serial: 8250: Support rs485 devicetree properties (fe7f0fa4) · Commits · 戴 / test

Retrieve rs485 devicetree properties on registration of 8250 ports in case they are attached to an rs485 transceiver. If the property "linux,rs485-enabled-at-boot-time" is present, invoke the ->rs485_config() callback to immediately deassert RTS, thereby ceasing control of the bus. Signed-off-by:

Lukas Wunner <lukas@wunner.de> Cc: Giulio Benetti <giulio.benetti@micronovasrl.com> Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/5908ea89b7f9da54872d6634b606d83db032297a.1582895077.git.lukas@wunner.de Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_core.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -1013,8 +1013,10 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
		if (uart->port.fifosize && !uart->tx_loadsz)
		uart->tx_loadsz = uart->port.fifosize;

		if (up->port.dev)
		if (up->port.dev) {
		uart->port.dev = up->port.dev;
		uart_get_rs485_mode(uart->port.dev, &uart->port.rs485);
		}

		if (up->port.flags & UPF_FIXED_TYPE)
		uart->port.type = up->port.type;

drivers/tty/serial/8250/8250_port.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -2989,6 +2989,9 @@ static void serial8250_config_port(struct uart_port *port, int flags)
		if (flags & UART_CONFIG_TYPE)
		autoconfig(up);

		if (port->rs485.flags & SER_RS485_ENABLED)
		port->rs485_config(port, &port->rs485);

		/* if access method is AU, it is a 16550 with a quirk */
		if (port->type == PORT_16550A && port->iotype == UPIO_AU)
		up->bugs \|= UART_BUG_NOMSR;

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