[PATCH 1/3] ARM: dts: stm32: update uart4 pin configuration for low power on stm32mp157

From: Erwan Le Ray
Date: Thu May 28 2020 - 03:39:35 EST


Sleep pin configuration is refined for low power modes:
- "sleep" (no wakeup & console suspend enabled): put pins in analog state
to optimize power
- "idle" (wakeup capability): keep Rx pin in alternate function

Signed-off-by: Bich Hemon <bich.hemon@xxxxxx>
Signed-off-by: Erwan Le Ray <erwan.leray@xxxxxx>

diff --git a/arch/arm/boot/dts/stm32mp15-pinctrl.dtsi b/arch/arm/boot/dts/stm32mp15-pinctrl.dtsi
index 7eb858732d6d..7cf535dc05f5 100644
--- a/arch/arm/boot/dts/stm32mp15-pinctrl.dtsi
+++ b/arch/arm/boot/dts/stm32mp15-pinctrl.dtsi
@@ -1648,6 +1648,23 @@
};
};

+ uart4_idle_pins_a: uart4-idle-0 {
+ pins1 {
+ pinmux = <STM32_PINMUX('G', 11, ANALOG)>; /* UART4_TX */
+ };
+ pins2 {
+ pinmux = <STM32_PINMUX('B', 2, AF8)>; /* UART4_RX */
+ bias-disable;
+ };
+ };
+
+ uart4_sleep_pins_a: uart4-sleep-0 {
+ pins {
+ pinmux = <STM32_PINMUX('G', 11, ANALOG)>, /* UART4_TX */
+ <STM32_PINMUX('B', 2, ANALOG)>; /* UART4_RX */
+ };
+ };
+
uart4_pins_b: uart4-1 {
pins1 {
pinmux = <STM32_PINMUX('D', 1, AF8)>; /* UART4_TX */
--
2.17.1