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
ts72xx_wdt_start(struct watchdog_device * wdd)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
ts72xx_wdt_stop(struct watchdog_device * wdd)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
ts72xx_wdt_ping(struct watchdog_device * wdd)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
ts72xx_wdt_settimeout(struct watchdog_device * wdd,unsigned int to)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 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
ts72xx_wdt_probe(struct platform_device * pdev)123 static 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
165 static struct platform_driver ts72xx_wdt_driver = {
166 .probe = ts72xx_wdt_probe,
167 .driver = {
168 .name = "ts72xx-wdt",
169 },
170 };
171
172 module_platform_driver(ts72xx_wdt_driver);
173
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");
178