serial: stm32: rework wakeup management

Rework wakeup management by activating uart as wakeup source when usart
device OR its tty virtual device parent is wakeup source.

This patch aim to avoid potential misalignment between serial and tty
wakeup flags.
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>
Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>
Link: https://lore.kernel.org/r/20210319184253.5841-2-erwan.leray@foss.st.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/stm32-usart.c

@@ -1534,7 +1534,7 @@ static int __maybe_unused stm32_usart_serial_suspend(struct device *dev)
 
 	uart_suspend_port(&stm32_usart_driver, port);
 
-	if (device_may_wakeup(dev))
+	if (device_may_wakeup(dev) || device_wakeup_path(dev))
 		stm32_usart_serial_en_wakeup(port, true);
 	else
 		stm32_usart_serial_en_wakeup(port, false);
@@ -1546,7 +1546,7 @@ static int __maybe_unused stm32_usart_serial_suspend(struct device *dev)
 	 * capabilities.
 	 */
 	if (console_suspend_enabled || !uart_console(port)) {
-		if (device_may_wakeup(dev))
+		if (device_may_wakeup(dev) || device_wakeup_path(dev))
 			pinctrl_pm_select_idle_state(dev);
 		else
 			pinctrl_pm_select_sleep_state(dev);
@@ -1561,7 +1561,7 @@ static int __maybe_unused stm32_usart_serial_resume(struct device *dev)
 
 	pinctrl_pm_select_default_state(dev);
 
-	if (device_may_wakeup(dev))
+	if (device_may_wakeup(dev) || device_wakeup_path(dev))
 		stm32_usart_serial_en_wakeup(port, false);
 
 	return uart_resume_port(&stm32_usart_driver, port);