[PATCH 07/10] ARM: dts: stm32: update uart4 pin configurations for low power

From: Erwan Le Ray
Date: Tue Jun 04 2019 - 05:16:16 EST


Currently, pinctrl states defines only one "sleep" configuration for pins,
no matter the possible uart low power modes (Rx pin always kept active).

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
- "default" state remains untouched, to be used while the UART is active
or in case the no_console_suspend mode is enabled

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

diff --git a/arch/arm/boot/dts/stm32mp157-pinctrl.dtsi b/arch/arm/boot/dts/stm32mp157-pinctrl.dtsi
index 85c417d..2e1ab1b 100644
--- a/arch/arm/boot/dts/stm32mp157-pinctrl.dtsi
+++ b/arch/arm/boot/dts/stm32mp157-pinctrl.dtsi
@@ -599,6 +599,23 @@
bias-disable;
};
};
+
+ 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 */
+ };
+ };
};

pinctrl_z: pin-controller-z@54004000 {
--
1.9.1