From: Lino Sanfilippo <l.sanfilippo@xxxxxxxxxx>
In uart_get_rs485_mode() only try to get a termination GPIO if RS485 bus
termination is supported by the driver.
Signed-off-by: Lino Sanfilippo <l.sanfilippo@xxxxxxxxxx>
---
drivers/tty/serial/serial_core.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 1368b0ef7d7f..015f4e1da647 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -3384,17 +3384,20 @@ int uart_get_rs485_mode(struct uart_port *port)
rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
}
- /*
- * Disabling termination by default is the safe choice: Else if many
- * bus participants enable it, no communication is possible at all.
- * Works fine for short cables and users may enable for longer cables.
- */
- port->rs485_term_gpio = devm_gpiod_get_optional(dev, "rs485-term",
- GPIOD_OUT_LOW);
- if (IS_ERR(port->rs485_term_gpio)) {
- ret = PTR_ERR(port->rs485_term_gpio);
- port->rs485_term_gpio = NULL;
- return dev_err_probe(dev, ret, "Cannot get rs485-term-gpios\n");
+ if (port->rs485_supported->flags & SER_RS485_TERMINATE_BUS) {
+ /*
+ * Disabling termination by default is the safe choice: Else if
+ * many bus participants enable it, no communication is possible
+ * at all. Works fine for short cables and users may enable for
+ * longer cables.
+ */
+ port->rs485_term_gpio = devm_gpiod_get_optional(dev, "rs485-term",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(port->rs485_term_gpio)) {
+ ret = PTR_ERR(port->rs485_term_gpio);
+ port->rs485_term_gpio = NULL;
+ return dev_err_probe(dev, ret, "Cannot get rs485-term-gpios\n");
+ }
}
return 0;
--
2.36.1
