[PATCH v3 3/7] USB: serial: ftdi_sio: Extract SIO divisor code to function

["Pali Rohár" <pali@kernel.org>]

In preparation for following changes, extract divisor code for SIO chip
into new function ftdi_sio_baud_to_divisor(), as is done for other
chips.

No functional change.

Signed-off-by: Pali Rohár <pali@kernel.org>
Tested-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
---
 drivers/usb/serial/ftdi_sio.c | 45 ++++++++++++++++++++++++-----------
 1 file changed, 31 insertions(+), 14 deletions(-)

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index bfa601fc14fe..fe8a7c5fa0e9 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1155,6 +1155,34 @@ static struct usb_serial_driver * const serial_drivers[] = {
  * ***************************************************************************
  */
 
+static u32 ftdi_sio_baud_to_divisor(int baud)
+{
+	switch (baud) {
+	case 300:
+		return ftdi_sio_b300;
+	case 600:
+		return ftdi_sio_b600;
+	case 1200:
+		return ftdi_sio_b1200;
+	case 2400:
+		return ftdi_sio_b2400;
+	case 4800:
+		return ftdi_sio_b4800;
+	case 9600:
+		return ftdi_sio_b9600;
+	case 19200:
+		return ftdi_sio_b19200;
+	case 38400:
+		return ftdi_sio_b38400;
+	case 57600:
+		return ftdi_sio_b57600;
+	case 115200:
+		return ftdi_sio_b115200;
+	default:
+		return -1;
+	}
+}
+
 static unsigned short int ftdi_232am_baud_base_to_divisor(int baud, int base)
 {
 	unsigned short int divisor;
@@ -1314,23 +1342,12 @@ static u32 get_ftdi_divisor(struct tty_struct *tty,
 		baud = 9600;
 	switch (priv->chip_type) {
 	case SIO: /* SIO chip */
-		switch (baud) {
-		case 300: div_value = ftdi_sio_b300; break;
-		case 600: div_value = ftdi_sio_b600; break;
-		case 1200: div_value = ftdi_sio_b1200; break;
-		case 2400: div_value = ftdi_sio_b2400; break;
-		case 4800: div_value = ftdi_sio_b4800; break;
-		case 9600: div_value = ftdi_sio_b9600; break;
-		case 19200: div_value = ftdi_sio_b19200; break;
-		case 38400: div_value = ftdi_sio_b38400; break;
-		case 57600: div_value = ftdi_sio_b57600;  break;
-		case 115200: div_value = ftdi_sio_b115200; break;
-		} /* baud */
-		if (div_value == 0) {
+		div_value = ftdi_sio_baud_to_divisor(baud);
+		if (div_value == (u32)-1) {
 			dev_dbg(dev, "%s - Baudrate (%d) requested is not supported\n",
 				__func__,  baud);
-			div_value = ftdi_sio_b9600;
 			baud = 9600;
+			div_value = ftdi_sio_baud_to_divisor(baud);
 			div_okay = 0;
 		}
 		break;
-- 
2.20.1