Enable tristate for pin UART1_TXD

[yeshwanth.vn]

Hi,

We have configured the pin UART1_TXD (pin number 203 in som connector) as gpio input tristate in dtb. The dtb entry for the pin is given as below,

uart1_tx_pr2 {
nvidia,pins = “uart1_tx_pr2”;
nvidia,function = “rsvd1”;
nvidia,pull = <TEGRA_PIN_PULL_NONE>;
nvidia,tristate = <TEGRA_PIN_ENABLE>;
nvidia,enable-input = <TEGRA_PIN_ENABLE>;
nvidia,io-high-voltage = <TEGRA_PIN_DISABLE>;
nvidia,lpdr = <TEGRA_PIN_DISABLE>;
};

We observe the pinmux driver to set this pin in tristate (TEGRA_PINCONF_PARAM_TRISTATE switch case, tegra_pinconf_reg function(), kernel/kernel-4.9/drivers/pinctrl/tegra/pinctrl-tegra.c file), but probing the pin we don’t see tristate is enabled.

Could you please provide any idea on how to proceed this further?

[JerryChang]

hello yeshwanth.vn,

did you use the pinmux configuration, had you update the cfg file by full flash the target?

[yeshwanth.vn]

Hi,

We have tried writing 0x00000051 in 0x024300a8 in cfg file( tegra19x-mb1-pinmux-p3668-a01.cfg ) and flashed and checked, still we are not able to see that pin is in tristate.

Also we have tried using devmem2 (sudo devmem2 0x024300a8 w 0x00000051), still that pin is not seen in tristate. Please advise us on how to get this resolved.

[Trumany]

Hi, how do you measure the pin? Is the GPIO function of this in normal? There is a level shift for this pin on carrier board and also there is a buffer on module.