Re: atmel_serial: fix RTS high after initialization in RS485 mode

Andrew Morton
2010-10-25T22:54:45Z

On Sun, 24 Oct 2010 12:48:29 +0200
Claudio Scordino <claudio@evidence.eu.com> wrote:

> Hi Nicolas,
>
> when working in RS485 mode, the atmel_serial driver keeps RTS
> high after the initialization of the serial port. It goes low only after
> the first character has been sent.
>
> This patch fixes this behavior. It has been already tested by Arkadiusz (CC:-ed).
>
> Best regards,
>
> Claudio
>
>
> atmel_serial: RTS line low after initialization of the serial port
>
> Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
> Signed-off-by: Arkadiusz Bubala <arkadiusz.bubala@gmail.com>
> ---
> drivers/serial/atmel_serial.c | 9 +++++++++
> 1 files changed, 9 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
> index 3892666..85aa66f 100644
> --- a/drivers/serial/atmel_serial.c
> +++ b/drivers/serial/atmel_serial.c
> @@ -1732,6 +1732,15 @@ static int __devinit atmel_serial_probe(struct platform_device *pdev)
> device_init_wakeup(&pdev->dev, 1);
> platform_set_drvdata(pdev, port);
>
> + if (port->rs485.flags & SER_RS485_ENABLED) {
> + unsigned int control = 0;
> + unsigned int mode = 0;
> + control |= ATMEL_US_RTSEN;
> + mode |= ATMEL_US_USMODE_NORMAL;
> + UART_PUT_MR(&port->uart, mode);
> + UART_PUT_CR(&port->uart, control);
> + }
> +
> return 0;
>

That was a lot of code! How about just this?

if (port->rs485.flags & SER_RS485_ENABLED) {
UART_PUT_MR(&port->uart, ATMEL_US_USMODE_NORMAL);
UART_PUT_CR(&port->uart, ATMEL_US_RTSEN);
}