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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> | |
5a0e3ad6 | 23 | #include <linux/slab.h> |
80e45b1e TK |
24 | #include <linux/kernel.h> |
25 | #include <linux/fs.h> | |
26 | #include <linux/watchdog.h> | |
27 | #include <linux/platform_device.h> | |
28 | #include <linux/miscdevice.h> | |
29 | #include <linux/uaccess.h> | |
b07682b6 | 30 | #include <linux/i2c/twl.h> |
80e45b1e TK |
31 | |
32 | #define TWL4030_WATCHDOG_CFG_REG_OFFS 0x3 | |
33 | ||
34 | #define TWL4030_WDT_STATE_OPEN 0x1 | |
35 | #define TWL4030_WDT_STATE_ACTIVE 0x8 | |
36 | ||
37 | static struct platform_device *twl4030_wdt_dev; | |
38 | ||
39 | struct twl4030_wdt { | |
40 | struct miscdevice miscdev; | |
41 | int timer_margin; | |
42 | unsigned long state; | |
43 | }; | |
44 | ||
45 | static int nowayout = WATCHDOG_NOWAYOUT; | |
46 | module_param(nowayout, int, 0); | |
47 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " | |
48 | "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
49 | ||
50 | static int twl4030_wdt_write(unsigned char val) | |
51 | { | |
fc7b92fc | 52 | return twl_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, val, |
80e45b1e TK |
53 | TWL4030_WATCHDOG_CFG_REG_OFFS); |
54 | } | |
55 | ||
56 | static int twl4030_wdt_enable(struct twl4030_wdt *wdt) | |
57 | { | |
58 | return twl4030_wdt_write(wdt->timer_margin + 1); | |
59 | } | |
60 | ||
61 | static int twl4030_wdt_disable(struct twl4030_wdt *wdt) | |
62 | { | |
63 | return twl4030_wdt_write(0); | |
64 | } | |
65 | ||
66 | static int twl4030_wdt_set_timeout(struct twl4030_wdt *wdt, int timeout) | |
67 | { | |
68 | if (timeout < 0 || timeout > 30) { | |
69 | dev_warn(wdt->miscdev.parent, | |
70 | "Timeout can only be in the range [0-30] seconds"); | |
71 | return -EINVAL; | |
72 | } | |
73 | wdt->timer_margin = timeout; | |
74 | return twl4030_wdt_enable(wdt); | |
75 | } | |
76 | ||
77 | static ssize_t twl4030_wdt_write_fop(struct file *file, | |
78 | const char __user *data, size_t len, loff_t *ppos) | |
79 | { | |
80 | struct twl4030_wdt *wdt = file->private_data; | |
81 | ||
82 | if (len) | |
83 | twl4030_wdt_enable(wdt); | |
84 | ||
85 | return len; | |
86 | } | |
87 | ||
88 | static long twl4030_wdt_ioctl(struct file *file, | |
89 | unsigned int cmd, unsigned long arg) | |
90 | { | |
91 | void __user *argp = (void __user *)arg; | |
92 | int __user *p = argp; | |
93 | int new_margin; | |
94 | struct twl4030_wdt *wdt = file->private_data; | |
95 | ||
96 | static const struct watchdog_info twl4030_wd_ident = { | |
97 | .identity = "TWL4030 Watchdog", | |
98 | .options = WDIOF_SETTIMEOUT, | |
99 | .firmware_version = 0, | |
100 | }; | |
101 | ||
102 | switch (cmd) { | |
103 | case WDIOC_GETSUPPORT: | |
104 | return copy_to_user(argp, &twl4030_wd_ident, | |
105 | sizeof(twl4030_wd_ident)) ? -EFAULT : 0; | |
106 | ||
107 | case WDIOC_GETSTATUS: | |
108 | case WDIOC_GETBOOTSTATUS: | |
109 | return put_user(0, p); | |
110 | ||
111 | case WDIOC_KEEPALIVE: | |
112 | twl4030_wdt_enable(wdt); | |
113 | break; | |
114 | ||
115 | case WDIOC_SETTIMEOUT: | |
116 | if (get_user(new_margin, p)) | |
117 | return -EFAULT; | |
118 | if (twl4030_wdt_set_timeout(wdt, new_margin)) | |
119 | return -EINVAL; | |
120 | return put_user(wdt->timer_margin, p); | |
121 | ||
122 | case WDIOC_GETTIMEOUT: | |
123 | return put_user(wdt->timer_margin, p); | |
124 | ||
125 | default: | |
126 | return -ENOTTY; | |
127 | } | |
128 | ||
129 | return 0; | |
130 | } | |
131 | ||
132 | static int twl4030_wdt_open(struct inode *inode, struct file *file) | |
133 | { | |
134 | struct twl4030_wdt *wdt = platform_get_drvdata(twl4030_wdt_dev); | |
135 | ||
136 | /* /dev/watchdog can only be opened once */ | |
137 | if (test_and_set_bit(0, &wdt->state)) | |
138 | return -EBUSY; | |
139 | ||
140 | wdt->state |= TWL4030_WDT_STATE_ACTIVE; | |
141 | file->private_data = (void *) wdt; | |
142 | ||
143 | twl4030_wdt_enable(wdt); | |
144 | return nonseekable_open(inode, file); | |
145 | } | |
146 | ||
147 | static int twl4030_wdt_release(struct inode *inode, struct file *file) | |
148 | { | |
149 | struct twl4030_wdt *wdt = file->private_data; | |
150 | if (nowayout) { | |
151 | dev_alert(wdt->miscdev.parent, | |
152 | "Unexpected close, watchdog still running!\n"); | |
153 | twl4030_wdt_enable(wdt); | |
154 | } else { | |
155 | if (twl4030_wdt_disable(wdt)) | |
156 | return -EFAULT; | |
157 | wdt->state &= ~TWL4030_WDT_STATE_ACTIVE; | |
158 | } | |
159 | ||
160 | clear_bit(0, &wdt->state); | |
161 | return 0; | |
162 | } | |
163 | ||
164 | static const struct file_operations twl4030_wdt_fops = { | |
165 | .owner = THIS_MODULE, | |
166 | .llseek = no_llseek, | |
167 | .open = twl4030_wdt_open, | |
168 | .release = twl4030_wdt_release, | |
169 | .unlocked_ioctl = twl4030_wdt_ioctl, | |
170 | .write = twl4030_wdt_write_fop, | |
171 | }; | |
172 | ||
173 | static int __devinit twl4030_wdt_probe(struct platform_device *pdev) | |
174 | { | |
175 | int ret = 0; | |
176 | struct twl4030_wdt *wdt; | |
177 | ||
178 | wdt = kzalloc(sizeof(struct twl4030_wdt), GFP_KERNEL); | |
179 | if (!wdt) | |
180 | return -ENOMEM; | |
181 | ||
182 | wdt->state = 0; | |
183 | wdt->timer_margin = 30; | |
184 | wdt->miscdev.parent = &pdev->dev; | |
185 | wdt->miscdev.fops = &twl4030_wdt_fops; | |
186 | wdt->miscdev.minor = WATCHDOG_MINOR; | |
187 | wdt->miscdev.name = "watchdog"; | |
188 | ||
189 | platform_set_drvdata(pdev, wdt); | |
190 | ||
191 | twl4030_wdt_dev = pdev; | |
192 | ||
bb6f3607 AP |
193 | twl4030_wdt_disable(wdt); |
194 | ||
80e45b1e TK |
195 | ret = misc_register(&wdt->miscdev); |
196 | if (ret) { | |
197 | dev_err(wdt->miscdev.parent, | |
198 | "Failed to register misc device\n"); | |
199 | platform_set_drvdata(pdev, NULL); | |
200 | kfree(wdt); | |
201 | twl4030_wdt_dev = NULL; | |
202 | return ret; | |
203 | } | |
204 | return 0; | |
205 | } | |
206 | ||
207 | static int __devexit twl4030_wdt_remove(struct platform_device *pdev) | |
208 | { | |
209 | struct twl4030_wdt *wdt = platform_get_drvdata(pdev); | |
210 | ||
211 | if (wdt->state & TWL4030_WDT_STATE_ACTIVE) | |
212 | if (twl4030_wdt_disable(wdt)) | |
213 | return -EFAULT; | |
214 | ||
215 | wdt->state &= ~TWL4030_WDT_STATE_ACTIVE; | |
216 | misc_deregister(&wdt->miscdev); | |
217 | ||
218 | platform_set_drvdata(pdev, NULL); | |
219 | kfree(wdt); | |
220 | twl4030_wdt_dev = NULL; | |
221 | ||
222 | return 0; | |
223 | } | |
224 | ||
225 | #ifdef CONFIG_PM | |
226 | static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state) | |
227 | { | |
228 | struct twl4030_wdt *wdt = platform_get_drvdata(pdev); | |
229 | if (wdt->state & TWL4030_WDT_STATE_ACTIVE) | |
230 | return twl4030_wdt_disable(wdt); | |
231 | ||
232 | return 0; | |
233 | } | |
234 | ||
235 | static int twl4030_wdt_resume(struct platform_device *pdev) | |
236 | { | |
237 | struct twl4030_wdt *wdt = platform_get_drvdata(pdev); | |
238 | if (wdt->state & TWL4030_WDT_STATE_ACTIVE) | |
239 | return twl4030_wdt_enable(wdt); | |
240 | ||
241 | return 0; | |
242 | } | |
243 | #else | |
244 | #define twl4030_wdt_suspend NULL | |
245 | #define twl4030_wdt_resume NULL | |
246 | #endif | |
247 | ||
248 | static struct platform_driver twl4030_wdt_driver = { | |
249 | .probe = twl4030_wdt_probe, | |
250 | .remove = __devexit_p(twl4030_wdt_remove), | |
251 | .suspend = twl4030_wdt_suspend, | |
252 | .resume = twl4030_wdt_resume, | |
253 | .driver = { | |
254 | .owner = THIS_MODULE, | |
255 | .name = "twl4030_wdt", | |
256 | }, | |
257 | }; | |
258 | ||
259 | static int __devinit twl4030_wdt_init(void) | |
260 | { | |
261 | return platform_driver_register(&twl4030_wdt_driver); | |
262 | } | |
263 | module_init(twl4030_wdt_init); | |
264 | ||
265 | static void __devexit twl4030_wdt_exit(void) | |
266 | { | |
267 | platform_driver_unregister(&twl4030_wdt_driver); | |
268 | } | |
269 | module_exit(twl4030_wdt_exit); | |
270 | ||
271 | MODULE_AUTHOR("Nokia Corporation"); | |
272 | MODULE_LICENSE("GPL"); | |
273 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
274 | MODULE_ALIAS("platform:twl4030_wdt"); | |
275 |