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authorMika Westerberg <mika.westerberg@linux.intel.com>2016-10-21 17:21:30 +0300
committerLinus Walleij <linus.walleij@linaro.org>2016-10-24 17:33:11 +0300
commitc80f1ba75df25837fb76044e06686b6587d33f6a (patch)
treef39b7fd7795bf25d0d6f19df7a86b57b667c0f06 /Documentation/acpi
parent6f7194a10bdba1588357342c6daaaeef98e0004f (diff)
downloadlinux-c80f1ba75df25837fb76044e06686b6587d33f6a.tar.xz
ACPI / gpio: Add hogging support
GPIO hogging means that the GPIO controller can "hog" and configure certain GPIOs without need for a driver or userspace to do that. This is useful in open-connected boards where BIOS cannot possibly know beforehand which devices will be connected to the board. This adds GPIO hogging mechanism to ACPI analogous to Device Tree. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'Documentation/acpi')
-rw-r--r--Documentation/acpi/gpio-properties.txt35
1 files changed, 35 insertions, 0 deletions
diff --git a/Documentation/acpi/gpio-properties.txt b/Documentation/acpi/gpio-properties.txt
index 09cff657b82c..d9076af271f5 100644
--- a/Documentation/acpi/gpio-properties.txt
+++ b/Documentation/acpi/gpio-properties.txt
@@ -66,6 +66,41 @@ native:
}
}
+Other supported properties
+--------------------------
+
+Following Device Tree compatible device properties are also supported by
+_DSD device properties for GPIO controllers:
+
+- gpio-hog
+- output-high
+- output-low
+- input
+- line-name
+
+Example:
+
+ Name (_DSD, Package () {
+ // _DSD Hierarchical Properties Extension UUID
+ ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
+ Package () {
+ Package () {"hog-gpio8", "G8PU"}
+ }
+ })
+
+ Name (G8PU, Package () {
+ ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ Package () {
+ Package () {"gpio-hog", 1},
+ Package () {"gpios", Package () {8, 0}},
+ Package () {"output-high", 1},
+ Package () {"line-name", "gpio8-pullup"},
+ }
+ })
+
+See Documentation/devicetree/bindings/gpio/gpio.txt for more information
+about these properties.
+
ACPI GPIO Mappings Provided by Drivers
--------------------------------------