ti,cc13xx-cc26xx-timer-pwm

Vendor: Texas Instruments

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);
  }

Properties

Properties not inherited from the base binding file.

Name

Type

Details

#pwm-cells

int

Number of items to expect in a pwm specifier

This property is required.

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-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.

Specifier cell names

  • pwm cells: period