1 files changed, 146 insertions, 0 deletions
diff --git a/drivers/watchdog/ep93xx_wdt.c b/drivers/watchdog/ep93xx_wdt.c
new file mode 100644
index 000000000..38e26f160
--- /dev/null
+++ b/drivers/watchdog/ep93xx_wdt.c
@@ -0,0 +1,146 @@
+/*
+ * 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.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <linux/io.h>
+
+/* 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;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds.");
+
+#define EP93XX_WATCHDOG		0x00
+#define EP93XX_WDSTATUS		0x04
+
+struct ep93xx_wdt_priv {
+	void __iomem *mmio;
+	struct watchdog_device wdd;
+};
+
+static int ep93xx_wdt_start(struct watchdog_device *wdd)
+{
+	struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+	writel(0xaaaa, priv->mmio + EP93XX_WATCHDOG);
+
+	return 0;
+}
+
+static int ep93xx_wdt_stop(struct watchdog_device *wdd)
+{
+	struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+	writel(0xaa55, priv->mmio + EP93XX_WATCHDOG);
+
+	return 0;
+}
+
+static int ep93xx_wdt_ping(struct watchdog_device *wdd)
+{
+	struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+	writel(0x5555, priv->mmio + EP93XX_WATCHDOG);
+
+	return 0;
+}
+
+static const struct watchdog_info ep93xx_wdt_ident = {
+	.options	= WDIOF_CARDRESET |
+			  WDIOF_SETTIMEOUT |
+			  WDIOF_MAGICCLOSE |
+			  WDIOF_KEEPALIVEPING,
+	.identity	= "EP93xx Watchdog",
+};
+
+static const struct watchdog_ops ep93xx_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= ep93xx_wdt_start,
+	.stop		= ep93xx_wdt_stop,
+	.ping		= ep93xx_wdt_ping,
+};
+
+static int ep93xx_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ep93xx_wdt_priv *priv;
+	struct watchdog_device *wdd;
+	unsigned long val;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->mmio = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->mmio))
+		return PTR_ERR(priv->mmio);
+
+	val = readl(priv->mmio + EP93XX_WATCHDOG);
+
+	wdd = &priv->wdd;
+	wdd->bootstatus = (val & 0x01) ? WDIOF_CARDRESET : 0;
+	wdd->info = &ep93xx_wdt_ident;
+	wdd->ops = &ep93xx_wdt_ops;
+	wdd->min_timeout = 1;
+	wdd->max_hw_heartbeat_ms = 200;
+	wdd->parent = dev;
+
+	watchdog_set_nowayout(wdd, nowayout);
+
+	wdd->timeout = WDT_TIMEOUT;
+	watchdog_init_timeout(wdd, timeout, dev);
+
+	watchdog_set_drvdata(wdd, priv);
+
+	ret = devm_watchdog_register_device(dev, wdd);
+	if (ret)
+		return ret;
+
+	dev_info(dev, "EP93XX watchdog driver %s\n",
+		 (val & 0x08) ? " (nCS1 disable detected)" : "");
+
+	return 0;
+}
+
+static struct platform_driver ep93xx_wdt_driver = {
+	.driver		= {
+		.name	= "ep93xx-wdt",
+	},
+	.probe		= ep93xx_wdt_probe,
+};
+
+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");