diff options
Diffstat (limited to 'arch/riscv/kernel/time.c')
| -rw-r--r-- | arch/riscv/kernel/time.c | 48 |
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(); +} |