Starterware/DRA72XEVM: Writing an ISR

Hm, I'm more interested in what is going on in terms of the interrupts, such as setting the crossbar, and capturing a GPIO pin being pulled down, so I can correctly write an ISR. Do you mind explaining those aspects of the file? Thanks.

Thanks Rishabh,

I'm looking through that file, specifically the GPIO API calls within configurGpioInterrupt and I see the call "Intc_IntRegister()" has the following parameters:

* \param intrNum - Interrupt Number
* \param fnHandler - Function pointer to the ISR
* \param fun_arg - Argument to the ISR

can you please answer the following questions based on those parameters?

1. How do I know what interrupt number I need to choose to link to this: "#define XBAR_INST_MPU_IRQ_29 (24U)" (GPIO1_IRQ_1)
2. If the argument is null can I just use "null" as the argument

My next question pertains to "IRQXBARConnect()"

* \param baseAddr Memory address of IRQ XBAR.
* \param cpu CPU ID whose interrupt xbar instance is to be setup
* \param xbarInst IRQ XBAR instance number to be programmed
* \param intrSource Source interrupt to be selected via the IRQ XBAR instance

1. Where do I find the values for these parameters? I'm assuming they are in the TRM, but what should I look for in each one?

Thanks so much,

Barend

Hi Rishabh,

I've been caught up in some other work, but thanks for your answer!

I think I've got a pretty good grasp of what I need to do, but I do have a simple follow up question:

• Do I need to copy anything other than configurGpioInterrupt() and gpioIsr() from the gpio main.c file into the file I'm working on to detect a gpio high to low transition? I see the gpio clock/reset/enable functions being called in main(), but am not sure if they can be ported directly to a different file, such as mcspiMasterSlave_spi1_spi2.c

Thanks,

Barend

Rishabh,

One last thing:

• Can you confirm that the following code appropriately matches the screenshot of the TRM? I'm not sure what some of these variables represent, but I did my best to model them after your example. 

  uint32_t gpio_base_address = SOC_GPIO1_BASE;
  uint32_t gpio_pin          = 24;
  uint32_t interrupt_num     = 29;
  uint32_t xbar_cfg_required = 0;
  #define IRQ_XBAR_CFG_REQUIRED 1
  #define IRQ_XBAR_CPU_ID CPU_IPU1
  #define IRQ_XBAR_INST_NO XBAR_INST_MPU_IRQ_29
  #define IRQ_XBAR_INDEX GPIO1_IRQ_1
  
  /*...*/
  /*code*/
  /*...*/
  
  /*Disable interrupt*/
  GPIOPinIntDisable(gpio_base_address, GPIO_INT_LINE_1, gpio_pin);
  
  /*Read pin*/
  gpio_pin_value = GPIOPinRead(gpio_base_address, gpio_pin);
  
  UARTPuts(uartOutput, -1);
  UARTPutHexNum((gpio_pin_value & (0x1U << gpio_pin)) >> gpio_pin);
  
  GPIOPinIntClear(gpio_base_address, GPIO_INT_LINE_1, gpio_pin);
  
  /*Enable interrupt interrupt*/
  GPIOPinIntEnable(gpio_base_address, GPIO_INT_LINE_1, gpio_pin);

  

Using the Cortex_M4_IPU1_C0 core, I want to capture an interrupt from the MMC3_DAT6 (pin 31) pin on the EXP_P3 header on a J6 Eco EVM.

Thanks Rishabh,

So my code changes would from be:

#define IRQ_XBAR_INST_NO XBAR_INST_MPU_IRQ_29
#define IRQ_XBAR_INDEX GPIO1_IRQ_1

to

#define IRQ_XBAR_INST_NO XBAR_INST_IPU1_IRQ_29
#define IRQ_XBAR_INDEX IPU1_IRQ_Crossbar_inst_7 //128?

Does it matter that those are reserved? Also does the rest of my code look correct?

Barend

When I create a falling edge, but the gpioIsr() function in the following code isn't being evaluated when I place a breakpoint there.

#ifdef TDA2XX_FAMILY_BUILD
uint32_t gpio_base_address = SOC_GPIO1_BASE;
uint32_t gpio_pin          = 24;
uint32_t interrupt_num     = 29;
uint32_t xbar_cfg_required = 0;
#define IRQ_XBAR_CFG_REQUIRED 1
#define IRQ_XBAR_CPU_ID CPU_IPU1
#define IRQ_XBAR_INST_NO XBAR_INST_IPU1_IRQ_29
#define IRQ_XBAR_INDEX IPU1_IRQ_Crossbar_inst_7 //128
#endif

void configurGpioInterrupt()
{
#if IRQ_XBAR_CFG_REQUIRED
    PlatformUnlockMMR();
    IRQXBARConnect(SOC_IRQ_DMARQ_CROSSBAR_REGISTERS_BASE, CPU_IPU1, XBAR_INST_IPU1_IRQ_29, GPIO1_IRQ_1);
#endif
    Intc_Init();
    Intc_IntEnable(0);

    Intc_IntRegister(24, (IntrFuncPtr) gpioIsr, NULL);
    Intc_IntPrioritySet(interrupt_num, 1, 0);
    Intc_SystemEnable(interrupt_num);

}

void gpioIsr()
{
    TCAN_Int_Cnt++;
}


int main(void)
{
    PlatformUartConsoleSetPinMux();

    UARTStdioInit();

    /* Do GPIO pin mux */
    PlatformGPIOInputOutputSetPinMux();

    /*Configure interrupt controller*/
    configurGpioInterrupt();

    /*Enable GPIO clock */
    PlatformGPIOClockEnable();

    /*Reset GPIO*/
    GPIOModuleReset(gpio_base_address);

    /*Enable GPIO*/
    GPIOModuleEnable(gpio_base_address);

    //main_SPI1toSPI2();
    main_SPI1toTCAN4550();
    while(1)
    {
        if(TCAN_Int_Cnt > 0)
        {
            TCAN_Int_Cnt--;

            /*!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!ISR!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*/
            /*!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*/
            
            volatile uint32_t gpio_pin_value = 0;

            /*Disable interrupt*/
            GPIOPinIntDisable(gpio_base_address, GPIO_INT_LINE_1, gpio_pin);

            /*Read pin*/
            gpio_pin_value = GPIOPinRead(gpio_base_address, gpio_pin);

            UARTPuts(uartOutput, -1);
            UARTPutHexNum((gpio_pin_value & (0x1U << gpio_pin)) >> gpio_pin);

            GPIOPinIntClear(gpio_base_address, GPIO_INT_LINE_1, gpio_pin);

            /*Enable interrupt interrupt*/
            GPIOPinIntEnable(gpio_base_address, GPIO_INT_LINE_1, gpio_pin);
            
            uint32_t RXF0S = AHB_READ_B_FL_32(M_CAN_RXF0S);
            UARTPuts("RXF0S: ", -1); UARTPutHexNum(RXF0S); UARTPuts("\n", -1);
        }
    }
    return 1;
}

Thanks,

Barend

Hi Barend,

Interrupts should be registered using  interrupt line number and not GPIO pin number. Please make the below modification:

Intc_IntRegister(interrupt_num, (IntrFuncPtr) gpioIsr, NULL)

Regards,

RIshabh

Rishbh,

Thanks for looking through my code!

For some reason, when I put a breakpoint in my ISR, it's never being reached. It may be due to a bounce in the switch I'm using to emulate an interrupt from a pin. Here is a screenshot of what the signal looks like. 

I know this bouncing is an issue, but would it make it so the interrupt is never picked up in the first place?

Thanks,

Barend

Hi Barend,

You can set either Interrupt status or Interrupt Raw Status register i.e. GPIO_IRQSTATUS_RAW_0 0x4AE1_0024 or GPIO_IRQSTATUS_0 0x4AE1_002c for the particular pin.

Please look at the GPIO HAL Driver(<starterware_rootdir>/drivers) which uses the interrupt registers.

This will give a better idea as APIs are quite intuitive.

Regards,

Rishabh

Rishabh,

Is gpio_v2.c the file you were talking about in the /drivers directory? If so, I see that there is a function

GPIOTriggerPinInt(uint32_t baseAdd, uint32_t intLine, uint32_t pinNumber)

that calls

HW_WR_REG32(baseAdd + GPIO_IRQSTATUS_RAW_0, (uint32_t) 1 << pinNumber);

I'm assuming that in the memory browser, I just manually set it the address to what you provided me. However, I'm uncertain on two fronts: since my pin number is 24, would the value I write to the address be 48, and when I try to edit the contents of the register by clicking on the string of 0s and pressing enter, the value defaults back to the string of 0s. Is this not the correct way to change values? If not, could you point me to a guide? My search results didn't yield much.

Thanks,

Barend

Rishabh,

Thanks! Changing the memory triggered my interrupt, and it executed how I wanted. What steps should I take to check the Padmux settings?

So far I've added:

{DEVICE_MODULE_ID_VIP,   DEVICE_MODULE_VIP1_S1_PORTA_INST_ID_0,
 (BOARD_MODE_VIDEO_24BIT), CTRL_CORE_PAD_MMC3_DAT6, 0x4000E},

to the gBoardTda2exPinMuxData[] in the stw_boardTda2exPinmuxData.c file.

Thanks,

Barend

Hi Rishabh,

Thanks for the code! Unfortunately, flipping the switch still doesn't result in an interrupt. I checked the physical address of GPIO1_24(0x4A00 379C) and it evaluates to 0006000E, does this mean anything to you?

Is there a way to simply check the value of the pin before and after toggling the switch, to verify that the event is being recognized by the J6?

Thanks,

Barend

Hi Rishabh,

I called 

GPIOTriggerPinInt(gpio_base_address, GPIO_INT_LINE_1, gpio_pin);

in the main while loop and the interrupt is not being triggered. What does this mean?

Thanks,

Barend

Hi Rishabh,

Apologies for the delay, I was out last week.

After stepping through the code and observing the memory the following changes:

• 0x4AE10024 - 0000 0000 to 0100 0000
• 0x4AE10118 - 0000 0000 to 0100 0000

This second is not the same register that was set previously.

When I run gpio_input_interrupt_app what should I expect? I run it on the A15 and have teraterm up with a baud rate of 115200, 0 bits of parity and a stop of 1 bit.

Attached are the files I've changed. Please let me know if you need any others

Thanks,

Barend