Uart0_rts gpio pinmux

i want to set uart0_rts to output pin.


GPIO3_PD.03 = 3*8+3 = 27

i exec command:
cd /sys/class/gpio
echo 27 > export
cd gpio27
echo out > direction
cat value is 0
but the signal is high-level.
and when i set value to 1, the signal is high-level also.
how can i control the gpio 27?

hello y2zwei,

there’s customer usage to define the pin as UC3_RTS by default, its device tree configuration shown as below.

			uart3_rts_pd3 {
				nvidia,pins = "uart3_rts_pd3";
				nvidia,function = "uartc";
				nvidia,pull = <TEGRA_PIN_PULL_UP>;
				nvidia,tristate = <TEGRA_PIN_DISABLE>;
				nvidia,enable-input = <TEGRA_PIN_DISABLE>;

sry, I measured the wrong pin.