[U-Boot-Users] [PATCH] Round the serial port clock divisor value returned by calc_divisor()

[Jerry Van Baren]

Hugo Villeneuve wrote:
> Round the serial port clock divisor value returned by
> calc_divisor()
> 
> Signed-off-by: Hugo Villeneuve <hugo.villeneuve at lyrtech.com>

Acked-by: Gerald Van Baren <vanbaren at cideas.com>

(Hopefully this stops Wolfgang's pain!)

> 
> ---
> 
>  drivers/serial/serial.c |   12 +++---------
>  1 files changed, 3 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c
> index 4ccaee2..8bbfcf9 100644
> --- 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)
> 
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