[1/1] serial: 8250: Add helper for clearing IER

A number of places want to clear IER with the same CAP_UUE trick.
Create a helper for that.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/tty/serial/8250/8250_port.c | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

On Tue, Aug 16, 2022 at 3:14 PM Ilpo Järvinen
<ilpo.jarvinen@linux.intel.com> wrote:
>
> A number of places want to clear IER with the same CAP_UUE trick.
> Create a helper for that.

No objections,
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> ---
>  drivers/tty/serial/8250/8250_port.c | 24 +++++++++++-------------
>  1 file changed, 11 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
> index 39b35a61958c..25e4761e3c57 100644
> --- a/drivers/tty/serial/8250/8250_port.c
> +++ b/drivers/tty/serial/8250/8250_port.c
> @@ -752,6 +752,14 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
>         serial8250_rpm_put(p);
>  }
>
> +static void serial8250_clear_IER(struct uart_8250_port *up)
> +{
> +       if (up->capabilities & UART_CAP_UUE)
> +               serial_out(up, UART_IER, UART_IER_UUE);
> +       else
> +               serial_out(up, UART_IER, 0);
> +}
> +
>  #ifdef CONFIG_SERIAL_8250_RSA
>  /*
>   * Attempts to turn on the RSA FIFO.  Returns zero on failure.
> @@ -1329,10 +1337,7 @@ static void autoconfig(struct uart_8250_port *up)
>         serial8250_out_MCR(up, save_mcr);
>         serial8250_clear_fifos(up);
>         serial_in(up, UART_RX);
> -       if (up->capabilities & UART_CAP_UUE)
> -               serial_out(up, UART_IER, UART_IER_UUE);
> -       else
> -               serial_out(up, UART_IER, 0);
> +       serial8250_clear_IER(up);
>
>  out_unlock:
>         spin_unlock_irqrestore(&port->lock, flags);
> @@ -2142,10 +2147,7 @@ static void serial8250_put_poll_char(struct uart_port *port,
>          *      First save the IER then disable the interrupts
>          */
>         ier = serial_port_in(port, UART_IER);
> -       if (up->capabilities & UART_CAP_UUE)
> -               serial_port_out(port, UART_IER, UART_IER_UUE);
> -       else
> -               serial_port_out(port, UART_IER, 0);
> +       serial8250_clear_IER(up);
>
>         wait_for_xmitr(up, UART_LSR_BOTH_EMPTY);
>         /*
> @@ -3383,11 +3385,7 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
>          *      First save the IER then disable the interrupts
>          */
>         ier = serial_port_in(port, UART_IER);
> -
> -       if (up->capabilities & UART_CAP_UUE)
> -               serial_port_out(port, UART_IER, UART_IER_UUE);
> -       else
> -               serial_port_out(port, UART_IER, 0);
> +       serial8250_clear_IER(up);
>
>         /* check scratch reg to see if port powered off during system sleep */
>         if (up->canary && (up->canary != serial_port_in(port, UART_SCR))) {
> --
> 2.30.2
>