--- /dev/null
+/*
+ * 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/notifier.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.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;
+ struct notifier_block restart_handler;
+};
+
+static int heartbeat;
+
+static int moxart_restart_handle(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ struct moxart_wdt_dev *moxart_wdt = container_of(this,
+ struct moxart_wdt_dev,
+ restart_handler);
+ writel(1, moxart_wdt->base + REG_COUNT);
+ writel(0x5ab9, moxart_wdt->base + REG_MODE);
+ writel(0x03, moxart_wdt->base + REG_ENABLE);
+
+ return NOTIFY_DONE;
+}
+
+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;
+
+ moxart_wdt->restart_handler.notifier_call = moxart_restart_handle;
+ moxart_wdt->restart_handler.priority = 128;
+ err = register_restart_handler(&moxart_wdt->restart_handler);
+ if (err)
+ dev_err(dev, "cannot register restart notifier (err=%d)\n",
+ 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);
+
+ unregister_restart_handler(&moxart_wdt->restart_handler);
+ moxart_wdt_stop(&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",
+ .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>");
Code Review / kvmfornfv.git / blobdiff