stm32mp1: add pull-up for gpio button PA13 and PA14
When a push-button is released and PA13/PA14 are defined as input (high-Z)
the LED should not be active as the circuit is open but a small current
leak through PCB or push-button close the circuit and allows a small LED
bias giving erroneous level voltage.
So it is recommended to activate an internal pull-up in order to clearly
fix the voltage at PA13/PA14 when button is released and to wait
a short delay before to read the GPIO value only when the pull-up is
correctly configured.
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
diff --git a/arch/arm/dts/stm32mp157c-ed1-u-boot.dtsi b/arch/arm/dts/stm32mp157c-ed1-u-boot.dtsi
index 46a4337..fc6066a 100644
--- a/arch/arm/dts/stm32mp157c-ed1-u-boot.dtsi
+++ b/arch/arm/dts/stm32mp157c-ed1-u-boot.dtsi
@@ -16,8 +16,8 @@
u-boot,boot-led = "heartbeat";
u-boot,error-led = "error";
u-boot,mmc-env-partition = "ssbl";
- st,fastboot-gpios = <&gpioa 13 GPIO_ACTIVE_LOW>;
- st,stm32prog-gpios = <&gpioa 14 GPIO_ACTIVE_LOW>;
+ st,fastboot-gpios = <&gpioa 13 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
+ st,stm32prog-gpios = <&gpioa 14 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
};
firmware {