On Tue, May 05, 2020 at 04:42:04PM +0200, Lukas Wunner wrote:
> Commit e8759ad17d41 ("serial: uapi: Add support for bus termination")
> introduced the ability to enable rs485 bus termination from user space.
> So far the feature is only used by a single driver, 8250_exar.c, using a
> hardcoded GPIO pin specific to Siemens IOT2040 products.
>
> Provide for a more generic solution by allowing specification of an
> rs485 bus termination GPIO pin in the device tree: Amend the serial
> core to retrieve the GPIO from the device tree (or ACPI table) and amend
> the default ->rs485_config() callback for 8250 drivers to change the
> GPIO on request from user space.
...
> @@ -3331,6 +3332,29 @@ int uart_get_rs485_mode(struct uart_port *port)
> + devm_gpiod_put(dev, port->rs485_term_gpio);
> + port->rs485_term_gpio = devm_gpiod_get_optional(dev, "rs485-term",
Using devm_*() in uart_get_rs485_mode() seems not right.
Why do you need this?
> + GPIOD_FLAGS_BIT_DIR_SET | GPIOD_FLAGS_BIT_DIR_OUT);
Parameter has a specific macro GPIOD_OUT_HIGH.
--
With Best Regards,
Andy Shevchenko
