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authorOlof Johansson <olof@lixom.net>2013-01-07 21:09:17 -0800
committerOlof Johansson <olof@lixom.net>2013-01-07 21:11:12 -0800
commit5cf87a12cac05460666faa22711b655a327b2219 (patch)
tree123819235d0a5b6591ae79fe38fdb349dbd9ffcb /Documentation/devicetree
parent0e3a4a2eb67acdd710a833b767c20e9189cc3458 (diff)
parentba607b6238a1f418c45b9d7f73212bcc6922da53 (diff)
Merge tag 'mvebu_fixes_for_v3.8' of git://git.infradead.org/users/jcooper/linux into fixes
From Jason Cooper: fixes for mvebu/kirkwood v3.8 - use correct uart driver for mvebu boards - add a missing DT clocks - gpio-poweroff level vs. edge triggering, use gpio_is_valid() - remove an inappropriate __init, modules need to access function. - various DT fixes - error handling in mv_xor * tag 'mvebu_fixes_for_v3.8' of git://git.infradead.org/users/jcooper/linux: pinctrl: mvebu: make pdma clock on dove mandatory ARM: Dove: Add pinctrl clock to DT dma: mv_xor: fix error handling for clocks dma: mv_xor: fix error handling of mv_xor_channel_add() arm: mvebu: Add missing ; for cpu node. arm: mvebu: Armada XP MV78230 has only three Ethernet interfaces arm: mvebu: Armada XP MV78230 has two cores, not one clk: mvebu: Remove inappropriate __init tagging ARM: Kirkwood: Use fixed-regulator instead of board gpio call ARM: Kirkwood: Fix missing sdio clock ARM: Kirkwood: Switch TWSI1 of 88f6282 to DT clock providers Power: gpio-poweroff: Fix documentation and gpio_is_valid ARM: Kirkwood: Fix missing clk for USB device. arm: mvebu: Use dw-apb-uart instead of ns16650 as UART driver Signed-off-by: Olof Johansson <olof@lixom.net>
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r--Documentation/devicetree/bindings/gpio/gpio-poweroff.txt20
1 files changed, 17 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio-poweroff.txt b/Documentation/devicetree/bindings/gpio/gpio-poweroff.txt
index 558cdf3c9ab..d4eab9227ea 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-poweroff.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio-poweroff.txt
@@ -1,4 +1,19 @@
-GPIO line that should be set high/low to power off a device
+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 pm_power_off handler. 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 pm_power_off 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".
@@ -13,10 +28,9 @@ Optional properties:
property is not specified, the GPIO is initialized as an output in its
inactive state.
-
Examples:
gpio-poweroff {
compatible = "gpio-poweroff";
- gpios = <&gpio 4 0>; /* GPIO 4 Active Low */
+ gpios = <&gpio 4 0>;
};