[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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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:
		dev_dbg(pps->dev, "PPS_GETPARAMS\n");

		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:
		dev_dbg(pps->dev, "PPS_SETPARAMS\n");

		/* 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))) {
			dev_dbg(pps->dev, "capture mode unspecified (%x)\n",
								params.mode);
			return -EINVAL;
		}

		/* Check for supported capabilities */
		if ((params.mode & ~pps->info.mode) != 0) {
			dev_dbg(pps->dev, "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 */
			dev_dbg(pps->dev, "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:
		dev_dbg(pps->dev, "PPS_GETCAP\n");

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

		break;

	case PPS_FETCH: {
		struct pps_fdata fdata;
		unsigned int ev;

		dev_dbg(pps->dev, "PPS_FETCH\n");

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

		ev = pps->last_ev;

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

			dev_dbg(pps->dev, "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,
						ev != pps->last_ev,
						ticks);
				if (err == 0)
					return -ETIMEDOUT;
			}
		}

		/* Check for pending signals */
		if (err == -ERESTARTSYS) {
			dev_dbg(pps->dev, "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);
	file->private_data = pps;

	return 0;
}

static int pps_cdev_release(struct inode *inode, struct file *file)
{
	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;
	dev_t devt;

	devt = MKDEV(MAJOR(pps_devt), pps->id);

	cdev_init(&pps->cdev, &pps_cdev_fops);
	pps->cdev.owner = pps->info.owner;

	err = cdev_add(&pps->cdev, devt, 1);
	if (err) {
		pr_err("%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, devt, pps,
							"pps%d", pps->id);
	if (IS_ERR(pps->dev))
		goto del_cdev;

	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->dev->devt);
	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) {
		pr_err("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) {
		pr_err("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
7f7cce74	22	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
eae9d2ba RG	23
	24	#include <linux/kernel.h>
	25	#include <linux/module.h>
	26	#include <linux/init.h>
	27	#include <linux/sched.h>
	28	#include <linux/uaccess.h>
	29	#include <linux/idr.h>
	30	#include <linux/cdev.h>
	31	#include <linux/poll.h>
	32	#include <linux/pps_kernel.h>
	33
	34	/*
	35	* Local variables
	36	*/
	37
	38	static dev_t pps_devt;
	39	static struct class *pps_class;
	40
	41	/*
	42	* Char device methods
	43	*/
	44
	45	static unsigned int pps_cdev_poll(struct file file, poll_table wait)
	46	{
	47	struct pps_device *pps = file->private_data;
	48
	49	poll_wait(file, &pps->queue, wait);
	50
	51	return POLLIN \| POLLRDNORM;
	52	}
	53
	54	static int pps_cdev_fasync(int fd, struct file *file, int on)
	55	{
	56	struct pps_device *pps = file->private_data;
	57	return fasync_helper(fd, file, on, &pps->async_queue);
	58	}
	59
	60	static long pps_cdev_ioctl(struct file *file,
	61	unsigned int cmd, unsigned long arg)
	62	{
	63	struct pps_device *pps = file->private_data;
	64	struct pps_kparams params;
eae9d2ba RG	65	void __user uarg = (void __user ) arg;
	66	int __user iuarg = (int __user ) arg;
	67	int err;
	68
	69	switch (cmd) {
	70	case PPS_GETPARAMS:
7f7cce74	71	dev_dbg(pps->dev, "PPS_GETPARAMS\n");
eae9d2ba	72
cbf83cc5 RG	73	spin_lock_irq(&pps->lock);
	74
	75	/* Get the current parameters */
	76	params = pps->params;
	77
	78	spin_unlock_irq(&pps->lock);
	79
	80	err = copy_to_user(uarg, &params, sizeof(struct pps_kparams));
eae9d2ba RG	81	if (err)
	82	return -EFAULT;
	83
	84	break;
	85
	86	case PPS_SETPARAMS:
7f7cce74	87	dev_dbg(pps->dev, "PPS_SETPARAMS\n");
eae9d2ba RG	88
	89	/* Check the capabilities */
	90	if (!capable(CAP_SYS_TIME))
	91	return -EPERM;
	92
	93	err = copy_from_user(&params, uarg, sizeof(struct pps_kparams));
	94	if (err)
	95	return -EFAULT;
	96	if (!(params.mode & (PPS_CAPTUREASSERT \| PPS_CAPTURECLEAR))) {
7f7cce74	97	dev_dbg(pps->dev, "capture mode unspecified (%x)\n",
eae9d2ba RG	98	params.mode);
	99	return -EINVAL;
	100	}
	101
	102	/* Check for supported capabilities */
	103	if ((params.mode & ~pps->info.mode) != 0) {
7f7cce74	104	dev_dbg(pps->dev, "unsupported capabilities (%x)\n",
eae9d2ba RG	105	params.mode);
	106	return -EINVAL;
	107	}
	108
	109	spin_lock_irq(&pps->lock);
	110
	111	/* Save the new parameters */
	112	pps->params = params;
	113
	114	/* Restore the read only parameters */
	115	if ((params.mode & (PPS_TSFMT_TSPEC \| PPS_TSFMT_NTPFP)) == 0) {
	116	/* section 3.3 of RFC 2783 interpreted */
7f7cce74	117	dev_dbg(pps->dev, "time format unspecified (%x)\n",
eae9d2ba RG	118	params.mode);
	119	pps->params.mode \|= PPS_TSFMT_TSPEC;
	120	}
	121	if (pps->info.mode & PPS_CANWAIT)
	122	pps->params.mode \|= PPS_CANWAIT;
	123	pps->params.api_version = PPS_API_VERS;
	124
	125	spin_unlock_irq(&pps->lock);
	126
	127	break;
	128
	129	case PPS_GETCAP:
7f7cce74	130	dev_dbg(pps->dev, "PPS_GETCAP\n");
eae9d2ba RG	131
	132	err = put_user(pps->info.mode, iuarg);
	133	if (err)
	134	return -EFAULT;
	135
	136	break;
	137
86d921f9 AG	138	case PPS_FETCH: {
86d921f9 AG	139	struct pps_fdata fdata;
3003d55b	140	unsigned int ev;
86d921f9	141
7f7cce74	142	dev_dbg(pps->dev, "PPS_FETCH\n");
eae9d2ba RG	143
	144	err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata));
	145	if (err)
	146	return -EFAULT;
	147
3003d55b	148	ev = pps->last_ev;
eae9d2ba RG	149
	150	/* Manage the timeout */
	151	if (fdata.timeout.flags & PPS_TIME_INVALID)
3003d55b AG	152	err = wait_event_interruptible(pps->queue,
3003d55b AG	153	ev != pps->last_ev);
eae9d2ba	154	else {
86d921f9 AG	155	unsigned long ticks;
86d921f9 AG	156
7f7cce74	157	dev_dbg(pps->dev, "timeout %lld.%09d\n",
eae9d2ba RG	158	(long long) fdata.timeout.sec,
	159	fdata.timeout.nsec);
	160	ticks = fdata.timeout.sec * HZ;
	161	ticks += fdata.timeout.nsec / (NSEC_PER_SEC / HZ);
	162
	163	if (ticks != 0) {
	164	err = wait_event_interruptible_timeout(
3003d55b AG	165	pps->queue,
	166	ev != pps->last_ev,
	167	ticks);
eae9d2ba RG	168	if (err == 0)
	169	return -ETIMEDOUT;
	170	}
	171	}
	172
	173	/* Check for pending signals */
	174	if (err == -ERESTARTSYS) {
7f7cce74	175	dev_dbg(pps->dev, "pending signal caught\n");
eae9d2ba RG	176	return -EINTR;
	177	}
	178
	179	/* Return the fetched timestamp */
	180	spin_lock_irq(&pps->lock);
	181
	182	fdata.info.assert_sequence = pps->assert_sequence;
	183	fdata.info.clear_sequence = pps->clear_sequence;
	184	fdata.info.assert_tu = pps->assert_tu;
	185	fdata.info.clear_tu = pps->clear_tu;
	186	fdata.info.current_mode = pps->current_mode;
	187
	188	spin_unlock_irq(&pps->lock);
	189
	190	err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata));
	191	if (err)
	192	return -EFAULT;
	193
	194	break;
86d921f9	195	}
eae9d2ba RG	196	default:
	197	return -ENOTTY;
	198	break;
	199	}
	200
	201	return 0;
	202	}
	203
	204	static int pps_cdev_open(struct inode inode, struct file file)
	205	{
	206	struct pps_device *pps = container_of(inode->i_cdev,
	207	struct pps_device, cdev);
eae9d2ba RG	208	file->private_data = pps;
	209
	210	return 0;
	211	}
	212
	213	static int pps_cdev_release(struct inode inode, struct file file)
	214	{
eae9d2ba RG	215	return 0;
	216	}
	217
	218	/*
	219	* Char device stuff
	220	*/
	221
	222	static const struct file_operations pps_cdev_fops = {
	223	.owner = THIS_MODULE,
	224	.llseek = no_llseek,
	225	.poll = pps_cdev_poll,
	226	.fasync = pps_cdev_fasync,
	227	.unlocked_ioctl = pps_cdev_ioctl,
	228	.open = pps_cdev_open,
	229	.release = pps_cdev_release,
	230	};
	231
	232	int pps_register_cdev(struct pps_device *pps)
	233	{
	234	int err;
5e196d34 AG	235	dev_t devt;
	236
	237	devt = MKDEV(MAJOR(pps_devt), pps->id);
eae9d2ba	238
eae9d2ba RG	239	cdev_init(&pps->cdev, &pps_cdev_fops);
	240	pps->cdev.owner = pps->info.owner;
	241
5e196d34	242	err = cdev_add(&pps->cdev, devt, 1);
eae9d2ba	243	if (err) {
7f7cce74	244	pr_err("%s: failed to add char device %d:%d\n",
eae9d2ba RG	245	pps->info.name, MAJOR(pps_devt), pps->id);
	246	return err;
	247	}
5e196d34	248	pps->dev = device_create(pps_class, pps->info.dev, devt, pps,
eae9d2ba	249	"pps%d", pps->id);
054b2b13	250	if (IS_ERR(pps->dev))
eae9d2ba	251	goto del_cdev;
eae9d2ba RG	252
	253	pr_debug("source %s got cdev (%d:%d)\n", pps->info.name,
	254	MAJOR(pps_devt), pps->id);
	255
	256	return 0;
	257
	258	del_cdev:
	259	cdev_del(&pps->cdev);
	260
	261	return err;
	262	}
	263
	264	void pps_unregister_cdev(struct pps_device *pps)
	265	{
5e196d34	266	device_destroy(pps_class, pps->dev->devt);
eae9d2ba RG	267	cdev_del(&pps->cdev);
	268	}
	269
	270	/*
	271	* Module stuff
	272	*/
	273
	274	static void __exit pps_exit(void)
	275	{
	276	class_destroy(pps_class);
	277	unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES);
	278	}
	279
	280	static int __init pps_init(void)
	281	{
	282	int err;
	283
	284	pps_class = class_create(THIS_MODULE, "pps");
	285	if (!pps_class) {
7f7cce74	286	pr_err("failed to allocate class\n");
eae9d2ba RG	287	return -ENOMEM;
	288	}
	289	pps_class->dev_attrs = pps_attrs;
	290
	291	err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps");
	292	if (err < 0) {
7f7cce74	293	pr_err("failed to allocate char device region\n");
eae9d2ba RG	294	goto remove_class;
	295	}
	296
	297	pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS);
	298	pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
	299	"<giometti@linux.it>\n", PPS_VERSION);
	300
	301	return 0;
	302
	303	remove_class:
	304	class_destroy(pps_class);
	305
	306	return err;
	307	}
	308
	309	subsys_initcall(pps_init);
	310	module_exit(pps_exit);
	311
	312	MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
	313	MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION);
	314	MODULE_LICENSE("GPL");