arch/riscv/kernel/time.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2012 Regents of the University of California
   4  * Copyright (C) 2017 SiFive
   5  */
   6
   7 #include <linux/clocksource.h>
   8 #include <linux/delay.h>
   9 #include <asm/sbi.h>
  10 #include <asm/processor.h>
  11
  12 unsigned long riscv_timebase;
  13 EXPORT_SYMBOL_GPL(riscv_timebase);
  14
  15 void __init time_init(void)
  16 {
  17         struct device_node *cpu;
  18         u32 prop;
  19
  20         cpu = of_find_node_by_path("/cpus");
  21         if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
  22                 panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n");
  23         of_node_put(cpu);
  24         riscv_timebase = prop;
  25
  26         lpj_fine = riscv_timebase / HZ;
  27         timer_probe();
  28 }
  29
  30 void clocksource_arch_init(struct clocksource *cs)
  31 {
  32 #ifdef CONFIG_GENERIC_GETTIMEOFDAY
  33         cs->vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER;
  34 #else
  35         cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
  36 #endif
  37 }