From c54d48543689f821f6a5ade7e7fa828ada6a1195 Mon Sep 17 00:00:00 2001 From: Christoph Niedermaier Date: Fri, 2 Dec 2022 11:41:27 +0100 Subject: [PATCH] serial: stm32: 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. Controlled by this GPIO, now the hardware is responsible for connecting or disconnecting RX during TX. Signed-off-by: Christoph Niedermaier Link: https://lore.kernel.org/r/20221202104127.122761-4-cniedermaier@dh-electronics.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/stm32-usart.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index a149003..f1b1df7 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -226,7 +226,11 @@ static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *ter stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit)); - rs485conf->flags |= SER_RS485_RX_DURING_TX; + if (port->rs485_rx_during_tx_gpio) + gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, + !!(rs485conf->flags & SER_RS485_RX_DURING_TX)); + else + rs485conf->flags |= SER_RS485_RX_DURING_TX; if (rs485conf->flags & SER_RS485_ENABLED) { cr1 = readl_relaxed(port->membase + ofs->cr1); -- 2.7.4