tty: serial: fsl_lpuart: add polled console functions

This adds polling functions as used by kgdb.

Signed-off-by: Nicolae Rosia <nicolae_rosia@mentor.com>
Signed-off-by: Stefan Golinschi <stefan.golinschi@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index de9d510..49d7526 100644 (file)
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -431,6 +431,67 @@ static void lpuart_flush_buffer(struct uart_port *port)
        }
 }
 
+#if defined(CONFIG_CONSOLE_POLL)
+
+static int lpuart_poll_init(struct uart_port *port)
+{
+       struct lpuart_port *sport = container_of(port,
+                                       struct lpuart_port, port);
+       unsigned long flags;
+       unsigned char temp;
+
+       sport->port.fifosize = 0;
+
+       spin_lock_irqsave(&sport->port.lock, flags);
+       /* Disable Rx & Tx */
+       writeb(0, sport->port.membase + UARTCR2);
+
+       temp = readb(sport->port.membase + UARTPFIFO);
+       /* Enable Rx and Tx FIFO */
+       writeb(temp | UARTPFIFO_RXFE | UARTPFIFO_TXFE,
+                       sport->port.membase + UARTPFIFO);
+
+       /* flush Tx and Rx FIFO */
+       writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH,
+                       sport->port.membase + UARTCFIFO);
+
+       /* explicitly clear RDRF */
+       if (readb(sport->port.membase + UARTSR1) & UARTSR1_RDRF) {
+               readb(sport->port.membase + UARTDR);
+               writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO);
+       }
+
+       writeb(0, sport->port.membase + UARTTWFIFO);
+       writeb(1, sport->port.membase + UARTRWFIFO);
+
+       /* Enable Rx and Tx */
+       writeb(UARTCR2_RE | UARTCR2_TE, sport->port.membase + UARTCR2);
+       spin_unlock_irqrestore(&sport->port.lock, flags);
+
+       return 0;
+}
+
+static void lpuart_poll_put_char(struct uart_port *port, unsigned char c)
+{
+       unsigned int status;
+
+       /* drain */
+       while (!(readb(port->membase + UARTSR1) & UARTSR1_TDRE))
+               barrier();
+
+       writeb(c, port->membase + UARTDR);
+}
+
+static int lpuart_poll_get_char(struct uart_port *port)
+{
+       if (!(readb(port->membase + UARTSR1) & UARTSR1_RDRF))
+               return NO_POLL_CHAR;
+
+       return readb(port->membase + UARTDR);
+}
+
+#endif
+
 static inline void lpuart_transmit_buffer(struct lpuart_port *sport)
 {
        struct circ_buf *xmit = &sport->port.state->xmit;
@@ -1596,6 +1657,11 @@ static const struct uart_ops lpuart_pops = {
        .config_port    = lpuart_config_port,
        .verify_port    = lpuart_verify_port,
        .flush_buffer   = lpuart_flush_buffer,
+#if defined(CONFIG_CONSOLE_POLL)
+       .poll_init      = lpuart_poll_init,
+       .poll_get_char  = lpuart_poll_get_char,
+       .poll_put_char  = lpuart_poll_put_char,
+#endif
 };
 
 static const struct uart_ops lpuart32_pops = {