infineon,xmc4xxx-ccu4-pwm
Vendor: Infineon Technologies
Description
Infineon XMC4XXX PWM Capture Compare Unit 4 (CCU4) module
The are four CCU4 modules with dts node labels:
pwm_ccu40, pwm_ccu41, pwm_ccu42, pwm_ccu43.
Each module has four slices and each slice has one channel.
A channel is connected to a particular gpio pin, which are defined
using pinctrl in:
dts/arm/infineon/xmc4xxx_xxx-pinctrl.dtsi
The CCU4 modules uses the CCU clock source. Each slice applies a separate
prescalar which divides the clock.
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 channela
flag (PWM_POLARITY_NORMAL/PWM_POLARITY_INVERTED).
The pwm ccu4 node must define the slice-prescaler values and the pinctrl nodes:
&pwm_ccu40 {
slice-prescaler = <15 15 15 15>;
pinctrl-0 = <&pwm_out_p1_1_ccu40_ch2>;
pinctrl-names = "default";
};
Another node can reference the PWM as follows:
&test_node {
...
pwms = <&pwm_ccu40 0 PWM_SEC(1) PWM_POLARITY_NORMAL>;
...
};
The user must also explicitly set pinctrl properties.
The pin should be configured with drive-push-pull bool option and hwctrl should be set
to disabled. The drive-strength field can be set to any of the supported values:
&pwm_out_p1_1_ccu40_ch2 {
drive-strength = "strong-medium-edge";
drive-push-pull;
hwctrl = "disabled";
};
The CCU4 pinctrl nodes have a node labels in the format
pwm_out_p{PORT}_{PIN}_ccu4{MODULE_IDX}_ch{CHANNEL_IDX}, where MODULE_IDX and
CHANNEL_IDX refers to specific pwm_ccu4x module and channel, respectively.
PORT/PIN pair defines what gpio the channel connects to.
Properties
Properties not inherited from the base binding file.
Name |
Type |
Details |
|---|---|---|
|
|
Number of items to expect in a pwm specifier
This property is required. Constant value: |
|
|
Pin configuration/s for the first state. Content is specific to the
selected pin controller driver implementation.
This property is required. |
|
|
Pin configuration/s for the second state. See pinctrl-0.
|
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Pin configuration/s for the third state. See pinctrl-0.
|
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Pin configuration/s for the fourth state. See pinctrl-0.
|
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Pin configuration/s for the fifth state. See pinctrl-0.
|
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|
Names for the provided states. The number of names needs to match the
number of states.
This property is required. |
|
|
Defines the clock divider for each channel.
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. |
Deprecated properties not inherited from the base binding file.
(None)
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-ccu4-pwm” compatible.
Name |
Type |
Details |
|---|---|---|
|
|
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.
|
|
|
Power domain the device belongs to.
The device will be notified when the power domain it belongs to is either
suspended or resumed.
|
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|
Automatically configure the device for runtime power management after the
init function runs.
|
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|
indicates the operational status of a device
Legal values: See Important properties for more information. |
|
|
compatible strings
This property is required. See Important properties for more information. |
|
|
register space
This property is required. See Important properties for more information. |
|
|
name of each register space
|
|
|
interrupts for device
See Important properties for more information. |
|
|
extended interrupt specifier for device
|
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|
name of each interrupt
|
|
|
phandle to interrupt controller node
|
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|
Human readable string describing the device (used as device_get_binding() argument)
See Important properties for more information. This property is deprecated. |
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Clock gate information
|
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name of each clock
|
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number of address cells in reg property
|
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number of size cells in reg property
|
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DMA channels specifiers
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Provided names of DMA channel specifiers
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IO channels specifiers
|
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Provided names of IO channel specifiers
|
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mailbox / IPM channels specifiers
|
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Provided names of mailbox / IPM channel specifiers
|
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Do not initialize device automatically on boot. Device should be manually
initialized using device_init().
|
Specifier cell names
pwm cells: channel, period, flags