Bus helpers

Macros
#define	DT_BUS(node_id)
	Node's bus controller.
#define	DT_ON_BUS(node_id, bus)
	Is a node on a bus of a given type?

Detailed Description

Macro Definition Documentation

DT_BUS

#define DT_BUS

(

node_id

)

#include <zephyr/devicetree.h>

Value:

DT_CAT(node_id, _BUS)

Node's bus controller.

Get the node identifier of the node's bus controller. This can be used with DT_PROP() to get properties of the bus controller.

It is an error to use this with nodes which do not have bus controllers.

Example devicetree fragment:

i2c@deadbeef {
        status = "okay";
        clock-frequency = < 100000 >;
 
        i2c_device: accelerometer@12 {
                ...
        };
};

Example usage:

DT_PROP(DT_BUS(DT_NODELABEL(i2c_device)), clock_frequency) // 100000

Parameters

node_id

node identifier

Returns

a node identifier for the node's bus controller

DT_ON_BUS

#define DT_ON_BUS	(		node_id,
			bus )

#include <zephyr/devicetree.h>

Value:

IS_ENABLED(DT_CAT3(node_id, _BUS_, bus))

Is a node on a bus of a given type?

Example devicetree overlay:

&i2c0 {
       temp: temperature-sensor@76 {
                compatible = "vnd,some-sensor";
                reg = <0x76>;
       };
};

Example usage, assuming i2c0 is an I2C bus controller node, and therefore temp is on an I2C bus:

DT_ON_BUS(DT_NODELABEL(temp), i2c) // 1
DT_ON_BUS(DT_NODELABEL(temp), spi) // 0

Parameters

node_id	node identifier
bus	lowercase-and-underscores bus type as a C token (i.e. without quotes)

Returns

1 if the node is on a bus of the given type, 0 otherwise