espressif,esp32-mcpwm

Vendor: Espressif Systems

Note

An implementation of a driver matching this compatible is available in drivers/pwm/pwm_mc_esp32.c.

Description

Espressif's Motor Control Pulse Width Modulator (MCPWM) controller Node

The MCPWM peripheral is intended for motor and power control.
It provides six PWM outputs that can be set up to operate in several topologies

ESP32 contains two MCPWM peripherals: MCPWM0 and MCPWM1

Each MCPWM peripheral has one clock divider (prescaler), three PWM timers, three PWM operators,
and a capture module.

Every PWM operator has two PWM outputs: PWMxA and PWMxB. They can work independently, in symmetric
and asymmetric configuration. MCPWMxA and MCPWMxB will share the same timer, thus having the same
operating frequency.

The driver currently always use the timer x for operator x. Timer 0 will use operator 0 for
PWM0A/B.
Timer 1 will use operator 1 for PWM1A/B, and so on.

Mapping channel ID:
Channel 0 -> Timer 0, Operator 0, output PWM0A
Channel 1 -> Timer 0, Operator 0, output PWM0B
Channel 2 -> Timer 1, Operator 1, output PWM1A
Channel 3 -> Timer 1, Operator 1, output PWM1B
Channel 4 -> Timer 2, Operator 2, output PWM2A
Channel 5 -> Timer 2, Operator 2, output PWM2B
Channel 6 -> Capture 0
Channel 7 -> Capture 1
Channel 8 -> Capture 2

Example: Use PWM0A output and capture 0:

pwm_loopback_0 {
  compatible = "test-pwm-loopback";
  pwms = <&mcpwm0 0 0 PWM_POLARITY_NORMAL>, #Channel 0 -> Output PWM0A
         <&mcpwm0 6 0 PWM_POLARITY_NORMAL>; #Channel 6 -> Capture 0;
};

The mapping between the output PWMxA/B or CaptureX and GPIO is done through pinctrl:

  &mcpwm0 {
    pinctrl-0 = <&mcpwm0_default>;
    pinctrl-names = "default";
  }

The 'mcpwm0_default' node is defined inside the pinctrl node.

  &pinctrl {
    mcpwm0_default: mcpwm0_default {
      group1 {
        pinmux = <MCPWM0_OUT0A_GPIO0>,
          <MCPWM0_OUT0B_GPIO2>,
          <MCPWM0_OUT1A_GPIO4>;
        output-enable;
      };
      group2 {
        pinmux = <MCPWM0_CAP0_GPIO5>;
      };
    };
  };

Note: Check espressif,esp32-pinctrl.yaml for complete documentation regarding pinctrl.

Use the prescale-timerX property to configure the timers:

  &mcpwm0 {
    pinctrl-0 = <&mcpwm0_default>;
    pinctrl-names = "default";
    prescale = <255>;
    prescale-timer0 = <103>;
    prescale-timer1 = <0>;
    prescale-timer2 = <255>;
    status = "okay";
  };

Properties

Node specific properties

Properties not inherited from the base binding file.

Name	Type	Details
prescale	int	8 bit timer prescale for the global clock. Period of PWM_clk = 6.25ns * (PWM_CLK_PRESCALE + 1). This property is required.
#pwm-cells	int	Number of items to expect in a pwm specifier This property is required. Constant value: 3
prescale-timer0	int	8 bit timer prescale for timer 0. Period of PT0_clk = Period of PWM_clk * (PWM_TIMER0_PRESCALE + 1).
prescale-timer1	int	8 bit timer prescale for timer 1. Period of PT1_clk = Period of PWM_clk * (PWM_TIMER1_PRESCALE + 1).
prescale-timer2	int	8 bit timer prescale for timer 2. Period of PT2_clk = Period of PWM_clk * (PWM_TIMER2_PRESCALE + 1).
pinctrl-0	phandles	Pin configuration/s for the first state. Content is specific to the selected pin controller driver implementation.
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.
pinctrl-names	string-array	Names for the provided states. The number of names needs to match the number of states.

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 “espressif,esp32-mcpwm” compatible.

Name	Type	Details
status	string	indicates the operational status of a device Legal values: 'ok', 'okay', 'disabled', 'reserved', 'fail', 'fail-sss' See Important properties for more information.
compatible	string-array	compatible strings This property is required. See Important properties for more information.
reg	array	register space See Important properties for more information.
reg-names	string-array	name of each register space
interrupts	array	interrupts for device See Important properties for more information.
interrupts-extended	compound	extended interrupt specifier for device
interrupt-names	string-array	name of each interrupt
interrupt-parent	phandle	phandle to interrupt controller node
label	string	Human readable string describing the device (used as device_get_binding() argument) See Important properties for more information. This property is deprecated.
clocks	phandle-array	Clock gate information
clock-names	string-array	name of each clock
#address-cells	int	number of address cells in reg property
#size-cells	int	number of size cells in reg property
dmas	phandle-array	DMA channels specifiers
dma-names	string-array	Provided names of DMA channel specifiers
io-channels	phandle-array	IO channels specifiers
io-channel-names	string-array	Provided names of IO channel specifiers
mboxes	phandle-array	mailbox / IPM channels specifiers
mbox-names	string-array	Provided names of mailbox / IPM channel specifiers
power-domains	phandle-array	Power domain specifiers
power-domain-names	string-array	Provided names of power domain specifiers
#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