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 <[email protected]>
---
Following suggestions from Alan and Russell moved the may_wake_up checks
to serial_core.c. This time actually tested - it does even work. Could
someone, please, verify, that put_device after device_find_child is
correct? Also would be nice to test with a Natsemi UART, that can wake up
the system, if such systems exist.
Thanks
Guennadi
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 9c57486..8a3d6ea 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1934,9 +1934,24 @@ static void uart_change_pm(struct uart_state *state, int pm_state)
}
}
+struct uart_match {
+ struct uart_port *port;
+ struct uart_driver *driver;
+};
+
+static int serial_match_port(struct device *dev, void *data)
+{
+ struct uart_match *match = data;
+ dev_t devt = MKDEV(match->driver->major, match->driver->minor) + match->port->line;
+
+ return dev->devt == devt; /* Actually, only one tty per port */
+}
+
int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
{
struct uart_state *state = drv->state + port->line;
+ struct device *tty_dev;
+ struct uart_match match = {port, drv};
mutex_lock(&state->mutex);
@@ -1947,6 +1962,15 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
}
#endif
+ tty_dev = device_find_child(port->dev, &match, serial_match_port);
+ if (device_may_wakeup(tty_dev)) {
+ enable_irq_wake(port->irq);
+ put_device(tty_dev);
+ mutex_unlock(&state->mutex);
+ return 0;
+ }
+ port->suspended = 1;
+
if (state->info && state->info->flags & UIF_INITIALIZED) {
const struct uart_ops *ops = port->ops;
@@ -1995,6 +2019,13 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
}
#endif
+ if (!port->suspended) {
+ disable_irq_wake(port->irq);
+ mutex_unlock(&state->mutex);
+ return 0;
+ }
+ port->suspended = 0;
+
uart_change_pm(state, 0);
/*
@@ -2266,6 +2297,7 @@ 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 +2333,13 @@ 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
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 773d8d8..60dedc0 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -291,7 +291,8 @@ struct uart_port {
unsigned long mapbase; /* for ioremap */
struct device *dev; /* parent device */
unsigned char hub6; /* this should be in the 8250 driver */
- unsigned char unused[3];
+ unsigned char suspended;
+ unsigned char unused[2];
void *private_data; /* generic platform data pointer */
};
-
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