nxp,s32-emios-pwm
Vendor: NXP Semiconductors N.V.
Note
An implementation of a driver matching this compatible is available in drivers/pwm/pwm_nxp_s32_emios.c.
Description
NXP S32 eMIOS PWM node for S32 SoCs. Each channel in eMIOS can be configured
to use for PWM operation. There are several PWM modes supported by this module,
some modes only support on channels that have internal counter, some modes
require to use a reference timebase from a master bus.
For example to configuring eMIOS instance 0 with:
- Channel 0 for mode OPWFMB
- Channel 1 for mode OPWMB
- Channel 2 for mode OPWMCB with deadtime inserted at leading edge
- Channel 3 for mode SAIC, use internal timebase with input filter = 2 eMIOS clock
emios0_pwm: pwm {
pwm_0 {
channel = <0>;
pwm-mode = "OPWFMB";
prescaler = <8>;
period = <65534>;
duty-cycle = <32768>;
polarity = "ACTIVE_HIGH";
};
pwm_1 {
channel = <1>;
master-bus = <&emios1_bus_a>;
pwm-mode = "OPWMB";
duty-cycle = <32768>;
phase-shift = <100>;
polarity = "ACTIVE_LOW";
};
pwm_2 {
channel = <2>;
master-bus = <&emios1_bus_b>;
pwm-mode = "OPWMCB_LEAD_EDGE";
duty-cycle = <32768>;
dead-time = <100>;
polarity = "ACTIVE_LOW";
};
pwm_3 {
channel = <3>;
pwm-mode = "SAIC";
prescaler = <8>;
input-filter = <2>;
};
};
OPWMB and OPWMCB modes use reference timebase, the master bus is chosen over
phandle 'master-bus'. For OPWMB mode, PWM's period is master bus's period and
is 2 * master bus's period - 2 for OPWMCB mode. Please notice that the devicetree
node for master bus should be enabled and configured for using, please see
'nxp,s32-emios' bindings.
Properties
Top level properties
These property descriptions apply to “nxp,s32-emios-pwm” nodes themselves. This page also describes child node properties in the following sections.
Node specific properties
Properties not inherited from the base binding file.
Name |
Type |
Details |
|---|---|---|
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Pin configuration/s for the first state. Content is specific to the
selected pin controller driver implementation.
This property is required. |
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Names for the provided states. The number of names needs to match the
number of states.
This property is required. |
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Number of items to expect in a pwm specifier
This property is required. Constant value: |
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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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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 “nxp,s32-emios-pwm” compatible.
Name |
Type |
Details |
|---|---|---|
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indicates the operational status of a device
Legal values: See Important properties for more information. |
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compatible strings
This property is required. See Important properties for more information. |
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register space
See Important properties for more information. |
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name of each register space
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interrupts for device
See Important properties for more information. |
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extended interrupt specifier for device
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name of each interrupt
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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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Power domain specifiers
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Provided names of power domain specifiers
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Number of cells in power-domains property
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Do not initialize device automatically on boot. Device should be manually
initialized using device_init().
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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.
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Automatically configure the device for runtime power management after the
init function runs.
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List of power states that will disable this device power.
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Child node properties
Name |
Type |
Details |
|---|---|---|
|
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eMIOS PWM channel
This property is required. |
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A phandle to master-bus node that will be used as external timebase
for current channel, this can be bypassed if internal counter is used
for PWM operation. A master bus must be used exclusively, such as if
is used as a timebase for a channel in SAIC mode, do not use that
master bus as a timebase for generate PWM pulse.
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Select PWM mode:
- OPWFMB: provides waveforms with variable duty cycle and frequency,
this mode uses internal counter.
- OPWMB: generate pulses with programmable leading and trailing
edge placement. The period is determined by period of
an external counter driven in MCB Up Mode. Changing PWM period
at runtime will impact to all channels share the same timebase.
The new period and cycle take effect in next period boundary.
- OPWMCB: generates a center aligned PWM with dead time insertion to the
leading or trailing edge. The period is determined by period of
an external counter driven in MCB Up Down Mode. Changing PWM period
at runtime will impact to all channels share the same timebase,
The new period and cycle take effect in next period boundary.
- SAIC: single action input capture mode, the eMIOS captures events as soon as
they occur. The value of latest captured event is stored and can be read
by software.
This property is required. Legal values: |
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Output polarity for PWM channel.
Legal values: |
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Duty-cycle (in ticks) for PWM channel at boot time.
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Period (in ticks) for OPWFMB at boot time. Period for the rest
of PWM mode depends on period's master bus. Must be in range [2 ... 65535].
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Freeze individual internal counter when the chip enters Debug mode.
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Select clock source for internal counter prescaler.
Default value: Legal values: |
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The clock divider for internal counter prescaler.
Legal values: |
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Dead time (in ticks) for PWM channel in OPWMCB mode.
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Phase Shift (in ticks) for PWM channel in OPWMB mode.
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Select the minimum input pulse width, in filter clock cycles that can pass
through the input filter. The filter latency - the difference in time between
the input and the response is three clock edges. Default 0 means the filter
is bypassed. The clock source for programmable input filter is eMIOS clock.
Legal values: |
Specifier cell names
pwm cells: channel, period, flags