[PATCH v4 3/3] clocksource: timer-riscv: Set CLOCK_EVT_FEAT_C3STOP based on DT

Anup Patel
2022-11-29T14:04:12Z

We should set CLOCK_EVT_FEAT_C3STOP for a clock_event_device only
when riscv,timer-cant-wake-up DT property is present in the RISC-V
timer DT node.

This way CLOCK_EVT_FEAT_C3STOP feature is set for clock_event_device
based on RISC-V platform capabilities rather than having it set for
all RISC-V platforms.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
drivers/clocksource/timer-riscv.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
index 969a552da8d2..0c8bdd168a45 100644
--- a/drivers/clocksource/timer-riscv.c
+++ b/drivers/clocksource/timer-riscv.c
@@ -28,6 +28,7 @@
#include <asm/timex.h>

static DEFINE_STATIC_KEY_FALSE(riscv_sstc_available);
+static bool riscv_timer_cant_wake_cpu;

static int riscv_clock_next_event(unsigned long delta,
struct clock_event_device *ce)
@@ -51,7 +52,7 @@ static int riscv_clock_next_event(unsigned long delta,
static unsigned int riscv_clock_event_irq;
static DEFINE_PER_CPU(struct clock_event_device, riscv_clock_event) = {
.name = "riscv_timer_clockevent",
- .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP,
+ .features = CLOCK_EVT_FEAT_ONESHOT,
.rating = 100,
.set_next_event = riscv_clock_next_event,
};
@@ -85,6 +86,8 @@ static int riscv_timer_starting_cpu(unsigned int cpu)

ce->cpumask = cpumask_of(cpu);
ce->irq = riscv_clock_event_irq;
+ if (riscv_timer_cant_wake_cpu)
+ ce->features |= CLOCK_EVT_FEAT_C3STOP;
clockevents_config_and_register(ce, riscv_timebase, 100, 0x7fffffff);

enable_percpu_irq(riscv_clock_event_irq,
@@ -139,6 +142,13 @@ static int __init riscv_timer_init_dt(struct device_node *n)
if (cpuid != smp_processor_id())
return 0;

+ child = of_find_compatible_node(NULL, NULL, "riscv,timer");
+ if (child) {
+ riscv_timer_cant_wake_cpu = of_property_read_bool(child,
+ "riscv,timer-cant-wake-cpu");
+ of_node_put(child);
+ }
+
domain = NULL;
child = of_get_compatible_child(n, "riscv,cpu-intc");
if (!child) {
--
2.34.1