Commit 0c11b888 authored by Heiko Schocher's avatar Heiko Schocher Committed by Greg Kroah-Hartman
Browse files

tty: 8250_of: Use software emulated RS485 direction control 



Use software emulated RS485 direction control to provide RS485 API

Currently it is not possible to use rs485 as pointer to
rs485_config struct in struct uart_port is NULL in case we
configure the port through device tree.

Signed-off-by: default avatarHeiko Schocher <hs@denx.de>

Link: https://lore.kernel.org/r/20190913050105.1132080-1-hs@denx.de


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 39f80919

drivers/tty/serial/8250/8250_of.c

+31 −0
Original line number Diff line number Diff line
@@ -48,6 +48,36 @@ static inline void tegra_serial_handle_break(struct uart_port *port) 
}

#endif



static int of_8250_rs485_config(struct uart_port *port,

				  struct serial_rs485 *rs485)

{

	struct uart_8250_port *up = up_to_u8250p(port);



	/* Clamp the delays to [0, 100ms] */

	rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);

	rs485->delay_rts_after_send  = min(rs485->delay_rts_after_send, 100U);



	port->rs485 = *rs485;



	/*

	 * Both serial8250_em485_init and serial8250_em485_destroy

	 * are idempotent

	 */

	if (rs485->flags & SER_RS485_ENABLED) {

		int ret = serial8250_em485_init(up);



		if (ret) {

			rs485->flags &= ~SER_RS485_ENABLED;

			port->rs485.flags &= ~SER_RS485_ENABLED;

		}

		return ret;

	}



	serial8250_em485_destroy(up);



	return 0;

}



/*

 * Fill a struct uart_port for a given device node

 */
@@ -178,6 +208,7 @@ static int of_platform_serial_setup(struct platform_device *ofdev, 
		port->flags |= UPF_SKIP_TEST;



	port->dev = &ofdev->dev;

	port->rs485_config = of_8250_rs485_config;



	switch (type) {

	case PORT_TEGRA:

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