UART Async support with SHELL when interrupts are not used?

[gonzalezjl]

Hello,

Is their planned future support or using UART_ASYNC_API with SHELL when interrupts are not used?

static int uarte_nrfx_poll_in(struct device *dev, unsigned char *c)
{

	const struct uarte_nrfx_data *data = get_dev_data(dev);
	NRF_UARTE_Type *uarte = get_uarte_instance(dev);

#ifdef CONFIG_UART_ASYNC_API
	if (data->async) {
		return -ENOTSUP;
	}
#endif

	if (!nrf_uarte_event_check(uarte, NRF_UARTE_EVENT_ENDRX)) {
		return -1;
	}

	*c = data->rx_data;

	/* clear the interrupt */
	nrf_uarte_event_clear(uarte, NRF_UARTE_EVENT_ENDRX);
	nrf_uarte_task_trigger(uarte, NRF_UARTE_TASK_STARTRX);

	return 0;
}

Thanks!

[Jakub Rzeszutko]

Hi,

But this is already supported! :)

We let a lot of flexibility and you can adopt it to your needs using Kconfig.

You need to first disable interrupt driven UART backend in shell options and next disable interrupt driven UART driver.

[Jakub Rzeszutko]

However such approach in my opinion has a lot of disadvantages. You won't be able to paste text to shell. There will be too many characters and you will lost most of them during uart polling.

The same goes with meta keys. For istance history feature may not work. Up arrow is composed of 3 characters sent in short period of time. This can be lost when using non interrupt mode.

[gonzalezjl]

Hello Jakub,

I have tried that configuration both through the project.conf and by using ninja menuconfig.  The results are the same.  The shell starts up, but I can't poll UART_0 because of a ENOTSUP error when UART ASYNC API is used. See code above and picture below.

Thanks,

Juan

[Mierunski]

Hi,

We don't plan on supporting uart_poll_in function in UART_ASYNC_API due to many ambiguities on how it should be handled.

If you decide to use uart instance with UART_ASYNC_API please use uart_rx_enable function for receiving.

Best regards,
Mieszko Mieruński