Linux/PROCESSOR-SDK-AM335X: Different interrupt number from TRM table6.1 and gpio_to_irq?

Part Number:PROCESSOR-SDK-AM335X

Tool/software: Linux

Hi, 

I am using sdk 05.03, am335x-evm board. 

I try to use XDAM_EVENT_INTR0(GPIO0[19], INT_NUM 123 in TRM table 6.1)  for FPGA interrupt, and add it to kernel device tree as following:

&am33xx_pinmux {

        pinctrl-names = "default";

       xdma0_pins: xdma0_pins {

                pinctrl-single,pins = <

                        AM33XX_IOPAD(0x9b0, PIN_INPUT | MUX_MODE0)  /*xdam_event_intr0.intr0*/

>;

};

Then I did the following to enable GPIO0[19] as interrupt and try to request the irq line:

echo 19 > /sys/class/gpio/export

echo in > /sys/class/gpio/gpio19/direction

call request_irq(123, xxx) in driver,    but got error -EINVAL

Then I changed the way to use linux/gpio.h functions:

gpio_request(19);

request_irq(gpio_to_irq(19),xxx);  This works. 

Can anybody help me to figure out why XDMA_EVENT_INTR0 is using a different INT_NUM other than the one listed in table 6.1?

Thank you.