serial: fsl_lpuart: RS485 RTS polariy is inverse

commit 846651eca073e2e02e37490a4a52752415d84781 upstream.

The setting of RS485 RTS polarity is inverse in the current driver.

When the property of 'rs485-rts-active-low' is enabled in the dts node,
the RTS signal should be LOW during sending. Otherwise, if there is no
such a property, the RTS should be HIGH during sending.

Fixes: 03895cf41d ("tty: serial: fsl_lpuart: Add support for RS-485")
Cc: stable <stable@kernel.org>
Signed-off-by: Nicolas Diaz <nicolas.diaz@nxp.com>
Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
Link: https://lore.kernel.org/r/20220805144529.604856-1-shenwei.wang@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Shenwei Wang 2022-08-05 09:45:29 -05:00 committed by Greg Kroah-Hartman
parent ae5e8d0baa
commit a65a2a33c6

View File

@ -1277,9 +1277,9 @@ static int lpuart_config_rs485(struct uart_port *port,
* Note: UART is assumed to be active high.
*/
if (rs485->flags & SER_RS485_RTS_ON_SEND)
modem &= ~UARTMODEM_TXRTSPOL;
else if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
modem |= UARTMODEM_TXRTSPOL;
else if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
modem &= ~UARTMODEM_TXRTSPOL;
}
/* Store the new configuration */