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path: root/drivers/watchdog/stmp3xxx_rtc_wdt.c
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Diffstat (limited to 'drivers/watchdog/stmp3xxx_rtc_wdt.c')
-rw-r--r--drivers/watchdog/stmp3xxx_rtc_wdt.c111
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);