blob: 8162a40d15220aed9f2b6cfe972f9221a4520166 [file] [log] [blame]
Timo Kokkonen80e45b12009-03-27 16:42:17 +02001/*
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/kernel.h>
24#include <linux/fs.h>
25#include <linux/watchdog.h>
26#include <linux/platform_device.h>
27#include <linux/miscdevice.h>
28#include <linux/uaccess.h>
Santosh Shilimkarb07682b2009-12-13 20:05:51 +010029#include <linux/i2c/twl.h>
Timo Kokkonen80e45b12009-03-27 16:42:17 +020030
31#define TWL4030_WATCHDOG_CFG_REG_OFFS 0x3
32
33#define TWL4030_WDT_STATE_OPEN 0x1
34#define TWL4030_WDT_STATE_ACTIVE 0x8
35
36static struct platform_device *twl4030_wdt_dev;
37
38struct twl4030_wdt {
39 struct miscdevice miscdev;
40 int timer_margin;
41 unsigned long state;
42};
43
44static int nowayout = WATCHDOG_NOWAYOUT;
45module_param(nowayout, int, 0);
46MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
47 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
48
49static int twl4030_wdt_write(unsigned char val)
50{
Balaji T Kfc7b92f2009-12-13 21:23:33 +010051 return twl_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, val,
Timo Kokkonen80e45b12009-03-27 16:42:17 +020052 TWL4030_WATCHDOG_CFG_REG_OFFS);
53}
54
55static int twl4030_wdt_enable(struct twl4030_wdt *wdt)
56{
57 return twl4030_wdt_write(wdt->timer_margin + 1);
58}
59
60static int twl4030_wdt_disable(struct twl4030_wdt *wdt)
61{
62 return twl4030_wdt_write(0);
63}
64
65static int twl4030_wdt_set_timeout(struct twl4030_wdt *wdt, int timeout)
66{
67 if (timeout < 0 || timeout > 30) {
68 dev_warn(wdt->miscdev.parent,
69 "Timeout can only be in the range [0-30] seconds");
70 return -EINVAL;
71 }
72 wdt->timer_margin = timeout;
73 return twl4030_wdt_enable(wdt);
74}
75
76static ssize_t twl4030_wdt_write_fop(struct file *file,
77 const char __user *data, size_t len, loff_t *ppos)
78{
79 struct twl4030_wdt *wdt = file->private_data;
80
81 if (len)
82 twl4030_wdt_enable(wdt);
83
84 return len;
85}
86
87static long twl4030_wdt_ioctl(struct file *file,
88 unsigned int cmd, unsigned long arg)
89{
90 void __user *argp = (void __user *)arg;
91 int __user *p = argp;
92 int new_margin;
93 struct twl4030_wdt *wdt = file->private_data;
94
95 static const struct watchdog_info twl4030_wd_ident = {
96 .identity = "TWL4030 Watchdog",
97 .options = WDIOF_SETTIMEOUT,
98 .firmware_version = 0,
99 };
100
101 switch (cmd) {
102 case WDIOC_GETSUPPORT:
103 return copy_to_user(argp, &twl4030_wd_ident,
104 sizeof(twl4030_wd_ident)) ? -EFAULT : 0;
105
106 case WDIOC_GETSTATUS:
107 case WDIOC_GETBOOTSTATUS:
108 return put_user(0, p);
109
110 case WDIOC_KEEPALIVE:
111 twl4030_wdt_enable(wdt);
112 break;
113
114 case WDIOC_SETTIMEOUT:
115 if (get_user(new_margin, p))
116 return -EFAULT;
117 if (twl4030_wdt_set_timeout(wdt, new_margin))
118 return -EINVAL;
119 return put_user(wdt->timer_margin, p);
120
121 case WDIOC_GETTIMEOUT:
122 return put_user(wdt->timer_margin, p);
123
124 default:
125 return -ENOTTY;
126 }
127
128 return 0;
129}
130
131static int twl4030_wdt_open(struct inode *inode, struct file *file)
132{
133 struct twl4030_wdt *wdt = platform_get_drvdata(twl4030_wdt_dev);
134
135 /* /dev/watchdog can only be opened once */
136 if (test_and_set_bit(0, &wdt->state))
137 return -EBUSY;
138
139 wdt->state |= TWL4030_WDT_STATE_ACTIVE;
140 file->private_data = (void *) wdt;
141
142 twl4030_wdt_enable(wdt);
143 return nonseekable_open(inode, file);
144}
145
146static int twl4030_wdt_release(struct inode *inode, struct file *file)
147{
148 struct twl4030_wdt *wdt = file->private_data;
149 if (nowayout) {
150 dev_alert(wdt->miscdev.parent,
151 "Unexpected close, watchdog still running!\n");
152 twl4030_wdt_enable(wdt);
153 } else {
154 if (twl4030_wdt_disable(wdt))
155 return -EFAULT;
156 wdt->state &= ~TWL4030_WDT_STATE_ACTIVE;
157 }
158
159 clear_bit(0, &wdt->state);
160 return 0;
161}
162
163static const struct file_operations twl4030_wdt_fops = {
164 .owner = THIS_MODULE,
165 .llseek = no_llseek,
166 .open = twl4030_wdt_open,
167 .release = twl4030_wdt_release,
168 .unlocked_ioctl = twl4030_wdt_ioctl,
169 .write = twl4030_wdt_write_fop,
170};
171
172static int __devinit twl4030_wdt_probe(struct platform_device *pdev)
173{
174 int ret = 0;
175 struct twl4030_wdt *wdt;
176
177 wdt = kzalloc(sizeof(struct twl4030_wdt), GFP_KERNEL);
178 if (!wdt)
179 return -ENOMEM;
180
181 wdt->state = 0;
182 wdt->timer_margin = 30;
183 wdt->miscdev.parent = &pdev->dev;
184 wdt->miscdev.fops = &twl4030_wdt_fops;
185 wdt->miscdev.minor = WATCHDOG_MINOR;
186 wdt->miscdev.name = "watchdog";
187
188 platform_set_drvdata(pdev, wdt);
189
190 twl4030_wdt_dev = pdev;
191
192 ret = misc_register(&wdt->miscdev);
193 if (ret) {
194 dev_err(wdt->miscdev.parent,
195 "Failed to register misc device\n");
196 platform_set_drvdata(pdev, NULL);
197 kfree(wdt);
198 twl4030_wdt_dev = NULL;
199 return ret;
200 }
201 return 0;
202}
203
204static int __devexit twl4030_wdt_remove(struct platform_device *pdev)
205{
206 struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
207
208 if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
209 if (twl4030_wdt_disable(wdt))
210 return -EFAULT;
211
212 wdt->state &= ~TWL4030_WDT_STATE_ACTIVE;
213 misc_deregister(&wdt->miscdev);
214
215 platform_set_drvdata(pdev, NULL);
216 kfree(wdt);
217 twl4030_wdt_dev = NULL;
218
219 return 0;
220}
221
222#ifdef CONFIG_PM
223static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state)
224{
225 struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
226 if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
227 return twl4030_wdt_disable(wdt);
228
229 return 0;
230}
231
232static int twl4030_wdt_resume(struct platform_device *pdev)
233{
234 struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
235 if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
236 return twl4030_wdt_enable(wdt);
237
238 return 0;
239}
240#else
241#define twl4030_wdt_suspend NULL
242#define twl4030_wdt_resume NULL
243#endif
244
245static struct platform_driver twl4030_wdt_driver = {
246 .probe = twl4030_wdt_probe,
247 .remove = __devexit_p(twl4030_wdt_remove),
248 .suspend = twl4030_wdt_suspend,
249 .resume = twl4030_wdt_resume,
250 .driver = {
251 .owner = THIS_MODULE,
252 .name = "twl4030_wdt",
253 },
254};
255
256static int __devinit twl4030_wdt_init(void)
257{
258 return platform_driver_register(&twl4030_wdt_driver);
259}
260module_init(twl4030_wdt_init);
261
262static void __devexit twl4030_wdt_exit(void)
263{
264 platform_driver_unregister(&twl4030_wdt_driver);
265}
266module_exit(twl4030_wdt_exit);
267
268MODULE_AUTHOR("Nokia Corporation");
269MODULE_LICENSE("GPL");
270MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
271MODULE_ALIAS("platform:twl4030_wdt");
272