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authorLukas Wunner <lukas@wunner.de>2017-11-24 23:26:40 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-11-28 16:05:19 +0100
commitf1e5b618c1c26cb8b5818e36f996e8c2fbedbeb7 (patch)
treed75fec5220f2f86305a22a7c877cfe272d85309a /drivers/tty/serial
parent6abe9ea8a5a5904d935b8a482117a7fd9b25f09e (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')
-rw-r--r--drivers/tty/serial/imx.c1
-rw-r--r--drivers/tty/serial/omap-serial.c7
-rw-r--r--drivers/tty/serial/serial_core.c13
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);