[PATCH RFC 4/9] serial: serial_meson: add minimal non-DM driver

[Ferass El Hafidi]

On Wed Sep 10, 2025 at 7:53 PM UTC, Heinrich Schuchardt wrote:
> <...>
>> +static int meson_serial_getc(void)
>> +{
>> +	struct meson_uart *const uart = (struct meson_uart *)CONFIG_VAL(DEBUG_UART_BASE);
>> +	uint32_t status = readl(&uart->status);
>> +
>> +	if (status & AML_UART_RX_EMPTY)
>> +		return -EAGAIN;
>> +
>> +	if (status & AML_UART_ERR) {
>> +		u32 val = readl(&uart->control);
>> +
>> +		/* Clear error */
>> +		val |= AML_UART_CLR_ERR;
>> +		writel(val, &uart->control);
>> +		val &= ~AML_UART_CLR_ERR;
>> +		writel(val, &uart->control);
>> +
>> +		/* Remove spurious byte from fifo */
>> +		readl(&uart->rfifo);
>> +		return -EIO;
>> +	}
>> +
>> +	return readl(&uart->rfifo) & 0xff;
>> +}
>> +
>> +static int meson_serial_tstc(void)
>> +{
>> +	struct meson_uart *const uart = (struct meson_uart *)CONFIG_VAL(DEBUG_UART_BASE);
>
> CONFIG_SPL_DEBUG_UART_BASE only exists for CONFIG_DEBUG_UART=y and 
> CONFIG_SPL=y. Shall all configurations depend on CONFIG_DEBUG_UART=y?
>
> Creating this dependency does not look right to me.
>

All Amlogic defconfigs have CONFIG_DEBUG_UART enabled, but I can remove
the dependency on CONFIG_DEBUG_UART_BASE if you think it doesn't look
right.

> Best regards
>
> Heinrich
>

Thanks.