[deliverable/linux.git] / drivers / pps / pps.c

/*
 * PPS core file
 *
 *
 * Copyright (C) 2005-2009   Rodolfo Giometti <giometti@linux.it>
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */


#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
#include <linux/idr.h>
#include <linux/cdev.h>
#include <linux/poll.h>
#include <linux/pps_kernel.h>

/*
 * Local variables
 */

static dev_t pps_devt;
static struct class *pps_class;

/*
 * Char device methods
 */

static unsigned int pps_cdev_poll(struct file *file, poll_table *wait)
{
	struct pps_device *pps = file->private_data;

	poll_wait(file, &pps->queue, wait);

	return POLLIN | POLLRDNORM;
}

static int pps_cdev_fasync(int fd, struct file *file, int on)
{
	struct pps_device *pps = file->private_data;
	return fasync_helper(fd, file, on, &pps->async_queue);
}

static long pps_cdev_ioctl(struct file *file,
		unsigned int cmd, unsigned long arg)
{
	struct pps_device *pps = file->private_data;
	struct pps_kparams params;
	void __user *uarg = (void __user *) arg;
	int __user *iuarg = (int __user *) arg;
	int err;

	switch (cmd) {
	case PPS_GETPARAMS:
		pr_debug("PPS_GETPARAMS: source %d\n", pps->id);

		spin_lock_irq(&pps->lock);

		/* Get the current parameters */
		params = pps->params;

		spin_unlock_irq(&pps->lock);

		err = copy_to_user(uarg, &params, sizeof(struct pps_kparams));
		if (err)
			return -EFAULT;

		break;

	case PPS_SETPARAMS:
		pr_debug("PPS_SETPARAMS: source %d\n", pps->id);

		/* Check the capabilities */
		if (!capable(CAP_SYS_TIME))
			return -EPERM;

		err = copy_from_user(&params, uarg, sizeof(struct pps_kparams));
		if (err)
			return -EFAULT;
		if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) {
			pr_debug("capture mode unspecified (%x)\n",
								params.mode);
			return -EINVAL;
		}

		/* Check for supported capabilities */
		if ((params.mode & ~pps->info.mode) != 0) {
			pr_debug("unsupported capabilities (%x)\n",
								params.mode);
			return -EINVAL;
		}

		spin_lock_irq(&pps->lock);

		/* Save the new parameters */
		pps->params = params;

		/* Restore the read only parameters */
		if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
			/* section 3.3 of RFC 2783 interpreted */
			pr_debug("time format unspecified (%x)\n",
								params.mode);
			pps->params.mode |= PPS_TSFMT_TSPEC;
		}
		if (pps->info.mode & PPS_CANWAIT)
			pps->params.mode |= PPS_CANWAIT;
		pps->params.api_version = PPS_API_VERS;

		spin_unlock_irq(&pps->lock);

		break;

	case PPS_GETCAP:
		pr_debug("PPS_GETCAP: source %d\n", pps->id);

		err = put_user(pps->info.mode, iuarg);
		if (err)
			return -EFAULT;

		break;

	case PPS_FETCH: {
		struct pps_fdata fdata;

		pr_debug("PPS_FETCH: source %d\n", pps->id);

		err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata));
		if (err)
			return -EFAULT;

		pps->go = 0;

		/* Manage the timeout */
		if (fdata.timeout.flags & PPS_TIME_INVALID)
			err = wait_event_interruptible(pps->queue, pps->go);
		else {
			unsigned long ticks;

			pr_debug("timeout %lld.%09d\n",
					(long long) fdata.timeout.sec,
					fdata.timeout.nsec);
			ticks = fdata.timeout.sec * HZ;
			ticks += fdata.timeout.nsec / (NSEC_PER_SEC / HZ);

			if (ticks != 0) {
				err = wait_event_interruptible_timeout(
						pps->queue, pps->go, ticks);
				if (err == 0)
					return -ETIMEDOUT;
			}
		}

		/* Check for pending signals */
		if (err == -ERESTARTSYS) {
			pr_debug("pending signal caught\n");
			return -EINTR;
		}

		/* Return the fetched timestamp */
		spin_lock_irq(&pps->lock);

		fdata.info.assert_sequence = pps->assert_sequence;
		fdata.info.clear_sequence = pps->clear_sequence;
		fdata.info.assert_tu = pps->assert_tu;
		fdata.info.clear_tu = pps->clear_tu;
		fdata.info.current_mode = pps->current_mode;

		spin_unlock_irq(&pps->lock);

		err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata));
		if (err)
			return -EFAULT;

		break;
	}
	default:
		return -ENOTTY;
		break;
	}

	return 0;
}

static int pps_cdev_open(struct inode *inode, struct file *file)
{
	struct pps_device *pps = container_of(inode->i_cdev,
						struct pps_device, cdev);
	int found;

	found = pps_get_source(pps->id) != 0;
	if (!found)
		return -ENODEV;

	file->private_data = pps;

	return 0;
}

static int pps_cdev_release(struct inode *inode, struct file *file)
{
	struct pps_device *pps = file->private_data;

	/* Free the PPS source and wake up (possible) deregistration */
	pps_put_source(pps);

	return 0;
}

/*
 * Char device stuff
 */

static const struct file_operations pps_cdev_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.poll		= pps_cdev_poll,
	.fasync		= pps_cdev_fasync,
	.unlocked_ioctl	= pps_cdev_ioctl,
	.open		= pps_cdev_open,
	.release	= pps_cdev_release,
};

int pps_register_cdev(struct pps_device *pps)
{
	int err;

	pps->devno = MKDEV(MAJOR(pps_devt), pps->id);
	cdev_init(&pps->cdev, &pps_cdev_fops);
	pps->cdev.owner = pps->info.owner;

	err = cdev_add(&pps->cdev, pps->devno, 1);
	if (err) {
		printk(KERN_ERR "pps: %s: failed to add char device %d:%d\n",
				pps->info.name, MAJOR(pps_devt), pps->id);
		return err;
	}
	pps->dev = device_create(pps_class, pps->info.dev, pps->devno, NULL,
							"pps%d", pps->id);
	if (IS_ERR(pps->dev))
		goto del_cdev;
	dev_set_drvdata(pps->dev, pps);

	pr_debug("source %s got cdev (%d:%d)\n", pps->info.name,
			MAJOR(pps_devt), pps->id);

	return 0;

del_cdev:
	cdev_del(&pps->cdev);

	return err;
}

void pps_unregister_cdev(struct pps_device *pps)
{
	device_destroy(pps_class, pps->devno);
	cdev_del(&pps->cdev);
}

/*
 * Module stuff
 */

static void __exit pps_exit(void)
{
	class_destroy(pps_class);
	unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES);
}

static int __init pps_init(void)
{
	int err;

	pps_class = class_create(THIS_MODULE, "pps");
	if (!pps_class) {
		printk(KERN_ERR "pps: failed to allocate class\n");
		return -ENOMEM;
	}
	pps_class->dev_attrs = pps_attrs;

	err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps");
	if (err < 0) {
		printk(KERN_ERR "pps: failed to allocate char device region\n");
		goto remove_class;
	}

	pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS);
	pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
		"<giometti@linux.it>\n", PPS_VERSION);

	return 0;

remove_class:
	class_destroy(pps_class);

	return err;
}

subsys_initcall(pps_init);
module_exit(pps_exit);

MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION);
MODULE_LICENSE("GPL");
Commit	Line	Data
eae9d2ba RG	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;
eae9d2ba RG	64	void __user uarg = (void __user ) arg;
	65	int __user iuarg = (int __user ) arg;
	66	int err;
	67
	68	switch (cmd) {
	69	case PPS_GETPARAMS:
	70	pr_debug("PPS_GETPARAMS: source %d\n", pps->id);
	71
cbf83cc5 RG	72	spin_lock_irq(&pps->lock);
	73
	74	/* Get the current parameters */
	75	params = pps->params;
	76
	77	spin_unlock_irq(&pps->lock);
	78
	79	err = copy_to_user(uarg, &params, sizeof(struct pps_kparams));
eae9d2ba RG	80	if (err)
	81	return -EFAULT;
	82
	83	break;
	84
	85	case PPS_SETPARAMS:
	86	pr_debug("PPS_SETPARAMS: source %d\n", pps->id);
	87
	88	/* Check the capabilities */
	89	if (!capable(CAP_SYS_TIME))
	90	return -EPERM;
	91
	92	err = copy_from_user(&params, uarg, sizeof(struct pps_kparams));
	93	if (err)
	94	return -EFAULT;
	95	if (!(params.mode & (PPS_CAPTUREASSERT \| PPS_CAPTURECLEAR))) {
	96	pr_debug("capture mode unspecified (%x)\n",
	97	params.mode);
	98	return -EINVAL;
	99	}
	100
	101	/* Check for supported capabilities */
	102	if ((params.mode & ~pps->info.mode) != 0) {
	103	pr_debug("unsupported capabilities (%x)\n",
	104	params.mode);
	105	return -EINVAL;
	106	}
	107
	108	spin_lock_irq(&pps->lock);
	109
	110	/* Save the new parameters */
	111	pps->params = params;
	112
	113	/* Restore the read only parameters */
	114	if ((params.mode & (PPS_TSFMT_TSPEC \| PPS_TSFMT_NTPFP)) == 0) {
	115	/* section 3.3 of RFC 2783 interpreted */
	116	pr_debug("time format unspecified (%x)\n",
	117	params.mode);
	118	pps->params.mode \|= PPS_TSFMT_TSPEC;
	119	}
	120	if (pps->info.mode & PPS_CANWAIT)
	121	pps->params.mode \|= PPS_CANWAIT;
	122	pps->params.api_version = PPS_API_VERS;
	123
	124	spin_unlock_irq(&pps->lock);
	125
	126	break;
	127
	128	case PPS_GETCAP:
	129	pr_debug("PPS_GETCAP: source %d\n", pps->id);
	130
	131	err = put_user(pps->info.mode, iuarg);
	132	if (err)
	133	return -EFAULT;
	134
	135	break;
	136
86d921f9 AG	137	case PPS_FETCH: {
	138	struct pps_fdata fdata;
	139
eae9d2ba RG	140	pr_debug("PPS_FETCH: source %d\n", pps->id);
	141
	142	err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata));
	143	if (err)
	144	return -EFAULT;
	145
	146	pps->go = 0;
	147
	148	/* Manage the timeout */
	149	if (fdata.timeout.flags & PPS_TIME_INVALID)
	150	err = wait_event_interruptible(pps->queue, pps->go);
	151	else {
86d921f9 AG	152	unsigned long ticks;
86d921f9 AG	153
eae9d2ba RG	154	pr_debug("timeout %lld.%09d\n",
	155	(long long) fdata.timeout.sec,
	156	fdata.timeout.nsec);
	157	ticks = fdata.timeout.sec * HZ;
	158	ticks += fdata.timeout.nsec / (NSEC_PER_SEC / HZ);
	159
	160	if (ticks != 0) {
	161	err = wait_event_interruptible_timeout(
	162	pps->queue, pps->go, ticks);
	163	if (err == 0)
	164	return -ETIMEDOUT;
	165	}
	166	}
	167
	168	/* Check for pending signals */
	169	if (err == -ERESTARTSYS) {
	170	pr_debug("pending signal caught\n");
	171	return -EINTR;
	172	}
	173
	174	/* Return the fetched timestamp */
	175	spin_lock_irq(&pps->lock);
	176
	177	fdata.info.assert_sequence = pps->assert_sequence;
	178	fdata.info.clear_sequence = pps->clear_sequence;
	179	fdata.info.assert_tu = pps->assert_tu;
	180	fdata.info.clear_tu = pps->clear_tu;
	181	fdata.info.current_mode = pps->current_mode;
	182
	183	spin_unlock_irq(&pps->lock);
	184
	185	err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata));
	186	if (err)
	187	return -EFAULT;
	188
	189	break;
86d921f9	190	}
eae9d2ba RG	191	default:
	192	return -ENOTTY;
	193	break;
	194	}
	195
	196	return 0;
	197	}
	198
	199	static int pps_cdev_open(struct inode inode, struct file file)
	200	{
	201	struct pps_device *pps = container_of(inode->i_cdev,
	202	struct pps_device, cdev);
	203	int found;
	204
	205	found = pps_get_source(pps->id) != 0;
	206	if (!found)
	207	return -ENODEV;
	208
	209	file->private_data = pps;
	210
	211	return 0;
	212	}
	213
	214	static int pps_cdev_release(struct inode inode, struct file file)
	215	{
	216	struct pps_device *pps = file->private_data;
	217
	218	/* Free the PPS source and wake up (possible) deregistration */
	219	pps_put_source(pps);
	220
	221	return 0;
	222	}
	223
	224	/*
	225	* Char device stuff
	226	*/
	227
	228	static const struct file_operations pps_cdev_fops = {
	229	.owner = THIS_MODULE,
	230	.llseek = no_llseek,
	231	.poll = pps_cdev_poll,
	232	.fasync = pps_cdev_fasync,
	233	.unlocked_ioctl = pps_cdev_ioctl,
	234	.open = pps_cdev_open,
	235	.release = pps_cdev_release,
	236	};
	237
	238	int pps_register_cdev(struct pps_device *pps)
	239	{
	240	int err;
	241
	242	pps->devno = MKDEV(MAJOR(pps_devt), pps->id);
	243	cdev_init(&pps->cdev, &pps_cdev_fops);
	244	pps->cdev.owner = pps->info.owner;
	245
	246	err = cdev_add(&pps->cdev, pps->devno, 1);
	247	if (err) {
	248	printk(KERN_ERR "pps: %s: failed to add char device %d:%d\n",
	249	pps->info.name, MAJOR(pps_devt), pps->id);
	250	return err;
	251	}
	252	pps->dev = device_create(pps_class, pps->info.dev, pps->devno, NULL,
	253	"pps%d", pps->id);
054b2b13	254	if (IS_ERR(pps->dev))
eae9d2ba RG	255	goto del_cdev;
	256	dev_set_drvdata(pps->dev, pps);
	257
	258	pr_debug("source %s got cdev (%d:%d)\n", pps->info.name,
	259	MAJOR(pps_devt), pps->id);
	260
	261	return 0;
	262
	263	del_cdev:
	264	cdev_del(&pps->cdev);
	265
	266	return err;
	267	}
	268
	269	void pps_unregister_cdev(struct pps_device *pps)
	270	{
	271	device_destroy(pps_class, pps->devno);
	272	cdev_del(&pps->cdev);
	273	}
	274
	275	/*
	276	* Module stuff
	277	*/
	278
	279	static void __exit pps_exit(void)
	280	{
	281	class_destroy(pps_class);
	282	unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES);
	283	}
	284
	285	static int __init pps_init(void)
	286	{
	287	int err;
	288
	289	pps_class = class_create(THIS_MODULE, "pps");
	290	if (!pps_class) {
	291	printk(KERN_ERR "pps: failed to allocate class\n");
	292	return -ENOMEM;
	293	}
	294	pps_class->dev_attrs = pps_attrs;
	295
	296	err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps");
	297	if (err < 0) {
	298	printk(KERN_ERR "pps: failed to allocate char device region\n");
	299	goto remove_class;
	300	}
	301
	302	pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS);
	303	pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
	304	"<giometti@linux.it>\n", PPS_VERSION);
	305
	306	return 0;
	307
	308	remove_class:
	309	class_destroy(pps_class);
	310
	311	return err;
	312	}
	313
	314	subsys_initcall(pps_init);
	315	module_exit(pps_exit);
	316
	317	MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
	318	MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION);
319	MODULE_LICENSE("GPL");