[RFC] ns16550: support for UART with broken FIFO

Sascha Hauer s.hauer at pengutronix.de
Tue Jan 17 08:09:17 EST 2012


On Tue, Jan 17, 2012 at 02:39:06PM +0400, Antony Pavlov wrote:
> Signed-off-by: Antony Pavlov <antonynpavlov at gmail.com>
> ---
>  drivers/serial/serial_ns16550.c |   19 +++++++++++++++++--
>  include/ns16550.h               |    2 ++
>  2 files changed, 19 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/serial/serial_ns16550.c b/drivers/serial/serial_ns16550.c
> index 1217a5f..01de964 100644
> --- a/drivers/serial/serial_ns16550.c
> +++ b/drivers/serial/serial_ns16550.c
> @@ -139,6 +139,8 @@ static unsigned int ns16550_calc_divisor(struct console_device *cdev,
>  static void ns16550_serial_init_port(struct console_device *cdev)
>  {
>  	unsigned int baud_divisor;
> +	struct NS16550_plat *plat = (struct NS16550_plat *)
> +	    cdev->dev->platform_data;
>  
>  	/* Setup the serial port with the defaults first */
>  	baud_divisor = ns16550_calc_divisor(cdev, CONFIG_BAUDRATE);
> @@ -153,7 +155,13 @@ static void ns16550_serial_init_port(struct console_device *cdev)
>  	ns16550_write(cdev, (baud_divisor >> 8) & 0xff, dlm);
>  	ns16550_write(cdev, LCRVAL, lcr);
>  	ns16550_write(cdev, MCRVAL, mcr);
> -	ns16550_write(cdev, FCRVAL, fcr);
> +
> +	if (plat->flags & NS16650_FLAG_DISABLE_FIFO) {
> +		ns16550_write(cdev, FCRVAL & ~FCR_FIFO_EN, fcr);
> +	} else {
> +		ns16550_write(cdev, FCRVAL, fcr);
> +	}

unnecessary braces here..

> +
>  #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS
>  	ns16550_write(cdev, 0x00,  mdr1);
>  #endif
> @@ -211,6 +219,8 @@ static int ns16550_tstc(struct console_device *cdev)
>  static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
>  {
>  	unsigned int baud_divisor = ns16550_calc_divisor(cdev, baud_rate);
> +	struct NS16550_plat *plat = (struct NS16550_plat *)
> +	    cdev->dev->platform_data;
>  
>  	ns16550_write(cdev, 0x00, ier);
>  	ns16550_write(cdev, LCR_BKSE, lcr);
> @@ -218,7 +228,12 @@ static int ns16550_setbaudrate(struct console_device *cdev, int baud_rate)
>  	ns16550_write(cdev, (baud_divisor >> 8) & 0xff, dlm);
>  	ns16550_write(cdev, LCRVAL, lcr);
>  	ns16550_write(cdev, MCRVAL, mcr);
> -	ns16550_write(cdev, FCRVAL, fcr);
> +	if (plat->flags & NS16650_FLAG_DISABLE_FIFO) {
> +		ns16550_write(cdev, FCRVAL & ~FCR_FIFO_EN, fcr);
> +	} else {
> +		ns16550_write(cdev, FCRVAL, fcr);
> +	}

and here. Otherwise this looks ok.

Sascha


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