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