[PATCH 1/1] arm: KGDB support for PXA

[PATCH 1/1] arm: KGDB support for PXA

[Denis V. Lunev]

From: "Denis V. Lunev" <den@openvz.org>

Actually, in order to support KGDB over serial console one must
implement two callbacks for character polling. Clone them from
8250 driver with a bit of tuning.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Marko Katic <dromede@gmail.com>
CC: Eric Miao <eric.y.miao@gmail.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: Haojian Zhuang <haojian.zhuang@gmail.com>
CC: <linux-arm-kernel@lists.infradead.org>
---
This patch has been originally posted by me to LKML in 2009 and postponed.
I was contacted last week by Marko who has kindly ported the patch to the
latest v3.6 kernel and asked to re-send it.

Here it is :)

 drivers/tty/serial/pxa.c |   55 ++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 55 insertions(+), 0 deletions(-)

diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c
index 5847a4b..54cbb02 100644
--- a/drivers/tty/serial/pxa.c
+++ b/drivers/tty/serial/pxa.c
@@ -691,6 +691,57 @@ serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
 	clk_disable_unprepare(up->clk);
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context.
+ */
+
+static int serial_pxa_get_poll_char(struct uart_port *port)
+{
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+	unsigned char lsr = serial_in(up, UART_LSR);
+
+	while (!(lsr & UART_LSR_DR))
+		lsr = serial_in(up, UART_LSR);
+
+	return serial_in(up, UART_RX);
+}
+
+
+static void serial_pxa_put_poll_char(struct uart_port *port,
+			 unsigned char c)
+{
+	unsigned int ier;
+	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
+
+	/*
+	 *	First save the IER then disable the interrupts
+	 */
+	ier = serial_in(up, UART_IER);
+	serial_out(up, UART_IER, UART_IER_UUE);
+
+	wait_for_xmitr(up);
+	/*
+	 *	Send the character out.
+	 *	If a LF, also do CR...
+	 */
+	serial_out(up, UART_TX, c);
+	if (c == 10) {
+		wait_for_xmitr(up);
+		serial_out(up, UART_TX, 13);
+	}
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(up);
+	serial_out(up, UART_IER, ier);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
 static int __init
 serial_pxa_console_setup(struct console *co, char *options)
 {
@@ -745,6 +796,10 @@ struct uart_ops serial_pxa_pops = {
 	.request_port	= serial_pxa_request_port,
 	.config_port	= serial_pxa_config_port,
 	.verify_port	= serial_pxa_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char = serial_pxa_get_poll_char,
+	.poll_put_char = serial_pxa_put_poll_char,
+#endif
 };
 
 static struct uart_driver serial_pxa_reg = {
-- 
1.7.7.6

[PATCH 1/1] arm: KGDB support for PXA

[Haojian Zhuang]

On Tue, Aug 28, 2012 at 5:12 PM, Denis V. Lunev <den@openvz.org> wrote:
> From: "Denis V. Lunev" <den@openvz.org>
>
> Actually, in order to support KGDB over serial console one must
> implement two callbacks for character polling. Clone them from
> 8250 driver with a bit of tuning.
>
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> Signed-off-by: Marko Katic <dromede@gmail.com>
> CC: Eric Miao <eric.y.miao@gmail.com>
> CC: Russell King <linux@arm.linux.org.uk>
> CC: Haojian Zhuang <haojian.zhuang@gmail.com>
> CC: <linux-arm-kernel@lists.infradead.org>
> ---
> This patch has been originally posted by me to LKML in 2009 and postponed.
> I was contacted last week by Marko who has kindly ported the patch to the
> latest v3.6 kernel and asked to re-send it.
>
> Here it is :)
>
>  drivers/tty/serial/pxa.c |   55 ++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 55 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c
> index 5847a4b..54cbb02 100644
> --- a/drivers/tty/serial/pxa.c
> +++ b/drivers/tty/serial/pxa.c
> @@ -691,6 +691,57 @@ serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
>         clk_disable_unprepare(up->clk);
>  }
>
> +#ifdef CONFIG_CONSOLE_POLL
> +/*
> + * Console polling routines for writing and reading from the uart while
> + * in an interrupt or debug context.
> + */
> +
> +static int serial_pxa_get_poll_char(struct uart_port *port)
> +{
> +       struct uart_pxa_port *up = (struct uart_pxa_port *)port;
> +       unsigned char lsr = serial_in(up, UART_LSR);
> +
> +       while (!(lsr & UART_LSR_DR))
> +               lsr = serial_in(up, UART_LSR);
> +
> +       return serial_in(up, UART_RX);
> +}
> +
> +
> +static void serial_pxa_put_poll_char(struct uart_port *port,
> +                        unsigned char c)
> +{
> +       unsigned int ier;
> +       struct uart_pxa_port *up = (struct uart_pxa_port *)port;
> +
> +       /*
> +        *      First save the IER then disable the interrupts
> +        */
> +       ier = serial_in(up, UART_IER);
> +       serial_out(up, UART_IER, UART_IER_UUE);
> +
> +       wait_for_xmitr(up);
> +       /*
> +        *      Send the character out.
> +        *      If a LF, also do CR...
> +        */
> +       serial_out(up, UART_TX, c);
> +       if (c == 10) {
> +               wait_for_xmitr(up);
> +               serial_out(up, UART_TX, 13);
> +       }
> +
> +       /*
> +        *      Finally, wait for transmitter to become empty
> +        *      and restore the IER
> +        */
> +       wait_for_xmitr(up);
> +       serial_out(up, UART_IER, ier);
> +}
> +
> +#endif /* CONFIG_CONSOLE_POLL */
> +
>  static int __init
>  serial_pxa_console_setup(struct console *co, char *options)
>  {
> @@ -745,6 +796,10 @@ struct uart_ops serial_pxa_pops = {
>         .request_port   = serial_pxa_request_port,
>         .config_port    = serial_pxa_config_port,
>         .verify_port    = serial_pxa_verify_port,
> +#ifdef CONFIG_CONSOLE_POLL
> +       .poll_get_char = serial_pxa_get_poll_char,
> +       .poll_put_char = serial_pxa_put_poll_char,
> +#endif
>  };
>
>  static struct uart_driver serial_pxa_reg = {
> --
> 1.7.7.6
>

Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>

Greg,

Will you merge this patch into tty.git? or I merge it into arch-pxa tree?

Regards
Haojian

[PATCH 1/1] arm: KGDB support for PXA

[Marko Katić]

I'm still not seeing this patch in arch-pxa, tty or mainline trees.
Has it been forgotten again? Is there a problem with this patch that
needs to be fixed?

[PATCH 1/1] arm: KGDB support for PXA

[Haojian Zhuang]

On Thu, Oct 18, 2012 at 5:38 PM, Marko Kati? <dromede@gmail.com> wrote:
> I'm still not seeing this patch in arch-pxa, tty or mainline trees.
> Has it been forgotten again? Is there a problem with this patch that
> needs to be fixed?

Applied into arch-pxa now.

Greg,

If you have any comment, please let me know.

Regards
Haojian

[PATCH 1/1] arm: KGDB support for PXA

[Greg KH]

On Fri, Oct 19, 2012 at 05:47:09PM +0800, Haojian Zhuang wrote:
> On Thu, Oct 18, 2012 at 5:38 PM, Marko Kati? <dromede@gmail.com> wrote:
> > I'm still not seeing this patch in arch-pxa, tty or mainline trees.
> > Has it been forgotten again? Is there a problem with this patch that
> > needs to be fixed?
> 
> Applied into arch-pxa now.
> 
> Greg,
> 
> If you have any comment, please let me know.

No, no objection at all, the other patches are all in Linus's tree
already, so feel free to send them in whenever you want.

greg k-h