[PATCH v4 4/6] clocksource: exynos_mct: Add arch_timer cooperation mode for ARM64

From: Marek Szyprowski
Date: Thu Oct 18 2018 - 05:57:50 EST

To get ARM Architected Timers working on Samsung Exynos SoCs, one has to
first configure and enable Exynos Multi-Core Timer, because they both
share some common hardware blocks (global system counter). This patch
adds a mode of cooperation with arch_timer driver, so kernel can use
CP15 based timer interface via arch_timer driver, which is mandatory
on ARM64. In such mode MCT driver only enables its clocks and starts
global timer. Everything else will be handled by arch_timer driver.

Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Reviewed-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
Tested-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
drivers/clocksource/exynos_mct.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
index 4c886ff2941a..1f5249fb25fd 100644
--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c
@@ -606,6 +606,16 @@ static int __init mct_init_dt(struct device_node *np, unsigned int int_type)
if (ret)
return ret;

+ struct device_node *np = of_find_compatible_node(NULL, NULL,
+ "arm,armv8-timer");
+ if (np) {
+ of_node_put(np);
+ exynos4_mct_frc_start();
+ return 0;
+ }
+ }
ret = exynos4_timer_interrupts(np, int_type);
if (ret)
return ret;