[mirror_ubuntu-hirsute-kernel.git] / drivers / ptp / ptp_chardev.c

/*
 * PTP 1588 clock support - character device implementation.
 *
 * Copyright (C) 2010 OMICRON electronics GmbH
 *
 *  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.
 */
#include <linux/module.h>
#include <linux/posix-clock.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/timekeeping.h>

#include "ptp_private.h"

static int ptp_disable_pinfunc(struct ptp_clock_info *ops,
			       enum ptp_pin_function func, unsigned int chan)
{
	struct ptp_clock_request rq;
	int err = 0;

	memset(&rq, 0, sizeof(rq));

	switch (func) {
	case PTP_PF_NONE:
		break;
	case PTP_PF_EXTTS:
		rq.type = PTP_CLK_REQ_EXTTS;
		rq.extts.index = chan;
		err = ops->enable(ops, &rq, 0);
		break;
	case PTP_PF_PEROUT:
		rq.type = PTP_CLK_REQ_PEROUT;
		rq.perout.index = chan;
		err = ops->enable(ops, &rq, 0);
		break;
	case PTP_PF_PHYSYNC:
		break;
	default:
		return -EINVAL;
	}

	return err;
}

int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
		    enum ptp_pin_function func, unsigned int chan)
{
	struct ptp_clock_info *info = ptp->info;
	struct ptp_pin_desc *pin1 = NULL, *pin2 = &info->pin_config[pin];
	unsigned int i;

	/* Check to see if any other pin previously had this function. */
	for (i = 0; i < info->n_pins; i++) {
		if (info->pin_config[i].func == func &&
		    info->pin_config[i].chan == chan) {
			pin1 = &info->pin_config[i];
			break;
		}
	}
	if (pin1 && i == pin)
		return 0;

	/* Check the desired function and channel. */
	switch (func) {
	case PTP_PF_NONE:
		break;
	case PTP_PF_EXTTS:
		if (chan >= info->n_ext_ts)
			return -EINVAL;
		break;
	case PTP_PF_PEROUT:
		if (chan >= info->n_per_out)
			return -EINVAL;
		break;
	case PTP_PF_PHYSYNC:
		if (chan != 0)
			return -EINVAL;
		break;
	default:
		return -EINVAL;
	}

	if (info->verify(info, pin, func, chan)) {
		pr_err("driver cannot use function %u on pin %u\n", func, chan);
		return -EOPNOTSUPP;
	}

	/* Disable whatever function was previously assigned. */
	if (pin1) {
		ptp_disable_pinfunc(info, func, chan);
		pin1->func = PTP_PF_NONE;
		pin1->chan = 0;
	}
	ptp_disable_pinfunc(info, pin2->func, pin2->chan);
	pin2->func = func;
	pin2->chan = chan;

	return 0;
}

int ptp_open(struct posix_clock *pc, fmode_t fmode)
{
	return 0;
}

long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
{
	struct ptp_clock_caps caps;
	struct ptp_clock_request req;
	struct ptp_sys_offset *sysoff = NULL;
	struct ptp_sys_offset_precise precise_offset;
	struct ptp_pin_desc pd;
	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
	struct ptp_clock_info *ops = ptp->info;
	struct ptp_clock_time *pct;
	struct timespec64 ts;
	struct system_device_crosststamp xtstamp;
	int enable, err = 0;
	unsigned int i, pin_index;

	switch (cmd) {

	case PTP_CLOCK_GETCAPS:
		memset(&caps, 0, sizeof(caps));
		caps.max_adj = ptp->info->max_adj;
		caps.n_alarm = ptp->info->n_alarm;
		caps.n_ext_ts = ptp->info->n_ext_ts;
		caps.n_per_out = ptp->info->n_per_out;
		caps.pps = ptp->info->pps;
		caps.n_pins = ptp->info->n_pins;
		caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
		if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
			err = -EFAULT;
		break;

	case PTP_EXTTS_REQUEST:
		if (copy_from_user(&req.extts, (void __user *)arg,
				   sizeof(req.extts))) {
			err = -EFAULT;
			break;
		}
		if (req.extts.index >= ops->n_ext_ts) {
			err = -EINVAL;
			break;
		}
		req.type = PTP_CLK_REQ_EXTTS;
		enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
		err = ops->enable(ops, &req, enable);
		break;

	case PTP_PEROUT_REQUEST:
		if (copy_from_user(&req.perout, (void __user *)arg,
				   sizeof(req.perout))) {
			err = -EFAULT;
			break;
		}
		if (req.perout.index >= ops->n_per_out) {
			err = -EINVAL;
			break;
		}
		req.type = PTP_CLK_REQ_PEROUT;
		enable = req.perout.period.sec || req.perout.period.nsec;
		err = ops->enable(ops, &req, enable);
		break;

	case PTP_ENABLE_PPS:
		if (!capable(CAP_SYS_TIME))
			return -EPERM;
		req.type = PTP_CLK_REQ_PPS;
		enable = arg ? 1 : 0;
		err = ops->enable(ops, &req, enable);
		break;

	case PTP_SYS_OFFSET_PRECISE:
		if (!ptp->info->getcrosststamp) {
			err = -EOPNOTSUPP;
			break;
		}
		err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
		if (err)
			break;

		memset(&precise_offset, 0, sizeof(precise_offset));
		ts = ktime_to_timespec64(xtstamp.device);
		precise_offset.device.sec = ts.tv_sec;
		precise_offset.device.nsec = ts.tv_nsec;
		ts = ktime_to_timespec64(xtstamp.sys_realtime);
		precise_offset.sys_realtime.sec = ts.tv_sec;
		precise_offset.sys_realtime.nsec = ts.tv_nsec;
		ts = ktime_to_timespec64(xtstamp.sys_monoraw);
		precise_offset.sys_monoraw.sec = ts.tv_sec;
		precise_offset.sys_monoraw.nsec = ts.tv_nsec;
		if (copy_to_user((void __user *)arg, &precise_offset,
				 sizeof(precise_offset)))
			err = -EFAULT;
		break;

	case PTP_SYS_OFFSET:
		sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
		if (IS_ERR(sysoff)) {
			err = PTR_ERR(sysoff);
			sysoff = NULL;
			break;
		}
		if (sysoff->n_samples > PTP_MAX_SAMPLES) {
			err = -EINVAL;
			break;
		}
		pct = &sysoff->ts[0];
		for (i = 0; i < sysoff->n_samples; i++) {
			ktime_get_real_ts64(&ts);
			pct->sec = ts.tv_sec;
			pct->nsec = ts.tv_nsec;
			pct++;
			ptp->info->gettime64(ptp->info, &ts);
			pct->sec = ts.tv_sec;
			pct->nsec = ts.tv_nsec;
			pct++;
		}
		ktime_get_real_ts64(&ts);
		pct->sec = ts.tv_sec;
		pct->nsec = ts.tv_nsec;
		if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
			err = -EFAULT;
		break;

	case PTP_PIN_GETFUNC:
		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
			err = -EFAULT;
			break;
		}
		pin_index = pd.index;
		if (pin_index >= ops->n_pins) {
			err = -EINVAL;
			break;
		}
		if (mutex_lock_interruptible(&ptp->pincfg_mux))
			return -ERESTARTSYS;
		pd = ops->pin_config[pin_index];
		mutex_unlock(&ptp->pincfg_mux);
		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
			err = -EFAULT;
		break;

	case PTP_PIN_SETFUNC:
		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
			err = -EFAULT;
			break;
		}
		pin_index = pd.index;
		if (pin_index >= ops->n_pins) {
			err = -EINVAL;
			break;
		}
		if (mutex_lock_interruptible(&ptp->pincfg_mux))
			return -ERESTARTSYS;
		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
		mutex_unlock(&ptp->pincfg_mux);
		break;

	default:
		err = -ENOTTY;
		break;
	}

	kfree(sysoff);
	return err;
}

__poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
{
	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);

	poll_wait(fp, &ptp->tsev_wq, wait);

	return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
}

#define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))

ssize_t ptp_read(struct posix_clock *pc,
		 uint rdflags, char __user *buf, size_t cnt)
{
	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
	struct timestamp_event_queue *queue = &ptp->tsevq;
	struct ptp_extts_event *event;
	unsigned long flags;
	size_t qcnt, i;
	int result;

	if (cnt % sizeof(struct ptp_extts_event) != 0)
		return -EINVAL;

	if (cnt > EXTTS_BUFSIZE)
		cnt = EXTTS_BUFSIZE;

	cnt = cnt / sizeof(struct ptp_extts_event);

	if (mutex_lock_interruptible(&ptp->tsevq_mux))
		return -ERESTARTSYS;

	if (wait_event_interruptible(ptp->tsev_wq,
				     ptp->defunct || queue_cnt(queue))) {
		mutex_unlock(&ptp->tsevq_mux);
		return -ERESTARTSYS;
	}

	if (ptp->defunct) {
		mutex_unlock(&ptp->tsevq_mux);
		return -ENODEV;
	}

	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
	if (!event) {
		mutex_unlock(&ptp->tsevq_mux);
		return -ENOMEM;
	}

	spin_lock_irqsave(&queue->lock, flags);

	qcnt = queue_cnt(queue);

	if (cnt > qcnt)
		cnt = qcnt;

	for (i = 0; i < cnt; i++) {
		event[i] = queue->buf[queue->head];
		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
	}

	spin_unlock_irqrestore(&queue->lock, flags);

	cnt = cnt * sizeof(struct ptp_extts_event);

	mutex_unlock(&ptp->tsevq_mux);

	result = cnt;
	if (copy_to_user(buf, event, cnt))
		result = -EFAULT;

	kfree(event);
	return result;
}
Commit	Line	Data
d94ba80e RC	1	/*
	2	* PTP 1588 clock support - character device implementation.
	3	*
	4	* Copyright (C) 2010 OMICRON electronics GmbH
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	19	*/
	20	#include <linux/module.h>
	21	#include <linux/posix-clock.h>
	22	#include <linux/poll.h>
	23	#include <linux/sched.h>
c7ec0bad	24	#include <linux/slab.h>
719f1aa4	25	#include <linux/timekeeping.h>
d94ba80e RC	26
	27	#include "ptp_private.h"
	28
6092315d RC	29	static int ptp_disable_pinfunc(struct ptp_clock_info *ops,
	30	enum ptp_pin_function func, unsigned int chan)
	31	{
	32	struct ptp_clock_request rq;
	33	int err = 0;
	34
	35	memset(&rq, 0, sizeof(rq));
	36
	37	switch (func) {
	38	case PTP_PF_NONE:
	39	break;
	40	case PTP_PF_EXTTS:
	41	rq.type = PTP_CLK_REQ_EXTTS;
	42	rq.extts.index = chan;
	43	err = ops->enable(ops, &rq, 0);
	44	break;
	45	case PTP_PF_PEROUT:
	46	rq.type = PTP_CLK_REQ_PEROUT;
	47	rq.perout.index = chan;
	48	err = ops->enable(ops, &rq, 0);
	49	break;
	50	case PTP_PF_PHYSYNC:
	51	break;
	52	default:
	53	return -EINVAL;
	54	}
	55
	56	return err;
	57	}
	58
	59	int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
	60	enum ptp_pin_function func, unsigned int chan)
	61	{
	62	struct ptp_clock_info *info = ptp->info;
	63	struct ptp_pin_desc pin1 = NULL, pin2 = &info->pin_config[pin];
	64	unsigned int i;
	65
	66	/* Check to see if any other pin previously had this function. */
	67	for (i = 0; i < info->n_pins; i++) {
	68	if (info->pin_config[i].func == func &&
	69	info->pin_config[i].chan == chan) {
	70	pin1 = &info->pin_config[i];
	71	break;
	72	}
	73	}
	74	if (pin1 && i == pin)
	75	return 0;
	76
	77	/* Check the desired function and channel. */
	78	switch (func) {
	79	case PTP_PF_NONE:
	80	break;
	81	case PTP_PF_EXTTS:
	82	if (chan >= info->n_ext_ts)
	83	return -EINVAL;
	84	break;
	85	case PTP_PF_PEROUT:
	86	if (chan >= info->n_per_out)
	87	return -EINVAL;
	88	break;
	89	case PTP_PF_PHYSYNC:
72df7a72 SS	90	if (chan != 0)
72df7a72 SS	91	return -EINVAL;
9ba8376c	92	break;
6092315d RC	93	default:
	94	return -EINVAL;
	95	}
	96
6092315d RC	97	if (info->verify(info, pin, func, chan)) {
	98	pr_err("driver cannot use function %u on pin %u\n", func, chan);
	99	return -EOPNOTSUPP;
	100	}
	101
	102	/* Disable whatever function was previously assigned. */
	103	if (pin1) {
	104	ptp_disable_pinfunc(info, func, chan);
	105	pin1->func = PTP_PF_NONE;
	106	pin1->chan = 0;
	107	}
	108	ptp_disable_pinfunc(info, pin2->func, pin2->chan);
	109	pin2->func = func;
	110	pin2->chan = chan;
	111
	112	return 0;
	113	}
	114
d94ba80e RC	115	int ptp_open(struct posix_clock *pc, fmode_t fmode)
	116	{
	117	return 0;
	118	}
	119
	120	long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
	121	{
	122	struct ptp_clock_caps caps;
	123	struct ptp_clock_request req;
c3484c27	124	struct ptp_sys_offset *sysoff = NULL;
719f1aa4	125	struct ptp_sys_offset_precise precise_offset;
6092315d	126	struct ptp_pin_desc pd;
d94ba80e RC	127	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
d94ba80e RC	128	struct ptp_clock_info *ops = ptp->info;
215b13dd	129	struct ptp_clock_time *pct;
e13cfcb0	130	struct timespec64 ts;
719f1aa4	131	struct system_device_crosststamp xtstamp;
d94ba80e	132	int enable, err = 0;
6092315d	133	unsigned int i, pin_index;
d94ba80e RC	134
	135	switch (cmd) {
	136
	137	case PTP_CLOCK_GETCAPS:
	138	memset(&caps, 0, sizeof(caps));
	139	caps.max_adj = ptp->info->max_adj;
	140	caps.n_alarm = ptp->info->n_alarm;
	141	caps.n_ext_ts = ptp->info->n_ext_ts;
	142	caps.n_per_out = ptp->info->n_per_out;
	143	caps.pps = ptp->info->pps;
6092315d	144	caps.n_pins = ptp->info->n_pins;
719f1aa4	145	caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
e23ef227 DC	146	if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
e23ef227 DC	147	err = -EFAULT;
d94ba80e RC	148	break;
	149
	150	case PTP_EXTTS_REQUEST:
	151	if (copy_from_user(&req.extts, (void __user *)arg,
	152	sizeof(req.extts))) {
	153	err = -EFAULT;
	154	break;
	155	}
	156	if (req.extts.index >= ops->n_ext_ts) {
	157	err = -EINVAL;
	158	break;
	159	}
	160	req.type = PTP_CLK_REQ_EXTTS;
	161	enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
	162	err = ops->enable(ops, &req, enable);
	163	break;
	164
	165	case PTP_PEROUT_REQUEST:
	166	if (copy_from_user(&req.perout, (void __user *)arg,
	167	sizeof(req.perout))) {
	168	err = -EFAULT;
	169	break;
	170	}
	171	if (req.perout.index >= ops->n_per_out) {
	172	err = -EINVAL;
	173	break;
	174	}
	175	req.type = PTP_CLK_REQ_PEROUT;
	176	enable = req.perout.period.sec \|\| req.perout.period.nsec;
	177	err = ops->enable(ops, &req, enable);
	178	break;
	179
	180	case PTP_ENABLE_PPS:
	181	if (!capable(CAP_SYS_TIME))
	182	return -EPERM;
	183	req.type = PTP_CLK_REQ_PPS;
	184	enable = arg ? 1 : 0;
	185	err = ops->enable(ops, &req, enable);
	186	break;
	187
719f1aa4 CH	188	case PTP_SYS_OFFSET_PRECISE:
	189	if (!ptp->info->getcrosststamp) {
	190	err = -EOPNOTSUPP;
	191	break;
	192	}
	193	err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
	194	if (err)
	195	break;
	196
02a9079c	197	memset(&precise_offset, 0, sizeof(precise_offset));
719f1aa4 CH	198	ts = ktime_to_timespec64(xtstamp.device);
	199	precise_offset.device.sec = ts.tv_sec;
	200	precise_offset.device.nsec = ts.tv_nsec;
	201	ts = ktime_to_timespec64(xtstamp.sys_realtime);
	202	precise_offset.sys_realtime.sec = ts.tv_sec;
	203	precise_offset.sys_realtime.nsec = ts.tv_nsec;
	204	ts = ktime_to_timespec64(xtstamp.sys_monoraw);
	205	precise_offset.sys_monoraw.sec = ts.tv_sec;
	206	precise_offset.sys_monoraw.nsec = ts.tv_nsec;
	207	if (copy_to_user((void __user *)arg, &precise_offset,
	208	sizeof(precise_offset)))
	209	err = -EFAULT;
	210	break;
	211
215b13dd	212	case PTP_SYS_OFFSET:
2ece068e MFW	213	sysoff = memdup_user((void __user )arg, sizeof(sysoff));
	214	if (IS_ERR(sysoff)) {
	215	err = PTR_ERR(sysoff);
6756325a	216	sysoff = NULL;
215b13dd RC	217	break;
215b13dd RC	218	}
c3484c27	219	if (sysoff->n_samples > PTP_MAX_SAMPLES) {
215b13dd RC	220	err = -EINVAL;
	221	break;
	222	}
c3484c27 RC	223	pct = &sysoff->ts[0];
c3484c27 RC	224	for (i = 0; i < sysoff->n_samples; i++) {
f696a21c	225	ktime_get_real_ts64(&ts);
215b13dd RC	226	pct->sec = ts.tv_sec;
	227	pct->nsec = ts.tv_nsec;
	228	pct++;
ed7c6317	229	ptp->info->gettime64(ptp->info, &ts);
215b13dd RC	230	pct->sec = ts.tv_sec;
	231	pct->nsec = ts.tv_nsec;
	232	pct++;
	233	}
f696a21c	234	ktime_get_real_ts64(&ts);
215b13dd RC	235	pct->sec = ts.tv_sec;
215b13dd RC	236	pct->nsec = ts.tv_nsec;
c3484c27	237	if (copy_to_user((void __user )arg, sysoff, sizeof(sysoff)))
215b13dd RC	238	err = -EFAULT;
	239	break;
	240
6092315d RC	241	case PTP_PIN_GETFUNC:
	242	if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
	243	err = -EFAULT;
	244	break;
	245	}
	246	pin_index = pd.index;
	247	if (pin_index >= ops->n_pins) {
	248	err = -EINVAL;
	249	break;
	250	}
	251	if (mutex_lock_interruptible(&ptp->pincfg_mux))
	252	return -ERESTARTSYS;
	253	pd = ops->pin_config[pin_index];
	254	mutex_unlock(&ptp->pincfg_mux);
	255	if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
	256	err = -EFAULT;
	257	break;
	258
	259	case PTP_PIN_SETFUNC:
	260	if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
	261	err = -EFAULT;
	262	break;
	263	}
	264	pin_index = pd.index;
	265	if (pin_index >= ops->n_pins) {
	266	err = -EINVAL;
	267	break;
	268	}
	269	if (mutex_lock_interruptible(&ptp->pincfg_mux))
	270	return -ERESTARTSYS;
	271	err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
	272	mutex_unlock(&ptp->pincfg_mux);
	273	break;
	274
d94ba80e RC	275	default:
	276	err = -ENOTTY;
	277	break;
	278	}
c3484c27 RC	279
c3484c27 RC	280	kfree(sysoff);
d94ba80e RC	281	return err;
	282	}
	283
afc9a42b	284	__poll_t ptp_poll(struct posix_clock pc, struct file fp, poll_table *wait)
d94ba80e RC	285	{
	286	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
	287
	288	poll_wait(fp, &ptp->tsev_wq, wait);
	289
a9a08845	290	return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
d94ba80e RC	291	}
d94ba80e RC	292
c7ec0bad RC	293	#define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
c7ec0bad RC	294
d94ba80e RC	295	ssize_t ptp_read(struct posix_clock *pc,
	296	uint rdflags, char __user *buf, size_t cnt)
	297	{
	298	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
	299	struct timestamp_event_queue *queue = &ptp->tsevq;
c7ec0bad	300	struct ptp_extts_event *event;
d94ba80e RC	301	unsigned long flags;
d94ba80e RC	302	size_t qcnt, i;
c7ec0bad	303	int result;
d94ba80e RC	304
	305	if (cnt % sizeof(struct ptp_extts_event) != 0)
	306	return -EINVAL;
	307
c7ec0bad RC	308	if (cnt > EXTTS_BUFSIZE)
c7ec0bad RC	309	cnt = EXTTS_BUFSIZE;
d94ba80e RC	310
	311	cnt = cnt / sizeof(struct ptp_extts_event);
	312
	313	if (mutex_lock_interruptible(&ptp->tsevq_mux))
	314	return -ERESTARTSYS;
	315
	316	if (wait_event_interruptible(ptp->tsev_wq,
	317	ptp->defunct \|\| queue_cnt(queue))) {
	318	mutex_unlock(&ptp->tsevq_mux);
	319	return -ERESTARTSYS;
	320	}
	321
fb5a18cf DC	322	if (ptp->defunct) {
fb5a18cf DC	323	mutex_unlock(&ptp->tsevq_mux);
d94ba80e	324	return -ENODEV;
fb5a18cf	325	}
d94ba80e	326
c7ec0bad RC	327	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
	328	if (!event) {
	329	mutex_unlock(&ptp->tsevq_mux);
	330	return -ENOMEM;
	331	}
	332
d94ba80e RC	333	spin_lock_irqsave(&queue->lock, flags);
	334
	335	qcnt = queue_cnt(queue);
	336
	337	if (cnt > qcnt)
	338	cnt = qcnt;
	339
	340	for (i = 0; i < cnt; i++) {
	341	event[i] = queue->buf[queue->head];
	342	queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
	343	}
	344
	345	spin_unlock_irqrestore(&queue->lock, flags);
	346
	347	cnt = cnt * sizeof(struct ptp_extts_event);
	348
	349	mutex_unlock(&ptp->tsevq_mux);
	350
c7ec0bad	351	result = cnt;
fb5a18cf	352	if (copy_to_user(buf, event, cnt))
c7ec0bad	353	result = -EFAULT;
d94ba80e	354
c7ec0bad RC	355	kfree(event);
c7ec0bad RC	356	return result;
d94ba80e	357	}