4 files changed, 191 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/watchdog/moxa,moxart-watchdog.txt b/Documentation/devicetree/bindings/watchdog/moxa,moxart-watchdog.txt
new file mode 100644
index 000000000000..1169857d1d12
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/moxa,moxart-watchdog.txt
@@ -0,0 +1,15 @@
+MOXA ART Watchdog timer
+
+Required properties:
+
+- compatible : Must be "moxa,moxart-watchdog"
+- reg : Should contain registers location and length
+- clocks : Should contain phandle for the clock that drives the counter
+
+Example:
+
+        watchdog: watchdog@98500000 {
+                compatible = "moxa,moxart-watchdog";
+                reg = <0x98500000 0x10>;
+                clocks = <&coreclk>;
+        };
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 6df632e0bb55..7fc6e101923a 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -392,6 +392,16 @@ config RETU_WATCHDOG
           To compile this driver as a module, choose M here: the
           module will be called retu_wdt.
 
+config MOXART_WDT
+        tristate "MOXART watchdog"
+        depends on ARCH_MOXART
+        help
+          Say Y here to include Watchdog timer support for the watchdog
+          existing on the MOXA ART SoC series platforms.
+
+          To compile this driver as a module, choose M here: the
+          module will be called moxart_wdt.
+
 # AVR32 Architecture
 
 config AT32AP700X_WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 8c7b8bcbbdc5..40c36ccdd0d4 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -55,6 +55,7 @@ obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
 obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
 obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
 obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o
+obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o
 
 # AVR32 Architecture
 obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
diff --git a/drivers/watchdog/moxart_wdt.c b/drivers/watchdog/moxart_wdt.c
new file mode 100644
index 000000000000..4166e4d116a8
--- /dev/null
+++ b/drivers/watchdog/moxart_wdt.c
@@ -0,0 +1,165 @@
+/*
+ * MOXA ART SoCs watchdog driver.
+ *
+ * Copyright (C) 2013 Jonas Jensen
+ *
+ * Jonas Jensen <jonas.jensen@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+#include <linux/moduleparam.h>
+
+#define REG_COUNT                       0x4
+#define REG_MODE                        0x8
+#define REG_ENABLE                      0xC
+
+struct moxart_wdt_dev {
+        struct watchdog_device dev;
+        void __iomem *base;
+        unsigned int clock_frequency;
+};
+
+static int heartbeat;
+
+static int moxart_wdt_stop(struct watchdog_device *wdt_dev)
+{
+        struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
+
+        writel(0, moxart_wdt->base + REG_ENABLE);
+
+        return 0;
+}
+
+static int moxart_wdt_start(struct watchdog_device *wdt_dev)
+{
+        struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
+
+        writel(moxart_wdt->clock_frequency * wdt_dev->timeout,
+               moxart_wdt->base + REG_COUNT);
+        writel(0x5ab9, moxart_wdt->base + REG_MODE);
+        writel(0x03, moxart_wdt->base + REG_ENABLE);
+
+        return 0;
+}
+
+static int moxart_wdt_set_timeout(struct watchdog_device *wdt_dev,
+                                  unsigned int timeout)
+{
+        wdt_dev->timeout = timeout;
+
+        return 0;
+}
+
+static const struct watchdog_info moxart_wdt_info = {
+        .identity       = "moxart-wdt",
+        .options        = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
+                          WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops moxart_wdt_ops = {
+        .owner          = THIS_MODULE,
+        .start          = moxart_wdt_start,
+        .stop           = moxart_wdt_stop,
+        .set_timeout    = moxart_wdt_set_timeout,
+};
+
+static int moxart_wdt_probe(struct platform_device *pdev)
+{
+        struct moxart_wdt_dev *moxart_wdt;
+        struct device *dev = &pdev->dev;
+        struct device_node *node = dev->of_node;
+        struct resource *res;
+        struct clk *clk;
+        int err;
+        unsigned int max_timeout;
+        bool nowayout = WATCHDOG_NOWAYOUT;
+
+        moxart_wdt = devm_kzalloc(dev, sizeof(*moxart_wdt), GFP_KERNEL);
+        if (!moxart_wdt)
+                return -ENOMEM;
+
+        platform_set_drvdata(pdev, moxart_wdt);
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        moxart_wdt->base = devm_ioremap_resource(dev, res);
+        if (IS_ERR(moxart_wdt->base))
+                return PTR_ERR(moxart_wdt->base);
+
+        clk = of_clk_get(node, 0);
+        if (IS_ERR(clk)) {
+                pr_err("%s: of_clk_get failed\n", __func__);
+                return PTR_ERR(clk);
+        }
+
+        moxart_wdt->clock_frequency = clk_get_rate(clk);
+        if (moxart_wdt->clock_frequency == 0) {
+                pr_err("%s: incorrect clock frequency\n", __func__);
+                return -EINVAL;
+        }
+
+        max_timeout = UINT_MAX / moxart_wdt->clock_frequency;
+
+        moxart_wdt->dev.info = &moxart_wdt_info;
+        moxart_wdt->dev.ops = &moxart_wdt_ops;
+        moxart_wdt->dev.timeout = max_timeout;
+        moxart_wdt->dev.min_timeout = 1;
+        moxart_wdt->dev.max_timeout = max_timeout;
+        moxart_wdt->dev.parent = dev;
+
+        watchdog_init_timeout(&moxart_wdt->dev, heartbeat, dev);
+        watchdog_set_nowayout(&moxart_wdt->dev, nowayout);
+
+        watchdog_set_drvdata(&moxart_wdt->dev, moxart_wdt);
+
+        err = watchdog_register_device(&moxart_wdt->dev);
+        if (err)
+                return err;
+
+        dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n",
+                moxart_wdt->dev.timeout, nowayout);
+
+        return 0;
+}
+
+static int moxart_wdt_remove(struct platform_device *pdev)
+{
+        struct moxart_wdt_dev *moxart_wdt = platform_get_drvdata(pdev);
+
+        moxart_wdt_stop(&moxart_wdt->dev);
+        watchdog_unregister_device(&moxart_wdt->dev);
+
+        return 0;
+}
+
+static const struct of_device_id moxart_watchdog_match[] = {
+        { .compatible = "moxa,moxart-watchdog" },
+        { },
+};
+
+static struct platform_driver moxart_wdt_driver = {
+        .probe      = moxart_wdt_probe,
+        .remove     = moxart_wdt_remove,
+        .driver     = {
+                .name           = "moxart-watchdog",
+                .owner          = THIS_MODULE,
+                .of_match_table = moxart_watchdog_match,
+        },
+};
+module_platform_driver(moxart_wdt_driver);
+
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds");
+
+MODULE_DESCRIPTION("MOXART watchdog driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");