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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 | // SPDX-License-Identifier: GPL-2.0-only /* * 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 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 device *dev = &pdev->dev; struct ep93xx_wdt_priv *priv; struct watchdog_device *wdd; unsigned long val; int ret; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; priv->mmio = devm_platform_ioremap_resource(pdev, 0); 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 = dev; watchdog_set_nowayout(wdd, nowayout); wdd->timeout = WDT_TIMEOUT; watchdog_init_timeout(wdd, timeout, dev); watchdog_set_drvdata(wdd, priv); ret = devm_watchdog_register_device(dev, wdd); if (ret) return ret; dev_info(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"); |