--- /dev/null
+/*
+ * 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. 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.
+ *
+ * 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/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)");
+
+struct omap_wdt_dev {
+ 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 = watchdog_get_drvdata(wdog);
+ void __iomem *base = wdev->base;
+
+ mutex_lock(&wdev->lock);
+
+ wdev->omap_wdt_users = true;
+
+ pm_runtime_get_sync(wdev->dev);
+
+ /* 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 = watchdog_get_drvdata(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 = watchdog_get_drvdata(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 = watchdog_get_drvdata(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 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,
+};
+
+static int omap_wdt_probe(struct platform_device *pdev)
+{
+ struct omap_wd_timer_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ struct watchdog_device *omap_wdt;
+ struct resource *res;
+ struct omap_wdt_dev *wdev;
+ u32 rs;
+ int ret;
+
+ omap_wdt = devm_kzalloc(&pdev->dev, sizeof(*omap_wdt), GFP_KERNEL);
+ if (!omap_wdt)
+ return -ENOMEM;
+
+ 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 */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ wdev->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(wdev->base))
+ return PTR_ERR(wdev->base);
+
+ omap_wdt->info = &omap_wdt_info;
+ omap_wdt->ops = &omap_wdt_ops;
+ omap_wdt->min_timeout = TIMER_MARGIN_MIN;
+ omap_wdt->max_timeout = TIMER_MARGIN_MAX;
+
+ if (timer_margin >= TIMER_MARGIN_MIN &&
+ timer_margin <= TIMER_MARGIN_MAX)
+ omap_wdt->timeout = timer_margin;
+ else
+ omap_wdt->timeout = TIMER_MARGIN_DEFAULT;
+
+ watchdog_set_drvdata(omap_wdt, wdev);
+ watchdog_set_nowayout(omap_wdt, nowayout);
+
+ platform_set_drvdata(pdev, omap_wdt);
+
+ pm_runtime_enable(wdev->dev);
+ pm_runtime_get_sync(wdev->dev);
+
+ if (pdata && pdata->read_reset_sources)
+ rs = pdata->read_reset_sources();
+ else
+ rs = 0;
+ omap_wdt->bootstatus = (rs & (1 << OMAP_MPU_WD_RST_SRC_ID_SHIFT)) ?
+ WDIOF_CARDRESET : 0;
+
+ omap_wdt_disable(wdev);
+
+ ret = watchdog_register_device(omap_wdt);
+ if (ret) {
+ 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,
+ omap_wdt->timeout);
+
+ pm_runtime_put_sync(wdev->dev);
+
+ return 0;
+}
+
+static void omap_wdt_shutdown(struct platform_device *pdev)
+{
+ struct watchdog_device *wdog = platform_get_drvdata(pdev);
+ struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
+
+ 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 watchdog_device *wdog = platform_get_drvdata(pdev);
+ struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
+
+ pm_runtime_disable(wdev->dev);
+ watchdog_unregister_device(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 watchdog_device *wdog = platform_get_drvdata(pdev);
+ struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
+
+ 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 watchdog_device *wdog = platform_get_drvdata(pdev);
+ struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
+
+ 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");
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