diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 9af07fd92763..834222abbbdb 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1476,7 +1476,9 @@ config INDYDOG
 config JZ4740_WDT
 	tristate "Ingenic jz4740 SoC hardware watchdog"
 	depends on MACH_JZ4740 || MACH_JZ4780
+	depends on COMMON_CLK
 	select WATCHDOG_CORE
+	select INGENIC_TIMER
 	help
 	  Hardware driver for the built-in watchdog timer on Ingenic jz4740 SoCs.
 
diff --git a/drivers/watchdog/jz4740_wdt.c b/drivers/watchdog/jz4740_wdt.c
index ec4d99a830ba..aaa6fc87136c 100644
--- a/drivers/watchdog/jz4740_wdt.c
+++ b/drivers/watchdog/jz4740_wdt.c
@@ -13,6 +13,7 @@
  *
  */
 
+#include <linux/mfd/ingenic-tcu.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/types.h>
@@ -25,26 +26,7 @@
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/of.h>
-
-#include <asm/mach-jz4740/timer.h>
-
-#define JZ_REG_WDT_TIMER_DATA     0x0
-#define JZ_REG_WDT_COUNTER_ENABLE 0x4
-#define JZ_REG_WDT_TIMER_COUNTER  0x8
-#define JZ_REG_WDT_TIMER_CONTROL  0xC
-
-#define JZ_WDT_CLOCK_PCLK 0x1
-#define JZ_WDT_CLOCK_RTC  0x2
-#define JZ_WDT_CLOCK_EXT  0x4
-
-#define JZ_WDT_CLOCK_DIV_SHIFT   3
-
-#define JZ_WDT_CLOCK_DIV_1    (0 << JZ_WDT_CLOCK_DIV_SHIFT)
-#define JZ_WDT_CLOCK_DIV_4    (1 << JZ_WDT_CLOCK_DIV_SHIFT)
-#define JZ_WDT_CLOCK_DIV_16   (2 << JZ_WDT_CLOCK_DIV_SHIFT)
-#define JZ_WDT_CLOCK_DIV_64   (3 << JZ_WDT_CLOCK_DIV_SHIFT)
-#define JZ_WDT_CLOCK_DIV_256  (4 << JZ_WDT_CLOCK_DIV_SHIFT)
-#define JZ_WDT_CLOCK_DIV_1024 (5 << JZ_WDT_CLOCK_DIV_SHIFT)
+#include <linux/regmap.h>
 
 #define DEFAULT_HEARTBEAT 5
 #define MAX_HEARTBEAT     2048
@@ -64,15 +46,15 @@ MODULE_PARM_DESC(heartbeat,
 
 struct jz4740_wdt_drvdata {
 	struct watchdog_device wdt;
-	void __iomem *base;
-	struct clk *rtc_clk;
+	struct regmap *map;
+	struct clk *clk;
 };
 
 static int jz4740_wdt_ping(struct watchdog_device *wdt_dev)
 {
 	struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
 
-	writew(0x0, drvdata->base + JZ_REG_WDT_TIMER_COUNTER);
+	regmap_write(drvdata->map, TCU_REG_WDT_TCNT, 0);
 	return 0;
 }
 
@@ -80,52 +62,65 @@ static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev,
 				    unsigned int new_timeout)
 {
 	struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
-	unsigned int rtc_clk_rate;
-	unsigned int timeout_value;
-	unsigned short clock_div = JZ_WDT_CLOCK_DIV_1;
-
-	rtc_clk_rate = clk_get_rate(drvdata->rtc_clk);
-
-	timeout_value = rtc_clk_rate * new_timeout;
-	while (timeout_value > 0xffff) {
-		if (clock_div == JZ_WDT_CLOCK_DIV_1024) {
-			/* Requested timeout too high;
-			* use highest possible value. */
-			timeout_value = 0xffff;
-			break;
-		}
-		timeout_value >>= 2;
-		clock_div += (1 << JZ_WDT_CLOCK_DIV_SHIFT);
+	struct clk *clk = drvdata->clk;
+	unsigned long clk_rate, timeout_value;
+	bool change_rate = false;
+	u32 tcer;
+	int ret = 0;
+
+	clk_rate = clk_get_rate(clk);
+	timeout_value = clk_rate * new_timeout;
+
+	if (timeout_value > 0xffff) {
+		clk_rate = clk_round_rate(clk, 0xffff / new_timeout);
+		timeout_value = clk_rate * new_timeout;
+		if (timeout_value > 0xffff)
+			return -EINVAL;
+		change_rate = true;
 	}
 
-	writeb(0x0, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE);
-	writew(clock_div, drvdata->base + JZ_REG_WDT_TIMER_CONTROL);
+	regmap_read(drvdata->map, TCU_REG_WDT_TCER, &tcer);
+	regmap_write(drvdata->map, TCU_REG_WDT_TCER, 0);
 
-	writew((u16)timeout_value, drvdata->base + JZ_REG_WDT_TIMER_DATA);
-	writew(0x0, drvdata->base + JZ_REG_WDT_TIMER_COUNTER);
-	writew(clock_div | JZ_WDT_CLOCK_RTC,
-		drvdata->base + JZ_REG_WDT_TIMER_CONTROL);
+	if (change_rate) {
+		clk_disable_unprepare(clk);
+		ret = clk_set_rate(clk, clk_rate);
+		clk_prepare_enable(clk);
+		if (ret)
+			goto done;
+	}
 
-	writeb(0x1, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE);
+	regmap_write(drvdata->map, TCU_REG_WDT_TDR, (u16)timeout_value);
+	regmap_write(drvdata->map, TCU_REG_WDT_TCNT, 0);
 
 	wdt_dev->timeout = new_timeout;
-	return 0;
+
+done:
+	regmap_write(drvdata->map, TCU_REG_WDT_TCER, tcer & TCU_WDT_TCER_TCEN);
+	return ret;
 }
 
 static int jz4740_wdt_start(struct watchdog_device *wdt_dev)
 {
-	jz4740_timer_enable_watchdog();
-	jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
+	struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
+	int ret;
 
-	return 0;
+	clk_prepare_enable(drvdata->clk);
+	ret = jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
+	if (ret)
+		clk_disable_unprepare(drvdata->clk);
+	else
+		regmap_write(drvdata->map, TCU_REG_WDT_TCER, TCU_WDT_TCER_TCEN);
+
+	return ret;
 }
 
 static int jz4740_wdt_stop(struct watchdog_device *wdt_dev)
 {
 	struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
 
-	writeb(0x0, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE);
-	jz4740_timer_disable_watchdog();
+	regmap_write(drvdata->map, TCU_REG_WDT_TCER, 0);
+	clk_disable_unprepare(drvdata->clk);
 
 	return 0;
 }
@@ -163,13 +158,17 @@ MODULE_DEVICE_TABLE(of, jz4740_wdt_of_matches);
 
 static int jz4740_wdt_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct jz4740_wdt_drvdata *drvdata;
 	struct watchdog_device *jz4740_wdt;
-	struct resource	*res;
 	int ret;
 
-	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct jz4740_wdt_drvdata),
-			       GFP_KERNEL);
+	if (!dev->of_node) {
+		dev_err(dev, "jz4740-wdt must be probed via devicetree\n");
+		return -ENODEV;
+	}
+
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
 	if (!drvdata)
 		return -ENOMEM;
 
@@ -182,19 +181,20 @@ static int jz4740_wdt_probe(struct platform_device *pdev)
 	jz4740_wdt->timeout = heartbeat;
 	jz4740_wdt->min_timeout = 1;
 	jz4740_wdt->max_timeout = MAX_HEARTBEAT;
-	jz4740_wdt->parent = &pdev->dev;
+	jz4740_wdt->parent = dev;
 	watchdog_set_nowayout(jz4740_wdt, nowayout);
 	watchdog_set_drvdata(jz4740_wdt, drvdata);
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	drvdata->base = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(drvdata->base))
-		return PTR_ERR(drvdata->base);
+	drvdata->map = dev_get_regmap(dev->parent, NULL);
+	if (IS_ERR(drvdata->map)) {
+		dev_warn(dev, "regmap not found\n");
+		return PTR_ERR(drvdata->map);
+	}
 
-	drvdata->rtc_clk = devm_clk_get(&pdev->dev, "rtc");
-	if (IS_ERR(drvdata->rtc_clk)) {
-		dev_err(&pdev->dev, "cannot find RTC clock\n");
-		return PTR_ERR(drvdata->rtc_clk);
+	drvdata->clk = devm_clk_get(&pdev->dev, "wdt");
+	if (IS_ERR(drvdata->clk)) {
+		dev_err(&pdev->dev, "cannot find WDT clock\n");
+		return PTR_ERR(drvdata->clk);
 	}
 
 	ret = devm_watchdog_register_device(&pdev->dev, &drvdata->wdt);
