Round the serial port clock divisor value returned by calc_divisor()

Round the serial port clock divisor value returned by
calc_divisor()

Signed-off-by: Hugo Villeneuve <hugo.villeneuve@lyrtech.com>
Acked-by: Gerald Van Baren <vanbaren@cideas.com>

diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c
index 4ccaee28b054379d5899a417246da191a0898743..8bbfcf9c0cba8a7115d1c3b5b680791d1e2e36f6 100644 (file)
--- a/drivers/serial/serial.c
+++ b/drivers/serial/serial.c
@@ -124,8 +124,6 @@ static NS16550_t serial_ports[4] = {
 
 static int calc_divisor (NS16550_t port)
 {
-       uint32_t clk_divisor;
-
 #ifdef CONFIG_OMAP1510
        /* If can't cleanly clock 115200 set div to 1 */
        if ((CFG_NS16550_CLK == 12000000) && (gd->baudrate == 115200)) {
@@ -149,15 +147,11 @@ static int calc_divisor (NS16550_t port)
 
        /* Compute divisor value. Normally, we should simply return:
         *   CFG_NS16550_CLK) / MODE_X_DIV / gd->baudrate
-        * but we need to round that value by adding 0.5 (2/4).
+        * but we need to round that value by adding 0.5.
         * Rounding is especially important at high baud rates.
         */
-       clk_divisor = (((4 * CFG_NS16550_CLK) /
-                       (MODE_X_DIV * gd->baudrate)) + 2) / 4;
-
-       debug("NS16550 clock divisor = %d\n", clk_divisor);
-
-       return clk_divisor;
+       return (CFG_NS16550_CLK + (gd->baudrate * (MODE_X_DIV / 2))) /
+               (MODE_X_DIV * gd->baudrate);
 }
 
 #if !defined(CONFIG_SERIAL_MULTI)