From f1e5b618c1c26cb8b5818e36f996e8c2fbedbeb7 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Fri, 24 Nov 2017 23:26:40 +0100 Subject: [PATCH] serial: core: Support common rs485 binding for RTS polarity MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Cc: Michał Oleszczyk Cc: Rafael Gago Castano Cc: Sascha Hauer Signed-off-by: Lukas Wunner Acked-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/imx.c | 1 - drivers/tty/serial/omap-serial.c | 7 +++++-- drivers/tty/serial/serial_core.c | 13 ++++++++++--- 3 files changed, 15 insertions(+), 6 deletions(-) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index aca3b7dbd09c..d2c7d88d5774 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -2060,7 +2060,6 @@ static int serial_imx_probe(struct platform_device *pdev) sport->port.fifosize = 32; sport->port.ops = &imx_pops; sport->port.rs485_config = imx_rs485_config; - sport->port.rs485.flags |= SER_RS485_RTS_ON_SEND; sport->port.flags = UPF_BOOT_AUTOCONF; timer_setup(&sport->timer, imx_timeout, 0); diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 227347548fff..56e683373d6d 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -1613,10 +1613,13 @@ static int serial_omap_probe_rs485(struct uart_omap_port *up, uart_get_rs485_mode(up->dev, rs485conf); - if (of_property_read_bool(np, "rs485-rts-active-high")) + if (of_property_read_bool(np, "rs485-rts-active-high")) { rs485conf->flags |= SER_RS485_RTS_ON_SEND; - else + rs485conf->flags &= ~SER_RS485_RTS_AFTER_SEND; + } else { + rs485conf->flags &= ~SER_RS485_RTS_ON_SEND; rs485conf->flags |= SER_RS485_RTS_AFTER_SEND; + } /* check for tx enable gpio */ up->rts_gpio = of_get_named_gpio_flags(np, "rts-gpio", 0, &flags); 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); -- GitLab