tty: serial: KGDB support for PXA

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>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
 drivers/tty/serial/pxa.c |   55 ++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 55 insertions(+), 0 deletions(-)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c
index 9033fc6..2764828 100644 (file)
--- a/drivers/tty/serial/pxa.c
+++ b/drivers/tty/serial/pxa.c
@@ -705,6 +705,57 @@ 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)
 {
@@ -759,6 +810,10 @@ 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 = {