On 08/05/2014 04:24 PM, Matthias Brugger wrote:

(...)

+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/serial_8250.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/pm_runtime.h>
+#include "8250.h"
+

Better if we have includes in alphabetical order..

+#define MTK_UART_RATE_FIX 0x0D /* UART Rate Fix Register */
+
+struct mtk8250_data {
+	int			line;
+	struct clk		*clk;
+};
+
+static void
+mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
+{
+	if (!state)
+		pm_runtime_get_sync(port->dev);
+
+	serial8250_do_pm(port, state, old);
+
+	if (state)
+		pm_runtime_put_sync_suspend(port->dev);
+}
+
+static int mtk8250_probe_of(struct uart_port *p,
+			   struct mtk8250_data *data)

static int mtk8250_probe_of(struct uart_port *p,
			    struct mtk8250_data *data)

+{
+	int err;
+	struct device_node	*np = p->dev->of_node;
+
+	data->clk = of_clk_get(np, 0);
+	if (IS_ERR(data->clk)) {
+		pr_warn("Can't get timer clock");

missed terminating new line...

+		return PTR_ERR(data->clk);
+	}
+
+	err = clk_prepare_enable(data->clk);
+	if (err) {
+		pr_warn("Can't prepare clock");

same...

+		clk_put(data->clk);
+		return err;
+	}
+	p->uartclk = clk_get_rate(data->clk);
+
+	return 0;
+}

(...)

+static struct platform_driver mtk8250_platform_driver = {
+	.driver = {
+		.name		= "mt6577-uart",
+		.owner		= THIS_MODULE,

No need to update this field...

+		.pm		= &mtk8250_pm_ops,
+		.of_match_table	= mtk8250_of_match,
+	},
+	.probe			= mtk8250_probe,
+	.remove			= mtk8250_remove,
+};
+module_platform_driver(mtk8250_platform_driver);

-- 
Regards,
Varka Bhadram.