aboutsummaryrefslogtreecommitdiff
path: root/doc/device-tree-bindings
diff options
context:
space:
mode:
Diffstat (limited to 'doc/device-tree-bindings')
-rw-r--r--doc/device-tree-bindings/interrupt-controller/interrupts.txt131
1 files changed, 131 insertions, 0 deletions
diff --git a/doc/device-tree-bindings/interrupt-controller/interrupts.txt b/doc/device-tree-bindings/interrupt-controller/interrupts.txt
new file mode 100644
index 00000000000..38a399a6b1b
--- /dev/null
+++ b/doc/device-tree-bindings/interrupt-controller/interrupts.txt
@@ -0,0 +1,131 @@
+Specifying interrupt information for devices
+============================================
+
+1) Interrupt client nodes
+-------------------------
+
+Nodes that describe devices which generate interrupts must contain an
+"interrupts" property, an "interrupts-extended" property, or both. If both are
+present, the latter should take precedence; the former may be provided simply
+for compatibility with software that does not recognize the latter. These
+properties contain a list of interrupt specifiers, one per output interrupt. The
+format of the interrupt specifier is determined by the interrupt controller to
+which the interrupts are routed; see section 2 below for details.
+
+ Example:
+ interrupt-parent = <&intc1>;
+ interrupts = <5 0>, <6 0>;
+
+The "interrupt-parent" property is used to specify the controller to which
+interrupts are routed and contains a single phandle referring to the interrupt
+controller node. This property is inherited, so it may be specified in an
+interrupt client node or in any of its parent nodes. Interrupts listed in the
+"interrupts" property are always in reference to the node's interrupt parent.
+
+The "interrupts-extended" property is a special form; useful when a node needs
+to reference multiple interrupt parents or a different interrupt parent than
+the inherited one. Each entry in this property contains both the parent phandle
+and the interrupt specifier.
+
+ Example:
+ interrupts-extended = <&intc1 5 1>, <&intc2 1 0>;
+
+(NOTE: only this 'special form' is supported in U-Boot)
+
+
+2) Interrupt controller nodes
+-----------------------------
+
+A device is marked as an interrupt controller with the "interrupt-controller"
+property. This is a empty, boolean property. An additional "#interrupt-cells"
+property defines the number of cells needed to specify a single interrupt.
+
+It is the responsibility of the interrupt controller's binding to define the
+length and format of the interrupt specifier. The following two variants are
+commonly used:
+
+ a) one cell
+ -----------
+ The #interrupt-cells property is set to 1 and the single cell defines the
+ index of the interrupt within the controller.
+
+ Example:
+
+ vic: intc@10140000 {
+ compatible = "arm,versatile-vic";
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ reg = <0x10140000 0x1000>;
+ };
+
+ sic: intc@10003000 {
+ compatible = "arm,versatile-sic";
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ reg = <0x10003000 0x1000>;
+ interrupt-parent = <&vic>;
+ interrupts = <31>; /* Cascaded to vic */
+ };
+
+ b) two cells
+ ------------
+ The #interrupt-cells property is set to 2 and the first cell defines the
+ index of the interrupt within the controller, while the second cell is used
+ to specify any of the following flags:
+ - bits[3:0] trigger type and level flags
+ 1 = low-to-high edge triggered
+ 2 = high-to-low edge triggered
+ 4 = active high level-sensitive
+ 8 = active low level-sensitive
+
+ Example:
+
+ i2c@7000c000 {
+ gpioext: gpio-adnp@41 {
+ compatible = "ad,gpio-adnp";
+ reg = <0x41>;
+
+ interrupt-parent = <&gpio>;
+ interrupts = <160 1>;
+
+ gpio-controller;
+ #gpio-cells = <1>;
+
+ interrupt-controller;
+ #interrupt-cells = <2>;
+
+ nr-gpios = <64>;
+ };
+
+ sx8634@2b {
+ compatible = "smtc,sx8634";
+ reg = <0x2b>;
+
+ interrupt-parent = <&gpioext>;
+ interrupts = <3 0x8>;
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ threshold = <0x40>;
+ sensitivity = <7>;
+ };
+ };
+
+
+Example of special form (supported by U-Boot):
+
+ acpi_gpe: general-purpose-events {
+ reg = <IOMAP_ACPI_BASE IOMAP_ACPI_SIZE>;
+ compatible = "intel,acpi-gpe";
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ };
+
+ tpm@50 {
+ reg = <0x50>;
+ compatible = "google,cr50";
+ u-boot,i2c-offset-len = <0>;
+ ready-gpio = <&gpio_n 28 GPIO_ACTIVE_LOW>;
+ interrupts-extended = <&acpi_gpe 0x3c 0>;
+ };