PWM led pin configuration

[AndyM]

I have a custom nRF52840 based board with 2 LED's 

In the .dtsi they are defined as follows

pwm0_default: pwm0_default {

        group1 {

            psels = <NRF_PSEL(PWM_OUT0, 0, 29)>,

                    <NRF_PSEL(PWM_OUT1, 0, 31)>;

            nordic,invert;

        };

    };

    pwm0_sleep: pwm0_sleep {

        group1 {

            psels = <NRF_PSEL(PWM_OUT0, 0, 29)>,

                    <NRF_PSEL(PWM_OUT1, 0, 31)>;

            low-power-enable;

        };

    };

The .dts file references the pins as follows

pwmleds {

       

        compatible = "pwm-leds";

        pwm_led1_red: pwm_led_1 {

            // Second parameter is offset into the array defined in pinctrl.dtsi

            pwms = <&pwm0 0 PWM_MSEC(20) PWM_POLARITY_INVERTED>;

            label = "RED_PWM_LED_1";

        };

        

        pwm_led2_blue: pwm_led_2 {

            pwms = <&pwm0 1 PWM_MSEC(20) PWM_POLARITY_INVERTED>;

            label = "BLUE_PWM_LED_2";

        };

    };

In the code the pwm device is obtained from dts without errors

const struct device *  _led_pwm = device_get_binding(LED_PWM_DEV_NAME);

However when I try to call

led_set_brightness(_led_pwm, <0 or 1>, 100 ) API I get error -22

Any ideas why?
Here is the screenshot of the LED schematics

Perhaps the pins are not configured correctly ? I'm having trouble accessing individual pins within the structure outlined above

A sample would be great

Thank you

[Øivind]

Hi,

led_set_brightness() is probably not from the api you want to use.
Take a look at the sample at zephyr/samples/basic/blinky_pwm
And the api in zephyr/include/zephyr/drivers/pwm.h

[AndyM]

My bad, the API call made is

led_on(_led_pwm, led_num);

Anything in the schematics and the dts or dtsi that jumps out?

What are my options to troubleshoot?

Thank you

 

[Øivind]

Hi,

For that api, you want the device to be the node containing:

    compatible = "pwm-leds";

which is the parent node.

You need CONFIG_LED=y and CONFIG_PWM=y

You can also try using DEVICE_DT_GET() instead of device_get_binding(). DEVICE_DT_GET() needs the node identifier for the pwmleds node.

[AndyM]

Update

There problem was that one of the LED pins had an overlapping assignment with another component 
After that got resolved the PWM works just fine with the LEDs

Thank you for help