tty: exynos_tty: add suspending flag

suspending flag for ourport is introduced,
to prevent rts toggling due to sicd power mode during suspend.

suspending flag is set to 1 at the start of suspend sequence
and set to 0 at the end of suspend sequence.

BUG: 322129034
Test: build test build and run BCST
Change-Id: I15940a5dc64735c8e56471eff9d5cdb14a6575b3
Signed-off-by: Sophie Hu <sophiehu@google.com>

drivers/tty/serial/exynos_tty.c

@@ -185,6 +185,7 @@ struct exynos_uart_port {
 	struct uart_local_buf		uart_local_buf;
 	struct logbuffer *log;
 	bool show_uart_logging_packets;
+	unsigned char suspending;
 };
 
 /* conversion functions */
@@ -2523,6 +2524,9 @@ static int exynos_serial_notifier(struct notifier_block *self,
 			if (port->state->pm_state == UART_PM_STATE_OFF)
 				continue;
 
+			if (ourport->suspending)
+				continue;
+
 			if (ourport->rts_alive_control)
 				disable_auto_flow_control(ourport);
 
@@ -2540,6 +2544,9 @@ static int exynos_serial_notifier(struct notifier_block *self,
 			if (port->state->pm_state == UART_PM_STATE_OFF)
 				continue;
 
+			if (ourport->suspending)
+				continue;
+
 			if (ourport->rts_alive_control)
 				enable_auto_flow_control(ourport);
 
@@ -2790,6 +2797,7 @@ static int exynos_serial_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "failed to create sysfs file.\n");
 
 	ourport->dbg_mode = 0;
+	ourport->suspending = 0;
 
 	if (ourport->uart_logging == 1) {
 		/* Allocate memory for UART logging */
@@ -2847,6 +2855,7 @@ static int exynos_serial_suspend(struct device *dev)
 	unsigned int ucon;
 
 	if (port) {
+		ourport->suspending = 1;
 		/*
 		 * If rts line must be protected while suspending
 		 * we change the gpio pad as output high
@@ -2882,6 +2891,8 @@ static int exynos_serial_suspend(struct device *dev)
 		}
 		if (ourport->dbg_mode & UART_DBG_MODE)
 			dev_err(dev, "UART suspend notification for tty framework.\n");
+
+		ourport->suspending = 0;
 	}
 
 	return 0;