kgdb: kgdboc pl011 I/O module

Implement the serial polling hooks for the pl011 uart for use with
kgdboc.

This patch was specifically tested on the ARM Versatile AB reference
platform.

[ mingo@elte.hu: minor cleanups. ]

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 30 insertions, 0 deletions

diff --git a/drivers/serial/amba-pl011.c b/drivers/serial/amba-pl011.c
index 40604a09292..08adc1de4a7 100644
--- a/drivers/serial/amba-pl011.c
+++ b/drivers/serial/amba-pl011.c
@@ -314,6 +314,32 @@ static void pl011_break_ctl(struct uart_port *port, int break_state)
         spin_unlock_irqrestore(&uap->port.lock, flags);
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+static int pl010_get_poll_char(struct uart_port *port)
+{
+        struct uart_amba_port *uap = (struct uart_amba_port *)port;
+        unsigned int status;
+
+        do {
+                status = readw(uap->port.membase + UART01x_FR);
+        } while (status & UART01x_FR_RXFE);
+
+        return readw(uap->port.membase + UART01x_DR);
+}
+
+static void pl010_put_poll_char(struct uart_port *port,
+                         unsigned char ch)
+{
+        struct uart_amba_port *uap = (struct uart_amba_port *)port;
+
+        while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_TXFF)
+                barrier();
+
+        writew(ch, uap->port.membase + UART01x_DR);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
 static int pl011_startup(struct uart_port *port)
 {
         struct uart_amba_port *uap = (struct uart_amba_port *)port;
@@ -572,6 +598,10 @@ static struct uart_ops amba_pl011_pops = {
         .request_port   = pl010_request_port,
         .config_port    = pl010_config_port,
         .verify_port    = pl010_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+        .poll_get_char = pl010_get_poll_char,
+        .poll_put_char = pl010_put_poll_char,
+#endif
 };
 
 static struct uart_amba_port *amba_ports[UART_NR];