[PATCH] imx: add polled io uart methods
Dirk Behme
dirk.behme at de.bosch.com
Thu Dec 1 05:32:43 EST 2011
On 19.10.2011 05:52, Saleem Abdulrasool wrote:
> On Tue, 18 Oct 2011, Uwe Kleine-König wrote:
>
>> 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 at 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
>
> Removed.
>
>>> +#if defined(CONFIG_CONSOLE_POLL)
>>> +static int imx_poll_get_char(struct uart_port *port)
>>> +{
>>> + volatile unsigned int status;
>> Why is that volatile?
>
> It shouldnt be, removed the volatile attribute. Im not sure why that was there,
> it really doesnt make any sense since there isnt any inline assembler there to
> confuse the compiler.
>
>>> + 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
>
> Thanks for the review. Ive not attached the updated patch since Id like to make
> the changes that Sascha suggested, and I shall post the updated patch
> subsequently.
Any update on this?
Many thanks
Dirk
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