summaryrefslogtreecommitdiff
path: root/Documentation/acpi
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2016-12-13 18:54:57 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-13 18:54:57 +0300
commit061ad5038ca5ac75419204b216bddc2806008ead (patch)
treeedd48af16a121d6a457f5e29119cac91b3a9c61c /Documentation/acpi
parente7aa8c2eb11ba69b1b69099c3c7bd6be3087b0ba (diff)
parentacf1fcf77247efa01d7213f53082451f6c9c8f3b (diff)
downloadlinux-061ad5038ca5ac75419204b216bddc2806008ead.tar.xz
Merge tag 'gpio-v4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO updates from Luinus Walleij: "Bulk GPIO changes for the v4.10 kernel cycle: Core changes: - Simplify threaded interrupt handling: instead of passing numbed parameters to gpiochip_irqchip_add_chained() we create a new call: gpiochip_irqchip_add_nested() so the two types are clearly semantically different. Also make sure that all nested chips call gpiochip_set_nested_irqchip() which is necessary for IRQ resend to work properly if it happens. - Return error on seek operations for the chardev. - Clamp values set as part of gpio[d]_direction_output() so that anything != 0 will be send down to the driver as "1" not the value passed in. - ACPI can now support naming of GPIO lines, hogs and holes in the GPIO lists. New drivers: - The SX150x driver was deemed unfit for the GPIO subsystem and was moved over to a combined GPIO+pinctrl driver in the pinctrl subsystem. New features: - Various cleanups to various drivers" * tag 'gpio-v4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (49 commits) gpio: merrifield: Implement gpio_get_direction callback gpio: merrifield: Add support for hardware debouncer gpio: chardev: Return error for seek operations gpio: arizona: Tidy up probe error path gpio: arizona: Remove pointless set of platform drvdata gpio: pl061: delete platform data handling gpio: pl061: move platform data into driver gpio: pl061: rename variable from chip to pl061 gpio: pl061: rename state container struct gpio: pl061: use local state for parent IRQ storage gpio: set explicit nesting on drivers gpio: simplify adding threaded interrupts gpio: vf610: use builtin_platform_driver gpio: axp209: use correct register for GPIO input status gpio: stmpe: fix interrupt handling bug gpio: em: depnd on ARCH_SHMOBILE gpio: zx: depend on ARCH_ZX gpio: x86: update config dependencies for x86 specific hardware gpio: mb86s7x: use builtin_platform_driver gpio: etraxfs: use builtin_platform_driver ...
Diffstat (limited to 'Documentation/acpi')
-rw-r--r--Documentation/acpi/gpio-properties.txt62
1 files changed, 62 insertions, 0 deletions
diff --git a/Documentation/acpi/gpio-properties.txt b/Documentation/acpi/gpio-properties.txt
index 5aafe0b351a1..2aff0349facd 100644
--- a/Documentation/acpi/gpio-properties.txt
+++ b/Documentation/acpi/gpio-properties.txt
@@ -51,6 +51,68 @@ it to 1 marks the GPIO as active low.
In our Bluetooth example the "reset-gpios" refers to the second GpioIo()
resource, second pin in that resource with the GPIO number of 31.
+It is possible to leave holes in the array of GPIOs. This is useful in
+cases like with SPI host controllers where some chip selects may be
+implemented as GPIOs and some as native signals. For example a SPI host
+controller can have chip selects 0 and 2 implemented as GPIOs and 1 as
+native:
+
+ Package () {
+ "cs-gpios",
+ Package () {
+ ^GPIO, 19, 0, 0, // chip select 0: GPIO
+ 0, // chip select 1: native signal
+ ^GPIO, 20, 0, 0, // chip select 2: GPIO
+ }
+ }
+
+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"},
+ }
+ })
+
+- gpio-line-names
+
+Example:
+
+ Package () {
+ "gpio-line-names",
+ Package () {
+ "SPI0_CS_N", "EXP2_INT", "MUX6_IO", "UART0_RXD", "MUX7_IO",
+ "LVL_C_A1", "MUX0_IO", "SPI1_MISO"
+ }
+ }
+
+See Documentation/devicetree/bindings/gpio/gpio.txt for more information
+about these properties.
+
ACPI GPIO Mappings Provided by Drivers
--------------------------------------