ColdFire: Fix UART baudrate formula

The formula "counter = (u32) (gd->bus_clk / gd->baudrate) / 32"
can generate the wrong divisor due to integer division truncation.
Round the calculated divisor value by adding 1/2 the baudrate
before dividing by the baudrate.

Signed-off-by: TsiChung Liew <Tsi-Chung.Liew@freescale.com>
Acked-by: Gerald Van Baren <vanbaren@cideas.com>

diff --git a/drivers/serial/mcfuart.c b/drivers/serial/mcfuart.c
index 88f3eb1..5eb4f45 100644 (file)
--- a/drivers/serial/mcfuart.c
+++ b/drivers/serial/mcfuart.c
@@ -63,8 +63,8 @@ int serial_init(void)
        uart->umr = UART_UMR_SB_STOP_BITS_1;
 
        /* Setting up BaudRate */
-       counter = (u32) (gd->bus_clk / (gd->baudrate));
-       counter >>= 5;
+       counter = (u32) ((gd->bus_clk / 32) + (gd->baudrate / 2));
+       counter = counter / gd->baudrate;
 
        /* write to CTUR: divide counter upper byte */
        uart->ubg1 = (u8) ((counter & 0xff00) >> 8);