kgdb: kgdboc console poll hooks for serial_txx9 uart

Implement the serial polling hooks for the serial_txx9 uart for use with
kgdboc.

This patch once got SOB from Jason on Jul 2008 and (perhaps) merged into
kgdb-next branch, but lost somewhere then.  I resend it now with Jason's
Acked-by.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 92 insertions, 21 deletions

diff --git a/drivers/serial/serial_txx9.c b/drivers/serial/serial_txx9.c
index 7313c2edcb83..54dd16d66a4b 100644
--- a/drivers/serial/serial_txx9.c
+++ b/drivers/serial/serial_txx9.c
@@ -461,6 +461,94 @@ static void serial_txx9_break_ctl(struct uart_port *port, int break_state)
         spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
+#if defined(CONFIG_SERIAL_TXX9_CONSOLE) || (CONFIG_CONSOLE_POLL)
+/*
+ *      Wait for transmitter & holding register to empty
+ */
+static void wait_for_xmitr(struct uart_txx9_port *up)
+{
+        unsigned int tmout = 10000;
+
+        /* Wait up to 10ms for the character(s) to be sent. */
+        while (--tmout &&
+               !(sio_in(up, TXX9_SICISR) & TXX9_SICISR_TXALS))
+                udelay(1);
+
+        /* Wait up to 1s for flow control if necessary */
+        if (up->port.flags & UPF_CONS_FLOW) {
+                tmout = 1000000;
+                while (--tmout &&
+                       (sio_in(up, TXX9_SICISR) & TXX9_SICISR_CTSS))
+                        udelay(1);
+        }
+}
+#endif
+
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context.
+ */
+
+static int serial_txx9_get_poll_char(struct uart_port *port)
+{
+        unsigned int ier;
+        unsigned char c;
+        struct uart_txx9_port *up = (struct uart_txx9_port *)port;
+
+        /*
+         *      First save the IER then disable the interrupts
+         */
+        ier = sio_in(up, TXX9_SIDICR);
+        sio_out(up, TXX9_SIDICR, 0);
+
+        while (sio_in(up, TXX9_SIDISR) & TXX9_SIDISR_UVALID)
+                ;
+
+        c = sio_in(up, TXX9_SIRFIFO);
+
+        /*
+         *      Finally, clear RX interrupt status
+         *      and restore the IER
+         */
+        sio_mask(up, TXX9_SIDISR, TXX9_SIDISR_RDIS);
+        sio_out(up, TXX9_SIDICR, ier);
+        return c;
+}
+
+
+static void serial_txx9_put_poll_char(struct uart_port *port, unsigned char c)
+{
+        unsigned int ier;
+        struct uart_txx9_port *up = (struct uart_txx9_port *)port;
+
+        /*
+         *      First save the IER then disable the interrupts
+         */
+        ier = sio_in(up, TXX9_SIDICR);
+        sio_out(up, TXX9_SIDICR, 0);
+
+        wait_for_xmitr(up);
+        /*
+         *      Send the character out.
+         *      If a LF, also do CR...
+         */
+        sio_out(up, TXX9_SITFIFO, c);
+        if (c == 10) {
+                wait_for_xmitr(up);
+                sio_out(up, TXX9_SITFIFO, 13);
+        }
+
+        /*
+         *      Finally, wait for transmitter to become empty
+         *      and restore the IER
+         */
+        wait_for_xmitr(up);
+        sio_out(up, TXX9_SIDICR, ier);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
 static int serial_txx9_startup(struct uart_port *port)
 {
         struct uart_txx9_port *up = (struct uart_txx9_port *)port;
@@ -781,6 +869,10 @@ static struct uart_ops serial_txx9_pops = {
         .release_port   = serial_txx9_release_port,
         .request_port   = serial_txx9_request_port,
         .config_port    = serial_txx9_config_port,
+#ifdef CONFIG_CONSOLE_POLL
+        .poll_get_char  = serial_txx9_get_poll_char,
+        .poll_put_char  = serial_txx9_put_poll_char,
+#endif
 };
 
 static struct uart_txx9_port serial_txx9_ports[UART_NR];
@@ -803,27 +895,6 @@ static void __init serial_txx9_register_ports(struct uart_driver *drv,
 
 #ifdef CONFIG_SERIAL_TXX9_CONSOLE
 
-/*
- *      Wait for transmitter & holding register to empty
- */
-static inline void wait_for_xmitr(struct uart_txx9_port *up)
-{
-        unsigned int tmout = 10000;
-
-        /* Wait up to 10ms for the character(s) to be sent. */
-        while (--tmout &&
-               !(sio_in(up, TXX9_SICISR) & TXX9_SICISR_TXALS))
-                udelay(1);
-
-        /* Wait up to 1s for flow control if necessary */
-        if (up->port.flags & UPF_CONS_FLOW) {
-                tmout = 1000000;
-                while (--tmout &&
-                       (sio_in(up, TXX9_SICISR) & TXX9_SICISR_CTSS))
-                        udelay(1);
-        }
-}
-
 static void serial_txx9_console_putchar(struct uart_port *port, int ch)
 {
         struct uart_txx9_port *up = (struct uart_txx9_port *)port;