virtio-mem: simplify high-level unplug handling in Sub Block Mode
[linux-2.6-microblaze.git] / drivers / watchdog / ts72xx_wdt.c
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 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
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");