[mirror_ubuntu-bionic-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;

		/*
		 * 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
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
f6b03f2b ML	169	/*
	170	* Clear unused fields of pps_kparams to avoid leaking
	171	* uninitialized data of the PPS_SETPARAMS caller via
	172	* PPS_GETPARAMS
	173	*/
	174	pps->params.assert_off_tu.flags = 0;
	175	pps->params.clear_off_tu.flags = 0;
	176
eae9d2ba RG	177	spin_unlock_irq(&pps->lock);
	178
	179	break;
	180
	181	case PPS_GETCAP:
7f7cce74	182	dev_dbg(pps->dev, "PPS_GETCAP\n");
eae9d2ba RG	183
	184	err = put_user(pps->info.mode, iuarg);
	185	if (err)
	186	return -EFAULT;
	187
	188	break;
	189
86d921f9 AG	190	case PPS_FETCH: {
	191	struct pps_fdata fdata;
	192
7f7cce74	193	dev_dbg(pps->dev, "PPS_FETCH\n");
eae9d2ba RG	194
	195	err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata));
	196	if (err)
	197	return -EFAULT;
	198
c2a49fe8 MR	199	err = pps_cdev_pps_fetch(pps, &fdata);
	200	if (err)
	201	return err;
eae9d2ba RG	202
	203	/* Return the fetched timestamp */
	204	spin_lock_irq(&pps->lock);
	205
	206	fdata.info.assert_sequence = pps->assert_sequence;
	207	fdata.info.clear_sequence = pps->clear_sequence;
	208	fdata.info.assert_tu = pps->assert_tu;
	209	fdata.info.clear_tu = pps->clear_tu;
	210	fdata.info.current_mode = pps->current_mode;
	211
	212	spin_unlock_irq(&pps->lock);
	213
	214	err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata));
	215	if (err)
	216	return -EFAULT;
	217
	218	break;
86d921f9	219	}
717c0336 AG	220	case PPS_KC_BIND: {
	221	struct pps_bind_args bind_args;
	222
	223	dev_dbg(pps->dev, "PPS_KC_BIND\n");
	224
	225	/* Check the capabilities */
	226	if (!capable(CAP_SYS_TIME))
	227	return -EPERM;
	228
	229	if (copy_from_user(&bind_args, uarg,
	230	sizeof(struct pps_bind_args)))
	231	return -EFAULT;
	232
	233	/* Check for supported capabilities */
	234	if ((bind_args.edge & ~pps->info.mode) != 0) {
	235	dev_err(pps->dev, "unsupported capabilities (%x)\n",
	236	bind_args.edge);
	237	return -EINVAL;
	238	}
	239
	240	/* Validate parameters roughly */
	241	if (bind_args.tsformat != PPS_TSFMT_TSPEC \|\|
	242	(bind_args.edge & ~PPS_CAPTUREBOTH) != 0 \|\|
	243	bind_args.consumer != PPS_KC_HARDPPS) {
	244	dev_err(pps->dev, "invalid kernel consumer bind"
	245	" parameters (%x)\n", bind_args.edge);
	246	return -EINVAL;
	247	}
	248
	249	err = pps_kc_bind(pps, &bind_args);
	250	if (err < 0)
	251	return err;
	252
	253	break;
	254	}
eae9d2ba RG	255	default:
eae9d2ba RG	256	return -ENOTTY;
eae9d2ba RG	257	}
	258
	259	return 0;
	260	}
	261
2ac66657 MR	262	#ifdef CONFIG_COMPAT
	263	static long pps_cdev_compat_ioctl(struct file *file,
	264	unsigned int cmd, unsigned long arg)
	265	{
c2a49fe8 MR	266	struct pps_device *pps = file->private_data;
	267	void __user uarg = (void __user ) arg;
	268
2ac66657 MR	269	cmd = _IOC(_IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), sizeof(void *));
2ac66657 MR	270
c2a49fe8 MR	271	if (cmd == PPS_FETCH) {
	272	struct pps_fdata_compat compat;
	273	struct pps_fdata fdata;
	274	int err;
	275
	276	dev_dbg(pps->dev, "PPS_FETCH\n");
	277
	278	err = copy_from_user(&compat, uarg, sizeof(struct pps_fdata_compat));
	279	if (err)
	280	return -EFAULT;
	281
	282	memcpy(&fdata.timeout, &compat.timeout,
	283	sizeof(struct pps_ktime_compat));
	284
	285	err = pps_cdev_pps_fetch(pps, &fdata);
	286	if (err)
	287	return err;
	288
	289	/* Return the fetched timestamp */
	290	spin_lock_irq(&pps->lock);
	291
	292	compat.info.assert_sequence = pps->assert_sequence;
	293	compat.info.clear_sequence = pps->clear_sequence;
	294	compat.info.current_mode = pps->current_mode;
	295
	296	memcpy(&compat.info.assert_tu, &pps->assert_tu,
	297	sizeof(struct pps_ktime_compat));
	298	memcpy(&compat.info.clear_tu, &pps->clear_tu,
	299	sizeof(struct pps_ktime_compat));
	300
	301	spin_unlock_irq(&pps->lock);
	302
	303	return copy_to_user(uarg, &compat,
	304	sizeof(struct pps_fdata_compat)) ? -EFAULT : 0;
	305	}
	306
2ac66657 MR	307	return pps_cdev_ioctl(file, cmd, arg);
	308	}
	309	#else
	310	#define pps_cdev_compat_ioctl NULL
	311	#endif
	312
eae9d2ba RG	313	static int pps_cdev_open(struct inode inode, struct file file)
	314	{
	315	struct pps_device *pps = container_of(inode->i_cdev,
	316	struct pps_device, cdev);
eae9d2ba	317	file->private_data = pps;
d953e0e8	318	kobject_get(&pps->dev->kobj);
eae9d2ba RG	319	return 0;
	320	}
	321
	322	static int pps_cdev_release(struct inode inode, struct file file)
	323	{
d953e0e8 GS	324	struct pps_device *pps = container_of(inode->i_cdev,
	325	struct pps_device, cdev);
	326	kobject_put(&pps->dev->kobj);
eae9d2ba RG	327	return 0;
	328	}
	329
	330	/*
	331	* Char device stuff
	332	*/
	333
	334	static const struct file_operations pps_cdev_fops = {
	335	.owner = THIS_MODULE,
	336	.llseek = no_llseek,
	337	.poll = pps_cdev_poll,
	338	.fasync = pps_cdev_fasync,
2ac66657	339	.compat_ioctl = pps_cdev_compat_ioctl,
eae9d2ba RG	340	.unlocked_ioctl = pps_cdev_ioctl,
	341	.open = pps_cdev_open,
	342	.release = pps_cdev_release,
	343	};
	344
083e5866 AG	345	static void pps_device_destruct(struct device *dev)
	346	{
	347	struct pps_device *pps = dev_get_drvdata(dev);
	348
d953e0e8 GS	349	cdev_del(&pps->cdev);
	350
	351	/* Now we can release the ID for re-use */
	352	pr_debug("deallocating pps%d\n", pps->id);
2a5cd6e2	353	mutex_lock(&pps_idr_lock);
083e5866	354	idr_remove(&pps_idr, pps->id);
2a5cd6e2	355	mutex_unlock(&pps_idr_lock);
083e5866 AG	356
	357	kfree(dev);
	358	kfree(pps);
	359	}
	360
eae9d2ba RG	361	int pps_register_cdev(struct pps_device *pps)
	362	{
	363	int err;
5e196d34 AG	364	dev_t devt;
5e196d34 AG	365
2a5cd6e2	366	mutex_lock(&pps_idr_lock);
19dd2da3 TH	367	/*
	368	* Get new ID for the new PPS source. After idr_alloc() calling
	369	* the new source will be freely available into the kernel.
083e5866	370	*/
19dd2da3 TH	371	err = idr_alloc(&pps_idr, pps, 0, PPS_MAX_SOURCES, GFP_KERNEL);
	372	if (err < 0) {
	373	if (err == -ENOSPC) {
	374	pr_err("%s: too many PPS sources in the system\n",
	375	pps->info.name);
	376	err = -EBUSY;
	377	}
	378	goto out_unlock;
083e5866	379	}
19dd2da3 TH	380	pps->id = err;
19dd2da3 TH	381	mutex_unlock(&pps_idr_lock);
083e5866	382
5e196d34	383	devt = MKDEV(MAJOR(pps_devt), pps->id);
eae9d2ba	384
eae9d2ba RG	385	cdev_init(&pps->cdev, &pps_cdev_fops);
	386	pps->cdev.owner = pps->info.owner;
	387
5e196d34	388	err = cdev_add(&pps->cdev, devt, 1);
eae9d2ba	389	if (err) {
7f7cce74	390	pr_err("%s: failed to add char device %d:%d\n",
eae9d2ba	391	pps->info.name, MAJOR(pps_devt), pps->id);
083e5866	392	goto free_idr;
eae9d2ba	393	}
5e196d34	394	pps->dev = device_create(pps_class, pps->info.dev, devt, pps,
eae9d2ba	395	"pps%d", pps->id);
668f06b9 EG	396	if (IS_ERR(pps->dev)) {
668f06b9 EG	397	err = PTR_ERR(pps->dev);
eae9d2ba	398	goto del_cdev;
668f06b9	399	}
eae9d2ba	400
d953e0e8	401	/* Override the release function with our own */
083e5866 AG	402	pps->dev->release = pps_device_destruct;
083e5866 AG	403
eae9d2ba RG	404	pr_debug("source %s got cdev (%d:%d)\n", pps->info.name,
	405	MAJOR(pps_devt), pps->id);
	406
	407	return 0;
	408
	409	del_cdev:
	410	cdev_del(&pps->cdev);
	411
083e5866	412	free_idr:
2a5cd6e2	413	mutex_lock(&pps_idr_lock);
083e5866	414	idr_remove(&pps_idr, pps->id);
19dd2da3	415	out_unlock:
2a5cd6e2	416	mutex_unlock(&pps_idr_lock);
eae9d2ba RG	417	return err;
	418	}
	419
	420	void pps_unregister_cdev(struct pps_device *pps)
	421	{
d953e0e8	422	pr_debug("unregistering pps%d\n", pps->id);
513b032c	423	pps->lookup_cookie = NULL;
5e196d34	424	device_destroy(pps_class, pps->dev->devt);
eae9d2ba RG	425	}
eae9d2ba RG	426
513b032c GS	427	/*
	428	* Look up a pps device by magic cookie.
	429	* The cookie is usually a pointer to some enclosing device, but this
	430	* code doesn't care; you should never be dereferencing it.
	431	*
	432	* This is a bit of a kludge that is currently used only by the PPS
	433	* serial line discipline. It may need to be tweaked when a second user
	434	* is found.
	435	*
	436	* There is no function interface for setting the lookup_cookie field.
	437	* It's initialized to NULL when the pps device is created, and if a
	438	* client wants to use it, just fill it in afterward.
	439	*
	440	* The cookie is automatically set to NULL in pps_unregister_source()
	441	* so that it will not be used again, even if the pps device cannot
	442	* be removed from the idr due to pending references holding the minor
	443	* number in use.
	444	*/
	445	struct pps_device pps_lookup_dev(void const cookie)
	446	{
	447	struct pps_device *pps;
	448	unsigned id;
	449
	450	rcu_read_lock();
	451	idr_for_each_entry(&pps_idr, pps, id)
	452	if (cookie == pps->lookup_cookie)
	453	break;
	454	rcu_read_unlock();
	455	return pps;
	456	}
	457	EXPORT_SYMBOL(pps_lookup_dev);
	458
eae9d2ba RG	459	/*
	460	* Module stuff
	461	*/
	462
	463	static void __exit pps_exit(void)
	464	{
	465	class_destroy(pps_class);
	466	unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES);
	467	}
	468
	469	static int __init pps_init(void)
	470	{
	471	int err;
	472
	473	pps_class = class_create(THIS_MODULE, "pps");
7ad12566	474	if (IS_ERR(pps_class)) {
7f7cce74	475	pr_err("failed to allocate class\n");
7ad12566	476	return PTR_ERR(pps_class);
eae9d2ba	477	}
bd0eae4e	478	pps_class->dev_groups = pps_groups;
eae9d2ba RG	479
	480	err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps");
	481	if (err < 0) {
7f7cce74	482	pr_err("failed to allocate char device region\n");
eae9d2ba RG	483	goto remove_class;
	484	}
	485
	486	pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS);
	487	pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
	488	"<giometti@linux.it>\n", PPS_VERSION);
	489
	490	return 0;
	491
	492	remove_class:
	493	class_destroy(pps_class);
	494
	495	return err;
	496	}
	497
	498	subsys_initcall(pps_init);
	499	module_exit(pps_exit);
	500
	501	MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
	502	MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION);
	503	MODULE_LICENSE("GPL");