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/of_clk.h>
   8 #include <linux/clocksource.h>
   9 #include <linux/delay.h>
  10 #include <asm/sbi.h>
  11 #include <asm/processor.h>
  12 #include <asm/timex.h>
  13
  14 unsigned long riscv_timebase;
  15 EXPORT_SYMBOL_GPL(riscv_timebase);
  16
  17 void __init time_init(void)
  18 {
  19         struct device_node *cpu;
  20         u32 prop;
  21
  22         cpu = of_find_node_by_path("/cpus");
  23         if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
  24                 panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n");
  25         of_node_put(cpu);
  26         riscv_timebase = prop;
  27
  28         lpj_fine = riscv_timebase / HZ;
  29
  30         of_clk_init(NULL);
  31         timer_probe();
  32 }
  33
  34 void clocksource_arch_init(struct clocksource *cs)
  35 {
  36 #ifdef CONFIG_GENERIC_GETTIMEOFDAY
  37         cs->vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER;
  38 #else
  39         cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
  40 #endif
  41 }