1 files changed, 383 insertions, 0 deletions
diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c
new file mode 100644
index 000000000..74d785b2b
--- /dev/null
+++ b/drivers/watchdog/omap_wdt.c
@@ -0,0 +1,383 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * omap_wdt.c
+ *
+ * Watchdog driver for the TI OMAP 16xx & 24xx/34xx 32KHz (non-secure) watchdog
+ *
+ * Author: MontaVista Software, Inc.
+ *	 <gdavis@mvista.com> or <source@mvista.com>
+ *
+ * 2003 (c) MontaVista Software, Inc.
+ *
+ * History:
+ *
+ * 20030527: George G. Davis <gdavis@mvista.com>
+ *	Initially based on linux-2.4.19-rmk7-pxa1/drivers/char/sa1100_wdt.c
+ *	(c) Copyright 2000 Oleg Drokin <green@crimea.edu>
+ *	Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
+ *
+ * Copyright (c) 2004 Texas Instruments.
+ *	1. Modified to support OMAP1610 32-KHz watchdog timer
+ *	2. Ported to 2.6 kernel
+ *
+ * Copyright (c) 2005 David Brownell
+ *	Use the driver model and standard identifiers; handle bigger timeouts.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/watchdog.h>
+#include <linux/reboot.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/moduleparam.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/pm_runtime.h>
+#include <linux/platform_data/omap-wd-timer.h>
+
+#include "omap_wdt.h"
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
+	"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static unsigned timer_margin;
+module_param(timer_margin, uint, 0);
+MODULE_PARM_DESC(timer_margin, "initial watchdog timeout (in seconds)");
+
+#define to_omap_wdt_dev(_wdog)	container_of(_wdog, struct omap_wdt_dev, wdog)
+
+static bool early_enable;
+module_param(early_enable, bool, 0);
+MODULE_PARM_DESC(early_enable,
+	"Watchdog is started on module insertion (default=0)");
+
+struct omap_wdt_dev {
+	struct watchdog_device wdog;
+	void __iomem    *base;          /* physical */
+	struct device   *dev;
+	bool		omap_wdt_users;
+	int		wdt_trgr_pattern;
+	struct mutex	lock;		/* to avoid races with PM */
+};
+
+static void omap_wdt_reload(struct omap_wdt_dev *wdev)
+{
+	void __iomem    *base = wdev->base;
+
+	/* wait for posted write to complete */
+	while ((readl_relaxed(base + OMAP_WATCHDOG_WPS)) & 0x08)
+		cpu_relax();
+
+	wdev->wdt_trgr_pattern = ~wdev->wdt_trgr_pattern;
+	writel_relaxed(wdev->wdt_trgr_pattern, (base + OMAP_WATCHDOG_TGR));
+
+	/* wait for posted write to complete */
+	while ((readl_relaxed(base + OMAP_WATCHDOG_WPS)) & 0x08)
+		cpu_relax();
+	/* reloaded WCRR from WLDR */
+}
+
+static void omap_wdt_enable(struct omap_wdt_dev *wdev)
+{
+	void __iomem *base = wdev->base;
+
+	/* Sequence to enable the watchdog */
+	writel_relaxed(0xBBBB, base + OMAP_WATCHDOG_SPR);
+	while ((readl_relaxed(base + OMAP_WATCHDOG_WPS)) & 0x10)
+		cpu_relax();
+
+	writel_relaxed(0x4444, base + OMAP_WATCHDOG_SPR);
+	while ((readl_relaxed(base + OMAP_WATCHDOG_WPS)) & 0x10)
+		cpu_relax();
+}
+
+static void omap_wdt_disable(struct omap_wdt_dev *wdev)
+{
+	void __iomem *base = wdev->base;
+
+	/* sequence required to disable watchdog */
+	writel_relaxed(0xAAAA, base + OMAP_WATCHDOG_SPR);	/* TIMER_MODE */
+	while (readl_relaxed(base + OMAP_WATCHDOG_WPS) & 0x10)
+		cpu_relax();
+
+	writel_relaxed(0x5555, base + OMAP_WATCHDOG_SPR);	/* TIMER_MODE */
+	while (readl_relaxed(base + OMAP_WATCHDOG_WPS) & 0x10)
+		cpu_relax();
+}
+
+static void omap_wdt_set_timer(struct omap_wdt_dev *wdev,
+				   unsigned int timeout)
+{
+	u32 pre_margin = GET_WLDR_VAL(timeout);
+	void __iomem *base = wdev->base;
+
+	/* just count up at 32 KHz */
+	while (readl_relaxed(base + OMAP_WATCHDOG_WPS) & 0x04)
+		cpu_relax();
+
+	writel_relaxed(pre_margin, base + OMAP_WATCHDOG_LDR);
+	while (readl_relaxed(base + OMAP_WATCHDOG_WPS) & 0x04)
+		cpu_relax();
+}
+
+static int omap_wdt_start(struct watchdog_device *wdog)
+{
+	struct omap_wdt_dev *wdev = to_omap_wdt_dev(wdog);
+	void __iomem *base = wdev->base;
+
+	mutex_lock(&wdev->lock);
+
+	wdev->omap_wdt_users = true;
+
+	pm_runtime_get_sync(wdev->dev);
+
+	/*
+	 * Make sure the watchdog is disabled. This is unfortunately required
+	 * because writing to various registers with the watchdog running has no
+	 * effect.
+	 */
+	omap_wdt_disable(wdev);
+
+	/* initialize prescaler */
+	while (readl_relaxed(base + OMAP_WATCHDOG_WPS) & 0x01)
+		cpu_relax();
+
+	writel_relaxed((1 << 5) | (PTV << 2), base + OMAP_WATCHDOG_CNTRL);
+	while (readl_relaxed(base + OMAP_WATCHDOG_WPS) & 0x01)
+		cpu_relax();
+
+	omap_wdt_set_timer(wdev, wdog->timeout);
+	omap_wdt_reload(wdev); /* trigger loading of new timeout value */
+	omap_wdt_enable(wdev);
+
+	mutex_unlock(&wdev->lock);
+
+	return 0;
+}
+
+static int omap_wdt_stop(struct watchdog_device *wdog)
+{
+	struct omap_wdt_dev *wdev = to_omap_wdt_dev(wdog);
+
+	mutex_lock(&wdev->lock);
+	omap_wdt_disable(wdev);
+	pm_runtime_put_sync(wdev->dev);
+	wdev->omap_wdt_users = false;
+	mutex_unlock(&wdev->lock);
+	return 0;
+}
+
+static int omap_wdt_ping(struct watchdog_device *wdog)
+{
+	struct omap_wdt_dev *wdev = to_omap_wdt_dev(wdog);
+
+	mutex_lock(&wdev->lock);
+	omap_wdt_reload(wdev);
+	mutex_unlock(&wdev->lock);
+
+	return 0;
+}
+
+static int omap_wdt_set_timeout(struct watchdog_device *wdog,
+				unsigned int timeout)
+{
+	struct omap_wdt_dev *wdev = to_omap_wdt_dev(wdog);
+
+	mutex_lock(&wdev->lock);
+	omap_wdt_disable(wdev);
+	omap_wdt_set_timer(wdev, timeout);
+	omap_wdt_enable(wdev);
+	omap_wdt_reload(wdev);
+	wdog->timeout = timeout;
+	mutex_unlock(&wdev->lock);
+
+	return 0;
+}
+
+static unsigned int omap_wdt_get_timeleft(struct watchdog_device *wdog)
+{
+	struct omap_wdt_dev *wdev = to_omap_wdt_dev(wdog);
+	void __iomem *base = wdev->base;
+	u32 value;
+
+	value = readl_relaxed(base + OMAP_WATCHDOG_CRR);
+	return GET_WCCR_SECS(value);
+}
+
+static const struct watchdog_info omap_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
+	.identity = "OMAP Watchdog",
+};
+
+static const struct watchdog_ops omap_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= omap_wdt_start,
+	.stop		= omap_wdt_stop,
+	.ping		= omap_wdt_ping,
+	.set_timeout	= omap_wdt_set_timeout,
+	.get_timeleft	= omap_wdt_get_timeleft,
+};
+
+static int omap_wdt_probe(struct platform_device *pdev)
+{
+	struct omap_wd_timer_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	struct omap_wdt_dev *wdev;
+	int ret;
+
+	wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
+	if (!wdev)
+		return -ENOMEM;
+
+	wdev->omap_wdt_users	= false;
+	wdev->dev		= &pdev->dev;
+	wdev->wdt_trgr_pattern	= 0x1234;
+	mutex_init(&wdev->lock);
+
+	/* reserve static register mappings */
+	wdev->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(wdev->base))
+		return PTR_ERR(wdev->base);
+
+	wdev->wdog.info = &omap_wdt_info;
+	wdev->wdog.ops = &omap_wdt_ops;
+	wdev->wdog.min_timeout = TIMER_MARGIN_MIN;
+	wdev->wdog.max_timeout = TIMER_MARGIN_MAX;
+	wdev->wdog.timeout = TIMER_MARGIN_DEFAULT;
+	wdev->wdog.parent = &pdev->dev;
+
+	watchdog_init_timeout(&wdev->wdog, timer_margin, &pdev->dev);
+
+	watchdog_set_nowayout(&wdev->wdog, nowayout);
+
+	platform_set_drvdata(pdev, wdev);
+
+	pm_runtime_enable(wdev->dev);
+	pm_runtime_get_sync(wdev->dev);
+
+	if (pdata && pdata->read_reset_sources) {
+		u32 rs = pdata->read_reset_sources();
+		if (rs & (1 << OMAP_MPU_WD_RST_SRC_ID_SHIFT))
+			wdev->wdog.bootstatus = WDIOF_CARDRESET;
+	}
+
+	if (early_enable) {
+		omap_wdt_start(&wdev->wdog);
+		set_bit(WDOG_HW_RUNNING, &wdev->wdog.status);
+	} else {
+		omap_wdt_disable(wdev);
+	}
+
+	ret = watchdog_register_device(&wdev->wdog);
+	if (ret) {
+		pm_runtime_put(wdev->dev);
+		pm_runtime_disable(wdev->dev);
+		return ret;
+	}
+
+	pr_info("OMAP Watchdog Timer Rev 0x%02x: initial timeout %d sec\n",
+		readl_relaxed(wdev->base + OMAP_WATCHDOG_REV) & 0xFF,
+		wdev->wdog.timeout);
+
+	if (early_enable)
+		omap_wdt_start(&wdev->wdog);
+
+	pm_runtime_put(wdev->dev);
+
+	return 0;
+}
+
+static void omap_wdt_shutdown(struct platform_device *pdev)
+{
+	struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
+
+	mutex_lock(&wdev->lock);
+	if (wdev->omap_wdt_users) {
+		omap_wdt_disable(wdev);
+		pm_runtime_put_sync(wdev->dev);
+	}
+	mutex_unlock(&wdev->lock);
+}
+
+static int omap_wdt_remove(struct platform_device *pdev)
+{
+	struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
+
+	pm_runtime_disable(wdev->dev);
+	watchdog_unregister_device(&wdev->wdog);
+
+	return 0;
+}
+
+#ifdef	CONFIG_PM
+
+/* REVISIT ... not clear this is the best way to handle system suspend; and
+ * it's very inappropriate for selective device suspend (e.g. suspending this
+ * through sysfs rather than by stopping the watchdog daemon).  Also, this
+ * may not play well enough with NOWAYOUT...
+ */
+
+static int omap_wdt_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
+
+	mutex_lock(&wdev->lock);
+	if (wdev->omap_wdt_users) {
+		omap_wdt_disable(wdev);
+		pm_runtime_put_sync(wdev->dev);
+	}
+	mutex_unlock(&wdev->lock);
+
+	return 0;
+}
+
+static int omap_wdt_resume(struct platform_device *pdev)
+{
+	struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
+
+	mutex_lock(&wdev->lock);
+	if (wdev->omap_wdt_users) {
+		pm_runtime_get_sync(wdev->dev);
+		omap_wdt_enable(wdev);
+		omap_wdt_reload(wdev);
+	}
+	mutex_unlock(&wdev->lock);
+
+	return 0;
+}
+
+#else
+#define	omap_wdt_suspend	NULL
+#define	omap_wdt_resume		NULL
+#endif
+
+static const struct of_device_id omap_wdt_of_match[] = {
+	{ .compatible = "ti,omap3-wdt", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, omap_wdt_of_match);
+
+static struct platform_driver omap_wdt_driver = {
+	.probe		= omap_wdt_probe,
+	.remove		= omap_wdt_remove,
+	.shutdown	= omap_wdt_shutdown,
+	.suspend	= omap_wdt_suspend,
+	.resume		= omap_wdt_resume,
+	.driver		= {
+		.name	= "omap_wdt",
+		.of_match_table = omap_wdt_of_match,
+	},
+};
+
+module_platform_driver(omap_wdt_driver);
+
+MODULE_AUTHOR("George G. Davis");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:omap_wdt");