[PATCH] imx: add polled io uart methods

[u.kleine-koenig@pengutronix.de (Uwe Kleine-König)]

On Sun, Oct 16, 2011 at 08:22:01PM -0700, Saleem Abdulrasool wrote:
> These methods are invoked if the iMX uart is used in conjuction with kgdb during
> early boot.  In order to access the UART without the interrupts, the kernel uses
> the basic polling methods for IO with the device.  With these methods
> implemented, it is now possible to enable kgdb during early boot over serial.
> 
> Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>
> ---
>  drivers/tty/serial/imx.c |   77 ++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 77 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index 7e91b3d..4fcf9ca 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -102,6 +102,7 @@
>  #define  UCR2_STPB       (1<<6)	 /* Stop */
>  #define  UCR2_WS         (1<<5)	 /* Word size */
>  #define  UCR2_RTSEN      (1<<4)	 /* Request to send interrupt enable */
> +#define  UCR2_ATEN       (1<<3)  /* Aging Timer Enable */
>  #define  UCR2_TXEN       (1<<2)	 /* Transmitter enabled */
>  #define  UCR2_RXEN       (1<<1)	 /* Receiver enabled */
>  #define  UCR2_SRST 	 (1<<0)	 /* SW reset */
> @@ -1075,6 +1076,77 @@ imx_verify_port(struct uart_port *port, struct serial_struct *ser)
>  	return ret;
>  }
>  
> +
needless newline

> +#if defined(CONFIG_CONSOLE_POLL)
> +static int imx_poll_get_char(struct uart_port *port)
> +{
> +	volatile unsigned int status;
Why is that volatile?

> +	unsigned int cr1, cr2, cr3;
> +	unsigned char c;
> +
> +	/* save control registers */
> +	cr1 = readl(port->membase + UCR1);
> +	cr2 = readl(port->membase + UCR2);
> +	cr3 = readl(port->membase + UCR3);
> +

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-K?nig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |