mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-28 13:22:57 +00:00
Code Issues Releases Wiki Activity

clocksource/drivers/exynos_mct: Support frc-shared property

Browse source 
When the FRC is shared with another main processor, the other processor
is assumed to have started it and this processor should not write to the
global registers.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/20220609112738.359385-3-vincent.whitchurch@axis.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
This commit is contained in:
Vincent Whitchurch 2022-06-09 13:27:36 +02:00 committed by Daniel Lezcano
parent 99b701fd27
commit e8550f0e7b
1 changed files with 18 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

21
drivers/clocksource/exynos_mct.c
View file

@ -233,9 +233,16 @@ static cycles_t exynos4_read_current_timer(void)
} }
#endif #endif
static int __init exynos4_clocksource_init(void) static int __init exynos4_clocksource_init(bool frc_shared)
{ {
exynos4_mct_frc_start(); /*
* When the frc is shared, the main processer should have already
* turned it on and we shouldn't be writing to TCON.
*/
if (frc_shared)
mct_frc.resume = NULL;
else
exynos4_mct_frc_start();
#if defined(CONFIG_ARM) #if defined(CONFIG_ARM)
exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer; exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer;
@ -605,6 +612,7 @@ static int __init exynos4_timer_interrupts(struct device_node *np,
static int __init mct_init_dt(struct device_node *np, unsigned int int_type) static int __init mct_init_dt(struct device_node *np, unsigned int int_type)
{ {
bool frc_shared = of_property_read_bool(np, "samsung,frc-shared");
int ret; int ret;
ret = exynos4_timer_resources(np); ret = exynos4_timer_resources(np);
@ -615,10 +623,17 @@ static int __init mct_init_dt(struct device_node *np, unsigned int int_type)
if (ret) if (ret)
return ret; return ret;
ret = exynos4_clocksource_init(); ret = exynos4_clocksource_init(frc_shared);
if (ret) if (ret)
return ret; return ret;
/*
* When the FRC is shared with a main processor, this secondary
* processor cannot use the global comparator.
*/
if (frc_shared)
return ret;
return exynos4_clockevent_init(); return exynos4_clockevent_init();
} }