Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 39 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/power/reset/gpio-poweroff.txt b/Documentation/devicetree/bindings/power/reset/gpio-poweroff.txt
new file mode 100644
index 000000000..6d8980c18
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/reset/gpio-poweroff.txt
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+Driver a GPIO line that can be used to turn the power off.
+
+The driver supports both level triggered and edge triggered power off.
+At driver load time, the driver will request the given gpio line and
+install a handler to power off the system. If the optional properties
+'input' is not found, the GPIO line will be driven in the inactive
+state. Otherwise its configured as an input.
+
+When the power-off handler is called, the gpio is configured as an
+output, and drive active, so triggering a level triggered power off
+condition. This will also cause an inactive->active edge condition, so
+triggering positive edge triggered power off. After a delay of 100ms,
+the GPIO is set to inactive, thus causing an active->inactive edge,
+triggering negative edge triggered power off. After another 100ms
+delay the GPIO is driver active again. If the power is still on and
+the CPU still running after a 3000ms delay, a WARN_ON(1) is emitted.
+
+Required properties:
+- compatible : should be "gpio-poweroff".
+- gpios : The GPIO to set high/low, see "gpios property" in
+  Documentation/devicetree/bindings/gpio/gpio.txt. If the pin should be
+  low to power down the board set it to "Active Low", otherwise set
+  gpio to "Active High".
+
+Optional properties:
+- input : Initially configure the GPIO line as an input. Only reconfigure
+  it to an output when the power-off handler is called. If this optional
+  property is not specified, the GPIO is initialized as an output in its
+  inactive state.
+- timeout-ms: Time to wait before asserting a WARN_ON(1). If nothing is
+              specified, 3000 ms is used.
+
+Examples:
+
+gpio-poweroff {
+	compatible = "gpio-poweroff";
+	gpios = <&gpio 4 0>;
+	timeout-ms = <3000>;
+};