How to disable UART20 runtime for low power

[Marco Tavan]

Dear support,

We need to disable the UART20 runtime. Currently it is configured as follows:

CONFIG_SERIAL=y

CONFIG_UART_ASYNC_API=y

CONFIG_UART_INTERRUPT_DRIVEN=y

CONFIG_UART_20_INTERRUPT_DRIVEN=n

CONFIG_UART_20_ASYNC=y

I need to disable permanently this UART runtime from the application, i.e., 1 minute after boot.

Can you help me disable the UART safely with a snippet of code for low power consumption? 

thank you

marco

[Kenneth]

Hello,

Conceptually (not tested) it should be done like below:

Zephyr provides a power management API to suspend and resume devices, including UART.

Suspend UART

#include <zephyr/pm/device.h>

const struct device *uart_dev = DEVICE_DT_GET(DT_NODELABEL(uart0)); // or uart1, etc.

if (device_is_ready(uart_dev)) {
pm_device_action_run(uart_dev, PM_DEVICE_ACTION_SUSPEND);
}

Resume UART

if (device_is_ready(uart_dev)) {
pm_device_action_run(uart_dev, PM_DEVICE_ACTION_RESUME);
}

In your prj.conf:
CONFIG_PM=y
CONFIG_PM_DEVICE=y

Hope that helps,
Kenneth