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serial: imx: Allow passing 'rst-gpios' for rs485 mode 

According to Documentation/devicetree/bindings/serial/serial.txt the
generic 'rts-gpios' property can be used to specify the GPIO for RTS
functionality.

Currently it is not possible to use the imx UART port in rs485 mode when
the 'rts-gpios' property is passed in the device tree.

The imx uart driver only checks for the presence of the built-in RTS pin,
via 'uart-has-rtscts' property and disable the rs485 flag if this property
is absent.

So fix this logic by also checking if RTS pin has been passed via GPIO.

Tested on a imx6dl based board.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Tested-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Fabio Estevam 2017-01-07 19:29:13 -02:00 committed by Greg Kroah-Hartman
parent 3f08087826
commit 7b7e8e8e8f
1 changed files with 5 additions and 1 deletions
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6
drivers/tty/serial/imx.c
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@ -205,6 +205,7 @@ struct imx_port {
struct timer_list timer;
unsigned int old_status;
unsigned int have_rtscts:1;
unsigned int have_rtsgpio:1;
unsigned int dte_mode:1;
unsigned int irda_inv_rx:1;
unsigned int irda_inv_tx:1;
@ -1725,7 +1726,7 @@ static int imx_rs485_config(struct uart_port *port,
rs485conf->delay_rts_after_send = 0;
/* RTS is required to control the transmitter */
if (!sport->have_rtscts)
if (!sport->have_rtscts && !sport->have_rtsgpio)
rs485conf->flags &= ~SER_RS485_ENABLED;
if (rs485conf->flags & SER_RS485_ENABLED) {
@ -2048,6 +2049,9 @@ static int serial_imx_probe_dt(struct imx_port *sport,
if (of_get_property(np, "fsl,dte-mode", NULL))
sport->dte_mode = 1;
if (of_get_property(np, "rts-gpios", NULL))
sport->have_rtsgpio = 1;
return 0;
}
#else