]> git.kernelconcepts.de Git - karo-tx-linux.git/blob - drivers/watchdog/twl4030_wdt.c
Merge tag 'drm-intel-next-2013-07-12' of git://people.freedesktop.org/~danvet/drm...
[karo-tx-linux.git] / drivers / watchdog / twl4030_wdt.c
1 /*
2  * Copyright (C) Nokia Corporation
3  *
4  * Written by Timo Kokkonen <timo.t.kokkonen at nokia.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19  */
20
21 #include <linux/module.h>
22 #include <linux/types.h>
23 #include <linux/slab.h>
24 #include <linux/kernel.h>
25 #include <linux/watchdog.h>
26 #include <linux/platform_device.h>
27 #include <linux/i2c/twl.h>
28
29 #define TWL4030_WATCHDOG_CFG_REG_OFFS   0x3
30
31 static bool nowayout = WATCHDOG_NOWAYOUT;
32 module_param(nowayout, bool, 0);
33 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
34         "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
35
36 static int twl4030_wdt_write(unsigned char val)
37 {
38         return twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, val,
39                                         TWL4030_WATCHDOG_CFG_REG_OFFS);
40 }
41
42 static int twl4030_wdt_start(struct watchdog_device *wdt)
43 {
44         return twl4030_wdt_write(wdt->timeout + 1);
45 }
46
47 static int twl4030_wdt_stop(struct watchdog_device *wdt)
48 {
49         return twl4030_wdt_write(0);
50 }
51
52 static int twl4030_wdt_set_timeout(struct watchdog_device *wdt,
53                                    unsigned int timeout)
54 {
55         wdt->timeout = timeout;
56         return 0;
57 }
58
59 static const struct watchdog_info twl4030_wdt_info = {
60         .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
61         .identity = "TWL4030 Watchdog",
62 };
63
64 static const struct watchdog_ops twl4030_wdt_ops = {
65         .owner          = THIS_MODULE,
66         .start          = twl4030_wdt_start,
67         .stop           = twl4030_wdt_stop,
68         .set_timeout    = twl4030_wdt_set_timeout,
69 };
70
71 static int twl4030_wdt_probe(struct platform_device *pdev)
72 {
73         int ret = 0;
74         struct watchdog_device *wdt;
75
76         wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
77         if (!wdt)
78                 return -ENOMEM;
79
80         wdt->info               = &twl4030_wdt_info;
81         wdt->ops                = &twl4030_wdt_ops;
82         wdt->status             = 0;
83         wdt->timeout            = 30;
84         wdt->min_timeout        = 1;
85         wdt->max_timeout        = 30;
86
87         watchdog_set_nowayout(wdt, nowayout);
88         platform_set_drvdata(pdev, wdt);
89
90         twl4030_wdt_stop(wdt);
91
92         ret = watchdog_register_device(wdt);
93         if (ret)
94                 return ret;
95
96         return 0;
97 }
98
99 static int twl4030_wdt_remove(struct platform_device *pdev)
100 {
101         struct watchdog_device *wdt = platform_get_drvdata(pdev);
102
103         watchdog_unregister_device(wdt);
104
105         return 0;
106 }
107
108 #ifdef CONFIG_PM
109 static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state)
110 {
111         struct watchdog_device *wdt = platform_get_drvdata(pdev);
112         if (watchdog_active(wdt))
113                 return twl4030_wdt_stop(wdt);
114
115         return 0;
116 }
117
118 static int twl4030_wdt_resume(struct platform_device *pdev)
119 {
120         struct watchdog_device *wdt = platform_get_drvdata(pdev);
121         if (watchdog_active(wdt))
122                 return twl4030_wdt_start(wdt);
123
124         return 0;
125 }
126 #else
127 #define twl4030_wdt_suspend        NULL
128 #define twl4030_wdt_resume         NULL
129 #endif
130
131 static const struct of_device_id twl_wdt_of_match[] = {
132         { .compatible = "ti,twl4030-wdt", },
133         { },
134 };
135 MODULE_DEVICE_TABLE(of, twl_wdt_of_match);
136
137 static struct platform_driver twl4030_wdt_driver = {
138         .probe          = twl4030_wdt_probe,
139         .remove         = twl4030_wdt_remove,
140         .suspend        = twl4030_wdt_suspend,
141         .resume         = twl4030_wdt_resume,
142         .driver         = {
143                 .owner          = THIS_MODULE,
144                 .name           = "twl4030_wdt",
145                 .of_match_table = twl_wdt_of_match,
146         },
147 };
148
149 module_platform_driver(twl4030_wdt_driver);
150
151 MODULE_AUTHOR("Nokia Corporation");
152 MODULE_LICENSE("GPL");
153 MODULE_ALIAS("platform:twl4030_wdt");
154