[ARM PATCH] 2440/1: S3C2410 - serial auto-flow-control enable

Patch from Ben Dooks

Patch from Shannon Holland
Enable automatic flow control if requested.

Signed-off-by: Shannon Holland

Signed-off-by: Ben Dooks
Signed-off-by: Russell King

drivers/serial/s3c2410.c

@@ -744,11 +744,12 @@ static void s3c24xx_serial_set_termios(struct uart_port *port,
 	unsigned long flags;
 	unsigned int baud, quot;
 	unsigned int ulcon;
+	unsigned int umcon;
 
 	/*
 	 * We don't support modem control lines.
 	 */
-	termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
+	termios->c_cflag &= ~(HUPCL | CMSPAR);
 	termios->c_cflag |= CLOCAL;
 
 	/*
@@ -806,6 +807,8 @@ static void s3c24xx_serial_set_termios(struct uart_port *port,
 	if (termios->c_cflag & CSTOPB)
 		ulcon |= S3C2410_LCON_STOPB;
 
+	umcon = (termios->c_cflag & CRTSCTS) ? S3C2410_UMCOM_AFC : 0;
+
 	if (termios->c_cflag & PARENB) {
 		if (termios->c_cflag & PARODD)
 			ulcon |= S3C2410_LCON_PODD;
@@ -821,6 +824,7 @@ static void s3c24xx_serial_set_termios(struct uart_port *port,
 
 	wr_regl(port, S3C2410_ULCON, ulcon);
 	wr_regl(port, S3C2410_UBRDIV, quot);
+	wr_regl(port, S3C2410_UMCON, umcon);
 
 	dbg("uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n",
 	    rd_regl(port, S3C2410_ULCON),

include/asm-arm/arch-s3c2410/regs-serial.h

@@ -113,6 +113,9 @@
 				   S3C2410_UFCON_TXTRIG0  | \
 				   S3C2410_UFCON_RXTRIG8 )
 
+#define	S3C2410_UMCOM_AFC	  (1<<4)
+#define	S3C2410_UMCOM_RTS_LOW	  (1<<0)
+
 #define S3C2410_UFSTAT_TXFULL	  (1<<9)
 #define S3C2410_UFSTAT_RXFULL	  (1<<8)
 #define S3C2410_UFSTAT_TXMASK	  (15<<4)