blob: 77c1c2ae2cc2499f91928c6b3d69ddf34663f71b [file] [log] [blame]
Domen Puncer8cf18972007-06-18 08:17:57 +02001#include <linux/init.h>
2#include <linux/module.h>
3#include <linux/miscdevice.h>
4#include <linux/watchdog.h>
5#include <linux/io.h>
Wim Van Sebroeckde812252007-07-20 21:22:58 +00006#include <linux/spinlock.h>
Stephen Rothwell75195da2008-05-23 16:42:56 +10007#include <linux/of_platform.h>
Domen Puncer8cf18972007-06-18 08:17:57 +02008#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
17struct 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;
Wim Van Sebroeckde812252007-07-20 21:22:58 +000023 spinlock_t io_lock;
Domen Puncer8cf18972007-06-18 08:17:57 +020024};
25
Wim Van Sebroeckde812252007-07-20 21:22:58 +000026/* is_active stores wether or not the /dev/watchdog device is opened */
27static unsigned long is_active;
Domen Puncer8cf18972007-06-18 08:17:57 +020028
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 */
32static struct mpc5200_wdt *wdt_global;
33
34
35/* helper to calculate timeout in timer counts */
36static 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) */
45static int mpc5200_wdt_get_timeout(struct mpc5200_wdt *wdt)
46{
47 return wdt->count * 0x10000 / wdt->ipb_freq;
48}
49
50
51/* watchdog operations */
52static int mpc5200_wdt_start(struct mpc5200_wdt *wdt)
53{
Wim Van Sebroeckde812252007-07-20 21:22:58 +000054 spin_lock(&wdt->io_lock);
Domen Puncer8cf18972007-06-18 08:17:57 +020055 /* 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);
Wim Van Sebroeckde812252007-07-20 21:22:58 +000061 spin_unlock(&wdt->io_lock);
Domen Puncer8cf18972007-06-18 08:17:57 +020062
63 return 0;
64}
65static int mpc5200_wdt_ping(struct mpc5200_wdt *wdt)
66{
Wim Van Sebroeckde812252007-07-20 21:22:58 +000067 spin_lock(&wdt->io_lock);
Domen Puncer8cf18972007-06-18 08:17:57 +020068 /* writing A5 to OCPW resets the watchdog */
69 out_be32(&wdt->regs->mode, 0xA5000000 | (0xffffff & in_be32(&wdt->regs->mode)));
Wim Van Sebroeckde812252007-07-20 21:22:58 +000070 spin_unlock(&wdt->io_lock);
Domen Puncer8cf18972007-06-18 08:17:57 +020071 return 0;
72}
73static int mpc5200_wdt_stop(struct mpc5200_wdt *wdt)
74{
Wim Van Sebroeckde812252007-07-20 21:22:58 +000075 spin_lock(&wdt->io_lock);
76 /* disable */
Domen Puncer8cf18972007-06-18 08:17:57 +020077 out_be32(&wdt->regs->mode, 0);
Wim Van Sebroeckde812252007-07-20 21:22:58 +000078 spin_unlock(&wdt->io_lock);
Domen Puncer8cf18972007-06-18 08:17:57 +020079 return 0;
80}
81
82
83/* file operations */
Al Viroa39f9d02007-10-14 19:34:20 +010084static ssize_t mpc5200_wdt_write(struct file *file, const char __user *data,
Domen Puncer8cf18972007-06-18 08:17:57 +020085 size_t len, loff_t *ppos)
86{
87 struct mpc5200_wdt *wdt = file->private_data;
88 mpc5200_wdt_ping(wdt);
89 return 0;
90}
91static struct watchdog_info mpc5200_wdt_info = {
92 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
93 .identity = "mpc5200 watchdog on GPT0",
94};
95static 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:
Wim Van Sebroeckde812252007-07-20 21:22:58 +0000105 ret = copy_to_user(data, &mpc5200_wdt_info,
106 sizeof(mpc5200_wdt_info));
Domen Puncer8cf18972007-06-18 08:17:57 +0200107 if (ret)
108 ret = -EFAULT;
109 break;
110
Wim Van Sebroeckde812252007-07-20 21:22:58 +0000111 case WDIOC_GETSTATUS:
112 case WDIOC_GETBOOTSTATUS:
113 ret = put_user(0, data);
114 break;
115
Domen Puncer8cf18972007-06-18 08:17:57 +0200116 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;
Wim Van Sebroeckde812252007-07-20 21:22:58 +0000132
133 default:
134 ret = -ENOTTY;
Domen Puncer8cf18972007-06-18 08:17:57 +0200135 }
136 return ret;
137}
138static int mpc5200_wdt_open(struct inode *inode, struct file *file)
139{
Wim Van Sebroeckde812252007-07-20 21:22:58 +0000140 /* /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 */
Domen Puncer8cf18972007-06-18 08:17:57 +0200145 mpc5200_wdt_set_timeout(wdt_global, 30);
146 mpc5200_wdt_start(wdt_global);
147 file->private_data = wdt_global;
Wim Van Sebroeckde812252007-07-20 21:22:58 +0000148 return nonseekable_open(inode, file);
Domen Puncer8cf18972007-06-18 08:17:57 +0200149}
150static 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
Wim Van Sebroeckde812252007-07-20 21:22:58 +0000157 clear_bit(0, &is_active);
Domen Puncer8cf18972007-06-18 08:17:57 +0200158 return 0;
159}
160
Jan Engelhardtb47a1662008-01-22 20:48:10 +0100161static const struct file_operations mpc5200_wdt_fops = {
Domen Puncer8cf18972007-06-18 08:17:57 +0200162 .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 */
170static 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)
Marian Balakowiczd24bc312007-10-19 04:44:24 +1000179 has_wdt = of_get_property(op->node, "fsl,has-wdt", NULL);
180 if (!has_wdt)
Domen Puncer8cf18972007-06-18 08:17:57 +0200181 return -ENODEV;
182
183 wdt = kzalloc(sizeof(*wdt), GFP_KERNEL);
184 if (!wdt)
185 return -ENOMEM;
186
187 wdt->ipb_freq = mpc52xx_find_ipb_freq(op->node);
188
189 err = of_address_to_resource(op->node, 0, &wdt->mem);
190 if (err)
191 goto out_free;
192 size = wdt->mem.end - wdt->mem.start + 1;
193 if (!request_mem_region(wdt->mem.start, size, "mpc5200_wdt")) {
194 err = -ENODEV;
195 goto out_free;
196 }
197 wdt->regs = ioremap(wdt->mem.start, size);
198 if (!wdt->regs) {
199 err = -ENODEV;
200 goto out_release;
201 }
202
203 dev_set_drvdata(&op->dev, wdt);
Wim Van Sebroeckde812252007-07-20 21:22:58 +0000204 spin_lock_init(&wdt->io_lock);
Domen Puncer8cf18972007-06-18 08:17:57 +0200205
206 wdt->miscdev = (struct miscdevice) {
207 .minor = WATCHDOG_MINOR,
208 .name = "watchdog",
209 .fops = &mpc5200_wdt_fops,
210 .parent = &op->dev,
211 };
212 wdt_global = wdt;
213 err = misc_register(&wdt->miscdev);
214 if (!err)
215 return 0;
216
217 iounmap(wdt->regs);
218 out_release:
219 release_mem_region(wdt->mem.start, size);
220 out_free:
221 kfree(wdt);
222 return err;
223}
224
225static int mpc5200_wdt_remove(struct of_device *op)
226{
227 struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
228
229 mpc5200_wdt_stop(wdt);
230 misc_deregister(&wdt->miscdev);
231 iounmap(wdt->regs);
232 release_mem_region(wdt->mem.start, wdt->mem.end - wdt->mem.start + 1);
233 kfree(wdt);
234
235 return 0;
236}
237static int mpc5200_wdt_suspend(struct of_device *op, pm_message_t state)
238{
239 struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
240 mpc5200_wdt_stop(wdt);
241 return 0;
242}
243static int mpc5200_wdt_resume(struct of_device *op)
244{
245 struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
246 if (wdt->count)
247 mpc5200_wdt_start(wdt);
248 return 0;
249}
250static int mpc5200_wdt_shutdown(struct of_device *op)
251{
252 struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
253 mpc5200_wdt_stop(wdt);
254 return 0;
255}
256
257static struct of_device_id mpc5200_wdt_match[] = {
258 { .compatible = "mpc5200-gpt", },
Marian Balakowiczd24bc312007-10-19 04:44:24 +1000259 { .compatible = "fsl,mpc5200-gpt", },
Domen Puncer8cf18972007-06-18 08:17:57 +0200260 {},
261};
262static struct of_platform_driver mpc5200_wdt_driver = {
263 .owner = THIS_MODULE,
264 .name = "mpc5200-gpt-wdt",
265 .match_table = mpc5200_wdt_match,
266 .probe = mpc5200_wdt_probe,
267 .remove = mpc5200_wdt_remove,
268 .suspend = mpc5200_wdt_suspend,
269 .resume = mpc5200_wdt_resume,
270 .shutdown = mpc5200_wdt_shutdown,
271};
272
273
274static int __init mpc5200_wdt_init(void)
275{
276 return of_register_platform_driver(&mpc5200_wdt_driver);
277}
278
279static void __exit mpc5200_wdt_exit(void)
280{
281 of_unregister_platform_driver(&mpc5200_wdt_driver);
282}
283
284module_init(mpc5200_wdt_init);
285module_exit(mpc5200_wdt_exit);
286
287MODULE_AUTHOR("Domen Puncer <domen.puncer@telargo.com>");
288MODULE_LICENSE("Dual BSD/GPL");
Wim Van Sebroeckde812252007-07-20 21:22:58 +0000289MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);