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Commit 344cee24 authored by Matwey V. Kornilov's avatar Matwey V. Kornilov Committed by Greg Kroah-Hartman
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tty: 8250_omap: Use software emulated RS485 direction control 



Use software emulated RS485 direction control to provide RS485 API
existed in omap_serial driver. Note that 8250_omap issues interrupt
on shift register empty which is single prerequesite for using software
emulated RS485.

Signed-off-by: default avatarMatwey V. Kornilov <matwey@sai.msu.ru>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e490c914

drivers/tty/serial/8250/8250_omap.c

+31 −0
Original line number Diff line number Diff line
@@ -697,6 +697,36 @@ static void omap_8250_throttle(struct uart_port *port) 
	pm_runtime_put_autosuspend(port->dev);

}



static int omap_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;

}



static void omap_8250_unthrottle(struct uart_port *port)

{

	unsigned long flags;
@@ -1146,6 +1176,7 @@ static int omap8250_probe(struct platform_device *pdev) 
	up.port.shutdown = omap_8250_shutdown;

	up.port.throttle = omap_8250_throttle;

	up.port.unthrottle = omap_8250_unthrottle;

	up.port.rs485_config = omap_8250_rs485_config;



	if (pdev->dev.of_node) {

		const struct of_device_id *id;