From 234abab143aef82c0ef1f2de409c0db96b666f3c Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 10 Sep 2014 21:29:56 +0200 Subject: [PATCH] tty: serial: 8250_core: allow to set ->throttle / ->unthrottle callbacks The OMAP UART provides support for HW assisted flow control. What is missing is the support to throttle / unthrottle callbacks which are used by the omap-serial driver at the moment. This patch adds the callbacks. It should be safe to add them since they are only invoked from the serial_core (uart_throttle()) if the feature flags are set. Reviewed-by: Tony Lindgren Tested-by: Tony Lindgren Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_core.c | 14 ++++++++++++++ include/linux/serial_core.h | 2 ++ 2 files changed, 16 insertions(+) diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index a0c1d64f34c5..68c44d97091b 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -1319,6 +1319,16 @@ static void serial8250_start_tx(struct uart_port *port) } } +static void serial8250_throttle(struct uart_port *port) +{ + port->throttle(port); +} + +static void serial8250_unthrottle(struct uart_port *port) +{ + port->unthrottle(port); +} + static void serial8250_stop_rx(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); @@ -2912,6 +2922,8 @@ static struct uart_ops serial8250_pops = { .get_mctrl = serial8250_get_mctrl, .stop_tx = serial8250_stop_tx, .start_tx = serial8250_start_tx, + .throttle = serial8250_throttle, + .unthrottle = serial8250_unthrottle, .stop_rx = serial8250_stop_rx, .enable_ms = serial8250_enable_ms, .break_ctl = serial8250_break_ctl, @@ -3462,6 +3474,8 @@ int serial8250_register_8250_port(struct uart_8250_port *up) uart->capabilities = up->capabilities; uart->rs485_config = up->rs485_config; uart->rs485 = up->rs485; + uart->port.throttle = up->port.throttle; + uart->port.unthrottle = up->port.unthrottle; /* Take tx_loadsz from fifosize if it wasn't set separately */ if (uart->port.fifosize && !uart->tx_loadsz) diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 204c452a7567..21c2e05c1bc3 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -125,6 +125,8 @@ struct uart_port { struct ktermios *old); int (*startup)(struct uart_port *port); void (*shutdown)(struct uart_port *port); + void (*throttle)(struct uart_port *port); + void (*unthrottle)(struct uart_port *port); int (*handle_irq)(struct uart_port *); void (*pm)(struct uart_port *, unsigned int state, unsigned int old); -- 2.20.1