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