tty: of_serial: add support for the DesignWare 8250

Support the DesignWare 8250 by a new compatible string and registering
the DesignWare helpers.  If the registration of the helpers fails, then
continue as a normal 8250 as we may still get some useful debug out.

Cc: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/tty/serial/of-serial.txt b/Documentation/devicetree/bindings/tty/serial/of-serial.txt
index b8b27b0aca10..b7ceaaa7602d 100644
--- a/Documentation/devicetree/bindings/tty/serial/of-serial.txt
+++ b/Documentation/devicetree/bindings/tty/serial/of-serial.txt
@@ -3,6 +3,7 @@
 Required properties:
 - compatible : one of:
         - "ns8250"
+        - "ns8250dw"
         - "ns16450"
         - "ns16550a"
         - "ns16550"
diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index e58cece6f443..024926c3be57 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -78,6 +78,12 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
                 }
         }
 
+        if (of_device_is_compatible(np, "ns8250dw")) {
+                ret = serial8250_use_designware_io(port);
+                if (ret)
+                        dev_warn(&ofdev->dev, "unable to register DesignWare 8250 helpers, continuing as a normal 8250\n");
+        }
+
         port->type = type;
         port->uartclk = clk;
         port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
@@ -176,6 +182,7 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
  */
 static struct of_device_id __devinitdata of_platform_serial_table[] = {
         { .compatible = "ns8250",   .data = (void *)PORT_8250, },
+        { .compatible = "ns8250dw", .data = (void *)PORT_8250, },
         { .compatible = "ns16450",  .data = (void *)PORT_16450, },
         { .compatible = "ns16550a", .data = (void *)PORT_16550A, },
         { .compatible = "ns16550",  .data = (void *)PORT_16550, },