1 /* 2 * Watchdog driver for Technologic Systems TS-72xx based SBCs 3 * (TS-7200, TS-7250 and TS-7260). These boards have external 4 * glue logic CPLD chip, which includes programmable watchdog 5 * timer. 6 * 7 * Copyright (c) 2009 Mika Westerberg <mika.westerberg@iki.fi> 8 * 9 * This driver is based on ep93xx_wdt and wm831x_wdt drivers. 10 * 11 * This file is licensed under the terms of the GNU General Public 12 * License version 2. This program is licensed "as is" without any 13 * warranty of any kind, whether express or implied. 14 */ 15 16 #include <linux/platform_device.h> 17 #include <linux/module.h> 18 #include <linux/watchdog.h> 19 #include <linux/io.h> 20 21 #define TS72XX_WDT_DEFAULT_TIMEOUT 30 22 23 static int timeout; 24 module_param(timeout, int, 0); 25 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds."); 26 27 static bool nowayout = WATCHDOG_NOWAYOUT; 28 module_param(nowayout, bool, 0); 29 MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close"); 30 31 /* priv->control_reg */ 32 #define TS72XX_WDT_CTRL_DISABLE 0x00 33 #define TS72XX_WDT_CTRL_250MS 0x01 34 #define TS72XX_WDT_CTRL_500MS 0x02 35 #define TS72XX_WDT_CTRL_1SEC 0x03 36 #define TS72XX_WDT_CTRL_RESERVED 0x04 37 #define TS72XX_WDT_CTRL_2SEC 0x05 38 #define TS72XX_WDT_CTRL_4SEC 0x06 39 #define TS72XX_WDT_CTRL_8SEC 0x07 40 41 /* priv->feed_reg */ 42 #define TS72XX_WDT_FEED_VAL 0x05 43 44 struct ts72xx_wdt_priv { 45 void __iomem *control_reg; 46 void __iomem *feed_reg; 47 struct watchdog_device wdd; 48 unsigned char regval; 49 }; 50 51 static int ts72xx_wdt_start(struct watchdog_device *wdd) 52 { 53 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd); 54 55 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg); 56 writeb(priv->regval, priv->control_reg); 57 58 return 0; 59 } 60 61 static int ts72xx_wdt_stop(struct watchdog_device *wdd) 62 { 63 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd); 64 65 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg); 66 writeb(TS72XX_WDT_CTRL_DISABLE, priv->control_reg); 67 68 return 0; 69 } 70 71 static int ts72xx_wdt_ping(struct watchdog_device *wdd) 72 { 73 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd); 74 75 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg); 76 77 return 0; 78 } 79 80 static int ts72xx_wdt_settimeout(struct watchdog_device *wdd, unsigned int to) 81 { 82 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd); 83 84 if (to == 1) { 85 priv->regval = TS72XX_WDT_CTRL_1SEC; 86 } else if (to == 2) { 87 priv->regval = TS72XX_WDT_CTRL_2SEC; 88 } else if (to <= 4) { 89 priv->regval = TS72XX_WDT_CTRL_4SEC; 90 to = 4; 91 } else { 92 priv->regval = TS72XX_WDT_CTRL_8SEC; 93 if (to <= 8) 94 to = 8; 95 } 96 97 wdd->timeout = to; 98 99 if (watchdog_active(wdd)) { 100 ts72xx_wdt_stop(wdd); 101 ts72xx_wdt_start(wdd); 102 } 103 104 return 0; 105 } 106 107 static const struct watchdog_info ts72xx_wdt_ident = { 108 .options = WDIOF_KEEPALIVEPING | 109 WDIOF_SETTIMEOUT | 110 WDIOF_MAGICCLOSE, 111 .firmware_version = 1, 112 .identity = "TS-72XX WDT", 113 }; 114 115 static struct watchdog_ops ts72xx_wdt_ops = { 116 .owner = THIS_MODULE, 117 .start = ts72xx_wdt_start, 118 .stop = ts72xx_wdt_stop, 119 .ping = ts72xx_wdt_ping, 120 .set_timeout = ts72xx_wdt_settimeout, 121 }; 122 123 static int ts72xx_wdt_probe(struct platform_device *pdev) 124 { 125 struct ts72xx_wdt_priv *priv; 126 struct watchdog_device *wdd; 127 struct resource *res; 128 int ret; 129 130 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); 131 if (!priv) 132 return -ENOMEM; 133 134 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 135 priv->control_reg = devm_ioremap_resource(&pdev->dev, res); 136 if (IS_ERR(priv->control_reg)) 137 return PTR_ERR(priv->control_reg); 138 139 res = platform_get_resource(pdev, IORESOURCE_MEM, 1); 140 priv->feed_reg = devm_ioremap_resource(&pdev->dev, res); 141 if (IS_ERR(priv->feed_reg)) 142 return PTR_ERR(priv->feed_reg); 143 144 wdd = &priv->wdd; 145 wdd->info = &ts72xx_wdt_ident; 146 wdd->ops = &ts72xx_wdt_ops; 147 wdd->min_timeout = 1; 148 wdd->max_hw_heartbeat_ms = 8000; 149 wdd->parent = &pdev->dev; 150 151 watchdog_set_nowayout(wdd, nowayout); 152 153 wdd->timeout = TS72XX_WDT_DEFAULT_TIMEOUT; 154 watchdog_init_timeout(wdd, timeout, &pdev->dev); 155 156 watchdog_set_drvdata(wdd, priv); 157 158 ret = devm_watchdog_register_device(&pdev->dev, wdd); 159 if (ret) 160 return ret; 161 162 dev_info(&pdev->dev, "TS-72xx Watchdog driver\n"); 163 164 return 0; 165 } 166 167 static struct platform_driver ts72xx_wdt_driver = { 168 .probe = ts72xx_wdt_probe, 169 .driver = { 170 .name = "ts72xx-wdt", 171 }, 172 }; 173 174 module_platform_driver(ts72xx_wdt_driver); 175 176 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@iki.fi>"); 177 MODULE_DESCRIPTION("TS-72xx SBC Watchdog"); 178 MODULE_LICENSE("GPL"); 179 MODULE_ALIAS("platform:ts72xx-wdt"); 180