summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--drivers/tty/serial/8250/8250_omap.c7
-rw-r--r--drivers/tty/serial/omap-serial.c7
-rw-r--r--drivers/tty/serial/serial_core.c76
-rw-r--r--include/linux/serial_core.h21
4 files changed, 59 insertions, 52 deletions
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 9191d05..6e4ff71 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -421,8 +421,11 @@ static void omap_8250_set_termios(struct uart_port *port,
priv->efr = 0;
up->mcr &= ~(UART_MCR_RTS | UART_MCR_XONANY);
+ up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
+
if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
/* Enable AUTORTS and AUTOCTS */
+ up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
priv->efr |= UART_EFR_CTS | UART_EFR_RTS;
} else if (up->port.flags & UPF_SOFT_FLOW) {
/*
@@ -438,8 +441,10 @@ static void omap_8250_set_termios(struct uart_port *port,
* Enable XON/XOFF flow control on output.
* Transmit XON1, XOFF1
*/
- if (termios->c_iflag & IXOFF)
+ if (termios->c_iflag & IXOFF) {
+ up->port.status |= UPSTAT_AUTOXOFF;
priv->efr |= OMAP_UART_SW_TX;
+ }
/*
* IXANY Flag:
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index b1cf9a3..6129fe5 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1053,8 +1053,11 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
+ up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
+
if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
/* Enable AUTORTS and AUTOCTS */
+ up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
up->efr |= UART_EFR_CTS | UART_EFR_RTS;
/* Ensure MCR RTS is asserted */
@@ -1081,8 +1084,10 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
* Enable XON/XOFF flow control on output.
* Transmit XON1, XOFF1
*/
- if (termios->c_iflag & IXOFF)
+ if (termios->c_iflag & IXOFF) {
+ up->port.status |= UPSTAT_AUTOXOFF;
up->efr |= OMAP_UART_SW_TX;
+ }
/*
* IXANY Flag:
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 2c67a077..6a1055a 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -179,14 +179,6 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
if (tty->termios.c_cflag & CBAUD)
uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
}
-
- spin_lock_irq(&uport->lock);
- if (uart_cts_enabled(uport) &&
- !(uport->ops->get_mctrl(uport) & TIOCM_CTS))
- uport->hw_stopped = 1;
- else
- uport->hw_stopped = 0;
- spin_unlock_irq(&uport->lock);
}
/*
@@ -442,6 +434,7 @@ static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
{
struct uart_port *uport = state->uart_port;
struct ktermios *termios;
+ int hw_stopped;
/*
* If we have no tty, termios, or the port does not exist,
@@ -466,6 +459,18 @@ static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
uport->status &= ~UPSTAT_DCD_ENABLE;
else
uport->status |= UPSTAT_DCD_ENABLE;
+
+ /* reset sw-assisted CTS flow control based on (possibly) new mode */
+ hw_stopped = uport->hw_stopped;
+ uport->hw_stopped = uart_softcts_mode(uport) &&
+ !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
+ if (uport->hw_stopped) {
+ if (!hw_stopped)
+ uport->ops->stop_tx(uport);
+ } else {
+ if (hw_stopped)
+ __uart_start(tty);
+ }
spin_unlock_irq(&uport->lock);
}
@@ -619,22 +624,22 @@ static void uart_throttle(struct tty_struct *tty)
{
struct uart_state *state = tty->driver_data;
struct uart_port *port = state->uart_port;
- upf_t mask = 0;
+ upstat_t mask = 0;
if (I_IXOFF(tty))
- mask |= UPF_SOFT_FLOW;
+ mask |= UPSTAT_AUTOXOFF;
if (tty->termios.c_cflag & CRTSCTS)
- mask |= UPF_HARD_FLOW;
+ mask |= UPSTAT_AUTORTS;
- if (port->flags & mask) {
+ if (port->status & mask) {
port->ops->throttle(port);
- mask &= ~port->flags;
+ mask &= ~port->status;
}
- if (mask & UPF_SOFT_FLOW)
+ if (mask & UPSTAT_AUTOXOFF)
uart_send_xchar(tty, STOP_CHAR(tty));
- if (mask & UPF_HARD_FLOW)
+ if (mask & UPSTAT_AUTORTS)
uart_clear_mctrl(port, TIOCM_RTS);
}
@@ -642,22 +647,22 @@ static void uart_unthrottle(struct tty_struct *tty)
{
struct uart_state *state = tty->driver_data;
struct uart_port *port = state->uart_port;
- upf_t mask = 0;
+ upstat_t mask = 0;
if (I_IXOFF(tty))
- mask |= UPF_SOFT_FLOW;
+ mask |= UPSTAT_AUTOXOFF;
if (tty->termios.c_cflag & CRTSCTS)
- mask |= UPF_HARD_FLOW;
+ mask |= UPSTAT_AUTORTS;
- if (port->flags & mask) {
+ if (port->status & mask) {
port->ops->unthrottle(port);
- mask &= ~port->flags;
+ mask &= ~port->status;
}
- if (mask & UPF_SOFT_FLOW)
+ if (mask & UPSTAT_AUTOXOFF)
uart_send_xchar(tty, START_CHAR(tty));
- if (mask & UPF_HARD_FLOW)
+ if (mask & UPSTAT_AUTORTS)
uart_set_mctrl(port, TIOCM_RTS);
}
@@ -1351,30 +1356,6 @@ static void uart_set_termios(struct tty_struct *tty,
mask |= TIOCM_RTS;
uart_set_mctrl(uport, mask);
}
-
- /*
- * If the port is doing h/w assisted flow control, do nothing.
- * We assume that port->hw_stopped has never been set.
- */
- if (uport->flags & UPF_HARD_FLOW)
- return;
-
- /* Handle turning off CRTSCTS */
- if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
- spin_lock_irq(&uport->lock);
- uport->hw_stopped = 0;
- __uart_start(tty);
- spin_unlock_irq(&uport->lock);
- }
- /* Handle turning on CRTSCTS */
- else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
- spin_lock_irq(&uport->lock);
- if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
- uport->hw_stopped = 1;
- uport->ops->stop_tx(uport);
- }
- spin_unlock_irq(&uport->lock);
- }
}
/*
@@ -2855,7 +2836,7 @@ void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
uport->icount.cts++;
- if (uart_cts_enabled(uport)) {
+ if (uart_softcts_mode(uport)) {
if (uport->hw_stopped) {
if (status) {
uport->hw_stopped = 0;
@@ -2868,6 +2849,7 @@ void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
uport->ops->stop_tx(uport);
}
}
+
}
}
EXPORT_SYMBOL_GPL(uart_handle_cts_change);
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index a0c7033..baf3e1d 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -191,8 +191,10 @@ struct uart_port {
#define UPF_NO_TXEN_TEST ((__force upf_t) (1 << 15))
#define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
-/* Port has hardware-assisted h/w flow control (iow, auto-RTS *not* auto-CTS) */
-#define UPF_HARD_FLOW ((__force upf_t) (1 << 21))
+/* Port has hardware-assisted h/w flow control */
+#define UPF_AUTO_CTS ((__force upf_t) (1 << 20))
+#define UPF_AUTO_RTS ((__force upf_t) (1 << 21))
+#define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
/* Port has hardware-assisted s/w flow control */
#define UPF_SOFT_FLOW ((__force upf_t) (1 << 22))
#define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
@@ -214,11 +216,17 @@ struct uart_port {
#error Change mask not equivalent to userspace-visible bit defines
#endif
- /* status must be updated while holding port lock */
+ /*
+ * Must hold termios_rwsem, port mutex and port lock to change;
+ * can hold any one lock to read.
+ */
upstat_t status;
#define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0))
#define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1))
+#define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2))
+#define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3))
+#define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4))
int hw_stopped; /* sw-assisted CTS flow state */
unsigned int mctrl; /* current modem ctrl settings */
@@ -392,6 +400,13 @@ static inline bool uart_cts_enabled(struct uart_port *uport)
return !!(uport->status & UPSTAT_CTS_ENABLE);
}
+static inline bool uart_softcts_mode(struct uart_port *uport)
+{
+ upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS;
+
+ return ((uport->status & mask) == UPSTAT_CTS_ENABLE);
+}
+
/*
* The following are helper functions for the low level drivers.
*/
OpenPOWER on IntegriCloud