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147 lines
3.7 KiB
147 lines
3.7 KiB
/*
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* Watchdog driver for Cirrus Logic EP93xx family of devices.
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*
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* Copyright (c) 2004 Ray Lehtiniemi
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* Copyright (c) 2006 Tower Technologies
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* Based on ep93xx driver, bits from alim7101_wdt.c
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*
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* Authors: Ray Lehtiniemi <rayl@mail.com>,
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* Alessandro Zummo <a.zummo@towertech.it>
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*
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* Copyright (c) 2012 H Hartley Sweeten <hsweeten@visionengravers.com>
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* Convert to a platform device and use the watchdog framework API
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*
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* This watchdog fires after 250msec, which is a too short interval
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* for us to rely on the user space daemon alone. So we ping the
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* wdt each ~200msec and eventually stop doing it if the user space
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* daemon dies.
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*/
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#include <linux/platform_device.h>
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#include <linux/module.h>
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#include <linux/watchdog.h>
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#include <linux/io.h>
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/* default timeout (secs) */
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#define WDT_TIMEOUT 30
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static bool nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
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static unsigned int timeout;
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module_param(timeout, uint, 0);
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MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds.");
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#define EP93XX_WATCHDOG 0x00
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#define EP93XX_WDSTATUS 0x04
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struct ep93xx_wdt_priv {
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void __iomem *mmio;
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struct watchdog_device wdd;
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};
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static int ep93xx_wdt_start(struct watchdog_device *wdd)
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{
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struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
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writel(0xaaaa, priv->mmio + EP93XX_WATCHDOG);
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return 0;
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}
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static int ep93xx_wdt_stop(struct watchdog_device *wdd)
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{
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struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
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writel(0xaa55, priv->mmio + EP93XX_WATCHDOG);
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return 0;
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}
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static int ep93xx_wdt_ping(struct watchdog_device *wdd)
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{
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struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
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writel(0x5555, priv->mmio + EP93XX_WATCHDOG);
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return 0;
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}
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static const struct watchdog_info ep93xx_wdt_ident = {
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.options = WDIOF_CARDRESET |
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WDIOF_SETTIMEOUT |
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WDIOF_MAGICCLOSE |
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WDIOF_KEEPALIVEPING,
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.identity = "EP93xx Watchdog",
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};
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static const struct watchdog_ops ep93xx_wdt_ops = {
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.owner = THIS_MODULE,
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.start = ep93xx_wdt_start,
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.stop = ep93xx_wdt_stop,
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.ping = ep93xx_wdt_ping,
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};
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static int ep93xx_wdt_probe(struct platform_device *pdev)
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{
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struct ep93xx_wdt_priv *priv;
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struct watchdog_device *wdd;
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struct resource *res;
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unsigned long val;
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int ret;
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priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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priv->mmio = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(priv->mmio))
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return PTR_ERR(priv->mmio);
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val = readl(priv->mmio + EP93XX_WATCHDOG);
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wdd = &priv->wdd;
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wdd->bootstatus = (val & 0x01) ? WDIOF_CARDRESET : 0;
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wdd->info = &ep93xx_wdt_ident;
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wdd->ops = &ep93xx_wdt_ops;
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wdd->min_timeout = 1;
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wdd->max_hw_heartbeat_ms = 200;
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wdd->parent = &pdev->dev;
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watchdog_set_nowayout(wdd, nowayout);
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wdd->timeout = WDT_TIMEOUT;
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watchdog_init_timeout(wdd, timeout, &pdev->dev);
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watchdog_set_drvdata(wdd, priv);
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ret = devm_watchdog_register_device(&pdev->dev, wdd);
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if (ret)
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return ret;
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dev_info(&pdev->dev, "EP93XX watchdog driver %s\n",
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(val & 0x08) ? " (nCS1 disable detected)" : "");
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return 0;
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}
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static struct platform_driver ep93xx_wdt_driver = {
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.driver = {
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.name = "ep93xx-wdt",
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},
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.probe = ep93xx_wdt_probe,
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};
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module_platform_driver(ep93xx_wdt_driver);
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MODULE_AUTHOR("Ray Lehtiniemi <rayl@mail.com>");
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MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
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MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
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MODULE_DESCRIPTION("EP93xx Watchdog");
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MODULE_LICENSE("GPL");
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