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Commit 3b43816f authored by Rabin Vincent's avatar Rabin Vincent Committed by Russell King
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ARM: 5933/1: amba-pl011: support hardware flow control 



Enable/disable automatic hardware flow control as requested by the
termios.  The controller does not allow us to control the RTS line when
auto-RTS is enabled, so we enable auto-RTS only if the kernel has not
disabled RTS.

Acked-by: default avatarLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: default avatarRabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 18fe1cad

drivers/serial/amba-pl011.c

+19 −0
Original line number Diff line number Diff line
@@ -71,6 +71,7 @@ struct uart_amba_port { 
	unsigned int		im;	/* interrupt mask */

	unsigned int		old_status;

	unsigned int		ifls;	/* vendor-specific */

	bool			autorts;

};



/* There is by now at least one vendor with differing details, so handle it */
@@ -308,6 +309,11 @@ static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl) 
	TIOCMBIT(TIOCM_OUT1, UART011_CR_OUT1);

	TIOCMBIT(TIOCM_OUT2, UART011_CR_OUT2);

	TIOCMBIT(TIOCM_LOOP, UART011_CR_LBE);



	if (uap->autorts) {

		/* We need to disable auto-RTS if we want to turn RTS off */

		TIOCMBIT(TIOCM_RTS, UART011_CR_RTSEN);

	}

#undef TIOCMBIT



	writew(cr, uap->port.membase + UART011_CR);
@@ -437,6 +443,7 @@ static void pl011_shutdown(struct uart_port *port) 
	/*

	 * disable the port

	 */

	uap->autorts = false;

	writew(UART01x_CR_UARTEN | UART011_CR_TXE, uap->port.membase + UART011_CR);



	/*
@@ -456,6 +463,7 @@ static void 
pl011_set_termios(struct uart_port *port, struct ktermios *termios,

		     struct ktermios *old)

{

	struct uart_amba_port *uap = (struct uart_amba_port *)port;

	unsigned int lcr_h, old_cr;

	unsigned long flags;

	unsigned int baud, quot;
@@ -532,6 +540,17 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios, 
	old_cr = readw(port->membase + UART011_CR);

	writew(0, port->membase + UART011_CR);



	if (termios->c_cflag & CRTSCTS) {

		if (old_cr & UART011_CR_RTS)

			old_cr |= UART011_CR_RTSEN;



		old_cr |= UART011_CR_CTSEN;

		uap->autorts = true;

	} else {

		old_cr &= ~(UART011_CR_CTSEN | UART011_CR_RTSEN);

		uap->autorts = false;

	}



	/* Set baud rate */

	writew(quot & 0x3f, port->membase + UART011_FBRD);

	writew(quot >> 6, port->membase + UART011_IBRD);