1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/watchdog/stmp3xxx_rtc_wdt.c b/drivers/watchdog/stmp3xxx_rtc_wdt.c
new file mode 100644
index 000000000..7caf3aa71
--- /dev/null
+++ b/drivers/watchdog/stmp3xxx_rtc_wdt.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Watchdog driver for the RTC based watchdog in STMP3xxx and i.MX23/28
+ *
+ * Author: Wolfram Sang <kernel@pengutronix.de>
+ *
+ * Copyright (C) 2011-12 Wolfram Sang, Pengutronix
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/stmp3xxx_rtc_wdt.h>
+#include <linux/notifier.h>
+#include <linux/reboot.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_get_platdata(dev);
+
+	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_get_platdata(dev);
+
+	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 wdt_notify_sys(struct notifier_block *nb, unsigned long code,
+			  void *unused)
+{
+	switch (code) {
+	case SYS_DOWN:	/* keep enabled, system might crash while going down */
+		break;
+	case SYS_HALT:	/* allow the system to actually halt */
+	case SYS_POWER_OFF:
+		wdt_stop(&stmp3xxx_wdd);
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block wdt_notifier = {
+	.notifier_call = wdt_notify_sys,
+};
+
+static int stmp3xxx_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	watchdog_set_drvdata(&stmp3xxx_wdd, dev);
+
+	stmp3xxx_wdd.timeout = clamp_t(unsigned, heartbeat, 1, STMP3XXX_MAX_TIMEOUT);
+	stmp3xxx_wdd.parent = dev;
+
+	ret = devm_watchdog_register_device(dev, &stmp3xxx_wdd);
+	if (ret < 0)
+		return ret;
+
+	if (register_reboot_notifier(&wdt_notifier))
+		dev_warn(dev, "cannot register reboot notifier\n");
+
+	dev_info(dev, "initialized watchdog with heartbeat %ds\n",
+		 stmp3xxx_wdd.timeout);
+	return 0;
+}
+
+static int stmp3xxx_wdt_remove(struct platform_device *pdev)
+{
+	unregister_reboot_notifier(&wdt_notifier);
+	return 0;
+}
+
+static int __maybe_unused stmp3xxx_wdt_suspend(struct device *dev)
+{
+	struct watchdog_device *wdd = &stmp3xxx_wdd;
+
+	if (watchdog_active(wdd))
+		return wdt_stop(wdd);
+
+	return 0;
+}
+
+static int __maybe_unused stmp3xxx_wdt_resume(struct device *dev)
+{
+	struct watchdog_device *wdd = &stmp3xxx_wdd;
+
+	if (watchdog_active(wdd))
+		return wdt_start(wdd);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(stmp3xxx_wdt_pm_ops,
+			 stmp3xxx_wdt_suspend, stmp3xxx_wdt_resume);
+
+static struct platform_driver stmp3xxx_wdt_driver = {
+	.driver = {
+		.name = "stmp3xxx_rtc_wdt",
+		.pm = &stmp3xxx_wdt_pm_ops,
+	},
+	.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 <kernel@pengutronix.de>");