How can i set PIN A20(I2C_GP1_DAT), A21(2C_GP2_CLK) as normal GPIO in TX2

I add a device to TX2, using 2-wire Serial Interface protocol to communication with TX2; And my device PIN connect with TX2 PIN A20(I2C_GP1_DAT), A21(2C_GP2_CLK);
How can i set this 2 PIN as a normal GPIO, Where should i start?
Im a new Drive developer, please try to be clear.

Hi, these pins are used as i2c only, they can not be set as gpio pins, please check pinmux sheet in DLC to find out which pins can be set as gpio.

As for how to set pin as gpio, you can search the related topics in forum. Below one is an example for your reference.

How can I write GPIO driver on TX2, my external device need to simulation IIC to communication with TX2,
I tried used GPIO on J21 and J26 in TX2 board, but in User space can not delay for microsecond.
The shortest delay time is 12 The shortest time is microsecond;
So I think I can only write my device control program in the kernel.
And where can I find the date sheet for GPIO driver program, and what is the name?

You may have a look to this article for information about GPIO interfacing on J21 header. This article is for TX1, you would adapt with TX2 J21 header pinout.

For kernel driver, you may have a look to file t18x/drivers/gpio/gpio-tegra186.c in kernel sources from sources package.