On Mon, Jun 17, 2019 at 2:42 PM Stefan Roese <sr@xxxxxxx> wrote:
>
> On 17.06.19 11:51, Yegor Yefremov wrote:
>
> <snip>
>
> >>> @@ -1944,11 +1948,15 @@ unsigned int serial8250_do_get_mctrl(struct uart_port *port)
> >>> {
> >>> struct uart_8250_port *up = up_to_u8250p(port);
> >>> unsigned int status;
> >>> + unsigned int val = 0;
> >>>
> >>> serial8250_rpm_get(up);
> >>> status = serial8250_modem_status(up);
> >>> serial8250_rpm_put(up);
> >>>
> >>> + if (up->gpios)
> >>> + return mctrl_gpio_get(up->gpios, &val);
> >>> +
> >>
> >> What happens when you have a mixed setup i.e. CTS controlled by UART
> >> but other status pins controlled by GPIO? In this case CTS status
> >> won't be returned. Do I see it right?
>
> Yes, your analysis does seem to be correct. Please note that I did
> not intentionally did change it this way. I was not thinking about
> such a "mixed design".
>
> > What about something like this:
> >
> > unsigned int serial8250_do_get_mctrl(struct uart_port *port)
> > {
> > struct uart_8250_port *up = up_to_u8250p(port);
> > unsigned int status;
> > unsigned int val;
> >
> > serial8250_rpm_get(up);
> > status = serial8250_modem_status(up);
> > serial8250_rpm_put(up);
> >
> > val = serial8250_MSR_to_TIOCM(status);
> > if (up->gpios)
> > mctrl_gpio_get(up->gpios, &val);
> >
> > return val;
> > }
>
> Looks good to me, thanks. Do you have such a setup with some modem
> control signal handled via GPIO and some via the UART? Could you
> test such a change?
I already have :-)
This my DTS file:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/am335x-baltos-ir5221.dts#n38
Yegor
