5 * Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it>
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.
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.
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.
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>
37 static dev_t pps_devt;
38 static struct class *pps_class;
44 static unsigned int pps_cdev_poll(struct file *file, poll_table *wait)
46 struct pps_device *pps = file->private_data;
48 poll_wait(file, &pps->queue, wait);
50 return POLLIN | POLLRDNORM;
53 static int pps_cdev_fasync(int fd, struct file *file, int on)
55 struct pps_device *pps = file->private_data;
56 return fasync_helper(fd, file, on, &pps->async_queue);
59 static long pps_cdev_ioctl(struct file *file,
60 unsigned int cmd, unsigned long arg)
62 struct pps_device *pps = file->private_data;
63 struct pps_kparams params;
64 struct pps_fdata fdata;
66 void __user *uarg = (void __user *) arg;
67 int __user *iuarg = (int __user *) arg;
72 pr_debug("PPS_GETPARAMS: source %d\n", pps->id);
74 /* Return current parameters */
75 err = copy_to_user(uarg, &pps->params,
76 sizeof(struct pps_kparams));
83 pr_debug("PPS_SETPARAMS: source %d\n", pps->id);
85 /* Check the capabilities */
86 if (!capable(CAP_SYS_TIME))
89 err = copy_from_user(¶ms, uarg, sizeof(struct pps_kparams));
92 if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) {
93 pr_debug("capture mode unspecified (%x)\n",
98 /* Check for supported capabilities */
99 if ((params.mode & ~pps->info.mode) != 0) {
100 pr_debug("unsupported capabilities (%x)\n",
105 spin_lock_irq(&pps->lock);
107 /* Save the new parameters */
108 pps->params = params;
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",
115 pps->params.mode |= PPS_TSFMT_TSPEC;
117 if (pps->info.mode & PPS_CANWAIT)
118 pps->params.mode |= PPS_CANWAIT;
119 pps->params.api_version = PPS_API_VERS;
121 spin_unlock_irq(&pps->lock);
126 pr_debug("PPS_GETCAP: source %d\n", pps->id);
128 err = put_user(pps->info.mode, iuarg);
135 pr_debug("PPS_FETCH: source %d\n", pps->id);
137 err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata));
143 /* Manage the timeout */
144 if (fdata.timeout.flags & PPS_TIME_INVALID)
145 err = wait_event_interruptible(pps->queue, pps->go);
147 pr_debug("timeout %lld.%09d\n",
148 (long long) fdata.timeout.sec,
150 ticks = fdata.timeout.sec * HZ;
151 ticks += fdata.timeout.nsec / (NSEC_PER_SEC / HZ);
154 err = wait_event_interruptible_timeout(
155 pps->queue, pps->go, ticks);
161 /* Check for pending signals */
162 if (err == -ERESTARTSYS) {
163 pr_debug("pending signal caught\n");
167 /* Return the fetched timestamp */
168 spin_lock_irq(&pps->lock);
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;
176 spin_unlock_irq(&pps->lock);
178 err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata));
192 static int pps_cdev_open(struct inode *inode, struct file *file)
194 struct pps_device *pps = container_of(inode->i_cdev,
195 struct pps_device, cdev);
198 found = pps_get_source(pps->id) != 0;
202 file->private_data = pps;
207 static int pps_cdev_release(struct inode *inode, struct file *file)
209 struct pps_device *pps = file->private_data;
211 /* Free the PPS source and wake up (possible) deregistration */
221 static const struct file_operations pps_cdev_fops = {
222 .owner = THIS_MODULE,
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,
231 int pps_register_cdev(struct pps_device *pps)
235 pps->devno = MKDEV(MAJOR(pps_devt), pps->id);
236 cdev_init(&pps->cdev, &pps_cdev_fops);
237 pps->cdev.owner = pps->info.owner;
239 err = cdev_add(&pps->cdev, pps->devno, 1);
241 printk(KERN_ERR "pps: %s: failed to add char device %d:%d\n",
242 pps->info.name, MAJOR(pps_devt), pps->id);
245 pps->dev = device_create(pps_class, pps->info.dev, pps->devno, NULL,
249 dev_set_drvdata(pps->dev, pps);
251 pr_debug("source %s got cdev (%d:%d)\n", pps->info.name,
252 MAJOR(pps_devt), pps->id);
257 cdev_del(&pps->cdev);
262 void pps_unregister_cdev(struct pps_device *pps)
264 device_destroy(pps_class, pps->devno);
265 cdev_del(&pps->cdev);
272 static void __exit pps_exit(void)
274 class_destroy(pps_class);
275 unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES);
278 static int __init pps_init(void)
282 pps_class = class_create(THIS_MODULE, "pps");
284 printk(KERN_ERR "pps: failed to allocate class\n");
287 pps_class->dev_attrs = pps_attrs;
289 err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps");
291 printk(KERN_ERR "pps: failed to allocate char device region\n");
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);
302 class_destroy(pps_class);
307 subsys_initcall(pps_init);
308 module_exit(pps_exit);
310 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
311 MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION);
312 MODULE_LICENSE("GPL");