1 files changed, 172 insertions, 0 deletions

diff --git a/kernel/drivers/watchdog/ep93xx_wdt.c b/kernel/drivers/watchdog/ep93xx_wdt.c
new file mode 100644
index 000000000..7a2cc7191
--- /dev/null
+++ b/kernel/drivers/watchdog/ep93xx_wdt.c
@@ -0,0 +1,172 @@
+/*
+ * Watchdog driver for Cirrus Logic EP93xx family of devices.
+ *
+ * Copyright (c) 2004 Ray Lehtiniemi
+ * Copyright (c) 2006 Tower Technologies
+ * Based on ep93xx driver, bits from alim7101_wdt.c
+ *
+ * Authors: Ray Lehtiniemi <rayl@mail.com>,
+ *	Alessandro Zummo <a.zummo@towertech.it>
+ *
+ * Copyright (c) 2012 H Hartley Sweeten <hsweeten@visionengravers.com>
+ *	Convert to a platform device and use the watchdog framework API
+ *
+ * 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.
+ *
+ * This watchdog fires after 250msec, which is a too short interval
+ * for us to rely on the user space daemon alone. So we ping the
+ * wdt each ~200msec and eventually stop doing it if the user space
+ * daemon dies.
+ *
+ * TODO:
+ *
+ *	- Test last reset from watchdog status
+ *	- Add a few missing ioctls
+ */
+
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <linux/timer.h>
+#include <linux/io.h>
+
+#define WDT_VERSION	"0.4"
+
+/* default timeout (secs) */
+#define WDT_TIMEOUT 30
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
+
+static unsigned int timeout = WDT_TIMEOUT;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout,
+	"Watchdog timeout in seconds. (1<=timeout<=3600, default="
+				__MODULE_STRING(WDT_TIMEOUT) ")");
+
+static void __iomem *mmio_base;
+static struct timer_list timer;
+static unsigned long next_heartbeat;
+
+#define EP93XX_WATCHDOG		0x00
+#define EP93XX_WDSTATUS		0x04
+
+/* reset the wdt every ~200ms - the heartbeat of the device is 0.250 seconds*/
+#define WDT_INTERVAL (HZ/5)
+
+static void ep93xx_wdt_timer_ping(unsigned long data)
+{
+	if (time_before(jiffies, next_heartbeat))
+		writel(0x5555, mmio_base + EP93XX_WATCHDOG);
+
+	/* Re-set the timer interval */
+	mod_timer(&timer, jiffies + WDT_INTERVAL);
+}
+
+static int ep93xx_wdt_start(struct watchdog_device *wdd)
+{
+	next_heartbeat = jiffies + (timeout * HZ);
+
+	writel(0xaaaa, mmio_base + EP93XX_WATCHDOG);
+	mod_timer(&timer, jiffies + WDT_INTERVAL);
+
+	return 0;
+}
+
+static int ep93xx_wdt_stop(struct watchdog_device *wdd)
+{
+	del_timer_sync(&timer);
+	writel(0xaa55, mmio_base + EP93XX_WATCHDOG);
+
+	return 0;
+}
+
+static int ep93xx_wdt_keepalive(struct watchdog_device *wdd)
+{
+	/* user land ping */
+	next_heartbeat = jiffies + (timeout * HZ);
+
+	return 0;
+}
+
+static const struct watchdog_info ep93xx_wdt_ident = {
+	.options	= WDIOF_CARDRESET |
+			  WDIOF_MAGICCLOSE |
+			  WDIOF_KEEPALIVEPING,
+	.identity	= "EP93xx Watchdog",
+};
+
+static struct watchdog_ops ep93xx_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= ep93xx_wdt_start,
+	.stop		= ep93xx_wdt_stop,
+	.ping		= ep93xx_wdt_keepalive,
+};
+
+static struct watchdog_device ep93xx_wdt_wdd = {
+	.info		= &ep93xx_wdt_ident,
+	.ops		= &ep93xx_wdt_ops,
+};
+
+static int ep93xx_wdt_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	unsigned long val;
+	int err;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mmio_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(mmio_base))
+		return PTR_ERR(mmio_base);
+
+	if (timeout < 1 || timeout > 3600) {
+		timeout = WDT_TIMEOUT;
+		dev_warn(&pdev->dev,
+			"timeout value must be 1<=x<=3600, using %d\n",
+			timeout);
+	}
+
+	val = readl(mmio_base + EP93XX_WATCHDOG);
+	ep93xx_wdt_wdd.bootstatus = (val & 0x01) ? WDIOF_CARDRESET : 0;
+	ep93xx_wdt_wdd.timeout = timeout;
+
+	watchdog_set_nowayout(&ep93xx_wdt_wdd, nowayout);
+
+	setup_timer(&timer, ep93xx_wdt_timer_ping, 1);
+
+	err = watchdog_register_device(&ep93xx_wdt_wdd);
+	if (err)
+		return err;
+
+	dev_info(&pdev->dev,
+		"EP93XX watchdog, driver version " WDT_VERSION "%s\n",
+		(val & 0x08) ? " (nCS1 disable detected)" : "");
+
+	return 0;
+}
+
+static int ep93xx_wdt_remove(struct platform_device *pdev)
+{
+	watchdog_unregister_device(&ep93xx_wdt_wdd);
+	return 0;
+}
+
+static struct platform_driver ep93xx_wdt_driver = {
+	.driver		= {
+		.name	= "ep93xx-wdt",
+	},
+	.probe		= ep93xx_wdt_probe,
+	.remove		= ep93xx_wdt_remove,
+};
+
+module_platform_driver(ep93xx_wdt_driver);
+
+MODULE_AUTHOR("Ray Lehtiniemi <rayl@mail.com>");
+MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
+MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
+MODULE_DESCRIPTION("EP93xx Watchdog");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(WDT_VERSION);