Define a device tree binding for an rs485 bus termination GPIO
(patch [1/2]), amend the serial core to retrieve the GPIO from
the device tree and amend the default ->rs485_config() callback
for 8250 drivers to change the GPIO on request from user space
(patch [2/2]).
Changes v2 -> v3:
* Patch [2/2]:
* Drop unnecessary NULL pointer check preceding gpiod_set_value(). (Heiko)
* Amend commit message to suggest moving 8250_exar.c to new binding. (Andy)
Add Jan to Cc and Andy's R-b tag.
Changes v1 -> v2:
* Patch [2/2]:
* Drop unnecessary devm_gpiod_put(). (Andy)
* Use GPIOD_OUT_LOW macro for brevity. (Andy)
* Document the rationale for disabling termination by default.
* Drop nonsensical read of GPIO after setting its direction to out.
Link to v2:
https://lore.kernel.org/linux-serial/cover.1589285873.git.lukas@xxxxxxxxx
Lukas Wunner (2):
dt-bindings: serial: Add binding for rs485 bus termination GPIO
serial: 8250: Support rs485 bus termination GPIO
.../devicetree/bindings/serial/rs485.yaml | 4 ++++
drivers/tty/serial/8250/8250_port.c | 3 +++
drivers/tty/serial/serial_core.c | 16 ++++++++++++++++
include/linux/serial_core.h | 2 ++
4 files changed, 25 insertions(+)
--
2.26.2
