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146 lines
3.6 KiB
146 lines
3.6 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 <[email protected]>, |
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* Alessandro Zummo <[email protected]> |
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* |
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* Copyright (c) 2012 H Hartley Sweeten <[email protected]> |
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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 device *dev = &pdev->dev; |
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struct ep93xx_wdt_priv *priv; |
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struct watchdog_device *wdd; |
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unsigned long val; |
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int ret; |
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priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); |
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if (!priv) |
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return -ENOMEM; |
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priv->mmio = devm_platform_ioremap_resource(pdev, 0); |
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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 = 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, dev); |
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watchdog_set_drvdata(wdd, priv); |
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ret = devm_watchdog_register_device(dev, wdd); |
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if (ret) |
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return ret; |
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dev_info(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 <[email protected]>"); |
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MODULE_AUTHOR("Alessandro Zummo <[email protected]>"); |
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MODULE_AUTHOR("H Hartley Sweeten <[email protected]>"); |
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MODULE_DESCRIPTION("EP93xx Watchdog"); |
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MODULE_LICENSE("GPL");
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