[PATCH 1/3] ARM: dts: at91: sama7g5ek: add suspend voltage for ddr3l rail

From: Claudiu Beznea
Date: Tue Sep 28 2021 - 04:43:24 EST


SAMA7G5-EK board has DDR3L type of memory soldered. This needs 1.35V. The
1.35V for DDR3L rail at run-time is selected by the proper configuration
on SELV2 pin (for 1.35V it needs to be in high-z state). When suspended
the MCP16502 PMIC soldered on SAMA7G5-EK will use different sets of
configuration registers to provide proper voltages on its rail. Run-time
configuration registers could be configured differently than suspend
configuration register for MCP16502 (VSEL2 affects only run-time
configuration). In suspend states the DDR3L memory soldered on SAMA7G5-EK
switches to self-refresh. Even on self-refresh it needs to be powered by
a 1.35V rail. Thus, make sure the PMIC is configured properly when system
is suspended.

Fixes: 7540629e2fc7 (ARM: dts: at91: add sama7g5 SoC DT and sama7g5-ek")
Signed-off-by: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
---
arch/arm/boot/dts/at91-sama7g5ek.dts | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/arm/boot/dts/at91-sama7g5ek.dts b/arch/arm/boot/dts/at91-sama7g5ek.dts
index 4e6bcb7fdfd4..be905eb1da31 100644
--- a/arch/arm/boot/dts/at91-sama7g5ek.dts
+++ b/arch/arm/boot/dts/at91-sama7g5ek.dts
@@ -206,11 +206,13 @@ vddioddr: VDD_DDR {

regulator-state-standby {
regulator-on-in-suspend;
+ regulator-suspend-microvolt = <1350000>;
regulator-mode = <4>;
};

regulator-state-mem {
regulator-on-in-suspend;
+ regulator-suspend-microvolt = <1350000>;
regulator-mode = <4>;
};
};
--
2.25.1