Getting the Trigger Source for a interrupt inside a Signle Callback Function

[Sameera]

Hi,

I am new to Nordic Semiconductors and Zephyr destribution.

I am trying to create a single callback function for multiple external interrupts from same port for a code library development.

Here is my code in IO.c library class:

ErrorCode configurePinInterrupt(PinList pin,button_event_handler_t buttonHandlerFn,gpio_flags_t interruptFlags){

    int ret = 0;
    uint8_t index = getPinIndex(pin);

    pressedButtonHandler = buttonHandlerFn;

    ret = gpio_pin_interrupt_configure_dt(&PinInfos[index].pinSpec,interruptFlags);

    if(ret!=0){
        setGPIO(LED1,HIGH);
        return GPIO_Pin_Set_Error;
    }
        
    gpio_init_callback(&intrcallBackStruct,interruptCallbackFn,BIT(PinInfos[index].pinSpec.pin));

    ret = gpio_add_callback(PinInfos[index].pinSpec.port,&intrcallBackStruct);
    if(ret!=0){
        setGPIO(LED1,HIGH);
        return GPIO_Pin_Set_Error;
    }
    
    return NO_ERROR;
}

static K_WORK_DELAYABLE_DEFINE (interruptDebouncing,buttonPressDebouncingHandler);

void interruptCallbackFn(const struct device *dev,struct gpio_callback *cb,uint32_t pins){

    currentPressedPin = Enable3V3;
    
    k_work_reschedule(&interruptDebouncing,K_MSEC(15));

}

void buttonPressDebouncingHandler(struct k_work buttonInterruptWork){

    ARG_UNUSED(buttonInterruptWork);

    int value = gpio_pin_get_dt(&PinInfos[getPinIndex(currentPressedPin)].pinSpec)?Button_Is_Pressed:Button_Is_Released;

    switch (value)
    {
        case Button_Is_Pressed:
            setGPIO(LED2,LOW);
            break;
        case Button_Is_Released:
            pressedButtonHandler(currentPressedPin);
            break;
    }

}

I need to find the pin number of the pin/pin spec inside "interruptCallbackFn" to differentiate between multiple external interrupt events.

Then I can pass that value to the main.c via pressedButtonHandler method.

Is there a way this can be done?

To make it easy:

1. A user can call the function "configurePinInterrupt" from main.c to configure interrupts for individual pins as below.

configurePinInterrupt(Enable3V3,enable3V3ButtonPressed,GPIO_INT_EDGE_RISING);

2. Then following method is invoked by the IO.c class, whenever an interrupt is generated.

void enable3V3ButtonPressed(PinList pin){

	switch (pin)
	{
		case Enable3V3:
			setGPIO(LED2,HIGH);
			break;
		
		default:
			break;
	}
}

Is there any possibility to achieve this functionality only using single callback function inside IO.c ?

[Johnny Nguyen]

Not really EXACTLY your application in the ticket, but a while ago I added two of the devkit buttons to a single callback in a separate io.c file in a project while practicing/learning.

Here's a link to that project, I uploaded it to a public repo just now (if it gives you any ideas while waiting for full DevZone support to respond, great!)

droidecahedron/nrf_io_practice: practicing io in zephyr as well breaking out separate source/header files in NCS (github.com)

Specifically, the following lines in io.c
nrf_io_practice/src/io.c at main · droidecahedron/nrf_io_practice (github.com)
and
nrf_io_practice/src/io.c at main · droidecahedron/nrf_io_practice (github.com)

there's a dk_buttons_and_leds.c library that has a way to init the IO on the Nordic Devkits that's pretty nice and instead of the weird cases of 2048/4096, it lets you parse by DK_BTNx_MSK in the switch case which is handy. (One sample off the top of my head that use that library are... mesh light switch.)

Either way, here's the output pressing the two different buttons going to the same callback:

 

It's mostly modified from the zephyr button sample. I set up the repo I linked to just be between the stock zephyr button sample, and the adjustments to add an extra source/header file and a shared callback for the two different buttons. Just looking at the diff for commit dec36ca in that repo can show the changes made to get the result described.

[Sameera]

Thank you very much for your support. How can i get the value for the parameter 

const struct device *dev,struct gpio_callback *cb,uint32_t pins 

here? Is there any documentation or somewhere which I should refer to? 

Thanks a lot again.

[Sameera]

Update: Value in the sense, is there any documentation that describes how this value is calculated for a specific Pin or kind of a table that contains this information? Because, for a library, such a list has to be hard coded.

[Johnny Nguyen]

If you looked at the code, it printed 2048 and 4096 for those callbacks, and the switch case just uses 2048 and 4096.

The reason for this is that it gives you the pin value in bit form. 

Button0 was Pin 11

Button1 was Pin 12.

1 << 11 (Which is pin 11) = 2048

1 << 12 (Which is pin 12) = 4096.

Here's a visual aid.

and within the device tree for the nRF52840dk this project was for:

The callbacks in the example I gave say button1 and button2 in the printk, but it's button0 and button1. (I fixed this in the new commit just now.)

I modified the project I linked you previously with some helpful print statements to illustrate this, as well as added button2 (pin24).

You can identify the pin from the pins variable using & with the bit, or left shifting with the pin number.

// Identifying pin # with shifting
pins & (1 << pin_num)

// Identifying pin # with bit
pins & BIT(pin_num)

As a heads up though, remember a switch case wants constant expressions. (Hence why I define the pinmsks at the top for the modified project)

Here is the new output:

best wishes,

[Sameera]

Sorry for my late reply. That worked well for me.

[Johnny Nguyen]

Glad I could be of assistance! Reach out if there's anything more, (otherwise feel free to select it as verified answer if that snippet gave you everything you needed).

Best wishes,