1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Watchdog driver for Technologic Systems TS-72xx based SBCs 4 * (TS-7200, TS-7250 and TS-7260). These boards have external 5 * glue logic CPLD chip, which includes programmable watchdog 6 * timer. 7 * 8 * Copyright (c) 2009 Mika Westerberg <mika.westerberg@iki.fi> 9 * 10 * This driver is based on ep93xx_wdt and wm831x_wdt drivers. 11 * 12 */ 13 14 #include <linux/platform_device.h> 15 #include <linux/mod_devicetable.h> 16 #include <linux/module.h> 17 #include <linux/watchdog.h> 18 #include <linux/io.h> 19 20 #define TS72XX_WDT_DEFAULT_TIMEOUT 30 21 22 static int timeout; 23 module_param(timeout, int, 0); 24 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds."); 25 26 static bool nowayout = WATCHDOG_NOWAYOUT; 27 module_param(nowayout, bool, 0); 28 MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close"); 29 30 /* priv->control_reg */ 31 #define TS72XX_WDT_CTRL_DISABLE 0x00 32 #define TS72XX_WDT_CTRL_250MS 0x01 33 #define TS72XX_WDT_CTRL_500MS 0x02 34 #define TS72XX_WDT_CTRL_1SEC 0x03 35 #define TS72XX_WDT_CTRL_RESERVED 0x04 36 #define TS72XX_WDT_CTRL_2SEC 0x05 37 #define TS72XX_WDT_CTRL_4SEC 0x06 38 #define TS72XX_WDT_CTRL_8SEC 0x07 39 40 /* priv->feed_reg */ 41 #define TS72XX_WDT_FEED_VAL 0x05 42 43 struct ts72xx_wdt_priv { 44 void __iomem *control_reg; 45 void __iomem *feed_reg; 46 struct watchdog_device wdd; 47 unsigned char regval; 48 }; 49 50 static int ts72xx_wdt_start(struct watchdog_device *wdd) 51 { 52 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd); 53 54 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg); 55 writeb(priv->regval, priv->control_reg); 56 57 return 0; 58 } 59 60 static int ts72xx_wdt_stop(struct watchdog_device *wdd) 61 { 62 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd); 63 64 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg); 65 writeb(TS72XX_WDT_CTRL_DISABLE, priv->control_reg); 66 67 return 0; 68 } 69 70 static int ts72xx_wdt_ping(struct watchdog_device *wdd) 71 { 72 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd); 73 74 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg); 75 76 return 0; 77 } 78 79 static int ts72xx_wdt_settimeout(struct watchdog_device *wdd, unsigned int to) 80 { 81 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd); 82 83 if (to == 1) { 84 priv->regval = TS72XX_WDT_CTRL_1SEC; 85 } else if (to == 2) { 86 priv->regval = TS72XX_WDT_CTRL_2SEC; 87 } else if (to <= 4) { 88 priv->regval = TS72XX_WDT_CTRL_4SEC; 89 to = 4; 90 } else { 91 priv->regval = TS72XX_WDT_CTRL_8SEC; 92 if (to <= 8) 93 to = 8; 94 } 95 96 wdd->timeout = to; 97 98 if (watchdog_active(wdd)) { 99 ts72xx_wdt_stop(wdd); 100 ts72xx_wdt_start(wdd); 101 } 102 103 return 0; 104 } 105 106 static const struct watchdog_info ts72xx_wdt_ident = { 107 .options = WDIOF_KEEPALIVEPING | 108 WDIOF_SETTIMEOUT | 109 WDIOF_MAGICCLOSE, 110 .firmware_version = 1, 111 .identity = "TS-72XX WDT", 112 }; 113 114 static const struct watchdog_ops ts72xx_wdt_ops = { 115 .owner = THIS_MODULE, 116 .start = ts72xx_wdt_start, 117 .stop = ts72xx_wdt_stop, 118 .ping = ts72xx_wdt_ping, 119 .set_timeout = ts72xx_wdt_settimeout, 120 }; 121 122 static int ts72xx_wdt_probe(struct platform_device *pdev) 123 { 124 struct device *dev = &pdev->dev; 125 struct ts72xx_wdt_priv *priv; 126 struct watchdog_device *wdd; 127 int ret; 128 129 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 130 if (!priv) 131 return -ENOMEM; 132 133 priv->control_reg = devm_platform_ioremap_resource(pdev, 0); 134 if (IS_ERR(priv->control_reg)) 135 return PTR_ERR(priv->control_reg); 136 137 priv->feed_reg = devm_platform_ioremap_resource(pdev, 1); 138 if (IS_ERR(priv->feed_reg)) 139 return PTR_ERR(priv->feed_reg); 140 141 wdd = &priv->wdd; 142 wdd->info = &ts72xx_wdt_ident; 143 wdd->ops = &ts72xx_wdt_ops; 144 wdd->min_timeout = 1; 145 wdd->max_hw_heartbeat_ms = 8000; 146 wdd->parent = dev; 147 148 watchdog_set_nowayout(wdd, nowayout); 149 150 wdd->timeout = TS72XX_WDT_DEFAULT_TIMEOUT; 151 watchdog_init_timeout(wdd, timeout, dev); 152 153 watchdog_set_drvdata(wdd, priv); 154 155 ret = devm_watchdog_register_device(dev, wdd); 156 if (ret) 157 return ret; 158 159 dev_info(dev, "TS-72xx Watchdog driver\n"); 160 161 return 0; 162 } 163 164 static const struct of_device_id ts72xx_wdt_of_ids[] = { 165 { .compatible = "technologic,ts7200-wdt" }, 166 { /* sentinel */ } 167 }; 168 MODULE_DEVICE_TABLE(of, ts72xx_wdt_of_ids); 169 170 static struct platform_driver ts72xx_wdt_driver = { 171 .probe = ts72xx_wdt_probe, 172 .driver = { 173 .name = "ts72xx-wdt", 174 .of_match_table = ts72xx_wdt_of_ids, 175 }, 176 }; 177 178 module_platform_driver(ts72xx_wdt_driver); 179 180 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@iki.fi>"); 181 MODULE_DESCRIPTION("TS-72xx SBC Watchdog"); 182 MODULE_LICENSE("GPL"); 183 MODULE_ALIAS("platform:ts72xx-wdt"); 184