[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/mutex.h>
#include <linux/cdev.h>
#include <linux/poll.h>
#include <linux/pps_kernel.h>
#include <linux/slab.h>

#include "kc.h"

/*
 * Local variables
 */

static dev_t pps_devt;
static struct class *pps_class;

static DEFINE_MUTEX(pps_idr_lock);
static DEFINE_IDR(pps_idr);

/*
 * 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;
	}
	case PPS_KC_BIND: {
		struct pps_bind_args bind_args;

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

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

		if (copy_from_user(&bind_args, uarg,
					sizeof(struct pps_bind_args)))
			return -EFAULT;

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

		/* Validate parameters roughly */
		if (bind_args.tsformat != PPS_TSFMT_TSPEC ||
				(bind_args.edge & ~PPS_CAPTUREBOTH) != 0 ||
				bind_args.consumer != PPS_KC_HARDPPS) {
			dev_err(pps->dev, "invalid kernel consumer bind"
					" parameters (%x)\n", bind_args.edge);
			return -EINVAL;
		}

		err = pps_kc_bind(pps, &bind_args);
		if (err < 0)
			return err;

		break;
	}
	default:
		return -ENOTTY;
	}

	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;
	kobject_get(&pps->dev->kobj);
	return 0;
}

static int pps_cdev_release(struct inode *inode, struct file *file)
{
	struct pps_device *pps = container_of(inode->i_cdev,
						struct pps_device, cdev);
	kobject_put(&pps->dev->kobj);
	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,
};

static void pps_device_destruct(struct device *dev)
{
	struct pps_device *pps = dev_get_drvdata(dev);

	cdev_del(&pps->cdev);

	/* Now we can release the ID for re-use */
	pr_debug("deallocating pps%d\n", pps->id);
	mutex_lock(&pps_idr_lock);
	idr_remove(&pps_idr, pps->id);
	mutex_unlock(&pps_idr_lock);

	kfree(dev);
	kfree(pps);
}

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

	mutex_lock(&pps_idr_lock);
	/*
	 * Get new ID for the new PPS source.  After idr_alloc() calling
	 * the new source will be freely available into the kernel.
	 */
	err = idr_alloc(&pps_idr, pps, 0, PPS_MAX_SOURCES, GFP_KERNEL);
	if (err < 0) {
		if (err == -ENOSPC) {
			pr_err("%s: too many PPS sources in the system\n",
			       pps->info.name);
			err = -EBUSY;
		}
		goto out_unlock;
	}
	pps->id = err;
	mutex_unlock(&pps_idr_lock);

	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);
		goto free_idr;
	}
	pps->dev = device_create(pps_class, pps->info.dev, devt, pps,
							"pps%d", pps->id);
	if (IS_ERR(pps->dev)) {
		err = PTR_ERR(pps->dev);
		goto del_cdev;
	}

	/* Override the release function with our own */
	pps->dev->release = pps_device_destruct;

	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);

free_idr:
	mutex_lock(&pps_idr_lock);
	idr_remove(&pps_idr, pps->id);
out_unlock:
	mutex_unlock(&pps_idr_lock);
	return err;
}

void pps_unregister_cdev(struct pps_device *pps)
{
	pr_debug("unregistering pps%d\n", pps->id);
	pps->lookup_cookie = NULL;
	device_destroy(pps_class, pps->dev->devt);
}

/*
 * Look up a pps device by magic cookie.
 * The cookie is usually a pointer to some enclosing device, but this
 * code doesn't care; you should never be dereferencing it.
 *
 * This is a bit of a kludge that is currently used only by the PPS
 * serial line discipline.  It may need to be tweaked when a second user
 * is found.
 *
 * There is no function interface for setting the lookup_cookie field.
 * It's initialized to NULL when the pps device is created, and if a
 * client wants to use it, just fill it in afterward.
 *
 * The cookie is automatically set to NULL in pps_unregister_source()
 * so that it will not be used again, even if the pps device cannot
 * be removed from the idr due to pending references holding the minor
 * number in use.
 */
struct pps_device *pps_lookup_dev(void const *cookie)
{
	struct pps_device *pps;
	unsigned id;

	rcu_read_lock();
	idr_for_each_entry(&pps_idr, pps, id)
		if (cookie == pps->lookup_cookie)
			break;
	rcu_read_unlock();
	return pps;
}
EXPORT_SYMBOL(pps_lookup_dev);

/*
 * 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 (IS_ERR(pps_class)) {
		pr_err("failed to allocate class\n");
		return PTR_ERR(pps_class);
	}
	pps_class->dev_groups = pps_groups;

	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>
2a5cd6e2	30	#include <linux/mutex.h>
eae9d2ba RG	31	#include <linux/cdev.h>
	32	#include <linux/poll.h>
	33	#include <linux/pps_kernel.h>
083e5866	34	#include <linux/slab.h>
eae9d2ba	35
717c0336 AG	36	#include "kc.h"
717c0336 AG	37
eae9d2ba RG	38	/*
	39	* Local variables
	40	*/
	41
	42	static dev_t pps_devt;
	43	static struct class *pps_class;
	44
2a5cd6e2	45	static DEFINE_MUTEX(pps_idr_lock);
083e5866 AG	46	static DEFINE_IDR(pps_idr);
083e5866 AG	47
eae9d2ba RG	48	/*
	49	* Char device methods
	50	*/
	51
	52	static unsigned int pps_cdev_poll(struct file file, poll_table wait)
	53	{
	54	struct pps_device *pps = file->private_data;
	55
	56	poll_wait(file, &pps->queue, wait);
	57
	58	return POLLIN \| POLLRDNORM;
	59	}
	60
	61	static int pps_cdev_fasync(int fd, struct file *file, int on)
	62	{
	63	struct pps_device *pps = file->private_data;
	64	return fasync_helper(fd, file, on, &pps->async_queue);
	65	}
	66
	67	static long pps_cdev_ioctl(struct file *file,
	68	unsigned int cmd, unsigned long arg)
	69	{
	70	struct pps_device *pps = file->private_data;
	71	struct pps_kparams params;
eae9d2ba RG	72	void __user uarg = (void __user ) arg;
	73	int __user iuarg = (int __user ) arg;
	74	int err;
	75
	76	switch (cmd) {
	77	case PPS_GETPARAMS:
7f7cce74	78	dev_dbg(pps->dev, "PPS_GETPARAMS\n");
eae9d2ba	79
cbf83cc5 RG	80	spin_lock_irq(&pps->lock);
	81
	82	/* Get the current parameters */
	83	params = pps->params;
	84
	85	spin_unlock_irq(&pps->lock);
	86
	87	err = copy_to_user(uarg, &params, sizeof(struct pps_kparams));
eae9d2ba RG	88	if (err)
	89	return -EFAULT;
	90
	91	break;
	92
	93	case PPS_SETPARAMS:
7f7cce74	94	dev_dbg(pps->dev, "PPS_SETPARAMS\n");
eae9d2ba RG	95
	96	/* Check the capabilities */
	97	if (!capable(CAP_SYS_TIME))
	98	return -EPERM;
	99
	100	err = copy_from_user(&params, uarg, sizeof(struct pps_kparams));
	101	if (err)
	102	return -EFAULT;
	103	if (!(params.mode & (PPS_CAPTUREASSERT \| PPS_CAPTURECLEAR))) {
7f7cce74	104	dev_dbg(pps->dev, "capture mode unspecified (%x)\n",
eae9d2ba RG	105	params.mode);
	106	return -EINVAL;
	107	}
	108
	109	/* Check for supported capabilities */
	110	if ((params.mode & ~pps->info.mode) != 0) {
7f7cce74	111	dev_dbg(pps->dev, "unsupported capabilities (%x)\n",
eae9d2ba RG	112	params.mode);
	113	return -EINVAL;
	114	}
	115
	116	spin_lock_irq(&pps->lock);
	117
	118	/* Save the new parameters */
	119	pps->params = params;
	120
	121	/* Restore the read only parameters */
	122	if ((params.mode & (PPS_TSFMT_TSPEC \| PPS_TSFMT_NTPFP)) == 0) {
	123	/* section 3.3 of RFC 2783 interpreted */
7f7cce74	124	dev_dbg(pps->dev, "time format unspecified (%x)\n",
eae9d2ba RG	125	params.mode);
	126	pps->params.mode \|= PPS_TSFMT_TSPEC;
	127	}
	128	if (pps->info.mode & PPS_CANWAIT)
	129	pps->params.mode \|= PPS_CANWAIT;
	130	pps->params.api_version = PPS_API_VERS;
	131
	132	spin_unlock_irq(&pps->lock);
	133
	134	break;
	135
	136	case PPS_GETCAP:
7f7cce74	137	dev_dbg(pps->dev, "PPS_GETCAP\n");
eae9d2ba RG	138
	139	err = put_user(pps->info.mode, iuarg);
	140	if (err)
	141	return -EFAULT;
	142
	143	break;
	144
86d921f9 AG	145	case PPS_FETCH: {
86d921f9 AG	146	struct pps_fdata fdata;
3003d55b	147	unsigned int ev;
86d921f9	148
7f7cce74	149	dev_dbg(pps->dev, "PPS_FETCH\n");
eae9d2ba RG	150
	151	err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata));
	152	if (err)
	153	return -EFAULT;
	154
3003d55b	155	ev = pps->last_ev;
eae9d2ba RG	156
	157	/* Manage the timeout */
	158	if (fdata.timeout.flags & PPS_TIME_INVALID)
3003d55b AG	159	err = wait_event_interruptible(pps->queue,
3003d55b AG	160	ev != pps->last_ev);
eae9d2ba	161	else {
86d921f9 AG	162	unsigned long ticks;
86d921f9 AG	163
7f7cce74	164	dev_dbg(pps->dev, "timeout %lld.%09d\n",
eae9d2ba RG	165	(long long) fdata.timeout.sec,
	166	fdata.timeout.nsec);
	167	ticks = fdata.timeout.sec * HZ;
	168	ticks += fdata.timeout.nsec / (NSEC_PER_SEC / HZ);
	169
	170	if (ticks != 0) {
	171	err = wait_event_interruptible_timeout(
3003d55b AG	172	pps->queue,
	173	ev != pps->last_ev,
	174	ticks);
eae9d2ba RG	175	if (err == 0)
	176	return -ETIMEDOUT;
	177	}
	178	}
	179
	180	/* Check for pending signals */
	181	if (err == -ERESTARTSYS) {
7f7cce74	182	dev_dbg(pps->dev, "pending signal caught\n");
eae9d2ba RG	183	return -EINTR;
	184	}
	185
	186	/* Return the fetched timestamp */
	187	spin_lock_irq(&pps->lock);
	188
	189	fdata.info.assert_sequence = pps->assert_sequence;
	190	fdata.info.clear_sequence = pps->clear_sequence;
	191	fdata.info.assert_tu = pps->assert_tu;
	192	fdata.info.clear_tu = pps->clear_tu;
	193	fdata.info.current_mode = pps->current_mode;
	194
	195	spin_unlock_irq(&pps->lock);
	196
	197	err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata));
	198	if (err)
	199	return -EFAULT;
	200
	201	break;
86d921f9	202	}
717c0336 AG	203	case PPS_KC_BIND: {
	204	struct pps_bind_args bind_args;
	205
	206	dev_dbg(pps->dev, "PPS_KC_BIND\n");
	207
	208	/* Check the capabilities */
	209	if (!capable(CAP_SYS_TIME))
	210	return -EPERM;
	211
	212	if (copy_from_user(&bind_args, uarg,
	213	sizeof(struct pps_bind_args)))
	214	return -EFAULT;
	215
	216	/* Check for supported capabilities */
	217	if ((bind_args.edge & ~pps->info.mode) != 0) {
	218	dev_err(pps->dev, "unsupported capabilities (%x)\n",
	219	bind_args.edge);
	220	return -EINVAL;
	221	}
	222
	223	/* Validate parameters roughly */
	224	if (bind_args.tsformat != PPS_TSFMT_TSPEC \|\|
	225	(bind_args.edge & ~PPS_CAPTUREBOTH) != 0 \|\|
	226	bind_args.consumer != PPS_KC_HARDPPS) {
	227	dev_err(pps->dev, "invalid kernel consumer bind"
	228	" parameters (%x)\n", bind_args.edge);
	229	return -EINVAL;
	230	}
	231
	232	err = pps_kc_bind(pps, &bind_args);
	233	if (err < 0)
	234	return err;
	235
	236	break;
	237	}
eae9d2ba RG	238	default:
eae9d2ba RG	239	return -ENOTTY;
eae9d2ba RG	240	}
	241
	242	return 0;
	243	}
	244
	245	static int pps_cdev_open(struct inode inode, struct file file)
	246	{
	247	struct pps_device *pps = container_of(inode->i_cdev,
	248	struct pps_device, cdev);
eae9d2ba	249	file->private_data = pps;
d953e0e8	250	kobject_get(&pps->dev->kobj);
eae9d2ba RG	251	return 0;
	252	}
	253
	254	static int pps_cdev_release(struct inode inode, struct file file)
	255	{
d953e0e8 GS	256	struct pps_device *pps = container_of(inode->i_cdev,
	257	struct pps_device, cdev);
	258	kobject_put(&pps->dev->kobj);
eae9d2ba RG	259	return 0;
	260	}
	261
	262	/*
	263	* Char device stuff
	264	*/
	265
	266	static const struct file_operations pps_cdev_fops = {
	267	.owner = THIS_MODULE,
	268	.llseek = no_llseek,
	269	.poll = pps_cdev_poll,
	270	.fasync = pps_cdev_fasync,
	271	.unlocked_ioctl = pps_cdev_ioctl,
	272	.open = pps_cdev_open,
	273	.release = pps_cdev_release,
	274	};
	275
083e5866 AG	276	static void pps_device_destruct(struct device *dev)
	277	{
	278	struct pps_device *pps = dev_get_drvdata(dev);
	279
d953e0e8 GS	280	cdev_del(&pps->cdev);
	281
	282	/* Now we can release the ID for re-use */
	283	pr_debug("deallocating pps%d\n", pps->id);
2a5cd6e2	284	mutex_lock(&pps_idr_lock);
083e5866	285	idr_remove(&pps_idr, pps->id);
2a5cd6e2	286	mutex_unlock(&pps_idr_lock);
083e5866 AG	287
	288	kfree(dev);
	289	kfree(pps);
	290	}
	291
eae9d2ba RG	292	int pps_register_cdev(struct pps_device *pps)
	293	{
	294	int err;
5e196d34 AG	295	dev_t devt;
5e196d34 AG	296
2a5cd6e2	297	mutex_lock(&pps_idr_lock);
19dd2da3 TH	298	/*
	299	* Get new ID for the new PPS source. After idr_alloc() calling
	300	* the new source will be freely available into the kernel.
083e5866	301	*/
19dd2da3 TH	302	err = idr_alloc(&pps_idr, pps, 0, PPS_MAX_SOURCES, GFP_KERNEL);
	303	if (err < 0) {
	304	if (err == -ENOSPC) {
	305	pr_err("%s: too many PPS sources in the system\n",
	306	pps->info.name);
	307	err = -EBUSY;
	308	}
	309	goto out_unlock;
083e5866	310	}
19dd2da3 TH	311	pps->id = err;
19dd2da3 TH	312	mutex_unlock(&pps_idr_lock);
083e5866	313
5e196d34	314	devt = MKDEV(MAJOR(pps_devt), pps->id);
eae9d2ba	315
eae9d2ba RG	316	cdev_init(&pps->cdev, &pps_cdev_fops);
	317	pps->cdev.owner = pps->info.owner;
	318
5e196d34	319	err = cdev_add(&pps->cdev, devt, 1);
eae9d2ba	320	if (err) {
7f7cce74	321	pr_err("%s: failed to add char device %d:%d\n",
eae9d2ba	322	pps->info.name, MAJOR(pps_devt), pps->id);
083e5866	323	goto free_idr;
eae9d2ba	324	}
5e196d34	325	pps->dev = device_create(pps_class, pps->info.dev, devt, pps,
eae9d2ba	326	"pps%d", pps->id);
668f06b9 EG	327	if (IS_ERR(pps->dev)) {
668f06b9 EG	328	err = PTR_ERR(pps->dev);
eae9d2ba	329	goto del_cdev;
668f06b9	330	}
eae9d2ba	331
d953e0e8	332	/* Override the release function with our own */
083e5866 AG	333	pps->dev->release = pps_device_destruct;
083e5866 AG	334
eae9d2ba RG	335	pr_debug("source %s got cdev (%d:%d)\n", pps->info.name,
	336	MAJOR(pps_devt), pps->id);
	337
	338	return 0;
	339
	340	del_cdev:
	341	cdev_del(&pps->cdev);
	342
083e5866	343	free_idr:
2a5cd6e2	344	mutex_lock(&pps_idr_lock);
083e5866	345	idr_remove(&pps_idr, pps->id);
19dd2da3	346	out_unlock:
2a5cd6e2	347	mutex_unlock(&pps_idr_lock);
eae9d2ba RG	348	return err;
	349	}
	350
	351	void pps_unregister_cdev(struct pps_device *pps)
	352	{
d953e0e8	353	pr_debug("unregistering pps%d\n", pps->id);
513b032c	354	pps->lookup_cookie = NULL;
5e196d34	355	device_destroy(pps_class, pps->dev->devt);
eae9d2ba RG	356	}
eae9d2ba RG	357
513b032c GS	358	/*
	359	* Look up a pps device by magic cookie.
	360	* The cookie is usually a pointer to some enclosing device, but this
	361	* code doesn't care; you should never be dereferencing it.
	362	*
	363	* This is a bit of a kludge that is currently used only by the PPS
	364	* serial line discipline. It may need to be tweaked when a second user
	365	* is found.
	366	*
	367	* There is no function interface for setting the lookup_cookie field.
	368	* It's initialized to NULL when the pps device is created, and if a
	369	* client wants to use it, just fill it in afterward.
	370	*
	371	* The cookie is automatically set to NULL in pps_unregister_source()
	372	* so that it will not be used again, even if the pps device cannot
	373	* be removed from the idr due to pending references holding the minor
	374	* number in use.
	375	*/
	376	struct pps_device pps_lookup_dev(void const cookie)
	377	{
	378	struct pps_device *pps;
	379	unsigned id;
	380
	381	rcu_read_lock();
	382	idr_for_each_entry(&pps_idr, pps, id)
	383	if (cookie == pps->lookup_cookie)
	384	break;
	385	rcu_read_unlock();
	386	return pps;
	387	}
	388	EXPORT_SYMBOL(pps_lookup_dev);
	389
eae9d2ba RG	390	/*
	391	* Module stuff
	392	*/
	393
	394	static void __exit pps_exit(void)
	395	{
	396	class_destroy(pps_class);
	397	unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES);
	398	}
	399
	400	static int __init pps_init(void)
	401	{
	402	int err;
	403
	404	pps_class = class_create(THIS_MODULE, "pps");
7ad12566	405	if (IS_ERR(pps_class)) {
7f7cce74	406	pr_err("failed to allocate class\n");
7ad12566	407	return PTR_ERR(pps_class);
eae9d2ba	408	}
bd0eae4e	409	pps_class->dev_groups = pps_groups;
eae9d2ba RG	410
	411	err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps");
	412	if (err < 0) {
7f7cce74	413	pr_err("failed to allocate char device region\n");
eae9d2ba RG	414	goto remove_class;
	415	}
	416
	417	pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS);
	418	pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
	419	"<giometti@linux.it>\n", PPS_VERSION);
	420
	421	return 0;
	422
	423	remove_class:
	424	class_destroy(pps_class);
	425
	426	return err;
	427	}
	428
	429	subsys_initcall(pps_init);
	430	module_exit(pps_exit);
	431
	432	MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
	433	MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION);
	434	MODULE_LICENSE("GPL");