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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/watchdog/ep93xx_wdt.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/watchdog/ep93xx_wdt.c')
-rw-r--r--drivers/watchdog/ep93xx_wdt.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/drivers/watchdog/ep93xx_wdt.c b/drivers/watchdog/ep93xx_wdt.c
new file mode 100644
index 000000000..f9b14e6ef
--- /dev/null
+++ b/drivers/watchdog/ep93xx_wdt.c
@@ -0,0 +1,147 @@
+/*
+ * Watchdog driver for Cirrus Logic EP93xx family of devices.
+ *
+ * Copyright (c) 2004 Ray Lehtiniemi
+ * Copyright (c) 2006 Tower Technologies
+ * Based on ep93xx driver, bits from alim7101_wdt.c
+ *
+ * Authors: Ray Lehtiniemi <rayl@mail.com>,
+ * Alessandro Zummo <a.zummo@towertech.it>
+ *
+ * Copyright (c) 2012 H Hartley Sweeten <hsweeten@visionengravers.com>
+ * Convert to a platform device and use the watchdog framework API
+ *
+ * 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.
+ *
+ * This watchdog fires after 250msec, which is a too short interval
+ * for us to rely on the user space daemon alone. So we ping the
+ * wdt each ~200msec and eventually stop doing it if the user space
+ * daemon dies.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <linux/io.h>
+
+/* default timeout (secs) */
+#define WDT_TIMEOUT 30
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
+
+static unsigned int timeout;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds.");
+
+#define EP93XX_WATCHDOG 0x00
+#define EP93XX_WDSTATUS 0x04
+
+struct ep93xx_wdt_priv {
+ void __iomem *mmio;
+ struct watchdog_device wdd;
+};
+
+static int ep93xx_wdt_start(struct watchdog_device *wdd)
+{
+ struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+ writel(0xaaaa, priv->mmio + EP93XX_WATCHDOG);
+
+ return 0;
+}
+
+static int ep93xx_wdt_stop(struct watchdog_device *wdd)
+{
+ struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+ writel(0xaa55, priv->mmio + EP93XX_WATCHDOG);
+
+ return 0;
+}
+
+static int ep93xx_wdt_ping(struct watchdog_device *wdd)
+{
+ struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+ writel(0x5555, priv->mmio + EP93XX_WATCHDOG);
+
+ return 0;
+}
+
+static const struct watchdog_info ep93xx_wdt_ident = {
+ .options = WDIOF_CARDRESET |
+ WDIOF_SETTIMEOUT |
+ WDIOF_MAGICCLOSE |
+ WDIOF_KEEPALIVEPING,
+ .identity = "EP93xx Watchdog",
+};
+
+static const struct watchdog_ops ep93xx_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = ep93xx_wdt_start,
+ .stop = ep93xx_wdt_stop,
+ .ping = ep93xx_wdt_ping,
+};
+
+static int ep93xx_wdt_probe(struct platform_device *pdev)
+{
+ struct ep93xx_wdt_priv *priv;
+ struct watchdog_device *wdd;
+ struct resource *res;
+ unsigned long val;
+ int ret;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ priv->mmio = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(priv->mmio))
+ return PTR_ERR(priv->mmio);
+
+ val = readl(priv->mmio + EP93XX_WATCHDOG);
+
+ wdd = &priv->wdd;
+ wdd->bootstatus = (val & 0x01) ? WDIOF_CARDRESET : 0;
+ wdd->info = &ep93xx_wdt_ident;
+ wdd->ops = &ep93xx_wdt_ops;
+ wdd->min_timeout = 1;
+ wdd->max_hw_heartbeat_ms = 200;
+ wdd->parent = &pdev->dev;
+
+ watchdog_set_nowayout(wdd, nowayout);
+
+ wdd->timeout = WDT_TIMEOUT;
+ watchdog_init_timeout(wdd, timeout, &pdev->dev);
+
+ watchdog_set_drvdata(wdd, priv);
+
+ ret = devm_watchdog_register_device(&pdev->dev, wdd);
+ if (ret)
+ return ret;
+
+ dev_info(&pdev->dev, "EP93XX watchdog driver %s\n",
+ (val & 0x08) ? " (nCS1 disable detected)" : "");
+
+ return 0;
+}
+
+static struct platform_driver ep93xx_wdt_driver = {
+ .driver = {
+ .name = "ep93xx-wdt",
+ },
+ .probe = ep93xx_wdt_probe,
+};
+
+module_platform_driver(ep93xx_wdt_driver);
+
+MODULE_AUTHOR("Ray Lehtiniemi <rayl@mail.com>");
+MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
+MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
+MODULE_DESCRIPTION("EP93xx Watchdog");
+MODULE_LICENSE("GPL");