diff options
| author | Lukas Wunner <lukas@wunner.de> | 2017-11-24 23:26:40 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-11-28 16:05:19 +0100 |
| commit | f1e5b618c1c26cb8b5818e36f996e8c2fbedbeb7 (patch) | |
| tree | d75fec5220f2f86305a22a7c877cfe272d85309a /drivers/tty/serial/serial_core.c | |
| parent | 6abe9ea8a5a5904d935b8a482117a7fd9b25f09e (diff) | |
serial: core: Support common rs485 binding for RTS polarity
When a driver invokes the uart_get_rs485_mode() helper, set the RTS
polarity to active high by default unless the newly introduced
"rs485-rts-active-low" property was specified.
imx contains a line to set the default RTS polarity to active high,
it is now superfluous and hence deleted.
omap-serial historically defaults to active low and supports an
"rs485-rts-active-high" property to inverse the polarity.
Retain that behavior for compatibility.
Cc: Mark Jackson <mpfj@newflow.co.uk>
Cc: Michał Oleszczyk <oleszczyk.m@gmail.com>
Cc: Rafael Gago Castano <rgc@hms.se>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/serial_core.c')
| -rw-r--r-- | drivers/tty/serial/serial_core.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index a59184a7afb0..f57969de2f1c 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -3036,16 +3036,23 @@ void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf) } /* - * clear full-duplex and enabled flags to get to a defined state with - * the two following properties. + * Clear full-duplex and enabled flags, set RTS polarity to active high + * to get to a defined state with the following properties: */ - rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED); + rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED | + SER_RS485_RTS_AFTER_SEND); + rs485conf->flags |= SER_RS485_RTS_ON_SEND; if (device_property_read_bool(dev, "rs485-rx-during-tx")) rs485conf->flags |= SER_RS485_RX_DURING_TX; if (device_property_read_bool(dev, "linux,rs485-enabled-at-boot-time")) rs485conf->flags |= SER_RS485_ENABLED; + + if (device_property_read_bool(dev, "rs485-rts-active-low")) { + rs485conf->flags &= ~SER_RS485_RTS_ON_SEND; + rs485conf->flags |= SER_RS485_RTS_AFTER_SEND; + } } EXPORT_SYMBOL_GPL(uart_get_rs485_mode); |