serial: pch_uart: add console poll support

Implement console poll for pch_uart, this could enable KGDBoC when
on pch-uart console.

Signed-off-by: Liang Li <liang.li@windriver.com>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index 7a6c989924b3e955d738abaa7049011d12d64c69..21a7e179edf36a2ef476553159000e7eef81c913 100644 (file)
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -1493,29 +1493,6 @@ static int pch_uart_verify_port(struct uart_port *port,
        return 0;
 }
 
-static struct uart_ops pch_uart_ops = {
-       .tx_empty = pch_uart_tx_empty,
-       .set_mctrl = pch_uart_set_mctrl,
-       .get_mctrl = pch_uart_get_mctrl,
-       .stop_tx = pch_uart_stop_tx,
-       .start_tx = pch_uart_start_tx,
-       .stop_rx = pch_uart_stop_rx,
-       .enable_ms = pch_uart_enable_ms,
-       .break_ctl = pch_uart_break_ctl,
-       .startup = pch_uart_startup,
-       .shutdown = pch_uart_shutdown,
-       .set_termios = pch_uart_set_termios,
-/*     .pm             = pch_uart_pm,          Not supported yet */
-/*     .set_wake       = pch_uart_set_wake,    Not supported yet */
-       .type = pch_uart_type,
-       .release_port = pch_uart_release_port,
-       .request_port = pch_uart_request_port,
-       .config_port = pch_uart_config_port,
-       .verify_port = pch_uart_verify_port
-};
-
-#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE
-
 /*
  *     Wait for transmitter & holding register to empty
  */
@@ -1547,6 +1524,84 @@ static void wait_for_xmitr(struct eg20t_port *up, int bits)
        }
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for communicate via uart while
+ * in an interrupt or debug context.
+ */
+static int pch_uart_get_poll_char(struct uart_port *port)
+{
+       struct eg20t_port *priv =
+               container_of(port, struct eg20t_port, port);
+       u8 lsr = ioread8(priv->membase + UART_LSR);
+
+       if (!(lsr & UART_LSR_DR))
+               return NO_POLL_CHAR;
+
+       return ioread8(priv->membase + PCH_UART_RBR);
+}
+
+
+static void pch_uart_put_poll_char(struct uart_port *port,
+                        unsigned char c)
+{
+       unsigned int ier;
+       struct eg20t_port *priv =
+               container_of(port, struct eg20t_port, port);
+
+       /*
+        * First save the IER then disable the interrupts
+        */
+       ier = ioread8(priv->membase + UART_IER);
+       pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_ALL_INT);
+
+       wait_for_xmitr(priv, UART_LSR_THRE);
+       /*
+        * Send the character out.
+        * If a LF, also do CR...
+        */
+       iowrite8(c, priv->membase + PCH_UART_THR);
+       if (c == 10) {
+               wait_for_xmitr(priv, UART_LSR_THRE);
+               iowrite8(13, priv->membase + PCH_UART_THR);
+       }
+
+       /*
+        * Finally, wait for transmitter to become empty
+        * and restore the IER
+        */
+       wait_for_xmitr(priv, BOTH_EMPTY);
+       iowrite8(ier, priv->membase + UART_IER);
+}
+#endif /* CONFIG_CONSOLE_POLL */
+
+static struct uart_ops pch_uart_ops = {
+       .tx_empty = pch_uart_tx_empty,
+       .set_mctrl = pch_uart_set_mctrl,
+       .get_mctrl = pch_uart_get_mctrl,
+       .stop_tx = pch_uart_stop_tx,
+       .start_tx = pch_uart_start_tx,
+       .stop_rx = pch_uart_stop_rx,
+       .enable_ms = pch_uart_enable_ms,
+       .break_ctl = pch_uart_break_ctl,
+       .startup = pch_uart_startup,
+       .shutdown = pch_uart_shutdown,
+       .set_termios = pch_uart_set_termios,
+/*     .pm             = pch_uart_pm,          Not supported yet */
+/*     .set_wake       = pch_uart_set_wake,    Not supported yet */
+       .type = pch_uart_type,
+       .release_port = pch_uart_release_port,
+       .request_port = pch_uart_request_port,
+       .config_port = pch_uart_config_port,
+       .verify_port = pch_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+       .poll_get_char = pch_uart_get_poll_char,
+       .poll_put_char = pch_uart_put_poll_char,
+#endif
+};
+
+#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE
+
 static void pch_console_putchar(struct uart_port *port, int ch)
 {
        struct eg20t_port *priv =
@@ -1655,7 +1710,7 @@ static struct console pch_console = {
 #define PCH_CONSOLE    (&pch_console)
 #else
 #define PCH_CONSOLE    NULL
-#endif
+#endif /* CONFIG_SERIAL_PCH_UART_CONSOLE */
 
 static struct uart_driver pch_uart_driver = {
        .owner = THIS_MODULE,