1 files changed, 48 insertions, 0 deletions
diff --git a/arch/riscv/kernel/time.c b/arch/riscv/kernel/time.c
new file mode 100644
index 0000000000..23641e82a9
--- /dev/null
+++ b/arch/riscv/kernel/time.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012 Regents of the University of California
+ * Copyright (C) 2017 SiFive
+ */
+
+#include <linux/acpi.h>
+#include <linux/of_clk.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/delay.h>
+#include <asm/sbi.h>
+#include <asm/processor.h>
+#include <asm/timex.h>
+
+unsigned long riscv_timebase __ro_after_init;
+EXPORT_SYMBOL_GPL(riscv_timebase);
+
+void __init time_init(void)
+{
+	struct device_node *cpu;
+	struct acpi_table_rhct *rhct;
+	acpi_status status;
+	u32 prop;
+
+	if (acpi_disabled) {
+		cpu = of_find_node_by_path("/cpus");
+		if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
+			panic("RISC-V system with no 'timebase-frequency' in DTS\n");
+
+		of_node_put(cpu);
+		riscv_timebase = prop;
+		of_clk_init(NULL);
+	} else {
+		status = acpi_get_table(ACPI_SIG_RHCT, 0, (struct acpi_table_header **)&rhct);
+		if (ACPI_FAILURE(status))
+			panic("RISC-V ACPI system with no RHCT table\n");
+
+		riscv_timebase = rhct->time_base_freq;
+		acpi_put_table((struct acpi_table_header *)rhct);
+	}
+
+	lpj_fine = riscv_timebase / HZ;
+
+	timer_probe();
+
+	tick_setup_hrtimer_broadcast();
+}