diff options
author | Wim Van Sebroeck <wim@iguana.be> | 2007-08-17 04:38:02 -0400 |
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committer | Wim Van Sebroeck <wim@iguana.be> | 2007-10-18 06:39:03 -0400 |
commit | b7e04f8c61a46d742de23af5d7ca2b41b33e40ac (patch) | |
tree | c52a7ea568648e2d8ed0d423098b42298de2058b /drivers/watchdog/mpc5200_wdt.c | |
parent | d85714d81cc0408daddb68c10f7fd69eafe7c213 (diff) |
mv watchdog tree under drivers
move watchdog tree from drivers/char/watchdog to drivers/watchdog.
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog/mpc5200_wdt.c')
-rw-r--r-- | drivers/watchdog/mpc5200_wdt.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/drivers/watchdog/mpc5200_wdt.c b/drivers/watchdog/mpc5200_wdt.c new file mode 100644 index 000000000000..9cfb97576623 --- /dev/null +++ b/drivers/watchdog/mpc5200_wdt.c | |||
@@ -0,0 +1,286 @@ | |||
1 | #include <linux/init.h> | ||
2 | #include <linux/module.h> | ||
3 | #include <linux/miscdevice.h> | ||
4 | #include <linux/watchdog.h> | ||
5 | #include <linux/io.h> | ||
6 | #include <linux/spinlock.h> | ||
7 | #include <asm/of_platform.h> | ||
8 | #include <asm/uaccess.h> | ||
9 | #include <asm/mpc52xx.h> | ||
10 | |||
11 | |||
12 | #define GPT_MODE_WDT (1<<15) | ||
13 | #define GPT_MODE_CE (1<<12) | ||
14 | #define GPT_MODE_MS_TIMER (0x4) | ||
15 | |||
16 | |||
17 | struct mpc5200_wdt { | ||
18 | unsigned count; /* timer ticks before watchdog kicks in */ | ||
19 | long ipb_freq; | ||
20 | struct miscdevice miscdev; | ||
21 | struct resource mem; | ||
22 | struct mpc52xx_gpt __iomem *regs; | ||
23 | spinlock_t io_lock; | ||
24 | }; | ||
25 | |||
26 | /* is_active stores wether or not the /dev/watchdog device is opened */ | ||
27 | static unsigned long is_active; | ||
28 | |||
29 | /* misc devices don't provide a way, to get back to 'dev' or 'miscdev' from | ||
30 | * file operations, which sucks. But there can be max 1 watchdog anyway, so... | ||
31 | */ | ||
32 | static struct mpc5200_wdt *wdt_global; | ||
33 | |||
34 | |||
35 | /* helper to calculate timeout in timer counts */ | ||
36 | static void mpc5200_wdt_set_timeout(struct mpc5200_wdt *wdt, int timeout) | ||
37 | { | ||
38 | /* use biggest prescaler of 64k */ | ||
39 | wdt->count = (wdt->ipb_freq + 0xffff) / 0x10000 * timeout; | ||
40 | |||
41 | if (wdt->count > 0xffff) | ||
42 | wdt->count = 0xffff; | ||
43 | } | ||
44 | /* return timeout in seconds (calculated from timer count) */ | ||
45 | static int mpc5200_wdt_get_timeout(struct mpc5200_wdt *wdt) | ||
46 | { | ||
47 | return wdt->count * 0x10000 / wdt->ipb_freq; | ||
48 | } | ||
49 | |||
50 | |||
51 | /* watchdog operations */ | ||
52 | static int mpc5200_wdt_start(struct mpc5200_wdt *wdt) | ||
53 | { | ||
54 | spin_lock(&wdt->io_lock); | ||
55 | /* disable */ | ||
56 | out_be32(&wdt->regs->mode, 0); | ||
57 | /* set timeout, with maximum prescaler */ | ||
58 | out_be32(&wdt->regs->count, 0x0 | wdt->count); | ||
59 | /* enable watchdog */ | ||
60 | out_be32(&wdt->regs->mode, GPT_MODE_CE | GPT_MODE_WDT | GPT_MODE_MS_TIMER); | ||
61 | spin_unlock(&wdt->io_lock); | ||
62 | |||
63 | return 0; | ||
64 | } | ||
65 | static int mpc5200_wdt_ping(struct mpc5200_wdt *wdt) | ||
66 | { | ||
67 | spin_lock(&wdt->io_lock); | ||
68 | /* writing A5 to OCPW resets the watchdog */ | ||
69 | out_be32(&wdt->regs->mode, 0xA5000000 | (0xffffff & in_be32(&wdt->regs->mode))); | ||
70 | spin_unlock(&wdt->io_lock); | ||
71 | return 0; | ||
72 | } | ||
73 | static int mpc5200_wdt_stop(struct mpc5200_wdt *wdt) | ||
74 | { | ||
75 | spin_lock(&wdt->io_lock); | ||
76 | /* disable */ | ||
77 | out_be32(&wdt->regs->mode, 0); | ||
78 | spin_unlock(&wdt->io_lock); | ||
79 | return 0; | ||
80 | } | ||
81 | |||
82 | |||
83 | /* file operations */ | ||
84 | static ssize_t mpc5200_wdt_write(struct file *file, const char __user *data, | ||
85 | size_t len, loff_t *ppos) | ||
86 | { | ||
87 | struct mpc5200_wdt *wdt = file->private_data; | ||
88 | mpc5200_wdt_ping(wdt); | ||
89 | return 0; | ||
90 | } | ||
91 | static struct watchdog_info mpc5200_wdt_info = { | ||
92 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | ||
93 | .identity = "mpc5200 watchdog on GPT0", | ||
94 | }; | ||
95 | static int mpc5200_wdt_ioctl(struct inode *inode, struct file *file, | ||
96 | unsigned int cmd, unsigned long arg) | ||
97 | { | ||
98 | struct mpc5200_wdt *wdt = file->private_data; | ||
99 | int __user *data = (int __user *)arg; | ||
100 | int timeout; | ||
101 | int ret = 0; | ||
102 | |||
103 | switch (cmd) { | ||
104 | case WDIOC_GETSUPPORT: | ||
105 | ret = copy_to_user(data, &mpc5200_wdt_info, | ||
106 | sizeof(mpc5200_wdt_info)); | ||
107 | if (ret) | ||
108 | ret = -EFAULT; | ||
109 | break; | ||
110 | |||
111 | case WDIOC_GETSTATUS: | ||
112 | case WDIOC_GETBOOTSTATUS: | ||
113 | ret = put_user(0, data); | ||
114 | break; | ||
115 | |||
116 | case WDIOC_KEEPALIVE: | ||
117 | mpc5200_wdt_ping(wdt); | ||
118 | break; | ||
119 | |||
120 | case WDIOC_SETTIMEOUT: | ||
121 | ret = get_user(timeout, data); | ||
122 | if (ret) | ||
123 | break; | ||
124 | mpc5200_wdt_set_timeout(wdt, timeout); | ||
125 | mpc5200_wdt_start(wdt); | ||
126 | /* fall through and return the timeout */ | ||
127 | |||
128 | case WDIOC_GETTIMEOUT: | ||
129 | timeout = mpc5200_wdt_get_timeout(wdt); | ||
130 | ret = put_user(timeout, data); | ||
131 | break; | ||
132 | |||
133 | default: | ||
134 | ret = -ENOTTY; | ||
135 | } | ||
136 | return ret; | ||
137 | } | ||
138 | static int mpc5200_wdt_open(struct inode *inode, struct file *file) | ||
139 | { | ||
140 | /* /dev/watchdog can only be opened once */ | ||
141 | if (test_and_set_bit(0, &is_active)) | ||
142 | return -EBUSY; | ||
143 | |||
144 | /* Set and activate the watchdog */ | ||
145 | mpc5200_wdt_set_timeout(wdt_global, 30); | ||
146 | mpc5200_wdt_start(wdt_global); | ||
147 | file->private_data = wdt_global; | ||
148 | return nonseekable_open(inode, file); | ||
149 | } | ||
150 | static int mpc5200_wdt_release(struct inode *inode, struct file *file) | ||
151 | { | ||
152 | #if WATCHDOG_NOWAYOUT == 0 | ||
153 | struct mpc5200_wdt *wdt = file->private_data; | ||
154 | mpc5200_wdt_stop(wdt); | ||
155 | wdt->count = 0; /* == disabled */ | ||
156 | #endif | ||
157 | clear_bit(0, &is_active); | ||
158 | return 0; | ||
159 | } | ||
160 | |||
161 | static struct file_operations mpc5200_wdt_fops = { | ||
162 | .owner = THIS_MODULE, | ||
163 | .write = mpc5200_wdt_write, | ||
164 | .ioctl = mpc5200_wdt_ioctl, | ||
165 | .open = mpc5200_wdt_open, | ||
166 | .release = mpc5200_wdt_release, | ||
167 | }; | ||
168 | |||
169 | /* module operations */ | ||
170 | static int mpc5200_wdt_probe(struct of_device *op, const struct of_device_id *match) | ||
171 | { | ||
172 | struct mpc5200_wdt *wdt; | ||
173 | int err; | ||
174 | const void *has_wdt; | ||
175 | int size; | ||
176 | |||
177 | has_wdt = of_get_property(op->node, "has-wdt", NULL); | ||
178 | if (!has_wdt) | ||
179 | return -ENODEV; | ||
180 | |||
181 | wdt = kzalloc(sizeof(*wdt), GFP_KERNEL); | ||
182 | if (!wdt) | ||
183 | return -ENOMEM; | ||
184 | |||
185 | wdt->ipb_freq = mpc52xx_find_ipb_freq(op->node); | ||
186 | |||
187 | err = of_address_to_resource(op->node, 0, &wdt->mem); | ||
188 | if (err) | ||
189 | goto out_free; | ||
190 | size = wdt->mem.end - wdt->mem.start + 1; | ||
191 | if (!request_mem_region(wdt->mem.start, size, "mpc5200_wdt")) { | ||
192 | err = -ENODEV; | ||
193 | goto out_free; | ||
194 | } | ||
195 | wdt->regs = ioremap(wdt->mem.start, size); | ||
196 | if (!wdt->regs) { | ||
197 | err = -ENODEV; | ||
198 | goto out_release; | ||
199 | } | ||
200 | |||
201 | dev_set_drvdata(&op->dev, wdt); | ||
202 | spin_lock_init(&wdt->io_lock); | ||
203 | |||
204 | wdt->miscdev = (struct miscdevice) { | ||
205 | .minor = WATCHDOG_MINOR, | ||
206 | .name = "watchdog", | ||
207 | .fops = &mpc5200_wdt_fops, | ||
208 | .parent = &op->dev, | ||
209 | }; | ||
210 | wdt_global = wdt; | ||
211 | err = misc_register(&wdt->miscdev); | ||
212 | if (!err) | ||
213 | return 0; | ||
214 | |||
215 | iounmap(wdt->regs); | ||
216 | out_release: | ||
217 | release_mem_region(wdt->mem.start, size); | ||
218 | out_free: | ||
219 | kfree(wdt); | ||
220 | return err; | ||
221 | } | ||
222 | |||
223 | static int mpc5200_wdt_remove(struct of_device *op) | ||
224 | { | ||
225 | struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev); | ||
226 | |||
227 | mpc5200_wdt_stop(wdt); | ||
228 | misc_deregister(&wdt->miscdev); | ||
229 | iounmap(wdt->regs); | ||
230 | release_mem_region(wdt->mem.start, wdt->mem.end - wdt->mem.start + 1); | ||
231 | kfree(wdt); | ||
232 | |||
233 | return 0; | ||
234 | } | ||
235 | static int mpc5200_wdt_suspend(struct of_device *op, pm_message_t state) | ||
236 | { | ||
237 | struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev); | ||
238 | mpc5200_wdt_stop(wdt); | ||
239 | return 0; | ||
240 | } | ||
241 | static int mpc5200_wdt_resume(struct of_device *op) | ||
242 | { | ||
243 | struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev); | ||
244 | if (wdt->count) | ||
245 | mpc5200_wdt_start(wdt); | ||
246 | return 0; | ||
247 | } | ||
248 | static int mpc5200_wdt_shutdown(struct of_device *op) | ||
249 | { | ||
250 | struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev); | ||
251 | mpc5200_wdt_stop(wdt); | ||
252 | return 0; | ||
253 | } | ||
254 | |||
255 | static struct of_device_id mpc5200_wdt_match[] = { | ||
256 | { .compatible = "mpc5200-gpt", }, | ||
257 | {}, | ||
258 | }; | ||
259 | static struct of_platform_driver mpc5200_wdt_driver = { | ||
260 | .owner = THIS_MODULE, | ||
261 | .name = "mpc5200-gpt-wdt", | ||
262 | .match_table = mpc5200_wdt_match, | ||
263 | .probe = mpc5200_wdt_probe, | ||
264 | .remove = mpc5200_wdt_remove, | ||
265 | .suspend = mpc5200_wdt_suspend, | ||
266 | .resume = mpc5200_wdt_resume, | ||
267 | .shutdown = mpc5200_wdt_shutdown, | ||
268 | }; | ||
269 | |||
270 | |||
271 | static int __init mpc5200_wdt_init(void) | ||
272 | { | ||
273 | return of_register_platform_driver(&mpc5200_wdt_driver); | ||
274 | } | ||
275 | |||
276 | static void __exit mpc5200_wdt_exit(void) | ||
277 | { | ||
278 | of_unregister_platform_driver(&mpc5200_wdt_driver); | ||
279 | } | ||
280 | |||
281 | module_init(mpc5200_wdt_init); | ||
282 | module_exit(mpc5200_wdt_exit); | ||
283 | |||
284 | MODULE_AUTHOR("Domen Puncer <domen.puncer@telargo.com>"); | ||
285 | MODULE_LICENSE("Dual BSD/GPL"); | ||
286 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||