[linux-2.6-block.git] / drivers / pps / pps.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * PPS core file
 *
 * Copyright (C) 2005-2009   Rodolfo Giometti <giometti@linux.it>
 */

#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 __poll_t pps_cdev_poll(struct file *file, poll_table *wait)
{
	struct pps_device *pps = file->private_data;

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

	return EPOLLIN | EPOLLRDNORM;
}

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;

		/*
		 * Clear unused fields of pps_kparams to avoid leaking
		 * uninitialized data of the PPS_SETPARAMS caller via
		 * PPS_GETPARAMS
		 */
		pps->params.assert_off_tu.flags = 0;
		pps->params.clear_off_tu.flags = 0;

		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
74ba9207	1	// SPDX-License-Identifier: GPL-2.0-or-later
eae9d2ba RG	2	/*
	3	* PPS core file
	4	*
eae9d2ba	5	* Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it>
eae9d2ba RG	6	*/
eae9d2ba RG	7
7f7cce74	8	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
eae9d2ba RG	9
	10	#include <linux/kernel.h>
	11	#include <linux/module.h>
	12	#include <linux/init.h>
	13	#include <linux/sched.h>
	14	#include <linux/uaccess.h>
	15	#include <linux/idr.h>
2a5cd6e2	16	#include <linux/mutex.h>
eae9d2ba RG	17	#include <linux/cdev.h>
	18	#include <linux/poll.h>
	19	#include <linux/pps_kernel.h>
083e5866	20	#include <linux/slab.h>
eae9d2ba	21
717c0336 AG	22	#include "kc.h"
717c0336 AG	23
eae9d2ba RG	24	/*
	25	* Local variables
	26	*/
	27
	28	static dev_t pps_devt;
	29	static struct class *pps_class;
	30
2a5cd6e2	31	static DEFINE_MUTEX(pps_idr_lock);
083e5866 AG	32	static DEFINE_IDR(pps_idr);
083e5866 AG	33
eae9d2ba RG	34	/*
	35	* Char device methods
	36	*/
	37
afc9a42b	38	static __poll_t pps_cdev_poll(struct file file, poll_table wait)
eae9d2ba RG	39	{
	40	struct pps_device *pps = file->private_data;
	41
	42	poll_wait(file, &pps->queue, wait);
	43
a9a08845	44	return EPOLLIN \| EPOLLRDNORM;
eae9d2ba RG	45	}
	46
	47	static int pps_cdev_fasync(int fd, struct file *file, int on)
	48	{
	49	struct pps_device *pps = file->private_data;
	50	return fasync_helper(fd, file, on, &pps->async_queue);
	51	}
	52
c2a49fe8 MR	53	static int pps_cdev_pps_fetch(struct pps_device pps, struct pps_fdata fdata)
	54	{
	55	unsigned int ev = pps->last_ev;
	56	int err = 0;
	57
	58	/* Manage the timeout */
	59	if (fdata->timeout.flags & PPS_TIME_INVALID)
	60	err = wait_event_interruptible(pps->queue,
	61	ev != pps->last_ev);
	62	else {
	63	unsigned long ticks;
	64
	65	dev_dbg(pps->dev, "timeout %lld.%09d\n",
	66	(long long) fdata->timeout.sec,
	67	fdata->timeout.nsec);
	68	ticks = fdata->timeout.sec * HZ;
	69	ticks += fdata->timeout.nsec / (NSEC_PER_SEC / HZ);
	70
	71	if (ticks != 0) {
	72	err = wait_event_interruptible_timeout(
	73	pps->queue,
	74	ev != pps->last_ev,
	75	ticks);
	76	if (err == 0)
	77	return -ETIMEDOUT;
	78	}
	79	}
	80
	81	/* Check for pending signals */
	82	if (err == -ERESTARTSYS) {
	83	dev_dbg(pps->dev, "pending signal caught\n");
	84	return -EINTR;
	85	}
	86
	87	return 0;
	88	}
	89
eae9d2ba RG	90	static long pps_cdev_ioctl(struct file *file,
	91	unsigned int cmd, unsigned long arg)
	92	{
	93	struct pps_device *pps = file->private_data;
	94	struct pps_kparams params;
eae9d2ba RG	95	void __user uarg = (void __user ) arg;
	96	int __user iuarg = (int __user ) arg;
	97	int err;
	98
	99	switch (cmd) {
	100	case PPS_GETPARAMS:
7f7cce74	101	dev_dbg(pps->dev, "PPS_GETPARAMS\n");
eae9d2ba	102
cbf83cc5 RG	103	spin_lock_irq(&pps->lock);
	104
	105	/* Get the current parameters */
	106	params = pps->params;
	107
	108	spin_unlock_irq(&pps->lock);
	109
	110	err = copy_to_user(uarg, &params, sizeof(struct pps_kparams));
eae9d2ba RG	111	if (err)
	112	return -EFAULT;
	113
	114	break;
	115
	116	case PPS_SETPARAMS:
7f7cce74	117	dev_dbg(pps->dev, "PPS_SETPARAMS\n");
eae9d2ba RG	118
	119	/* Check the capabilities */
	120	if (!capable(CAP_SYS_TIME))
	121	return -EPERM;
	122
	123	err = copy_from_user(&params, uarg, sizeof(struct pps_kparams));
	124	if (err)
	125	return -EFAULT;
	126	if (!(params.mode & (PPS_CAPTUREASSERT \| PPS_CAPTURECLEAR))) {
7f7cce74	127	dev_dbg(pps->dev, "capture mode unspecified (%x)\n",
eae9d2ba RG	128	params.mode);
	129	return -EINVAL;
	130	}
	131
	132	/* Check for supported capabilities */
	133	if ((params.mode & ~pps->info.mode) != 0) {
7f7cce74	134	dev_dbg(pps->dev, "unsupported capabilities (%x)\n",
eae9d2ba RG	135	params.mode);
	136	return -EINVAL;
	137	}
	138
	139	spin_lock_irq(&pps->lock);
	140
	141	/* Save the new parameters */
	142	pps->params = params;
	143
	144	/* Restore the read only parameters */
	145	if ((params.mode & (PPS_TSFMT_TSPEC \| PPS_TSFMT_NTPFP)) == 0) {
	146	/* section 3.3 of RFC 2783 interpreted */
7f7cce74	147	dev_dbg(pps->dev, "time format unspecified (%x)\n",
eae9d2ba RG	148	params.mode);
	149	pps->params.mode \|= PPS_TSFMT_TSPEC;
	150	}
	151	if (pps->info.mode & PPS_CANWAIT)
	152	pps->params.mode \|= PPS_CANWAIT;
	153	pps->params.api_version = PPS_API_VERS;
	154
5515e9a6 ML	155	/*
	156	* Clear unused fields of pps_kparams to avoid leaking
	157	* uninitialized data of the PPS_SETPARAMS caller via
	158	* PPS_GETPARAMS
	159	*/
	160	pps->params.assert_off_tu.flags = 0;
	161	pps->params.clear_off_tu.flags = 0;
	162
eae9d2ba RG	163	spin_unlock_irq(&pps->lock);
	164
	165	break;
	166
	167	case PPS_GETCAP:
7f7cce74	168	dev_dbg(pps->dev, "PPS_GETCAP\n");
eae9d2ba RG	169
	170	err = put_user(pps->info.mode, iuarg);
	171	if (err)
	172	return -EFAULT;
	173
	174	break;
	175
86d921f9 AG	176	case PPS_FETCH: {
	177	struct pps_fdata fdata;
	178
7f7cce74	179	dev_dbg(pps->dev, "PPS_FETCH\n");
eae9d2ba RG	180
	181	err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata));
	182	if (err)
	183	return -EFAULT;
	184
c2a49fe8 MR	185	err = pps_cdev_pps_fetch(pps, &fdata);
	186	if (err)
	187	return err;
eae9d2ba RG	188
	189	/* Return the fetched timestamp */
	190	spin_lock_irq(&pps->lock);
	191
	192	fdata.info.assert_sequence = pps->assert_sequence;
	193	fdata.info.clear_sequence = pps->clear_sequence;
	194	fdata.info.assert_tu = pps->assert_tu;
	195	fdata.info.clear_tu = pps->clear_tu;
	196	fdata.info.current_mode = pps->current_mode;
	197
	198	spin_unlock_irq(&pps->lock);
	199
	200	err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata));
	201	if (err)
	202	return -EFAULT;
	203
	204	break;
86d921f9	205	}
717c0336 AG	206	case PPS_KC_BIND: {
	207	struct pps_bind_args bind_args;
	208
	209	dev_dbg(pps->dev, "PPS_KC_BIND\n");
	210
	211	/* Check the capabilities */
	212	if (!capable(CAP_SYS_TIME))
	213	return -EPERM;
	214
	215	if (copy_from_user(&bind_args, uarg,
	216	sizeof(struct pps_bind_args)))
	217	return -EFAULT;
	218
	219	/* Check for supported capabilities */
	220	if ((bind_args.edge & ~pps->info.mode) != 0) {
	221	dev_err(pps->dev, "unsupported capabilities (%x)\n",
	222	bind_args.edge);
	223	return -EINVAL;
	224	}
	225
	226	/* Validate parameters roughly */
	227	if (bind_args.tsformat != PPS_TSFMT_TSPEC \|\|
	228	(bind_args.edge & ~PPS_CAPTUREBOTH) != 0 \|\|
	229	bind_args.consumer != PPS_KC_HARDPPS) {
	230	dev_err(pps->dev, "invalid kernel consumer bind"
	231	" parameters (%x)\n", bind_args.edge);
	232	return -EINVAL;
	233	}
	234
	235	err = pps_kc_bind(pps, &bind_args);
	236	if (err < 0)
	237	return err;
	238
	239	break;
	240	}
eae9d2ba RG	241	default:
eae9d2ba RG	242	return -ENOTTY;
eae9d2ba RG	243	}
	244
	245	return 0;
	246	}
	247
2ac66657 MR	248	#ifdef CONFIG_COMPAT
	249	static long pps_cdev_compat_ioctl(struct file *file,
	250	unsigned int cmd, unsigned long arg)
	251	{
c2a49fe8 MR	252	struct pps_device *pps = file->private_data;
	253	void __user uarg = (void __user ) arg;
	254
2ac66657 MR	255	cmd = _IOC(_IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), sizeof(void *));
2ac66657 MR	256
c2a49fe8 MR	257	if (cmd == PPS_FETCH) {
	258	struct pps_fdata_compat compat;
	259	struct pps_fdata fdata;
	260	int err;
	261
	262	dev_dbg(pps->dev, "PPS_FETCH\n");
	263
	264	err = copy_from_user(&compat, uarg, sizeof(struct pps_fdata_compat));
	265	if (err)
	266	return -EFAULT;
	267
	268	memcpy(&fdata.timeout, &compat.timeout,
	269	sizeof(struct pps_ktime_compat));
	270
	271	err = pps_cdev_pps_fetch(pps, &fdata);
	272	if (err)
	273	return err;
	274
	275	/* Return the fetched timestamp */
	276	spin_lock_irq(&pps->lock);
	277
	278	compat.info.assert_sequence = pps->assert_sequence;
	279	compat.info.clear_sequence = pps->clear_sequence;
	280	compat.info.current_mode = pps->current_mode;
	281
	282	memcpy(&compat.info.assert_tu, &pps->assert_tu,
	283	sizeof(struct pps_ktime_compat));
	284	memcpy(&compat.info.clear_tu, &pps->clear_tu,
	285	sizeof(struct pps_ktime_compat));
	286
	287	spin_unlock_irq(&pps->lock);
	288
	289	return copy_to_user(uarg, &compat,
	290	sizeof(struct pps_fdata_compat)) ? -EFAULT : 0;
	291	}
	292
2ac66657 MR	293	return pps_cdev_ioctl(file, cmd, arg);
	294	}
	295	#else
	296	#define pps_cdev_compat_ioctl NULL
	297	#endif
	298
eae9d2ba RG	299	static int pps_cdev_open(struct inode inode, struct file file)
	300	{
	301	struct pps_device *pps = container_of(inode->i_cdev,
	302	struct pps_device, cdev);
eae9d2ba	303	file->private_data = pps;
d953e0e8	304	kobject_get(&pps->dev->kobj);
eae9d2ba RG	305	return 0;
	306	}
	307
	308	static int pps_cdev_release(struct inode inode, struct file file)
	309	{
d953e0e8 GS	310	struct pps_device *pps = container_of(inode->i_cdev,
	311	struct pps_device, cdev);
	312	kobject_put(&pps->dev->kobj);
eae9d2ba RG	313	return 0;
	314	}
	315
	316	/*
	317	* Char device stuff
	318	*/
	319
	320	static const struct file_operations pps_cdev_fops = {
	321	.owner = THIS_MODULE,
	322	.llseek = no_llseek,
	323	.poll = pps_cdev_poll,
	324	.fasync = pps_cdev_fasync,
2ac66657	325	.compat_ioctl = pps_cdev_compat_ioctl,
eae9d2ba RG	326	.unlocked_ioctl = pps_cdev_ioctl,
	327	.open = pps_cdev_open,
	328	.release = pps_cdev_release,
	329	};
	330
083e5866 AG	331	static void pps_device_destruct(struct device *dev)
	332	{
	333	struct pps_device *pps = dev_get_drvdata(dev);
	334
d953e0e8 GS	335	cdev_del(&pps->cdev);
	336
	337	/* Now we can release the ID for re-use */
	338	pr_debug("deallocating pps%d\n", pps->id);
2a5cd6e2	339	mutex_lock(&pps_idr_lock);
083e5866	340	idr_remove(&pps_idr, pps->id);
2a5cd6e2	341	mutex_unlock(&pps_idr_lock);
083e5866 AG	342
	343	kfree(dev);
	344	kfree(pps);
	345	}
	346
eae9d2ba RG	347	int pps_register_cdev(struct pps_device *pps)
	348	{
	349	int err;
5e196d34 AG	350	dev_t devt;
5e196d34 AG	351
2a5cd6e2	352	mutex_lock(&pps_idr_lock);
19dd2da3 TH	353	/*
	354	* Get new ID for the new PPS source. After idr_alloc() calling
	355	* the new source will be freely available into the kernel.
083e5866	356	*/
19dd2da3 TH	357	err = idr_alloc(&pps_idr, pps, 0, PPS_MAX_SOURCES, GFP_KERNEL);
	358	if (err < 0) {
	359	if (err == -ENOSPC) {
	360	pr_err("%s: too many PPS sources in the system\n",
	361	pps->info.name);
	362	err = -EBUSY;
	363	}
	364	goto out_unlock;
083e5866	365	}
19dd2da3 TH	366	pps->id = err;
19dd2da3 TH	367	mutex_unlock(&pps_idr_lock);
083e5866	368
5e196d34	369	devt = MKDEV(MAJOR(pps_devt), pps->id);
eae9d2ba	370
eae9d2ba RG	371	cdev_init(&pps->cdev, &pps_cdev_fops);
	372	pps->cdev.owner = pps->info.owner;
	373
5e196d34	374	err = cdev_add(&pps->cdev, devt, 1);
eae9d2ba	375	if (err) {
7f7cce74	376	pr_err("%s: failed to add char device %d:%d\n",
eae9d2ba	377	pps->info.name, MAJOR(pps_devt), pps->id);
083e5866	378	goto free_idr;
eae9d2ba	379	}
5e196d34	380	pps->dev = device_create(pps_class, pps->info.dev, devt, pps,
eae9d2ba	381	"pps%d", pps->id);
668f06b9 EG	382	if (IS_ERR(pps->dev)) {
668f06b9 EG	383	err = PTR_ERR(pps->dev);
eae9d2ba	384	goto del_cdev;
668f06b9	385	}
eae9d2ba	386
d953e0e8	387	/* Override the release function with our own */
083e5866 AG	388	pps->dev->release = pps_device_destruct;
083e5866 AG	389
eae9d2ba RG	390	pr_debug("source %s got cdev (%d:%d)\n", pps->info.name,
	391	MAJOR(pps_devt), pps->id);
	392
	393	return 0;
	394
	395	del_cdev:
	396	cdev_del(&pps->cdev);
	397
083e5866	398	free_idr:
2a5cd6e2	399	mutex_lock(&pps_idr_lock);
083e5866	400	idr_remove(&pps_idr, pps->id);
19dd2da3	401	out_unlock:
2a5cd6e2	402	mutex_unlock(&pps_idr_lock);
eae9d2ba RG	403	return err;
	404	}
	405
	406	void pps_unregister_cdev(struct pps_device *pps)
	407	{
d953e0e8	408	pr_debug("unregistering pps%d\n", pps->id);
513b032c	409	pps->lookup_cookie = NULL;
5e196d34	410	device_destroy(pps_class, pps->dev->devt);
eae9d2ba RG	411	}
eae9d2ba RG	412
513b032c GS	413	/*
	414	* Look up a pps device by magic cookie.
	415	* The cookie is usually a pointer to some enclosing device, but this
	416	* code doesn't care; you should never be dereferencing it.
	417	*
	418	* This is a bit of a kludge that is currently used only by the PPS
	419	* serial line discipline. It may need to be tweaked when a second user
	420	* is found.
	421	*
	422	* There is no function interface for setting the lookup_cookie field.
	423	* It's initialized to NULL when the pps device is created, and if a
	424	* client wants to use it, just fill it in afterward.
	425	*
	426	* The cookie is automatically set to NULL in pps_unregister_source()
	427	* so that it will not be used again, even if the pps device cannot
	428	* be removed from the idr due to pending references holding the minor
	429	* number in use.
	430	*/
	431	struct pps_device pps_lookup_dev(void const cookie)
	432	{
	433	struct pps_device *pps;
	434	unsigned id;
	435
	436	rcu_read_lock();
	437	idr_for_each_entry(&pps_idr, pps, id)
	438	if (cookie == pps->lookup_cookie)
	439	break;
	440	rcu_read_unlock();
	441	return pps;
	442	}
	443	EXPORT_SYMBOL(pps_lookup_dev);
	444
eae9d2ba RG	445	/*
	446	* Module stuff
	447	*/
	448
	449	static void __exit pps_exit(void)
	450	{
	451	class_destroy(pps_class);
	452	unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES);
	453	}
	454
	455	static int __init pps_init(void)
	456	{
	457	int err;
	458
	459	pps_class = class_create(THIS_MODULE, "pps");
7ad12566	460	if (IS_ERR(pps_class)) {
7f7cce74	461	pr_err("failed to allocate class\n");
7ad12566	462	return PTR_ERR(pps_class);
eae9d2ba	463	}
bd0eae4e	464	pps_class->dev_groups = pps_groups;
eae9d2ba RG	465
	466	err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps");
	467	if (err < 0) {
7f7cce74	468	pr_err("failed to allocate char device region\n");
eae9d2ba RG	469	goto remove_class;
	470	}
	471
	472	pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS);
	473	pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
	474	"<giometti@linux.it>\n", PPS_VERSION);
	475
	476	return 0;
	477
	478	remove_class:
	479	class_destroy(pps_class);
	480
	481	return err;
	482	}
	483
	484	subsys_initcall(pps_init);
	485	module_exit(pps_exit);
	486
	487	MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
	488	MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION);
	489	MODULE_LICENSE("GPL");