Let GPIO pin Qualcomm 8250 surf board work

The reset state for all GPIOs is as an “input.” So, to get a GPIO value as input, simply read the
appropriate GPIO_IN register. Please note that GPIO 60 and 61 are only available after e-fuses are blown, indicating that their boot function is no longer being used. GPIO 61 corresponds to
BOOT_FROM_NOR, and GPIO 60 corresponds to BOOT_SECURE.

To drive the output pad as a general purpose output, configure the GPIO for alternate function 0,
and write the GPIO_OUT_X register with the desired value, then set (1) the corresponding bit in
the GPIO_OE_X register to enable the output path. For example, perform the following
programming to drive a 1 on GPIO[3] and a 0 on GPIO[1] (bit 3 and 1 of GPIO_OUT_0):
♦ m_write(GPIO_OUT_0, 0x4);
♦ m_write(GPIO_OE_0, 0xA);

To use any alternate GPIO functions, you must perform the following operations:

– Write the number of the GPIO to the GPIO_PAGE register (for example, to program
GPIO(X), write the value of X to GPIO_PAGE).
– Program the GPIO_CFG register to select which function to output.