From ca530cfa968c6fa197ee7df877a277954b87bad5 Mon Sep 17 00:00:00 2001 From: Christoph Niedermaier Date: Fri, 2 Dec 2022 11:41:26 +0100 Subject: [PATCH] serial: imx: Add support for RS485 RX_DURING_TX output GPIO If a RX_DURING_TX GPIO is defined by the DT property "rs485-rx-during-tx-gpios" this patch switches this GPIO accordingly to the RS485 flag RX_DURING_TX in user space. In addition, the i.MX UART receiver is no longer turned on and off during sending, because now the hardware is responsible for connecting or disconnecting RX during TX controlled by this GPIO. Signed-off-by: Christoph Niedermaier Link: https://lore.kernel.org/r/20221202104127.122761-3-cniedermaier@dh-electronics.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/imx.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 74c9e68fc3bd..f2b43fb497ff 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -476,7 +476,8 @@ static void imx_uart_stop_tx(struct uart_port *port) imx_uart_rts_inactive(sport, &ucr2); imx_uart_writel(sport, ucr2, UCR2); - imx_uart_start_rx(port); + if (!port->rs485_rx_during_tx_gpio) + imx_uart_start_rx(port); sport->tx_state = OFF; } @@ -705,7 +706,8 @@ static void imx_uart_start_tx(struct uart_port *port) imx_uart_rts_inactive(sport, &ucr2); imx_uart_writel(sport, ucr2, UCR2); - if (!(port->rs485.flags & SER_RS485_RX_DURING_TX)) + if (!(port->rs485.flags & SER_RS485_RX_DURING_TX) && + !port->rs485_rx_during_tx_gpio) imx_uart_stop_rx(port); sport->tx_state = WAIT_AFTER_RTS; @@ -1956,6 +1958,10 @@ static int imx_uart_rs485_config(struct uart_port *port, struct ktermios *termio rs485conf->flags & SER_RS485_RX_DURING_TX) imx_uart_start_rx(port); + if (port->rs485_rx_during_tx_gpio) + gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, + !!(rs485conf->flags & SER_RS485_RX_DURING_TX)); + return 0; } -- 2.25.1