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authorRabin Vincent <rabin.vincent@stericsson.com>2010-02-12 06:43:11 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-02-18 17:29:42 +0000
commit3b43816f685fc6c2531f43514662f796f4601ffc (patch)
tree3e7e484a8ce9c3ba1c8cedd195d0a6cc2346ab65 /drivers/serial/amba-pl011.c
parent18fe1cad889fe6c1acbf4dfc576e82a13cf1a30c (diff)
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 <linus.walleij@stericsson.com> Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/serial/amba-pl011.c')
-rw-r--r--drivers/serial/amba-pl011.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/serial/amba-pl011.c b/drivers/serial/amba-pl011.c
index ef7adc8135dd..ce6c35333ff7 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);