From 3b43816f685fc6c2531f43514662f796f4601ffc Mon Sep 17 00:00:00 2001 From: Rabin Vincent Date: Fri, 12 Feb 2010 06:43:11 +0100 Subject: 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: Linus Walleij Signed-off-by: Rabin Vincent Signed-off-by: Russell King --- drivers/serial/amba-pl011.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'drivers/serial') diff --git a/drivers/serial/amba-pl011.c b/drivers/serial/amba-pl011.c index ef7adc8135d..ce6c35333ff 100644 --- a/drivers/serial/amba-pl011.c +++ b/drivers/serial/amba-pl011.c @@ -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); -- cgit v1.2.3-70-g09d2