Re: [PATCH 2/3 v7] serial: 8250: Add MSR/MCR TIOCM conversion wrapper functions

[Yegor Yefremov]

On Mon, Jun 17, 2019 at 4:59 PM Stefan Roese <sr@xxxxxxx> wrote:
>
> This patch adds wrapper functions to convert MSR <-> TIOCM and also
> MCR <-> TIOCM. These functions are used now in serial8250_do_set_mctrl()
> and serial8250_do_get_mctrl().
>
> Signed-off-by: Stefan Roese <sr@xxxxxxx>
> Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Cc: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Cc: Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Giulio Benetti <giulio.benetti@xxxxxxxxxxxxxxxx>

Tested-by: Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx>

> ---
> v7:
> - No change
>
> v6:
> - New patch
>
>  drivers/tty/serial/8250/8250.h      | 54 +++++++++++++++++++++++++++++
>  drivers/tty/serial/8250/8250_port.c | 25 ++-----------
>  2 files changed, 57 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
> index ebfb0bd5bef5..793da2e510e0 100644
> --- a/drivers/tty/serial/8250/8250.h
> +++ b/drivers/tty/serial/8250/8250.h
> @@ -139,6 +139,60 @@ void serial8250_rpm_put_tx(struct uart_8250_port *p);
>  int serial8250_em485_init(struct uart_8250_port *p);
>  void serial8250_em485_destroy(struct uart_8250_port *p);
>
> +/* MCR <-> TIOCM conversion */
> +static inline int serial8250_TIOCM_to_MCR(int tiocm)
> +{
> +       int mcr = 0;
> +
> +       if (tiocm & TIOCM_RTS)
> +               mcr |= UART_MCR_RTS;
> +       if (tiocm & TIOCM_DTR)
> +               mcr |= UART_MCR_DTR;
> +       if (tiocm & TIOCM_OUT1)
> +               mcr |= UART_MCR_OUT1;
> +       if (tiocm & TIOCM_OUT2)
> +               mcr |= UART_MCR_OUT2;
> +       if (tiocm & TIOCM_LOOP)
> +               mcr |= UART_MCR_LOOP;
> +
> +       return mcr;
> +}
> +
> +static inline int serial8250_MCR_to_TIOCM(int mcr)
> +{
> +       int tiocm = 0;
> +
> +       if (mcr & UART_MCR_RTS)
> +               tiocm |= TIOCM_RTS;
> +       if (mcr & UART_MCR_DTR)
> +               tiocm |= TIOCM_DTR;
> +       if (mcr & UART_MCR_OUT1)
> +               tiocm |= TIOCM_OUT1;
> +       if (mcr & UART_MCR_OUT2)
> +               tiocm |= TIOCM_OUT2;
> +       if (mcr & UART_MCR_LOOP)
> +               tiocm |= TIOCM_LOOP;
> +
> +       return tiocm;
> +}
> +
> +/* MSR <-> TIOCM conversion */
> +static inline int serial8250_MSR_to_TIOCM(int msr)
> +{
> +       int tiocm = 0;
> +
> +       if (msr & UART_MSR_DCD)
> +               tiocm |= TIOCM_CAR;
> +       if (msr & UART_MSR_RI)
> +               tiocm |= TIOCM_RNG;
> +       if (msr & UART_MSR_DSR)
> +               tiocm |= TIOCM_DSR;
> +       if (msr & UART_MSR_CTS)
> +               tiocm |= TIOCM_CTS;
> +
> +       return tiocm;
> +}
> +
>  static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
>  {
>         serial_out(up, UART_MCR, value);
> diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
> index 2304a84eee3b..47f0a8d01a57 100644
> --- a/drivers/tty/serial/8250/8250_port.c
> +++ b/drivers/tty/serial/8250/8250_port.c
> @@ -1944,22 +1944,12 @@ unsigned int serial8250_do_get_mctrl(struct uart_port *port)
>  {
>         struct uart_8250_port *up = up_to_u8250p(port);
>         unsigned int status;
> -       unsigned int ret;
>
>         serial8250_rpm_get(up);
>         status = serial8250_modem_status(up);
>         serial8250_rpm_put(up);
>
> -       ret = 0;
> -       if (status & UART_MSR_DCD)
> -               ret |= TIOCM_CAR;
> -       if (status & UART_MSR_RI)
> -               ret |= TIOCM_RNG;
> -       if (status & UART_MSR_DSR)
> -               ret |= TIOCM_DSR;
> -       if (status & UART_MSR_CTS)
> -               ret |= TIOCM_CTS;
> -       return ret;
> +       return serial8250_MSR_to_TIOCM(status);
>  }
>  EXPORT_SYMBOL_GPL(serial8250_do_get_mctrl);
>
> @@ -1973,18 +1963,9 @@ static unsigned int serial8250_get_mctrl(struct uart_port *port)
>  void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl)
>  {
>         struct uart_8250_port *up = up_to_u8250p(port);
> -       unsigned char mcr = 0;
> +       unsigned char mcr;
>
> -       if (mctrl & TIOCM_RTS)
> -               mcr |= UART_MCR_RTS;
> -       if (mctrl & TIOCM_DTR)
> -               mcr |= UART_MCR_DTR;
> -       if (mctrl & TIOCM_OUT1)
> -               mcr |= UART_MCR_OUT1;
> -       if (mctrl & TIOCM_OUT2)
> -               mcr |= UART_MCR_OUT2;
> -       if (mctrl & TIOCM_LOOP)
> -               mcr |= UART_MCR_LOOP;
> +       mcr = serial8250_TIOCM_to_MCR(mctrl);
>
>         mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
>
> --
> 2.22.0
>