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/clockchips.h>
   9 #include <linux/clocksource.h>
  10 #include <linux/delay.h>
  11 #include <asm/sbi.h>
  12 #include <asm/processor.h>
  13 #include <asm/timex.h>
  14
  15 unsigned long riscv_timebase __ro_after_init;
  16 EXPORT_SYMBOL_GPL(riscv_timebase);
  17
  18 void __init time_init(void)
  19 {
  20         struct device_node *cpu;
  21         u32 prop;
  22
  23         cpu = of_find_node_by_path("/cpus");
  24         if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
  25                 panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n");
  26         of_node_put(cpu);
  27         riscv_timebase = prop;
  28
  29         lpj_fine = riscv_timebase / HZ;
  30
  31         of_clk_init(NULL);
  32         timer_probe();
  33
  34         tick_setup_hrtimer_broadcast();
  35 }
  36
  37 void clocksource_arch_init(struct clocksource *cs)
  38 {
  39 #ifdef CONFIG_GENERIC_GETTIMEOFDAY
  40         cs->vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER;
  41 #else
  42         cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
  43 #endif
  44 }