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
7 * Copyright (c) 2009 Mika Westerberg <mika.westerberg@iki.fi>
9 * This driver is based on ep93xx_wdt and wm831x_wdt drivers.
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.
16 #include <linux/platform_device.h>
17 #include <linux/module.h>
18 #include <linux/watchdog.h>
21 #define TS72XX_WDT_DEFAULT_TIMEOUT 30
24 module_param(timeout, int, 0);
25 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds.");
27 static bool nowayout = WATCHDOG_NOWAYOUT;
28 module_param(nowayout, bool, 0);
29 MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
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
42 #define TS72XX_WDT_FEED_VAL 0x05
44 struct ts72xx_wdt_priv {
45 void __iomem *control_reg;
46 void __iomem *feed_reg;
47 struct watchdog_device wdd;
51 static int ts72xx_wdt_start(struct watchdog_device *wdd)
53 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
55 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);
56 writeb(priv->regval, priv->control_reg);
61 static int ts72xx_wdt_stop(struct watchdog_device *wdd)
63 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
65 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);
66 writeb(TS72XX_WDT_CTRL_DISABLE, priv->control_reg);
71 static int ts72xx_wdt_ping(struct watchdog_device *wdd)
73 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
75 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);
80 static int ts72xx_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
82 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
85 priv->regval = TS72XX_WDT_CTRL_1SEC;
87 priv->regval = TS72XX_WDT_CTRL_2SEC;
89 priv->regval = TS72XX_WDT_CTRL_4SEC;
92 priv->regval = TS72XX_WDT_CTRL_8SEC;
99 if (watchdog_active(wdd)) {
100 ts72xx_wdt_stop(wdd);
101 ts72xx_wdt_start(wdd);
107 static const struct watchdog_info ts72xx_wdt_ident = {
108 .options = WDIOF_KEEPALIVEPING |
111 .firmware_version = 1,
112 .identity = "TS-72XX WDT",
115 static 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,
123 static int ts72xx_wdt_probe(struct platform_device *pdev)
125 struct device *dev = &pdev->dev;
126 struct ts72xx_wdt_priv *priv;
127 struct watchdog_device *wdd;
130 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
134 priv->control_reg = devm_platform_ioremap_resource(pdev, 0);
135 if (IS_ERR(priv->control_reg))
136 return PTR_ERR(priv->control_reg);
138 priv->feed_reg = devm_platform_ioremap_resource(pdev, 1);
139 if (IS_ERR(priv->feed_reg))
140 return PTR_ERR(priv->feed_reg);
143 wdd->info = &ts72xx_wdt_ident;
144 wdd->ops = &ts72xx_wdt_ops;
145 wdd->min_timeout = 1;
146 wdd->max_hw_heartbeat_ms = 8000;
149 watchdog_set_nowayout(wdd, nowayout);
151 wdd->timeout = TS72XX_WDT_DEFAULT_TIMEOUT;
152 watchdog_init_timeout(wdd, timeout, dev);
154 watchdog_set_drvdata(wdd, priv);
156 ret = devm_watchdog_register_device(dev, wdd);
160 dev_info(dev, "TS-72xx Watchdog driver\n");
165 static struct platform_driver ts72xx_wdt_driver = {
166 .probe = ts72xx_wdt_probe,
168 .name = "ts72xx-wdt",
172 module_platform_driver(ts72xx_wdt_driver);
174 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@iki.fi>");
175 MODULE_DESCRIPTION("TS-72xx SBC Watchdog");
176 MODULE_LICENSE("GPL");
177 MODULE_ALIAS("platform:ts72xx-wdt");