ts72xx_wdt.c (4283B)
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 23static int timeout; 24module_param(timeout, int, 0); 25MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds."); 26 27static bool nowayout = WATCHDOG_NOWAYOUT; 28module_param(nowayout, bool, 0); 29MODULE_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 44struct ts72xx_wdt_priv { 45 void __iomem *control_reg; 46 void __iomem *feed_reg; 47 struct watchdog_device wdd; 48 unsigned char regval; 49}; 50 51static 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 61static 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 71static 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 80static 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 107static 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 115static const 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 123static int ts72xx_wdt_probe(struct platform_device *pdev) 124{ 125 struct device *dev = &pdev->dev; 126 struct ts72xx_wdt_priv *priv; 127 struct watchdog_device *wdd; 128 int ret; 129 130 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 131 if (!priv) 132 return -ENOMEM; 133 134 priv->control_reg = devm_platform_ioremap_resource(pdev, 0); 135 if (IS_ERR(priv->control_reg)) 136 return PTR_ERR(priv->control_reg); 137 138 priv->feed_reg = devm_platform_ioremap_resource(pdev, 1); 139 if (IS_ERR(priv->feed_reg)) 140 return PTR_ERR(priv->feed_reg); 141 142 wdd = &priv->wdd; 143 wdd->info = &ts72xx_wdt_ident; 144 wdd->ops = &ts72xx_wdt_ops; 145 wdd->min_timeout = 1; 146 wdd->max_hw_heartbeat_ms = 8000; 147 wdd->parent = dev; 148 149 watchdog_set_nowayout(wdd, nowayout); 150 151 wdd->timeout = TS72XX_WDT_DEFAULT_TIMEOUT; 152 watchdog_init_timeout(wdd, timeout, dev); 153 154 watchdog_set_drvdata(wdd, priv); 155 156 ret = devm_watchdog_register_device(dev, wdd); 157 if (ret) 158 return ret; 159 160 dev_info(dev, "TS-72xx Watchdog driver\n"); 161 162 return 0; 163} 164 165static struct platform_driver ts72xx_wdt_driver = { 166 .probe = ts72xx_wdt_probe, 167 .driver = { 168 .name = "ts72xx-wdt", 169 }, 170}; 171 172module_platform_driver(ts72xx_wdt_driver); 173 174MODULE_AUTHOR("Mika Westerberg <mika.westerberg@iki.fi>"); 175MODULE_DESCRIPTION("TS-72xx SBC Watchdog"); 176MODULE_LICENSE("GPL"); 177MODULE_ALIAS("platform:ts72xx-wdt");