mirror of
https://github.com/torvalds/linux.git
synced 2024-12-19 17:41:29 +00:00
79d9701559
The standard interrupts property in device tree can only handle interrupts coming from a single interrupt parent. If a device is wired to multiple interrupt controllers, then it needs to be attached to a node with an interrupt-map property to demux the interrupt specifiers which is confusing. It would be a lot easier if there was a form of the interrupts property that allows for a separate interrupt phandle for each interrupt specifier. This patch does exactly that by creating a new interrupts-extended property which reuses the phandle+arguments pattern used by GPIOs and other core bindings. Signed-off-by: Grant Likely <grant.likely@linaro.org> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Kumar Gala <galak@codeaurora.org> [grant.likely: removed versatile platform hunks into separate patch] Cc: Rob Herring <rob.herring@calxeda.com>
113 lines
3.4 KiB
Plaintext
113 lines
3.4 KiB
Plaintext
Specifying interrupt information for devices
|
|
============================================
|
|
|
|
1) Interrupt client nodes
|
|
-------------------------
|
|
|
|
Nodes that describe devices which generate interrupts must contain an either an
|
|
"interrupts" property or an "interrupts-extended" property. 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 for use when a node needs
|
|
to reference multiple interrupt parents. Each entry in this property contains
|
|
both the parent phandle and the interrupt specifier. "interrupts-extended"
|
|
should only be used when a device has multiple interrupt parents.
|
|
|
|
Example:
|
|
interrupts-extended = <&intc1 5 1>, <&intc2 1 0>;
|
|
|
|
A device node may contain either "interrupts" or "interrupts-extended", but not
|
|
both. If both properties are present, then the operating system should log an
|
|
error and use only the data in "interrupts".
|
|
|
|
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>;
|
|
};
|
|
};
|