Enable wakeup from serial ports, make it run-time configurable over sysfs,
e.g.,
echo enabled > /sys/devices/platform/serial8250.0/tty/ttyS0/power/wakeup
Requires
# CONFIG_SYSFS_DEPRECATED is not set
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
---
I've sent this rfc/patch earlier to linuxppc-dev (I need it for a ppc
platform) and to linux-serial, and got no comments - but no objections
either from either of them. So, re-sending to a broader and hopefully more
relevant audience this time.
Thanks
Guennadi
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 0b3ec38..5118914 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -130,6 +130,7 @@ struct uart_8250_port {
unsigned char mcr_mask; /* mask of user bits */
unsigned char mcr_force; /* mask of forced bits */
unsigned char lsr_break_flag;
+ char suspended;
/*
* We provide a per-port pm hook.
@@ -2673,6 +2674,14 @@ static int __devexit serial8250_remove(struct platform_device *dev)
return 0;
}
+static int serial8250_match_port(struct device *dev, void *data)
+{
+ struct uart_port *port = data;
+ dev_t devt = MKDEV(serial8250_reg.major, serial8250_reg.minor) + port->line;
+
+ return dev->devt == devt; /* Actually, only one tty per port */
+}
+
static int serial8250_suspend(struct platform_device *dev, pm_message_t state)
{
int i;
@@ -2680,8 +2689,16 @@ static int serial8250_suspend(struct platform_device *dev, pm_message_t state)
for (i = 0; i < UART_NR; i++) {
struct uart_8250_port *up = &serial8250_ports[i];
- if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
- uart_suspend_port(&serial8250_reg, &up->port);
+ if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev) {
+ struct device *tty_dev = device_find_child(up->port.dev, &up->port,
+ serial8250_match_port);
+ if (device_may_wakeup(tty_dev))
+ enable_irq_wake(up->port.irq);
+ else {
+ uart_suspend_port(&serial8250_reg, &up->port);
+ up->suspended = 1;
+ }
+ }
}
return 0;
@@ -2694,8 +2711,13 @@ static int serial8250_resume(struct platform_device *dev)
for (i = 0; i < UART_NR; i++) {
struct uart_8250_port *up = &serial8250_ports[i];
- if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
- serial8250_resume_port(i);
+ if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev) {
+ if (up->suspended) {
+ serial8250_resume_port(i);
+ up->suspended = 0;
+ } else
+ disable_irq_wake(up->port.irq);
+ }
}
return 0;
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 9c57486..716fbe2 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -2266,6 +2266,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
{
struct uart_state *state;
int ret = 0;
+ struct device *tty_dev;
BUG_ON(in_interrupt());
@@ -2301,7 +2302,13 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
* Register the port whether it's detected or not. This allows
* setserial to be used to alter this ports parameters.
*/
- tty_register_device(drv->tty_driver, port->line, port->dev);
+ tty_dev = tty_register_device(drv->tty_driver, port->line, port->dev);
+ if (likely(!IS_ERR(tty_dev))) {
+ device_can_wakeup(tty_dev) = 1;
+ device_set_wakeup_enable(tty_dev, 0);
+ } else
+ printk(KERN_ERR "Cannot register tty device on line %d\n",
+ port->line);
/*
* If this driver supports console, and it hasn't been
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