2 files changed, 54 insertions, 4 deletions

diff --git a/Documentation/devicetree/bindings/serial/altera_uart.txt b/Documentation/devicetree/bindings/serial/altera_uart.txt
new file mode 100644
index 000000000000..71cae3f70100
--- /dev/null
+++ b/Documentation/devicetree/bindings/serial/altera_uart.txt
@@ -0,0 +1,7 @@
+Altera UART
+
+Required properties:
+- compatible : should be "ALTR,uart-1.0"
+
+Optional properties:
+- clock-frequency : frequency of the clock input to the UART
diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
index 721216292a50..1803c37d58ab 100644
--- a/drivers/tty/serial/altera_uart.c
+++ b/drivers/tty/serial/altera_uart.c
@@ -24,6 +24,7 @@
 #include <linux/serial.h>
 #include <linux/serial_core.h>
 #include <linux/platform_device.h>
+#include <linux/of.h>
 #include <linux/io.h>
 #include <linux/altera_uart.h>
 
@@ -511,6 +512,29 @@ static struct uart_driver altera_uart_driver = {
         .cons           = ALTERA_UART_CONSOLE,
 };
 
+#ifdef CONFIG_OF
+static int altera_uart_get_of_uartclk(struct platform_device *pdev,
+                                      struct uart_port *port)
+{
+        int len;
+        const __be32 *clk;
+
+        clk = of_get_property(pdev->dev.of_node, "clock-frequency", &len);
+        if (!clk || len < sizeof(__be32))
+                return -ENODEV;
+
+        port->uartclk = be32_to_cpup(clk);
+
+        return 0;
+}
+#else
+static int altera_uart_get_of_uartclk(struct platform_device *pdev,
+                                      struct uart_port *port)
+{
+        return -ENODEV;
+}
+#endif /* CONFIG_OF */
+
 static int __devinit altera_uart_probe(struct platform_device *pdev)
 {
         struct altera_uart_platform_uart *platp = pdev->dev.platform_data;
@@ -518,6 +542,7 @@ static int __devinit altera_uart_probe(struct platform_device *pdev)
         struct resource *res_mem;
         struct resource *res_irq;
         int i = pdev->id;
+        int ret;
 
         /* -1 emphasizes that the platform must have one port, no .N suffix */
         if (i == -1)
@@ -542,6 +567,15 @@ static int __devinit altera_uart_probe(struct platform_device *pdev)
         else if (platp->irq)
                 port->irq = platp->irq;
 
+        /* Check platform data first so we can override device node data */
+        if (platp)
+                port->uartclk = platp->uartclk;
+        else {
+                ret = altera_uart_get_of_uartclk(pdev, port);
+                if (ret)
+                        return ret;
+        }
+
         port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
         if (!port->membase)
                 return -ENOMEM;
@@ -549,7 +583,6 @@ static int __devinit altera_uart_probe(struct platform_device *pdev)
         port->line = i;
         port->type = PORT_ALTERA_UART;
         port->iotype = SERIAL_IO_MEM;
-        port->uartclk = platp->uartclk;
         port->ops = &altera_uart_ops;
         port->flags = UPF_BOOT_AUTOCONF;
         port->private_data = platp;
@@ -567,13 +600,23 @@ static int __devexit altera_uart_remove(struct platform_device *pdev)
         return 0;
 }
 
+#ifdef CONFIG_OF
+static struct of_device_id altera_uart_match[] = {
+        { .compatible = "ALTR,uart-1.0", },
+        {},
+};
+MODULE_DEVICE_TABLE(of, altera_uart_match);
+#else
+#define altera_uart_match NULL
+#endif /* CONFIG_OF */
+
 static struct platform_driver altera_uart_platform_driver = {
         .probe  = altera_uart_probe,
         .remove = __devexit_p(altera_uart_remove),
         .driver = {
-                .name   = DRV_NAME,
-                .owner  = THIS_MODULE,
-                .pm     = NULL,
+                .name           = DRV_NAME,
+                .owner          = THIS_MODULE,
+                .of_match_table = altera_uart_match,
         },
 };