Fixed MTP to work with TWRP

drivers/watchdog/moxart_wdt.c

@@ -0,0 +1,188 @@
+/*
+ * 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",
+		.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>");