dts/bindings/pwm/ti,cc13xx-cc26xx-timer-pwm.yaml

# Copyright (c) 2023, Zephyr Project
# SPDX-License-Identifier: Apache-2.0

description: |
  TI SimpleLink CC13xx/CC26xx GPT timer PWM Controller Node

  To configure a PWM node, you first need to define a board overlay with a
  pinctrl configuration for the pin on which the PWM signal should be present:

    &pinctrl {
      gpt0_pwm: gpt0_pwm {
        pinmux = <25 IOC_PORT_MCU_PORT_EVENT1>;
        bias-disable;
        drive-strength = <8>; /* in mA, can be 2, 4 or 8 */
      };
    };

  Please be aware that the port event depends on the GPT instance chosen. The
  following port events must be used for PWM:
    - GPT0: IOC_PORT_MCU_PORT_EVENT1
    - GPT1: IOC_PORT_MCU_PORT_EVENT3
    - GPT2: IOC_PORT_MCU_PORT_EVENT5
    - GPT3: IOC_PORT_MCU_PORT_EVENT7

  Be careful not to choose a pin that is already in use on your board, this
  might irreversible damage to your board as the given pin will be configured as
  output and actively driven by the PWM driver.

  Then enable the corresponding timer and PWM nodes and add a reference to the
  pinctrl entry:

    &gpt0 {
      status = "okay";
    };

    &pwm0 {
      status = "okay";
      pinctrl-0 = <&gpt0_pwm>;
      pinctrl-names = "default";
    };

  Now you can programmatically enable the PWM signal in your code:

    static const struct device *pwm = DEVICE_DT_GET(DT_NODELABEL(pwm0));

    int init_pwm(void)
    {
      uint32_t pwm_period_ns, pwm_pulse_ns;
      uint32_t pwm_duty_percent = 50U;
      uint32_t pwm_frequency = 1000U; /* 1kHz */

      if (!device_is_ready(pwm)) {
        LOG_ERR("Error: PWM device %s is not ready\n", pwm->name);
        return -ENODEV;
      }

      pwm_period_ns = NSEC_PER_SEC / pwm_frequency;
      pwm_pulse_ns = (pwm_duty_percent * pwm_period_ns) / 100;

      return pwm_set(pwm, 0, pwm_period_ns, pwm_pulse_ns, 0);
    }

compatible: "ti,cc13xx-cc26xx-timer-pwm"

include: [base.yaml, pwm-controller.yaml, pinctrl-device.yaml]

properties:
  pinctrl-0:
    required: true

pwm-cells:
  - channel
  - period
  - flags