[PATCH] ARM: dts: stm32: Add arm,no-tick-in-suspend to STM32MP15xx STGEN timer

[PATCH] ARM: dts: stm32: Add arm,no-tick-in-suspend to STM32MP15xx STGEN timer

[Marek Vasut]

STM32MP15xx RM0436 Rev 6 section 46.3 System timer generator (STGEN) states
"
Arm recommends that the system counter is in an always-on power domain.
This is not supported in the current implementation, therefore STGEN should
be saved and restored before Standby mode entry, and restored at Standby
exit by secure software.
...
"
Instead of piling up workarounds in the firmware which is difficult to
update, add "arm,no-tick-in-suspend" DT property into the timer node to
indicate the timer is stopped in suspend, and let the kernel fix the
timer up.

Fixes: 8471a20253eb ("ARM: dts: stm32: add stm32mp157c initial support")
Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-stm32@st-md-mailman.stormreply.com
---
 arch/arm/boot/dts/st/stm32mp151.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/st/stm32mp151.dtsi b/arch/arm/boot/dts/st/stm32mp151.dtsi
index 3b705e7fe5c0d..68846699b26fd 100644
--- a/arch/arm/boot/dts/st/stm32mp151.dtsi
+++ b/arch/arm/boot/dts/st/stm32mp151.dtsi
@@ -50,6 +50,7 @@ timer {
 			     <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(1) | IRQ_TYPE_LEVEL_LOW)>,
 			     <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(1) | IRQ_TYPE_LEVEL_LOW)>;
 		interrupt-parent = <&intc>;
+		arm,no-tick-in-suspend;
 	};
 
 	clocks {
-- 
2.43.0