infineon,xmc4xxx-ccu8-pwm

Vendor: Infineon Technologies

Note

An implementation of a driver matching this compatible is available in drivers/pwm/pwm_xmc4xxx_ccu8.c.

Description

Infineon XMC4XXX PWM Capture Compare Unit 8 (CCU8) module

The PWM CCU8 module can automatically generate a high-side
and a low-side PWM signal, where the two signals are complementary
to each other.

The module supports adding a dead time between the high-side and
low-side PWM signals.

The dead time ensures that there is a delay before the PWM state
transitions from 0 to 1, preventing the high-side and low-side
switches from being on simultaneously.

There are two CCU8 modules with DTS node labels: pwm_ccu80 and
pwm_ccu81. Each module has four slices, and each slice has
two channels. A channel consists of a corresponding high-side
and low-side PWM signal.

The CCU8 modules use the CCU clock source. Each slice applies
a separate prescaler to divide the clock. The clock divider is
defined by the 'slice-prescaler' property. Additionally, each
slice has a dead time prescaler, which divides the slice clock
for the dead time counter.

Device tree example:
A node can define a 'pwm' field, usually referenced in a 'pwms'
property, where the entries include the PWM module phandle,
channel number, pulse period (in nanoseconds or set using
PWM_XX() macros), and a channel
flag (PWM_POLARITY_NORMAL/PWM_POLARITY_INVERTED).

The 'pwm_ccu8' node must define the following fields:
&pwm_ccu80 {
        slice-prescaler = <15 15 15 15>;
        slice-deadtime-prescaler = <3 3 3 3>;
        channel-deadtime-high = <0 0 0 0 PWM_MSEC(100) 0 0 0>;
        channel-deadtime-low = <0 0 0 0 PWM_MSEC(100) 0 0 0>;
        pinctrl-0 = <&pwm_out_p5_9_ccu80_ch4_high &pwm_out_p0_0_ccu80_ch4_low>;
        pinctrl-names = "default";
};

This will configure channel 4 with a 100msec deadtime on the high
and low side PWM signals.

Another node can reference the PWM as follows:
&test_node {
   ...
   pwms = <&pwm_ccu80 0 PWM_SEC(1) PWM_POLARITY_NORMAL>;
   ...
};

The 'pwm_out_p{PORT}_{PIN}_ccu8{MODULE_IDX}_ch{CHANNEL_IDX}_{HIGH_LOW}'
format is used for CCU8 pinctrl nodes. 'MODULE_IDX' and 'CHANNEL_IDX'
refer to a specific 'pwm_ccu8x' module and channel, respectively.
'PORT/PIN' defines the GPIO that the channel connects to.
'HIGH_LOW' indicates whether the pin is for the high or low-side signal.

It's not necessary to specify both the high and low pinctrls. Only the low-side
signal can, for example, be used as PWM, but note that the duty cycle of the
low signal will be (1 - duty) as set via the API.

Note that a slice has two channels. Channels 0/1 are in slice 0,
channels 2/3 are in slice 1, and so on. Each channel can have its own
duty cycle and high/low dead times. But the pulse duration applies to
both channels. Thus, when using the PWM control api to modify the pulse width
on a channel 0, it will also be updated for channel 1 since they are
in the same slice.

Properties

Node specific properties

Properties not inherited from the base binding file.

Name

Type

Details

pinctrl-0

phandles

 
Pin configuration/s for the first state. Content is specific to the
selected pin controller driver implementation.

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.

slice-prescaler

array

 
Defines the clock divider for each slice.
The entry in the array will divide CCU clock by (2 << value).
The range for the prescaler values is [0, 15].
Reducing prescaler value will improve resolution but decrease the maximum period.

This property is required.

slice-deadtime-prescaler

array

 
Defines the clock divider for dead time counter for each slice.
The range for the values is [0, 3].
Reducing prescaler value will improve dead time resolution but decrease the
maximum dead time.

This property is required.

channel-deadtime-high

array

 
Defines the dead time in nanoseconds for the high-side PWM signal for each channel.

This property is required.

channel-deadtime-low

array

 
Defines the dead time in nanoseconds for the low-side PWM signal for each channel.

This property is required.

#pwm-cells

int

 
Number of items to expect in a pwm specifier

This property is required.

Constant value: 3

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-ccu8-pwm” 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.

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

array

 
Information about interrupts generated by the device, encoded as an array
of one or more interrupt specifiers. The format of the data in this property
varies by where the device appears in the interrupt tree. Devices with the same
"interrupt-parent" will use the same format in their interrupts properties.

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

See Important properties for more information.

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.

#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.

#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.

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.

Specifier cell names

  • pwm cells: channel, period, flags