Signed-off-by: Hector Martin <redacted>
---
 drivers/tty/serial/samsung_tty.c | 131 ++++++++++++++++++-------------
 1 file changed, 77 insertions(+), 54 deletions(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 6b661f3ec1ae..21955be680a4 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c

@@ -56,9 +56,15 @@
 /* flag to ignore all characters coming in */
 #define RXSTAT_DUMMY_READ (0x10000000)
 
+enum s3c24xx_port_type {
+	TYPE_S3C24XX,
+	TYPE_S3C6400,
+};
+
 struct s3c24xx_uart_info {
 	char			*name;
-	unsigned int		type;
+	enum s3c24xx_port_type	type;
+	unsigned int		port_type;
 	unsigned int		fifosize;
 	unsigned long		rx_fifomask;
 	unsigned long		rx_fifoshift;

@@ -70,6 +76,7 @@ struct s3c24xx_uart_info {
 	unsigned long		num_clks;
 	unsigned long		clksel_mask;
 	unsigned long		clksel_shift;
+	unsigned long		ucon_mask;
 
 	/* uart port features */
 

@@ -228,16 +235,6 @@ static int s3c24xx_serial_txempty_nofifo(struct uart_port *port)
 	return rd_regl(port, S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE;
 }
 
-/*
- * s3c64xx and later SoC's include the interrupt mask and status registers in
- * the controller itself, unlike the s3c24xx SoC's which have these registers
- * in the interrupt controller. Check if the port type is s3c64xx or higher.
- */
-static int s3c24xx_serial_has_interrupt_mask(struct uart_port *port)
-{
-	return to_ourport(port)->info->type == PORT_S3C6400;
-}
-
 static void s3c24xx_serial_rx_enable(struct uart_port *port)
 {
 	struct s3c24xx_uart_port *ourport = to_ourport(port);

@@ -289,10 +286,14 @@ static void s3c24xx_serial_stop_tx(struct uart_port *port)
 	if (!ourport->tx_enabled)
 		return;
 
-	if (s3c24xx_serial_has_interrupt_mask(port))
+	switch (ourport->info->type) {
+	case TYPE_S3C6400:
 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
-	else
+		break;
+	default:
 		disable_irq_nosync(ourport->tx_irq);
+		break;
+	}
 
 	if (dma && dma->tx_chan && ourport->tx_in_progress == S3C24XX_TX_DMA) {
 		dmaengine_pause(dma->tx_chan);

@@ -353,10 +354,14 @@ static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
 	u32 ucon;
 
 	/* Mask Tx interrupt */
-	if (s3c24xx_serial_has_interrupt_mask(port))
+	switch (ourport->info->type) {
+	case TYPE_S3C6400:
 		s3c24xx_set_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);
-	else
+		break;
+	default:
 		disable_irq_nosync(ourport->tx_irq);
+		break;
+	}
 
 	/* Enable tx dma mode */
 	ucon = rd_regl(port, S3C2410_UCON);

@@ -386,11 +391,14 @@ static void enable_tx_pio(struct s3c24xx_uart_port *ourport)
 	wr_regl(port,  S3C2410_UCON, ucon);
 
 	/* Unmask Tx interrupt */
-	if (s3c24xx_serial_has_interrupt_mask(port))
-		s3c24xx_clear_bit(port, S3C64XX_UINTM_TXD,
-				  S3C64XX_UINTM);
-	else
+	switch (ourport->info->type) {
+	case TYPE_S3C6400:
+		s3c24xx_clear_bit(port, S3C64XX_UINTM_TXD, S3C64XX_UINTM);

+		break;
+	default:
 		enable_irq(ourport->tx_irq);
+		break;
+	}
 
 	ourport->tx_mode = S3C24XX_TX_PIO;
 }

@@ -513,11 +521,14 @@ static void s3c24xx_serial_stop_rx(struct uart_port *port)
 
 	if (ourport->rx_enabled) {
 		dev_dbg(port->dev, "stopping rx\n");
-		if (s3c24xx_serial_has_interrupt_mask(port))
-			s3c24xx_set_bit(port, S3C64XX_UINTM_RXD,
-					S3C64XX_UINTM);