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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 | /* * MOXA ART SoCs watchdog driver. * * Copyright (C) 2013 Jonas Jensen * * Jonas Jensen <jonas.jensen@gmail.com> * * 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. */ #include <linux/clk.h> #include <linux/io.h> #include <linux/module.h> #include <linux/err.h> #include <linux/kernel.h> #include <linux/notifier.h> #include <linux/platform_device.h> #include <linux/reboot.h> #include <linux/watchdog.h> #include <linux/moduleparam.h> #define REG_COUNT 0x4 #define REG_MODE 0x8 #define REG_ENABLE 0xC struct moxart_wdt_dev { struct watchdog_device dev; void __iomem *base; unsigned int clock_frequency; struct notifier_block restart_handler; }; static int heartbeat; static int moxart_restart_handle(struct notifier_block *this, unsigned long mode, void *cmd) { struct moxart_wdt_dev *moxart_wdt = container_of(this, struct moxart_wdt_dev, restart_handler); writel(1, moxart_wdt->base + REG_COUNT); writel(0x5ab9, moxart_wdt->base + REG_MODE); writel(0x03, moxart_wdt->base + REG_ENABLE); return NOTIFY_DONE; } static int moxart_wdt_stop(struct watchdog_device *wdt_dev) { struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev); writel(0, moxart_wdt->base + REG_ENABLE); return 0; } static int moxart_wdt_start(struct watchdog_device *wdt_dev) { struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev); writel(moxart_wdt->clock_frequency * wdt_dev->timeout, moxart_wdt->base + REG_COUNT); writel(0x5ab9, moxart_wdt->base + REG_MODE); writel(0x03, moxart_wdt->base + REG_ENABLE); return 0; } static int moxart_wdt_set_timeout(struct watchdog_device *wdt_dev, unsigned int timeout) { wdt_dev->timeout = timeout; return 0; } static const struct watchdog_info moxart_wdt_info = { .identity = "moxart-wdt", .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, }; static const struct watchdog_ops moxart_wdt_ops = { .owner = THIS_MODULE, .start = moxart_wdt_start, .stop = moxart_wdt_stop, .set_timeout = moxart_wdt_set_timeout, }; static int moxart_wdt_probe(struct platform_device *pdev) { struct moxart_wdt_dev *moxart_wdt; struct device *dev = &pdev->dev; struct device_node *node = dev->of_node; struct resource *res; struct clk *clk; int err; unsigned int max_timeout; bool nowayout = WATCHDOG_NOWAYOUT; moxart_wdt = devm_kzalloc(dev, sizeof(*moxart_wdt), GFP_KERNEL); if (!moxart_wdt) return -ENOMEM; platform_set_drvdata(pdev, moxart_wdt); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); moxart_wdt->base = devm_ioremap_resource(dev, res); if (IS_ERR(moxart_wdt->base)) return PTR_ERR(moxart_wdt->base); clk = of_clk_get(node, 0); if (IS_ERR(clk)) { pr_err("%s: of_clk_get failed\n", __func__); return PTR_ERR(clk); } moxart_wdt->clock_frequency = clk_get_rate(clk); if (moxart_wdt->clock_frequency == 0) { pr_err("%s: incorrect clock frequency\n", __func__); return -EINVAL; } max_timeout = UINT_MAX / moxart_wdt->clock_frequency; moxart_wdt->dev.info = &moxart_wdt_info; moxart_wdt->dev.ops = &moxart_wdt_ops; moxart_wdt->dev.timeout = max_timeout; moxart_wdt->dev.min_timeout = 1; moxart_wdt->dev.max_timeout = max_timeout; moxart_wdt->dev.parent = dev; watchdog_init_timeout(&moxart_wdt->dev, heartbeat, dev); watchdog_set_nowayout(&moxart_wdt->dev, nowayout); watchdog_set_drvdata(&moxart_wdt->dev, moxart_wdt); err = watchdog_register_device(&moxart_wdt->dev); if (err) return err; moxart_wdt->restart_handler.notifier_call = moxart_restart_handle; moxart_wdt->restart_handler.priority = 128; err = register_restart_handler(&moxart_wdt->restart_handler); if (err) dev_err(dev, "cannot register restart notifier (err=%d)\n", err); dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n", moxart_wdt->dev.timeout, nowayout); return 0; } static int moxart_wdt_remove(struct platform_device *pdev) { struct moxart_wdt_dev *moxart_wdt = platform_get_drvdata(pdev); unregister_restart_handler(&moxart_wdt->restart_handler); moxart_wdt_stop(&moxart_wdt->dev); return 0; } static const struct of_device_id moxart_watchdog_match[] = { { .compatible = "moxa,moxart-watchdog" }, { }, }; static struct platform_driver moxart_wdt_driver = { .probe = moxart_wdt_probe, .remove = moxart_wdt_remove, .driver = { .name = "moxart-watchdog", .of_match_table = moxart_watchdog_match, }, }; module_platform_driver(moxart_wdt_driver); module_param(heartbeat, int, 0); MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds"); MODULE_DESCRIPTION("MOXART watchdog driver"); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>"); |