1 files changed, 111 insertions, 0 deletions

diff --git a/drivers/watchdog/stmp3xxx_rtc_wdt.c b/drivers/watchdog/stmp3xxx_rtc_wdt.c
new file mode 100644
index 000000000000..c97e98dcde62
--- /dev/null
+++ b/drivers/watchdog/stmp3xxx_rtc_wdt.c
@@ -0,0 +1,111 @@
+/*
+ * Watchdog driver for the RTC based watchdog in STMP3xxx and i.MX23/28
+ *
+ * Author: Wolfram Sang <w.sang@pengutronix.de>
+ *
+ * Copyright (C) 2011-12 Wolfram Sang, Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/stmp3xxx_rtc_wdt.h>
+
+#define WDOG_TICK_RATE 1000 /* 1 kHz clock */
+#define STMP3XXX_DEFAULT_TIMEOUT 19
+#define STMP3XXX_MAX_TIMEOUT (UINT_MAX / WDOG_TICK_RATE)
+
+static int heartbeat = STMP3XXX_DEFAULT_TIMEOUT;
+module_param(heartbeat, uint, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat period in seconds from 1 to "
+                 __MODULE_STRING(STMP3XXX_MAX_TIMEOUT) ", default "
+                 __MODULE_STRING(STMP3XXX_DEFAULT_TIMEOUT));
+
+static int wdt_start(struct watchdog_device *wdd)
+{
+        struct device *dev = watchdog_get_drvdata(wdd);
+        struct stmp3xxx_wdt_pdata *pdata = dev->platform_data;
+
+        pdata->wdt_set_timeout(dev->parent, wdd->timeout * WDOG_TICK_RATE);
+        return 0;
+}
+
+static int wdt_stop(struct watchdog_device *wdd)
+{
+        struct device *dev = watchdog_get_drvdata(wdd);
+        struct stmp3xxx_wdt_pdata *pdata = dev->platform_data;
+
+        pdata->wdt_set_timeout(dev->parent, 0);
+        return 0;
+}
+
+static int wdt_set_timeout(struct watchdog_device *wdd, unsigned new_timeout)
+{
+        wdd->timeout = new_timeout;
+        return wdt_start(wdd);
+}
+
+static const struct watchdog_info stmp3xxx_wdt_ident = {
+        .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+        .identity = "STMP3XXX RTC Watchdog",
+};
+
+static const struct watchdog_ops stmp3xxx_wdt_ops = {
+        .owner = THIS_MODULE,
+        .start = wdt_start,
+        .stop = wdt_stop,
+        .set_timeout = wdt_set_timeout,
+};
+
+static struct watchdog_device stmp3xxx_wdd = {
+        .info = &stmp3xxx_wdt_ident,
+        .ops = &stmp3xxx_wdt_ops,
+        .min_timeout = 1,
+        .max_timeout = STMP3XXX_MAX_TIMEOUT,
+        .status = WATCHDOG_NOWAYOUT_INIT_STATUS,
+};
+
+static int stmp3xxx_wdt_probe(struct platform_device *pdev)
+{
+        int ret;
+
+        watchdog_set_drvdata(&stmp3xxx_wdd, &pdev->dev);
+
+        stmp3xxx_wdd.timeout = clamp_t(unsigned, heartbeat, 1, STMP3XXX_MAX_TIMEOUT);
+
+        ret = watchdog_register_device(&stmp3xxx_wdd);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "cannot register watchdog device\n");
+                return ret;
+        }
+
+        dev_info(&pdev->dev, "initialized watchdog with heartbeat %ds\n",
+                        stmp3xxx_wdd.timeout);
+        return 0;
+}
+
+static int stmp3xxx_wdt_remove(struct platform_device *pdev)
+{
+        watchdog_unregister_device(&stmp3xxx_wdd);
+        return 0;
+}
+
+static struct platform_driver stmp3xxx_wdt_driver = {
+        .driver = {
+                .name = "stmp3xxx_rtc_wdt",
+        },
+        .probe = stmp3xxx_wdt_probe,
+        .remove = stmp3xxx_wdt_remove,
+};
+module_platform_driver(stmp3xxx_wdt_driver);
+
+MODULE_DESCRIPTION("STMP3XXX RTC Watchdog Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);