tty: serial: fsl_lpuart: support suspend/resume

Add suspend/resume support.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/fsl_lpuart.c

@@ -483,9 +483,8 @@ static void lpuart_dma_rx_complete(void *arg)
 	spin_unlock_irqrestore(&sport->port.lock, flags);
 }
 
-static void lpuart_timer_func(unsigned long data)
+static void lpuart_dma_rx_terminate(struct lpuart_port *sport)
 {
-	struct lpuart_port *sport = (struct lpuart_port *)data;
 	struct tty_port *port = &sport->port.state->port;
 	struct dma_tx_state state;
 	unsigned long flags;
@@ -510,6 +509,11 @@ static void lpuart_timer_func(unsigned long data)
 	spin_unlock_irqrestore(&sport->port.lock, flags);
 }
 
+static void lpuart_timer_func(unsigned long data)
+{
+	lpuart_dma_rx_terminate((struct lpuart_port *)data);
+}
+
 static inline void lpuart_prepare_rx(struct lpuart_port *sport)
 {
 	unsigned long flags;
@@ -1931,7 +1935,12 @@ static int lpuart_suspend(struct device *dev)
 		writeb(temp, sport->port.membase + UARTCR2);
 	}
 
+	if (sport->dma_rx_in_progress)
+		lpuart_dma_rx_terminate(sport);
+
 	uart_suspend_port(&lpuart_reg, &sport->port);
+	if (sport->port.suspended && !sport->port.irq_wake)
+		clk_disable_unprepare(sport->clk);
 
 	return 0;
 }
@@ -1941,6 +1950,9 @@ static int lpuart_resume(struct device *dev)
 	struct lpuart_port *sport = dev_get_drvdata(dev);
 	unsigned long temp;
 
+	if (sport->port.suspended && !sport->port.irq_wake)
+		clk_prepare_enable(sport->clk);
+
 	if (sport->lpuart32) {
 		lpuart32_setup_watermark(sport);
 		temp = lpuart32_read(sport->port.membase + UARTCTRL);