[mirror_ubuntu-artful-kernel.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 int pps_cdev_pps_fetch(struct pps_device *pps, struct pps_fdata *fdata)
{
	unsigned int ev = pps->last_ev;
	int err = 0;

	/* 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 0;
}

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;

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

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

		err = pps_cdev_pps_fetch(pps, &fdata);
		if (err)
			return err;

		/* 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;
}

#ifdef CONFIG_COMPAT
static long pps_cdev_compat_ioctl(struct file *file,
		unsigned int cmd, unsigned long arg)
{
	struct pps_device *pps = file->private_data;
	void __user *uarg = (void __user *) arg;

	cmd = _IOC(_IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), sizeof(void *));

	if (cmd == PPS_FETCH) {
		struct pps_fdata_compat compat;
		struct pps_fdata fdata;
		int err;

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

		err = copy_from_user(&compat, uarg, sizeof(struct pps_fdata_compat));
		if (err)
			return -EFAULT;

		memcpy(&fdata.timeout, &compat.timeout,
					sizeof(struct pps_ktime_compat));

		err = pps_cdev_pps_fetch(pps, &fdata);
		if (err)
			return err;

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

		compat.info.assert_sequence = pps->assert_sequence;
		compat.info.clear_sequence = pps->clear_sequence;
		compat.info.current_mode = pps->current_mode;

		memcpy(&compat.info.assert_tu, &pps->assert_tu,
				sizeof(struct pps_ktime_compat));
		memcpy(&compat.info.clear_tu, &pps->clear_tu,
				sizeof(struct pps_ktime_compat));

		spin_unlock_irq(&pps->lock);

		return copy_to_user(uarg, &compat,
				sizeof(struct pps_fdata_compat)) ? -EFAULT : 0;
	}

	return pps_cdev_ioctl(file, cmd, arg);
}
#else
#define pps_cdev_compat_ioctl	NULL
#endif

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,
	.compat_ioctl	= pps_cdev_compat_ioctl,
	.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
c2a49fe8 MR	67	static int pps_cdev_pps_fetch(struct pps_device pps, struct pps_fdata fdata)
	68	{
	69	unsigned int ev = pps->last_ev;
	70	int err = 0;
	71
	72	/* Manage the timeout */
	73	if (fdata->timeout.flags & PPS_TIME_INVALID)
	74	err = wait_event_interruptible(pps->queue,
	75	ev != pps->last_ev);
	76	else {
	77	unsigned long ticks;
	78
	79	dev_dbg(pps->dev, "timeout %lld.%09d\n",
	80	(long long) fdata->timeout.sec,
	81	fdata->timeout.nsec);
	82	ticks = fdata->timeout.sec * HZ;
	83	ticks += fdata->timeout.nsec / (NSEC_PER_SEC / HZ);
	84
	85	if (ticks != 0) {
	86	err = wait_event_interruptible_timeout(
	87	pps->queue,
	88	ev != pps->last_ev,
	89	ticks);
	90	if (err == 0)
	91	return -ETIMEDOUT;
	92	}
	93	}
	94
	95	/* Check for pending signals */
	96	if (err == -ERESTARTSYS) {
	97	dev_dbg(pps->dev, "pending signal caught\n");
	98	return -EINTR;
	99	}
	100
	101	return 0;
	102	}
	103
eae9d2ba RG	104	static long pps_cdev_ioctl(struct file *file,
	105	unsigned int cmd, unsigned long arg)
	106	{
	107	struct pps_device *pps = file->private_data;
	108	struct pps_kparams params;
eae9d2ba RG	109	void __user uarg = (void __user ) arg;
	110	int __user iuarg = (int __user ) arg;
	111	int err;
	112
	113	switch (cmd) {
	114	case PPS_GETPARAMS:
7f7cce74	115	dev_dbg(pps->dev, "PPS_GETPARAMS\n");
eae9d2ba	116
cbf83cc5 RG	117	spin_lock_irq(&pps->lock);
	118
	119	/* Get the current parameters */
	120	params = pps->params;
	121
	122	spin_unlock_irq(&pps->lock);
	123
	124	err = copy_to_user(uarg, &params, sizeof(struct pps_kparams));
eae9d2ba RG	125	if (err)
	126	return -EFAULT;
	127
	128	break;
	129
	130	case PPS_SETPARAMS:
7f7cce74	131	dev_dbg(pps->dev, "PPS_SETPARAMS\n");
eae9d2ba RG	132
	133	/* Check the capabilities */
	134	if (!capable(CAP_SYS_TIME))
	135	return -EPERM;
	136
	137	err = copy_from_user(&params, uarg, sizeof(struct pps_kparams));
	138	if (err)
	139	return -EFAULT;
	140	if (!(params.mode & (PPS_CAPTUREASSERT \| PPS_CAPTURECLEAR))) {
7f7cce74	141	dev_dbg(pps->dev, "capture mode unspecified (%x)\n",
eae9d2ba RG	142	params.mode);
	143	return -EINVAL;
	144	}
	145
	146	/* Check for supported capabilities */
	147	if ((params.mode & ~pps->info.mode) != 0) {
7f7cce74	148	dev_dbg(pps->dev, "unsupported capabilities (%x)\n",
eae9d2ba RG	149	params.mode);
	150	return -EINVAL;
	151	}
	152
	153	spin_lock_irq(&pps->lock);
	154
	155	/* Save the new parameters */
	156	pps->params = params;
	157
	158	/* Restore the read only parameters */
	159	if ((params.mode & (PPS_TSFMT_TSPEC \| PPS_TSFMT_NTPFP)) == 0) {
	160	/* section 3.3 of RFC 2783 interpreted */
7f7cce74	161	dev_dbg(pps->dev, "time format unspecified (%x)\n",
eae9d2ba RG	162	params.mode);
	163	pps->params.mode \|= PPS_TSFMT_TSPEC;
	164	}
	165	if (pps->info.mode & PPS_CANWAIT)
	166	pps->params.mode \|= PPS_CANWAIT;
	167	pps->params.api_version = PPS_API_VERS;
	168
	169	spin_unlock_irq(&pps->lock);
	170
	171	break;
	172
	173	case PPS_GETCAP:
7f7cce74	174	dev_dbg(pps->dev, "PPS_GETCAP\n");
eae9d2ba RG	175
	176	err = put_user(pps->info.mode, iuarg);
	177	if (err)
	178	return -EFAULT;
	179
	180	break;
	181
86d921f9 AG	182	case PPS_FETCH: {
	183	struct pps_fdata fdata;
	184
7f7cce74	185	dev_dbg(pps->dev, "PPS_FETCH\n");
eae9d2ba RG	186
	187	err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata));
	188	if (err)
	189	return -EFAULT;
	190
c2a49fe8 MR	191	err = pps_cdev_pps_fetch(pps, &fdata);
	192	if (err)
	193	return err;
eae9d2ba RG	194
	195	/* Return the fetched timestamp */
	196	spin_lock_irq(&pps->lock);
	197
	198	fdata.info.assert_sequence = pps->assert_sequence;
	199	fdata.info.clear_sequence = pps->clear_sequence;
	200	fdata.info.assert_tu = pps->assert_tu;
	201	fdata.info.clear_tu = pps->clear_tu;
	202	fdata.info.current_mode = pps->current_mode;
	203
	204	spin_unlock_irq(&pps->lock);
	205
	206	err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata));
	207	if (err)
	208	return -EFAULT;
	209
	210	break;
86d921f9	211	}
717c0336 AG	212	case PPS_KC_BIND: {
	213	struct pps_bind_args bind_args;
	214
	215	dev_dbg(pps->dev, "PPS_KC_BIND\n");
	216
	217	/* Check the capabilities */
	218	if (!capable(CAP_SYS_TIME))
	219	return -EPERM;
	220
	221	if (copy_from_user(&bind_args, uarg,
	222	sizeof(struct pps_bind_args)))
	223	return -EFAULT;
	224
	225	/* Check for supported capabilities */
	226	if ((bind_args.edge & ~pps->info.mode) != 0) {
	227	dev_err(pps->dev, "unsupported capabilities (%x)\n",
	228	bind_args.edge);
	229	return -EINVAL;
	230	}
	231
	232	/* Validate parameters roughly */
	233	if (bind_args.tsformat != PPS_TSFMT_TSPEC \|\|
	234	(bind_args.edge & ~PPS_CAPTUREBOTH) != 0 \|\|
	235	bind_args.consumer != PPS_KC_HARDPPS) {
	236	dev_err(pps->dev, "invalid kernel consumer bind"
	237	" parameters (%x)\n", bind_args.edge);
	238	return -EINVAL;
	239	}
	240
	241	err = pps_kc_bind(pps, &bind_args);
	242	if (err < 0)
	243	return err;
	244
	245	break;
	246	}
eae9d2ba RG	247	default:
eae9d2ba RG	248	return -ENOTTY;
eae9d2ba RG	249	}
	250
	251	return 0;
	252	}
	253
2ac66657 MR	254	#ifdef CONFIG_COMPAT
	255	static long pps_cdev_compat_ioctl(struct file *file,
	256	unsigned int cmd, unsigned long arg)
	257	{
c2a49fe8 MR	258	struct pps_device *pps = file->private_data;
	259	void __user uarg = (void __user ) arg;
	260
2ac66657 MR	261	cmd = _IOC(_IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), sizeof(void *));
2ac66657 MR	262
c2a49fe8 MR	263	if (cmd == PPS_FETCH) {
	264	struct pps_fdata_compat compat;
	265	struct pps_fdata fdata;
	266	int err;
	267
	268	dev_dbg(pps->dev, "PPS_FETCH\n");
	269
	270	err = copy_from_user(&compat, uarg, sizeof(struct pps_fdata_compat));
	271	if (err)
	272	return -EFAULT;
	273
	274	memcpy(&fdata.timeout, &compat.timeout,
	275	sizeof(struct pps_ktime_compat));
	276
	277	err = pps_cdev_pps_fetch(pps, &fdata);
	278	if (err)
	279	return err;
	280
	281	/* Return the fetched timestamp */
	282	spin_lock_irq(&pps->lock);
	283
	284	compat.info.assert_sequence = pps->assert_sequence;
	285	compat.info.clear_sequence = pps->clear_sequence;
	286	compat.info.current_mode = pps->current_mode;
	287
	288	memcpy(&compat.info.assert_tu, &pps->assert_tu,
	289	sizeof(struct pps_ktime_compat));
	290	memcpy(&compat.info.clear_tu, &pps->clear_tu,
	291	sizeof(struct pps_ktime_compat));
	292
	293	spin_unlock_irq(&pps->lock);
	294
	295	return copy_to_user(uarg, &compat,
	296	sizeof(struct pps_fdata_compat)) ? -EFAULT : 0;
	297	}
	298
2ac66657 MR	299	return pps_cdev_ioctl(file, cmd, arg);
	300	}
	301	#else
	302	#define pps_cdev_compat_ioctl NULL
	303	#endif
	304
eae9d2ba RG	305	static int pps_cdev_open(struct inode inode, struct file file)
	306	{
	307	struct pps_device *pps = container_of(inode->i_cdev,
	308	struct pps_device, cdev);
eae9d2ba	309	file->private_data = pps;
d953e0e8	310	kobject_get(&pps->dev->kobj);
eae9d2ba RG	311	return 0;
	312	}
	313
	314	static int pps_cdev_release(struct inode inode, struct file file)
	315	{
d953e0e8 GS	316	struct pps_device *pps = container_of(inode->i_cdev,
	317	struct pps_device, cdev);
	318	kobject_put(&pps->dev->kobj);
eae9d2ba RG	319	return 0;
	320	}
	321
	322	/*
	323	* Char device stuff
	324	*/
	325
	326	static const struct file_operations pps_cdev_fops = {
	327	.owner = THIS_MODULE,
	328	.llseek = no_llseek,
	329	.poll = pps_cdev_poll,
	330	.fasync = pps_cdev_fasync,
2ac66657	331	.compat_ioctl = pps_cdev_compat_ioctl,
eae9d2ba RG	332	.unlocked_ioctl = pps_cdev_ioctl,
	333	.open = pps_cdev_open,
	334	.release = pps_cdev_release,
	335	};
	336
083e5866 AG	337	static void pps_device_destruct(struct device *dev)
	338	{
	339	struct pps_device *pps = dev_get_drvdata(dev);
	340
d953e0e8 GS	341	cdev_del(&pps->cdev);
	342
	343	/* Now we can release the ID for re-use */
	344	pr_debug("deallocating pps%d\n", pps->id);
2a5cd6e2	345	mutex_lock(&pps_idr_lock);
083e5866	346	idr_remove(&pps_idr, pps->id);
2a5cd6e2	347	mutex_unlock(&pps_idr_lock);
083e5866 AG	348
	349	kfree(dev);
	350	kfree(pps);
	351	}
	352
eae9d2ba RG	353	int pps_register_cdev(struct pps_device *pps)
	354	{
	355	int err;
5e196d34 AG	356	dev_t devt;
5e196d34 AG	357
2a5cd6e2	358	mutex_lock(&pps_idr_lock);
19dd2da3 TH	359	/*
	360	* Get new ID for the new PPS source. After idr_alloc() calling
	361	* the new source will be freely available into the kernel.
083e5866	362	*/
19dd2da3 TH	363	err = idr_alloc(&pps_idr, pps, 0, PPS_MAX_SOURCES, GFP_KERNEL);
	364	if (err < 0) {
	365	if (err == -ENOSPC) {
	366	pr_err("%s: too many PPS sources in the system\n",
	367	pps->info.name);
	368	err = -EBUSY;
	369	}
	370	goto out_unlock;
083e5866	371	}
19dd2da3 TH	372	pps->id = err;
19dd2da3 TH	373	mutex_unlock(&pps_idr_lock);
083e5866	374
5e196d34	375	devt = MKDEV(MAJOR(pps_devt), pps->id);
eae9d2ba	376
eae9d2ba RG	377	cdev_init(&pps->cdev, &pps_cdev_fops);
	378	pps->cdev.owner = pps->info.owner;
	379
5e196d34	380	err = cdev_add(&pps->cdev, devt, 1);
eae9d2ba	381	if (err) {
7f7cce74	382	pr_err("%s: failed to add char device %d:%d\n",
eae9d2ba	383	pps->info.name, MAJOR(pps_devt), pps->id);
083e5866	384	goto free_idr;
eae9d2ba	385	}
5e196d34	386	pps->dev = device_create(pps_class, pps->info.dev, devt, pps,
eae9d2ba	387	"pps%d", pps->id);
668f06b9 EG	388	if (IS_ERR(pps->dev)) {
668f06b9 EG	389	err = PTR_ERR(pps->dev);
eae9d2ba	390	goto del_cdev;
668f06b9	391	}
eae9d2ba	392
d953e0e8	393	/* Override the release function with our own */
083e5866 AG	394	pps->dev->release = pps_device_destruct;
083e5866 AG	395
eae9d2ba RG	396	pr_debug("source %s got cdev (%d:%d)\n", pps->info.name,
	397	MAJOR(pps_devt), pps->id);
	398
	399	return 0;
	400
	401	del_cdev:
	402	cdev_del(&pps->cdev);
	403
083e5866	404	free_idr:
2a5cd6e2	405	mutex_lock(&pps_idr_lock);
083e5866	406	idr_remove(&pps_idr, pps->id);
19dd2da3	407	out_unlock:
2a5cd6e2	408	mutex_unlock(&pps_idr_lock);
eae9d2ba RG	409	return err;
	410	}
	411
	412	void pps_unregister_cdev(struct pps_device *pps)
	413	{
d953e0e8	414	pr_debug("unregistering pps%d\n", pps->id);
513b032c	415	pps->lookup_cookie = NULL;
5e196d34	416	device_destroy(pps_class, pps->dev->devt);
eae9d2ba RG	417	}
eae9d2ba RG	418
513b032c GS	419	/*
	420	* Look up a pps device by magic cookie.
	421	* The cookie is usually a pointer to some enclosing device, but this
	422	* code doesn't care; you should never be dereferencing it.
	423	*
	424	* This is a bit of a kludge that is currently used only by the PPS
	425	* serial line discipline. It may need to be tweaked when a second user
	426	* is found.
	427	*
	428	* There is no function interface for setting the lookup_cookie field.
	429	* It's initialized to NULL when the pps device is created, and if a
	430	* client wants to use it, just fill it in afterward.
	431	*
	432	* The cookie is automatically set to NULL in pps_unregister_source()
	433	* so that it will not be used again, even if the pps device cannot
	434	* be removed from the idr due to pending references holding the minor
	435	* number in use.
	436	*/
	437	struct pps_device pps_lookup_dev(void const cookie)
	438	{
	439	struct pps_device *pps;
	440	unsigned id;
	441
	442	rcu_read_lock();
	443	idr_for_each_entry(&pps_idr, pps, id)
	444	if (cookie == pps->lookup_cookie)
	445	break;
	446	rcu_read_unlock();
	447	return pps;
	448	}
	449	EXPORT_SYMBOL(pps_lookup_dev);
	450
eae9d2ba RG	451	/*
	452	* Module stuff
	453	*/
	454
	455	static void __exit pps_exit(void)
	456	{
	457	class_destroy(pps_class);
	458	unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES);
	459	}
	460
	461	static int __init pps_init(void)
	462	{
	463	int err;
	464
	465	pps_class = class_create(THIS_MODULE, "pps");
7ad12566	466	if (IS_ERR(pps_class)) {
7f7cce74	467	pr_err("failed to allocate class\n");
7ad12566	468	return PTR_ERR(pps_class);
eae9d2ba	469	}
bd0eae4e	470	pps_class->dev_groups = pps_groups;
eae9d2ba RG	471
	472	err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps");
	473	if (err < 0) {
7f7cce74	474	pr_err("failed to allocate char device region\n");
eae9d2ba RG	475	goto remove_class;
	476	}
	477
	478	pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS);
	479	pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
	480	"<giometti@linux.it>\n", PPS_VERSION);
	481
	482	return 0;
	483
	484	remove_class:
	485	class_destroy(pps_class);
	486
	487	return err;
	488	}
	489
	490	subsys_initcall(pps_init);
	491	module_exit(pps_exit);
	492
	493	MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
	494	MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION);
	495	MODULE_LICENSE("GPL");