On Mon, Apr 18, 2022 at 8:50 AM Yu Tu <yu.tu@xxxxxxxxxxx> wrote:
>
> A /2 divider over XTAL was introduced since G12A, and is preferred
> to be used over the still present /3 divider since it provides much
> closer frequencies vs the request baudrate.Especially the BT module
'e. E' (mind the space)
> uses 3Mhz baud rate. 8Mhz calculations can lead to baud rate bias,
> causing some problems.
...
> +struct meson_uart_data {
> + bool has_xtal_div2;
I would prefer to see this as an unsigned int and with a less
particular name, e.g. xtal_div would suffice.
> +};
...
> + unsigned int xtal_div = 3;
> + if (private_data && private_data->has_xtal_div2) {
> + xtal_div = 2;
Better to define privata data always
> + val |= AML_UART_BAUD_XTAL_DIV2;
> + }
> + val |= DIV_ROUND_CLOSEST(port->uartclk / xtal_div, baud) - 1;
--
With Best Regards,
Andy Shevchenko
