infineon,xmc4xxx-i2c

Vendor: Infineon Technologies

Note

An implementation of a driver matching this compatible is available in drivers/i2c/i2c_ifx_xmc4.c.

Description

These nodes are “i2c” bus nodes.

Infineon XMC4XXX I2C

This driver configures the USIC as an I2C device.

Example devicetree configuration with an adt7420 temperature sensor
connected on the bus:

&usic1ch1 {
    compatible = "infineon,xmc4xxx-i2c";
    status = "okay";

    pinctrl-0 = <&i2c_scl_p0_13_u1c1 &i2c_sda_p3_15_u1c1>;
    pinctrl-names = "default";
    scl-src = "DX1B";
    sda-src = "DX0A";
    interrupts = <94 1>;

    #address-cells = <1>;
    #size-cells = <0>;

    clock-frequency = <I2C_BITRATE_STANDARD>;
    adt7420@48 {
        compatible = "adi,adt7420";
        reg = <0x48>;
    };
};

The pinctrl nodes need to be configured as open-drain and
hwctrl should be disabled:

&i2c_scl_p0_13_u1c1 {
    drive-strength = "strong-sharp-edge";
    drive-open-drain;
    hwctrl = "disabled";
};

&i2c_sda_p3_15_u1c1 {
    drive-strength = "strong-soft-edge";
    drive-open-drain;
    hwctrl = "disabled";
};

Properties

Node specific properties

Properties not inherited from the base binding file.

Name

Type

Details

scl-src

string

 
Connects the I2C clock line (USIC DX1 input) to a specific GPIO pin.
The USIC DX1 input is a multiplexer which connects to different GPIO pins.
Refer to the XMC4XXX reference manual for the GPIO pin/mux mappings.

This property is required.

Legal values: 'DX1A', 'DX1B', 'DX1C', 'DX1D', 'DX1E', 'DX1F', 'DX1G'

sda-src

string

 
Connects the I2C data line (USIC DX0 input) to a specific GPIO pin.
The USIC DX0 input is a multiplexer which connects to different GPIO pins.
Refer to the XMC4XXX reference manual for the GPIO pin/mux mappings.

This property is required.

Legal values: 'DX0A', 'DX0B', 'DX0C', 'DX0D', 'DX0E', 'DX0F', 'DX0G'

pinctrl-0

phandles

 
PORT pin configuration for SCL, SDA signals.
We expect that the phandles will reference pinctrl nodes. These
nodes will have a nodelabel that matches the Infineon SoC Pinctrl
defines and have following
format: i2c_<signal>_p<port>_<pin>_<peripheral inst>

Examples:
  pinctrl-0 = <&i2c_scl_p5_2_u2c0 &i2c_sda_p5_0_u2c0>;

The pins should set to open-drain and hwctrl should be disabled.

&i2c_scl_p5_2_u2c0 {
    drive-strength = "strong-sharp-edge";
    drive-open-drain;
    hwctrl = "disabled";
};

In the above example, the pin is both an input and output (as is
required for I2C setup). It is internally connected to both DX0
and DOUT0 of USIC2 channel 0. (See XMC4700/4800 reference manual
page 18-110, Figure 18-50 for more details).
This limits the number of pins that can be used for the I2C module.

To get around this pin limitation, it is possible to use pins
that do not have this internal connection, and instead connect the
pins externally on the board.
For example, for the SDA line on USIC2 channel 0, P3.8 may be used
for DOUT0 and P6.5 for DX0. These type of pinctrl nodes will have
labels:
i2c_sda_dout0_p3_8_u2c0 and i2c_sda_dx0_p6_5_u2c0.
The generalized format is: i2c_<signal>_<type>_p<port>_<pin>_<peripheral inst>

An example for SCL and SDA signals on the xmc4700:
pinctrl-0 = <&i2c_sda_dout0_p3_8_u2c0 &i2c_sda_dx0_p6_5_u2c0
            &i2c_scl_dout1_p3_9_u2c0 &i2c_scl_p5_2_u2c0>;

Externally P3.8 should be connected to P6.5; P3.9 should be connected
to P5.2.

Note that any pins that do not have dout0/dx0 or dout1/dx1 can have either
function. Thus node i2c_scl_p5_0_u2c0 can be both dout1 and dx1.

For the pin configurations, the output pins (dout0 and dout1) should be set
to open-drain while the input pins (dx0 and dx1) should not include this setting.

&i2c_sda_dout0_p3_8_u2c0 {
    drive-strength = "strong-sharp-edge";
    drive-open-drain;
    hwctrl = "disabled";
};

&i2c_scl_dout1_p3_9_u2c0 {
    drive-strength = "strong-sharp-edge";
    drive-open-drain;
    hwctrl = "disabled";
};

&i2c_sda_dx0_p6_5_u2c0 {   /* will require USIC setting sda-src = DX0D */
    hwctrl = "disabled";
};

&i2c_scl_p5_2_u2c0 {  /* will require USIC scl-src = DX1A */
    hwctrl = "disabled";
};

This property is required.

pinctrl-names

string-array

 
Names for the provided states. The number of names needs to match the
number of states.

This property is required.

clock-frequency

int

 
Initial clock frequency in Hz

sq-size

int

 
Size of the submission queue for blocking requests

Default value: 4

cq-size

int

 
Size of the completion queue for blocking requests

Default value: 4

pinctrl-1

phandles

 
Pin configuration/s for the second state. See pinctrl-0.

pinctrl-2

phandles

 
Pin configuration/s for the third state. See pinctrl-0.

pinctrl-3

phandles

 
Pin configuration/s for the fourth state. See pinctrl-0.

pinctrl-4

phandles

 
Pin configuration/s for the fifth state. See pinctrl-0.

Deprecated node specific properties

Deprecated properties not inherited from the base binding file.

(None)

Base properties

Properties inherited from the base binding file, which defines common properties that may be set on many nodes. Not all of these may apply to the “infineon,xmc4xxx-i2c” compatible.

Name

Type

Details

reg

array

 
Information used to address the device. The value is specific to
the device (i.e. is different depending on the compatible
property).

The "reg" property is typically a sequence of (address, length) pairs.
Each pair is called a "register block". Values are
conventionally written in hex.

For details, see "2.3.6 reg" in Devicetree Specification v0.4.

This property is required.

See Important properties for more information.

interrupts

array

 
IRQ number and priority to use for interrupt driven by I2C.
Each USIC must use a certain interrupt range:
USIC0 = [84, 89]
USIC1 = [90, 95]
USIC2 = [96, 101]

This property is required.

See Important properties for more information.

#address-cells

int

 
This property encodes the number of <u32> cells used by address fields
in "reg" properties in this node's children.

For details, see "2.3.5 #address-cells and #size-cells" in Devicetree
Specification v0.4.

This property is required.

Constant value: 1

#size-cells

int

 
This property encodes the number of <u32> cells used by size fields in
"reg" properties in this node's children.

For details, see "2.3.5 #address-cells and #size-cells" in Devicetree
Specification v0.4.

This property is required.

status

string

 
Indicates the operational status of the hardware or other
resource that the node represents. In particular:

  - "okay" means the resource is operational and, for example,
    can be used by device drivers
  - "disabled" means the resource is not operational and the system
    should treat it as if it is not present

For details, see "2.3.4 status" in Devicetree Specification v0.4.

Legal values: 'ok', 'okay', 'disabled', 'reserved', 'fail', 'fail-sss'

See Important properties for more information.

compatible

string-array

 
This property is a list of strings that essentially define what
type of hardware or other resource this devicetree node
represents. Each device driver checks for specific compatible
property values to find the devicetree nodes that represent
resources that the driver should manage.

The recommended format is "vendor,device", The "vendor" part is
an abbreviated name of the vendor. The "device" is usually from
the datasheet.

The compatible property can have multiple values, ordered from
most- to least-specific. Having additional values is useful when the
device is a specific instance of a more general family, to allow the
system to match the most specific driver available.

For details, see "2.3.1 compatible" in Devicetree Specification v0.4.

This property is required.

See Important properties for more information.

reg-names

string-array

 
Optional names given to each register block in the "reg" property.
For example:

  / {
       soc {
           #address-cells = <1>;
           #size-cells = <1>;

           uart@1000 {
               reg = <0x1000 0x2000>, <0x3000 0x4000>;
               reg-names = "foo", "bar";
           };
       };
  };

The uart@1000 node has two register blocks:

  - one with base address 0x1000, size 0x2000, and name "foo"
  - another with base address 0x3000, size 0x4000, and name "bar"

interrupts-extended

compound

 
Extended interrupt specifier for device, used as an alternative to
the "interrupts" property.

For details, see "2.4 Interrupts and Interrupt Mapping" in
Devicetree Specification v0.4.

interrupt-names

string-array

 
Optional names given to each interrupt generated by a device.
The interrupts themselves are defined in either "interrupts" or
"interrupts-extended" properties.

For details, see "2.4 Interrupts and Interrupt Mapping" in
Devicetree Specification v0.4.

interrupt-parent

phandle

 
If present, this refers to the node which handles interrupts generated
by this device.

For details, see "2.4 Interrupts and Interrupt Mapping" in
Devicetree Specification v0.4.

label

string

 
Human readable string describing the device. Use of this property is
deprecated except as needed on a case-by-case basis.

For details, see "4.1.2 Miscellaneous Properties" in Devicetree
Specification v0.4.

See Important properties for more information.

clocks

phandle-array

 
Information about the device's clock providers. In general, this property
should follow conventions established in the dt-schema binding:

  https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/clock/clock.yaml

clock-names

string-array

 
Optional names given to each clock provider in the "clocks" property.

dmas

phandle-array

 
DMA channel specifiers relevant to the device.

dma-names

string-array

 
Optional names given to the DMA channel specifiers in the "dmas" property.

io-channels

phandle-array

 
IO channel specifiers relevant to the device.

io-channel-names

string-array

 
Optional names given to the IO channel specifiers in the "io-channels" property.

mboxes

phandle-array

 
Mailbox / IPM channel specifiers relevant to the device.

mbox-names

string-array

 
Optional names given to the mbox specifiers in the "mboxes" property.

power-domains

phandle-array

 
Power domain specifiers relevant to the device.

power-domain-names

string-array

 
Optional names given to the power domain specifiers in the "power-domains" property.

#power-domain-cells

int

 
Number of cells in power-domains property

zephyr,deferred-init

boolean

 
Do not initialize device automatically on boot. Device should be manually
initialized using device_init().

wakeup-source

boolean

 
Property to identify that a device can be used as wake up source.

When this property is provided a specific flag is set into the
device that tells the system that the device is capable of
wake up the system.

Wake up capable devices are disabled (interruptions will not wake up
the system) by default but they can be enabled at runtime if necessary.

zephyr,pm-device-runtime-auto

boolean

 
Automatically configure the device for runtime power management after the
init function runs.

zephyr,disabling-power-states

phandles

 
List of power states that will disable this device power.