diff options
| author | Sunil V L <sunilvl@ventanamicro.com> | 2023-05-15 11:19:26 +0530 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-06-01 08:45:13 -0700 |
| commit | 714aa1d1c8cad1c005bb93a1ba46dfa145ec2e6f (patch) | |
| tree | 47a3d542e509b39206461344061e6a6a4f3fa1db /arch/riscv/kernel/time.c | |
| parent | 21f4f92410dc302b43c6c8307191704ba93c748d (diff) | |
RISC-V: time.c: Add ACPI support for time_init()
On ACPI based platforms, timer related information is
available in RHCT. Add ACPI based probe support to the
timer initialization.
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230515054928.2079268-20-sunilvl@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/kernel/time.c')
| -rw-r--r-- | arch/riscv/kernel/time.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/arch/riscv/kernel/time.c b/arch/riscv/kernel/time.c index babaf3b48ba8..23641e82a9df 100644 --- a/arch/riscv/kernel/time.c +++ b/arch/riscv/kernel/time.c @@ -4,6 +4,7 @@ * Copyright (C) 2017 SiFive */ +#include <linux/acpi.h> #include <linux/of_clk.h> #include <linux/clockchips.h> #include <linux/clocksource.h> @@ -18,17 +19,29 @@ EXPORT_SYMBOL_GPL(riscv_timebase); void __init time_init(void) { struct device_node *cpu; + struct acpi_table_rhct *rhct; + acpi_status status; u32 prop; - cpu = of_find_node_by_path("/cpus"); - if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop)) - panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n"); - of_node_put(cpu); - riscv_timebase = 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; - of_clk_init(NULL); timer_probe(); tick_setup_hrtimer_broadcast(); |