overlays: gpio-shutdown: Add debounce parameter

Give the gpio-shutdown overlay a debounce parameter that requires
the GPIO to be held at the relevant level for a specified number
of milliseconds. The default value is 100 - higher than the driver
default of 5ms to avoid unfortunate glitches.

See: https://www.raspberrypi.org/forums/viewtopic.php?f=107&t=253680

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

diff --git a/arch/arm/boot/dts/overlays/README b/arch/arm/boot/dts/overlays/README
index 7b134fb..3bd7d4a 100644 (file)
--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -803,6 +803,9 @@ Params: gpio_pin                GPIO pin to trigger on (default 3)
                                 Note that the default pin (GPIO3) has an
                                 external pullup.
 
+        debounce                Specify the debounce interval in milliseconds
+                                (default 100)
+
 
 Name:   hd44780-lcd
 Info:   Configures an HD44780 compatible LCD display. Uses 4 gpio pins for

diff --git a/arch/arm/boot/dts/overlays/gpio-shutdown-overlay.dts b/arch/arm/boot/dts/overlays/gpio-shutdown-overlay.dts
index af80a6c..db07ba6 100644 (file)
--- a/arch/arm/boot/dts/overlays/gpio-shutdown-overlay.dts
+++ b/arch/arm/boot/dts/overlays/gpio-shutdown-overlay.dts
@@ -53,6 +53,7 @@
                                        label = "shutdown";
                                        linux,code = <116>; // KEY_POWER
                                        gpios = <&gpio 3 1>;
+                                       debounce-interval = <100>; // ms
                                };
                        };
                };
@@ -75,6 +76,7 @@
 
                // Allow setting the active_low flag. 0 = active high, 1 = active low
                active_low = <&button>,"gpios:8";
+               debounce = <&button>,"debounce-interval:0";
        };
 
 };