kgdb: kgdboc console poll hooks for cpm uart

Add in console polling hooks for the cpm uart for use with kgdb and
kgdboc.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
CC: galak@kernel.crashing.org

diff --git a/drivers/serial/cpm_uart/cpm_uart_core.c b/drivers/serial/cpm_uart/cpm_uart_core.c
index 93e407ee08b91a97614103cb9520c307c4c7fd53..1ff80de177db21be26be01ffa35831854821e97d 100644 (file)
--- a/drivers/serial/cpm_uart/cpm_uart_core.c
+++ b/drivers/serial/cpm_uart/cpm_uart_core.c
@@ -201,6 +201,10 @@ static void cpm_uart_int_tx(struct uart_port *port)
        cpm_uart_tx_pump(port);
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+static int serial_polled;
+#endif
+
 /*
  * Receive characters
  */
@@ -222,6 +226,12 @@ static void cpm_uart_int_rx(struct uart_port *port)
         */
        bdp = pinfo->rx_cur;
        for (;;) {
+#ifdef CONFIG_CONSOLE_POLL
+               if (unlikely(serial_polled)) {
+                       serial_polled = 0;
+                       return;
+               }
+#endif
                /* get status */
                status = in_be16(&bdp->cbd_sc);
                /* If this one is empty, return happy */
@@ -253,7 +263,12 @@ static void cpm_uart_int_rx(struct uart_port *port)
                                goto handle_error;
                        if (uart_handle_sysrq_char(port, ch))
                                continue;
-
+#ifdef CONFIG_CONSOLE_POLL
+                       if (unlikely(serial_polled)) {
+                               serial_polled = 0;
+                               return;
+                       }
+#endif
                      error_return:
                        tty_insert_flip_char(tty, ch, flg);
 
@@ -865,6 +880,80 @@ static void cpm_uart_config_port(struct uart_port *port, int flags)
                cpm_uart_request_port(port);
        }
 }
+
+#ifdef CONFIG_CONSOLE_POLL
+/* Serial polling routines for writing and reading from the uart while
+ * in an interrupt or debug context.
+ */
+
+#define GDB_BUF_SIZE   512     /* power of 2, please */
+
+static char poll_buf[GDB_BUF_SIZE];
+static char *pollp;
+static int poll_chars;
+
+static int poll_wait_key(char *obuf, struct uart_cpm_port *pinfo)
+{
+       u_char          c, *cp;
+       volatile cbd_t  *bdp;
+       int             i;
+
+       /* Get the address of the host memory buffer.
+        */
+       bdp = pinfo->rx_cur;
+       while (bdp->cbd_sc & BD_SC_EMPTY)
+               ;
+
+       /* If the buffer address is in the CPM DPRAM, don't
+        * convert it.
+        */
+       cp = cpm2cpu_addr(bdp->cbd_bufaddr, pinfo);
+
+       if (obuf) {
+               i = c = bdp->cbd_datlen;
+               while (i-- > 0)
+                       *obuf++ = *cp++;
+       } else
+               c = *cp;
+       bdp->cbd_sc &= ~(BD_SC_BR | BD_SC_FR | BD_SC_PR | BD_SC_OV | BD_SC_ID);
+       bdp->cbd_sc |= BD_SC_EMPTY;
+
+       if (bdp->cbd_sc & BD_SC_WRAP)
+               bdp = pinfo->rx_bd_base;
+       else
+               bdp++;
+       pinfo->rx_cur = (cbd_t *)bdp;
+
+       return (int)c;
+}
+
+static int cpm_get_poll_char(struct uart_port *port)
+{
+       struct uart_cpm_port *pinfo = (struct uart_cpm_port *)port;
+
+       if (!serial_polled) {
+               serial_polled = 1;
+               poll_chars = 0;
+       }
+       if (poll_chars <= 0) {
+               poll_chars = poll_wait_key(poll_buf, pinfo);
+               pollp = poll_buf;
+       }
+       poll_chars--;
+       return *pollp++;
+}
+
+static void cpm_put_poll_char(struct uart_port *port,
+                        unsigned char c)
+{
+       struct uart_cpm_port *pinfo = (struct uart_cpm_port *)port;
+       static char ch[2];
+
+       ch[0] = (char)c;
+       cpm_uart_early_write(pinfo->port.line, ch, 1);
+}
+#endif /* CONFIG_CONSOLE_POLL */
+
 static struct uart_ops cpm_uart_pops = {
        .tx_empty       = cpm_uart_tx_empty,
        .set_mctrl      = cpm_uart_set_mctrl,
@@ -882,6 +971,10 @@ static struct uart_ops cpm_uart_pops = {
        .request_port   = cpm_uart_request_port,
        .config_port    = cpm_uart_config_port,
        .verify_port    = cpm_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+       .poll_get_char = cpm_get_poll_char,
+       .poll_put_char = cpm_put_poll_char,
+#endif
 };
 
 struct uart_cpm_port cpm_uart_ports[UART_NR];