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 <cniedermaier@xxxxxxxxxxxxxxxxxx>
---
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Jiri Slaby <jirislaby@xxxxxxxxxx>
Cc: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>
Cc: Alexandre Torgue <alexandre.torgue@xxxxxxxxxxx>
Cc: Alexander Dahl <ada@xxxxxxxxxxx>
Cc: Marek Vasut <marex@xxxxxxx>
Cc: kernel@xxxxxxxxxxxxxxxxxx
Cc: linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
To: linux-serial@xxxxxxxxxxxxxxx
To: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
---
V2: - Rework of the commit message
V3: - No changes
V4: - Direct call of gpiod_set_value_cansleep() without if statement
---
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 a1490033aa16..f1b1df78118f 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);
--
2.11.0
