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1 | /* |
2 | * PPS core file | |
3 | * | |
4 | * | |
5 | * Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
20 | */ | |
21 | ||
22 | ||
23 | #include <linux/kernel.h> | |
24 | #include <linux/module.h> | |
25 | #include <linux/init.h> | |
26 | #include <linux/sched.h> | |
27 | #include <linux/uaccess.h> | |
28 | #include <linux/idr.h> | |
29 | #include <linux/cdev.h> | |
30 | #include <linux/poll.h> | |
31 | #include <linux/pps_kernel.h> | |
32 | ||
33 | /* | |
34 | * Local variables | |
35 | */ | |
36 | ||
37 | static dev_t pps_devt; | |
38 | static struct class *pps_class; | |
39 | ||
40 | /* | |
41 | * Char device methods | |
42 | */ | |
43 | ||
44 | static unsigned int pps_cdev_poll(struct file *file, poll_table *wait) | |
45 | { | |
46 | struct pps_device *pps = file->private_data; | |
47 | ||
48 | poll_wait(file, &pps->queue, wait); | |
49 | ||
50 | return POLLIN | POLLRDNORM; | |
51 | } | |
52 | ||
53 | static int pps_cdev_fasync(int fd, struct file *file, int on) | |
54 | { | |
55 | struct pps_device *pps = file->private_data; | |
56 | return fasync_helper(fd, file, on, &pps->async_queue); | |
57 | } | |
58 | ||
59 | static long pps_cdev_ioctl(struct file *file, | |
60 | unsigned int cmd, unsigned long arg) | |
61 | { | |
62 | struct pps_device *pps = file->private_data; | |
63 | struct pps_kparams params; | |
64 | struct pps_fdata fdata; | |
65 | unsigned long ticks; | |
66 | void __user *uarg = (void __user *) arg; | |
67 | int __user *iuarg = (int __user *) arg; | |
68 | int err; | |
69 | ||
70 | switch (cmd) { | |
71 | case PPS_GETPARAMS: | |
72 | pr_debug("PPS_GETPARAMS: source %d\n", pps->id); | |
73 | ||
74 | /* Return current parameters */ | |
75 | err = copy_to_user(uarg, &pps->params, | |
76 | sizeof(struct pps_kparams)); | |
77 | if (err) | |
78 | return -EFAULT; | |
79 | ||
80 | break; | |
81 | ||
82 | case PPS_SETPARAMS: | |
83 | pr_debug("PPS_SETPARAMS: source %d\n", pps->id); | |
84 | ||
85 | /* Check the capabilities */ | |
86 | if (!capable(CAP_SYS_TIME)) | |
87 | return -EPERM; | |
88 | ||
89 | err = copy_from_user(¶ms, uarg, sizeof(struct pps_kparams)); | |
90 | if (err) | |
91 | return -EFAULT; | |
92 | if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) { | |
93 | pr_debug("capture mode unspecified (%x)\n", | |
94 | params.mode); | |
95 | return -EINVAL; | |
96 | } | |
97 | ||
98 | /* Check for supported capabilities */ | |
99 | if ((params.mode & ~pps->info.mode) != 0) { | |
100 | pr_debug("unsupported capabilities (%x)\n", | |
101 | params.mode); | |
102 | return -EINVAL; | |
103 | } | |
104 | ||
105 | spin_lock_irq(&pps->lock); | |
106 | ||
107 | /* Save the new parameters */ | |
108 | pps->params = params; | |
109 | ||
110 | /* Restore the read only parameters */ | |
111 | if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) { | |
112 | /* section 3.3 of RFC 2783 interpreted */ | |
113 | pr_debug("time format unspecified (%x)\n", | |
114 | params.mode); | |
115 | pps->params.mode |= PPS_TSFMT_TSPEC; | |
116 | } | |
117 | if (pps->info.mode & PPS_CANWAIT) | |
118 | pps->params.mode |= PPS_CANWAIT; | |
119 | pps->params.api_version = PPS_API_VERS; | |
120 | ||
121 | spin_unlock_irq(&pps->lock); | |
122 | ||
123 | break; | |
124 | ||
125 | case PPS_GETCAP: | |
126 | pr_debug("PPS_GETCAP: source %d\n", pps->id); | |
127 | ||
128 | err = put_user(pps->info.mode, iuarg); | |
129 | if (err) | |
130 | return -EFAULT; | |
131 | ||
132 | break; | |
133 | ||
134 | case PPS_FETCH: | |
135 | pr_debug("PPS_FETCH: source %d\n", pps->id); | |
136 | ||
137 | err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata)); | |
138 | if (err) | |
139 | return -EFAULT; | |
140 | ||
141 | pps->go = 0; | |
142 | ||
143 | /* Manage the timeout */ | |
144 | if (fdata.timeout.flags & PPS_TIME_INVALID) | |
145 | err = wait_event_interruptible(pps->queue, pps->go); | |
146 | else { | |
147 | pr_debug("timeout %lld.%09d\n", | |
148 | (long long) fdata.timeout.sec, | |
149 | fdata.timeout.nsec); | |
150 | ticks = fdata.timeout.sec * HZ; | |
151 | ticks += fdata.timeout.nsec / (NSEC_PER_SEC / HZ); | |
152 | ||
153 | if (ticks != 0) { | |
154 | err = wait_event_interruptible_timeout( | |
155 | pps->queue, pps->go, ticks); | |
156 | if (err == 0) | |
157 | return -ETIMEDOUT; | |
158 | } | |
159 | } | |
160 | ||
161 | /* Check for pending signals */ | |
162 | if (err == -ERESTARTSYS) { | |
163 | pr_debug("pending signal caught\n"); | |
164 | return -EINTR; | |
165 | } | |
166 | ||
167 | /* Return the fetched timestamp */ | |
168 | spin_lock_irq(&pps->lock); | |
169 | ||
170 | fdata.info.assert_sequence = pps->assert_sequence; | |
171 | fdata.info.clear_sequence = pps->clear_sequence; | |
172 | fdata.info.assert_tu = pps->assert_tu; | |
173 | fdata.info.clear_tu = pps->clear_tu; | |
174 | fdata.info.current_mode = pps->current_mode; | |
175 | ||
176 | spin_unlock_irq(&pps->lock); | |
177 | ||
178 | err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata)); | |
179 | if (err) | |
180 | return -EFAULT; | |
181 | ||
182 | break; | |
183 | ||
184 | default: | |
185 | return -ENOTTY; | |
186 | break; | |
187 | } | |
188 | ||
189 | return 0; | |
190 | } | |
191 | ||
192 | static int pps_cdev_open(struct inode *inode, struct file *file) | |
193 | { | |
194 | struct pps_device *pps = container_of(inode->i_cdev, | |
195 | struct pps_device, cdev); | |
196 | int found; | |
197 | ||
198 | found = pps_get_source(pps->id) != 0; | |
199 | if (!found) | |
200 | return -ENODEV; | |
201 | ||
202 | file->private_data = pps; | |
203 | ||
204 | return 0; | |
205 | } | |
206 | ||
207 | static int pps_cdev_release(struct inode *inode, struct file *file) | |
208 | { | |
209 | struct pps_device *pps = file->private_data; | |
210 | ||
211 | /* Free the PPS source and wake up (possible) deregistration */ | |
212 | pps_put_source(pps); | |
213 | ||
214 | return 0; | |
215 | } | |
216 | ||
217 | /* | |
218 | * Char device stuff | |
219 | */ | |
220 | ||
221 | static const struct file_operations pps_cdev_fops = { | |
222 | .owner = THIS_MODULE, | |
223 | .llseek = no_llseek, | |
224 | .poll = pps_cdev_poll, | |
225 | .fasync = pps_cdev_fasync, | |
226 | .unlocked_ioctl = pps_cdev_ioctl, | |
227 | .open = pps_cdev_open, | |
228 | .release = pps_cdev_release, | |
229 | }; | |
230 | ||
231 | int pps_register_cdev(struct pps_device *pps) | |
232 | { | |
233 | int err; | |
234 | ||
235 | pps->devno = MKDEV(MAJOR(pps_devt), pps->id); | |
236 | cdev_init(&pps->cdev, &pps_cdev_fops); | |
237 | pps->cdev.owner = pps->info.owner; | |
238 | ||
239 | err = cdev_add(&pps->cdev, pps->devno, 1); | |
240 | if (err) { | |
241 | printk(KERN_ERR "pps: %s: failed to add char device %d:%d\n", | |
242 | pps->info.name, MAJOR(pps_devt), pps->id); | |
243 | return err; | |
244 | } | |
245 | pps->dev = device_create(pps_class, pps->info.dev, pps->devno, NULL, | |
246 | "pps%d", pps->id); | |
054b2b13 | 247 | if (IS_ERR(pps->dev)) |
eae9d2ba RG |
248 | goto del_cdev; |
249 | dev_set_drvdata(pps->dev, pps); | |
250 | ||
251 | pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, | |
252 | MAJOR(pps_devt), pps->id); | |
253 | ||
254 | return 0; | |
255 | ||
256 | del_cdev: | |
257 | cdev_del(&pps->cdev); | |
258 | ||
259 | return err; | |
260 | } | |
261 | ||
262 | void pps_unregister_cdev(struct pps_device *pps) | |
263 | { | |
264 | device_destroy(pps_class, pps->devno); | |
265 | cdev_del(&pps->cdev); | |
266 | } | |
267 | ||
268 | /* | |
269 | * Module stuff | |
270 | */ | |
271 | ||
272 | static void __exit pps_exit(void) | |
273 | { | |
274 | class_destroy(pps_class); | |
275 | unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES); | |
276 | } | |
277 | ||
278 | static int __init pps_init(void) | |
279 | { | |
280 | int err; | |
281 | ||
282 | pps_class = class_create(THIS_MODULE, "pps"); | |
283 | if (!pps_class) { | |
284 | printk(KERN_ERR "pps: failed to allocate class\n"); | |
285 | return -ENOMEM; | |
286 | } | |
287 | pps_class->dev_attrs = pps_attrs; | |
288 | ||
289 | err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps"); | |
290 | if (err < 0) { | |
291 | printk(KERN_ERR "pps: failed to allocate char device region\n"); | |
292 | goto remove_class; | |
293 | } | |
294 | ||
295 | pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS); | |
296 | pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti " | |
297 | "<giometti@linux.it>\n", PPS_VERSION); | |
298 | ||
299 | return 0; | |
300 | ||
301 | remove_class: | |
302 | class_destroy(pps_class); | |
303 | ||
304 | return err; | |
305 | } | |
306 | ||
307 | subsys_initcall(pps_init); | |
308 | module_exit(pps_exit); | |
309 | ||
310 | MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); | |
311 | MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION); | |
312 | MODULE_LICENSE("GPL"); |