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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 | /* * Watchdog driver for Broadcom BCM2835 * * "bcm2708_wdog" driver written by Luke Diamand that was obtained from * branch "rpi-3.6.y" of git://github.com/raspberrypi/linux.git was used * as a hardware reference for the Broadcom BCM2835 watchdog timer. * * Copyright (C) 2013 Lubomir Rintel <lkundrak@v3.sk> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. */ #include <linux/types.h> #include <linux/module.h> #include <linux/io.h> #include <linux/watchdog.h> #include <linux/platform_device.h> #include <linux/of_address.h> #define PM_RSTC 0x1c #define PM_WDOG 0x24 #define PM_PASSWORD 0x5a000000 #define PM_WDOG_TIME_SET 0x000fffff #define PM_RSTC_WRCFG_CLR 0xffffffcf #define PM_RSTC_WRCFG_SET 0x00000030 #define PM_RSTC_WRCFG_FULL_RESET 0x00000020 #define PM_RSTC_RESET 0x00000102 #define SECS_TO_WDOG_TICKS(x) ((x) << 16) #define WDOG_TICKS_TO_SECS(x) ((x) >> 16) struct bcm2835_wdt { void __iomem *base; spinlock_t lock; }; static unsigned int heartbeat; static bool nowayout = WATCHDOG_NOWAYOUT; static int bcm2835_wdt_start(struct watchdog_device *wdog) { struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog); uint32_t cur; unsigned long flags; spin_lock_irqsave(&wdt->lock, flags); writel_relaxed(PM_PASSWORD | (SECS_TO_WDOG_TICKS(wdog->timeout) & PM_WDOG_TIME_SET), wdt->base + PM_WDOG); cur = readl_relaxed(wdt->base + PM_RSTC); writel_relaxed(PM_PASSWORD | (cur & PM_RSTC_WRCFG_CLR) | PM_RSTC_WRCFG_FULL_RESET, wdt->base + PM_RSTC); spin_unlock_irqrestore(&wdt->lock, flags); return 0; } static int bcm2835_wdt_stop(struct watchdog_device *wdog) { struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog); writel_relaxed(PM_PASSWORD | PM_RSTC_RESET, wdt->base + PM_RSTC); dev_info(wdog->dev, "Watchdog timer stopped"); return 0; } static int bcm2835_wdt_set_timeout(struct watchdog_device *wdog, unsigned int t) { wdog->timeout = t; return 0; } static unsigned int bcm2835_wdt_get_timeleft(struct watchdog_device *wdog) { struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog); uint32_t ret = readl_relaxed(wdt->base + PM_WDOG); return WDOG_TICKS_TO_SECS(ret & PM_WDOG_TIME_SET); } static struct watchdog_ops bcm2835_wdt_ops = { .owner = THIS_MODULE, .start = bcm2835_wdt_start, .stop = bcm2835_wdt_stop, .set_timeout = bcm2835_wdt_set_timeout, .get_timeleft = bcm2835_wdt_get_timeleft, }; static struct watchdog_info bcm2835_wdt_info = { .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, .identity = "Broadcom BCM2835 Watchdog timer", }; static struct watchdog_device bcm2835_wdt_wdd = { .info = &bcm2835_wdt_info, .ops = &bcm2835_wdt_ops, .min_timeout = 1, .max_timeout = WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET), .timeout = WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET), }; static int bcm2835_wdt_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; struct bcm2835_wdt *wdt; int err; wdt = devm_kzalloc(dev, sizeof(struct bcm2835_wdt), GFP_KERNEL); if (!wdt) return -ENOMEM; platform_set_drvdata(pdev, wdt); spin_lock_init(&wdt->lock); wdt->base = of_iomap(np, 0); if (!wdt->base) { dev_err(dev, "Failed to remap watchdog regs"); return -ENODEV; } watchdog_set_drvdata(&bcm2835_wdt_wdd, wdt); watchdog_init_timeout(&bcm2835_wdt_wdd, heartbeat, dev); watchdog_set_nowayout(&bcm2835_wdt_wdd, nowayout); err = watchdog_register_device(&bcm2835_wdt_wdd); if (err) { dev_err(dev, "Failed to register watchdog device"); iounmap(wdt->base); return err; } dev_info(dev, "Broadcom BCM2835 watchdog timer"); return 0; } static int bcm2835_wdt_remove(struct platform_device *pdev) { struct bcm2835_wdt *wdt = platform_get_drvdata(pdev); watchdog_unregister_device(&bcm2835_wdt_wdd); iounmap(wdt->base); return 0; } static void bcm2835_wdt_shutdown(struct platform_device *pdev) { bcm2835_wdt_stop(&bcm2835_wdt_wdd); } static const struct of_device_id bcm2835_wdt_of_match[] = { { .compatible = "brcm,bcm2835-pm-wdt", }, {}, }; MODULE_DEVICE_TABLE(of, bcm2835_wdt_of_match); static struct platform_driver bcm2835_wdt_driver = { .probe = bcm2835_wdt_probe, .remove = bcm2835_wdt_remove, .shutdown = bcm2835_wdt_shutdown, .driver = { .name = "bcm2835-wdt", .owner = THIS_MODULE, .of_match_table = bcm2835_wdt_of_match, }, }; module_platform_driver(bcm2835_wdt_driver); module_param(heartbeat, uint, 0); MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds"); module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>"); MODULE_DESCRIPTION("Driver for Broadcom BCM2835 watchdog timer"); MODULE_LICENSE("GPL"); |