FDT_ADDR_T_NONE)
  68                         return -1;
  69
  70                 debug("TIMER: Base addr %lx\n", base);
  71                 tmr = (microblaze_timer_t *)base;
  72
  73                 ret = fdtdec_get_int_array(blob, node, "interrupts",
  74                                             cell, ARRAY_SIZE(cell));
  75                 if (ret)
  76                         return ret;
  77
  78                 irq = cell[0];
  79                 debug("TIMER: IRQ %x\n", irq);
  80
  81                 preload = fdtdec_get_int(blob, node, "clock-frequency", 0);
  82                 preload /= CONFIG_SYS_HZ;
  83         } else {
  84                 return node;
  85         }
  86
  87         if (tmr && preload && irq >= 0) {
  88                 tmr->loadreg = preload;
  89                 tmr->control = TIMER_INTERRUPT | TIMER_RESET;
  90                 tmr->control = TIMER_ENABLE | TIMER_ENABLE_INTR |\
  91                                         TIMER_RELOAD | TIMER_DOWN_COUNT;
  92                 timestamp = 0;
  93                 ret = install_interrupt_handler (irq, timer_isr, (void *)tmr);
  94                 if (ret)
  95                         tmr = NULL;
  96         }
  97         /* No problem if timer is not found/initialized */
  98         return 0;
  99 }
 100 #else
 101 int timer_init(void)
 102 {
 103         return 0;
 104 }
 105 #endif
 106
 107 /*
 108  * This function is derived from PowerPC code (read timebase as long long).
 109  * On Microblaze it just returns the timer value.
 110  */
 111 unsigned long long get_ticks(void)
 112 {
 113         return get_timer(0);
 114 }
 115
 116 /*
 117  * This function is derived from PowerPC code (timebase clock frequency).
 118  * On Microblaze it returns the number of timer ticks per second.
 119  */
 120 ulong get_tbclk(void)
 121 {
 122         return CONFIG_SYS_HZ;
 123 }