1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (c) 2016 Yang Ling <gnaygnil@gmail.com> 4 */ 5 6 #include <linux/clk.h> 7 #include <linux/module.h> 8 #include <linux/platform_device.h> 9 #include <linux/watchdog.h> 10 #include <loongson1.h> 11 12 #define DEFAULT_HEARTBEAT 30 13 14 static bool nowayout = WATCHDOG_NOWAYOUT; 15 module_param(nowayout, bool, 0444); 16 17 static unsigned int heartbeat; 18 module_param(heartbeat, uint, 0444); 19 20 struct ls1x_wdt_drvdata { 21 void __iomem *base; 22 struct clk *clk; 23 unsigned long clk_rate; 24 struct watchdog_device wdt; 25 }; 26 27 static int ls1x_wdt_ping(struct watchdog_device *wdt_dev) 28 { 29 struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); 30 31 writel(0x1, drvdata->base + WDT_SET); 32 33 return 0; 34 } 35 36 static int ls1x_wdt_set_timeout(struct watchdog_device *wdt_dev, 37 unsigned int timeout) 38 { 39 struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); 40 unsigned int max_hw_heartbeat = wdt_dev->max_hw_heartbeat_ms / 1000; 41 unsigned int counts; 42 43 wdt_dev->timeout = timeout; 44 45 counts = drvdata->clk_rate * min(timeout, max_hw_heartbeat); 46 writel(counts, drvdata->base + WDT_TIMER); 47 48 return 0; 49 } 50 51 static int ls1x_wdt_start(struct watchdog_device *wdt_dev) 52 { 53 struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); 54 55 writel(0x1, drvdata->base + WDT_EN); 56 57 return 0; 58 } 59 60 static int ls1x_wdt_stop(struct watchdog_device *wdt_dev) 61 { 62 struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); 63 64 writel(0x0, drvdata->base + WDT_EN); 65 66 return 0; 67 } 68 69 static const struct watchdog_info ls1x_wdt_info = { 70 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, 71 .identity = "Loongson1 Watchdog", 72 }; 73 74 static const struct watchdog_ops ls1x_wdt_ops = { 75 .owner = THIS_MODULE, 76 .start = ls1x_wdt_start, 77 .stop = ls1x_wdt_stop, 78 .ping = ls1x_wdt_ping, 79 .set_timeout = ls1x_wdt_set_timeout, 80 }; 81 82 static void ls1x_clk_disable_unprepare(void *data) 83 { 84 clk_disable_unprepare(data); 85 } 86 87 static int ls1x_wdt_probe(struct platform_device *pdev) 88 { 89 struct device *dev = &pdev->dev; 90 struct ls1x_wdt_drvdata *drvdata; 91 struct watchdog_device *ls1x_wdt; 92 unsigned long clk_rate; 93 int err; 94 95 drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); 96 if (!drvdata) 97 return -ENOMEM; 98 99 drvdata->base = devm_platform_ioremap_resource(pdev, 0); 100 if (IS_ERR(drvdata->base)) 101 return PTR_ERR(drvdata->base); 102 103 drvdata->clk = devm_clk_get(dev, pdev->name); 104 if (IS_ERR(drvdata->clk)) 105 return PTR_ERR(drvdata->clk); 106 107 err = clk_prepare_enable(drvdata->clk); 108 if (err) { 109 dev_err(dev, "clk enable failed\n"); 110 return err; 111 } 112 err = devm_add_action_or_reset(dev, ls1x_clk_disable_unprepare, 113 drvdata->clk); 114 if (err) 115 return err; 116 117 clk_rate = clk_get_rate(drvdata->clk); 118 if (!clk_rate) 119 return -EINVAL; 120 drvdata->clk_rate = clk_rate; 121 122 ls1x_wdt = &drvdata->wdt; 123 ls1x_wdt->info = &ls1x_wdt_info; 124 ls1x_wdt->ops = &ls1x_wdt_ops; 125 ls1x_wdt->timeout = DEFAULT_HEARTBEAT; 126 ls1x_wdt->min_timeout = 1; 127 ls1x_wdt->max_hw_heartbeat_ms = U32_MAX / clk_rate * 1000; 128 ls1x_wdt->parent = dev; 129 130 watchdog_init_timeout(ls1x_wdt, heartbeat, dev); 131 watchdog_set_nowayout(ls1x_wdt, nowayout); 132 watchdog_set_drvdata(ls1x_wdt, drvdata); 133 134 err = devm_watchdog_register_device(dev, &drvdata->wdt); 135 if (err) 136 return err; 137 138 platform_set_drvdata(pdev, drvdata); 139 140 dev_info(dev, "Loongson1 Watchdog driver registered\n"); 141 142 return 0; 143 } 144 145 static struct platform_driver ls1x_wdt_driver = { 146 .probe = ls1x_wdt_probe, 147 .driver = { 148 .name = "ls1x-wdt", 149 }, 150 }; 151 152 module_platform_driver(ls1x_wdt_driver); 153 154 MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>"); 155 MODULE_DESCRIPTION("Loongson1 Watchdog Driver"); 156 MODULE_LICENSE("GPL"); 157