[PATCH 0/2] serial: core: add transceiver interface select GPIO

[Tapio Reijonen]

Multiprotocol transceivers such as the LTC2873 provide an RS485
interface and an alternative interface, typically RS232, on the same
bus pins and choose between them with an interface select input. Add
an optional rs485-select-gpios property next to the existing
rs485-term-gpios and rs485-rx-during-tx-gpios, and let the serial core
drive it from the RS485 configuration state, so that every UART driver
using uart_get_rs485_mode() supports such transceivers without driver
changes.

Tested on an i.MX6SX UART and on a MAX14830 channel, each wired to an
LTC2873, by observing the bus line while switching RS485 on and off
with TIOCSRS485.

Signed-off-by: Tapio Reijonen <tapio.reijonen@xxxxxxxxxxx>
---
Tapio Reijonen (2):
      dt-bindings: serial: rs485: Add transceiver interface select GPIO
      serial: core: Drive the transceiver interface select GPIO

 .../devicetree/bindings/serial/rs485.yaml          |  8 ++++++
 drivers/tty/serial/serial_core.c                   | 29 +++++++++++++++++++++-
 include/linux/serial_core.h                        |  1 +
 3 files changed, 37 insertions(+), 1 deletion(-)
---
base-commit: 1184f87e2790e8af9be3116f608d2e86b4792d7d
change-id: 20261019-serial-rs485-mode-gpio-e76bb72b6f21

Best regards,
-- 
Tapio Reijonen <tapio.reijonen@xxxxxxxxxxx>