[linux-2.6-block.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;
	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;

		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 = kmalloc(sizeof(*sysoff), GFP_KERNEL);
		if (!sysoff) {
			err = -ENOMEM;
			break;
		}
		if (copy_from_user(sysoff, (void __user *)arg,
				   sizeof(*sysoff))) {
			err = -EFAULT;
			break;
		}
		if (sysoff->n_samples > PTP_MAX_SAMPLES) {
			err = -EINVAL;
			break;
		}
		pct = &sysoff->ts[0];
		for (i = 0; i < sysoff->n_samples; i++) {
			getnstimeofday64(&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++;
		}
		getnstimeofday64(&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;
}

unsigned int 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) ? POLLIN : 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;
6092315d RC	92	default:
	93	return -EINVAL;
	94	}
	95
6092315d RC	96	if (info->verify(info, pin, func, chan)) {
	97	pr_err("driver cannot use function %u on pin %u\n", func, chan);
	98	return -EOPNOTSUPP;
	99	}
	100
	101	/* Disable whatever function was previously assigned. */
	102	if (pin1) {
	103	ptp_disable_pinfunc(info, func, chan);
	104	pin1->func = PTP_PF_NONE;
	105	pin1->chan = 0;
	106	}
	107	ptp_disable_pinfunc(info, pin2->func, pin2->chan);
	108	pin2->func = func;
	109	pin2->chan = chan;
	110
	111	return 0;
	112	}
	113
d94ba80e RC	114	int ptp_open(struct posix_clock *pc, fmode_t fmode)
	115	{
	116	return 0;
	117	}
	118
	119	long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
	120	{
	121	struct ptp_clock_caps caps;
	122	struct ptp_clock_request req;
c3484c27	123	struct ptp_sys_offset *sysoff = NULL;
719f1aa4	124	struct ptp_sys_offset_precise precise_offset;
6092315d	125	struct ptp_pin_desc pd;
d94ba80e RC	126	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
d94ba80e RC	127	struct ptp_clock_info *ops = ptp->info;
215b13dd	128	struct ptp_clock_time *pct;
e13cfcb0	129	struct timespec64 ts;
719f1aa4	130	struct system_device_crosststamp xtstamp;
d94ba80e	131	int enable, err = 0;
6092315d	132	unsigned int i, pin_index;
d94ba80e RC	133
	134	switch (cmd) {
	135
	136	case PTP_CLOCK_GETCAPS:
	137	memset(&caps, 0, sizeof(caps));
	138	caps.max_adj = ptp->info->max_adj;
	139	caps.n_alarm = ptp->info->n_alarm;
	140	caps.n_ext_ts = ptp->info->n_ext_ts;
	141	caps.n_per_out = ptp->info->n_per_out;
	142	caps.pps = ptp->info->pps;
6092315d	143	caps.n_pins = ptp->info->n_pins;
719f1aa4	144	caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
e23ef227 DC	145	if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
e23ef227 DC	146	err = -EFAULT;
d94ba80e RC	147	break;
	148
	149	case PTP_EXTTS_REQUEST:
	150	if (copy_from_user(&req.extts, (void __user *)arg,
	151	sizeof(req.extts))) {
	152	err = -EFAULT;
	153	break;
	154	}
	155	if (req.extts.index >= ops->n_ext_ts) {
	156	err = -EINVAL;
	157	break;
	158	}
	159	req.type = PTP_CLK_REQ_EXTTS;
	160	enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
	161	err = ops->enable(ops, &req, enable);
	162	break;
	163
	164	case PTP_PEROUT_REQUEST:
	165	if (copy_from_user(&req.perout, (void __user *)arg,
	166	sizeof(req.perout))) {
	167	err = -EFAULT;
	168	break;
	169	}
	170	if (req.perout.index >= ops->n_per_out) {
	171	err = -EINVAL;
	172	break;
	173	}
	174	req.type = PTP_CLK_REQ_PEROUT;
	175	enable = req.perout.period.sec \|\| req.perout.period.nsec;
	176	err = ops->enable(ops, &req, enable);
	177	break;
	178
	179	case PTP_ENABLE_PPS:
	180	if (!capable(CAP_SYS_TIME))
	181	return -EPERM;
	182	req.type = PTP_CLK_REQ_PPS;
	183	enable = arg ? 1 : 0;
	184	err = ops->enable(ops, &req, enable);
	185	break;
	186
719f1aa4 CH	187	case PTP_SYS_OFFSET_PRECISE:
	188	if (!ptp->info->getcrosststamp) {
	189	err = -EOPNOTSUPP;
	190	break;
	191	}
	192	err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
	193	if (err)
	194	break;
	195
	196	ts = ktime_to_timespec64(xtstamp.device);
	197	precise_offset.device.sec = ts.tv_sec;
	198	precise_offset.device.nsec = ts.tv_nsec;
	199	ts = ktime_to_timespec64(xtstamp.sys_realtime);
	200	precise_offset.sys_realtime.sec = ts.tv_sec;
	201	precise_offset.sys_realtime.nsec = ts.tv_nsec;
	202	ts = ktime_to_timespec64(xtstamp.sys_monoraw);
	203	precise_offset.sys_monoraw.sec = ts.tv_sec;
	204	precise_offset.sys_monoraw.nsec = ts.tv_nsec;
	205	if (copy_to_user((void __user *)arg, &precise_offset,
	206	sizeof(precise_offset)))
	207	err = -EFAULT;
	208	break;
	209
215b13dd	210	case PTP_SYS_OFFSET:
c3484c27 RC	211	sysoff = kmalloc(sizeof(*sysoff), GFP_KERNEL);
	212	if (!sysoff) {
	213	err = -ENOMEM;
	214	break;
	215	}
	216	if (copy_from_user(sysoff, (void __user *)arg,
	217	sizeof(*sysoff))) {
215b13dd RC	218	err = -EFAULT;
	219	break;
	220	}
c3484c27	221	if (sysoff->n_samples > PTP_MAX_SAMPLES) {
215b13dd RC	222	err = -EINVAL;
	223	break;
	224	}
c3484c27 RC	225	pct = &sysoff->ts[0];
c3484c27 RC	226	for (i = 0; i < sysoff->n_samples; i++) {
e13cfcb0	227	getnstimeofday64(&ts);
215b13dd RC	228	pct->sec = ts.tv_sec;
	229	pct->nsec = ts.tv_nsec;
	230	pct++;
ed7c6317	231	ptp->info->gettime64(ptp->info, &ts);
215b13dd RC	232	pct->sec = ts.tv_sec;
	233	pct->nsec = ts.tv_nsec;
	234	pct++;
	235	}
e13cfcb0	236	getnstimeofday64(&ts);
215b13dd RC	237	pct->sec = ts.tv_sec;
215b13dd RC	238	pct->nsec = ts.tv_nsec;
c3484c27	239	if (copy_to_user((void __user )arg, sysoff, sizeof(sysoff)))
215b13dd RC	240	err = -EFAULT;
	241	break;
	242
6092315d RC	243	case PTP_PIN_GETFUNC:
	244	if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
	245	err = -EFAULT;
	246	break;
	247	}
	248	pin_index = pd.index;
	249	if (pin_index >= ops->n_pins) {
	250	err = -EINVAL;
	251	break;
	252	}
	253	if (mutex_lock_interruptible(&ptp->pincfg_mux))
	254	return -ERESTARTSYS;
	255	pd = ops->pin_config[pin_index];
	256	mutex_unlock(&ptp->pincfg_mux);
	257	if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
	258	err = -EFAULT;
	259	break;
	260
	261	case PTP_PIN_SETFUNC:
	262	if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
	263	err = -EFAULT;
	264	break;
	265	}
	266	pin_index = pd.index;
	267	if (pin_index >= ops->n_pins) {
	268	err = -EINVAL;
	269	break;
	270	}
	271	if (mutex_lock_interruptible(&ptp->pincfg_mux))
	272	return -ERESTARTSYS;
	273	err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
	274	mutex_unlock(&ptp->pincfg_mux);
	275	break;
	276
d94ba80e RC	277	default:
	278	err = -ENOTTY;
	279	break;
	280	}
c3484c27 RC	281
c3484c27 RC	282	kfree(sysoff);
d94ba80e RC	283	return err;
	284	}
	285
	286	unsigned int ptp_poll(struct posix_clock pc, struct file fp, poll_table *wait)
	287	{
	288	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
	289
	290	poll_wait(fp, &ptp->tsev_wq, wait);
	291
	292	return queue_cnt(&ptp->tsevq) ? POLLIN : 0;
	293	}
	294
c7ec0bad RC	295	#define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
c7ec0bad RC	296
d94ba80e RC	297	ssize_t ptp_read(struct posix_clock *pc,
	298	uint rdflags, char __user *buf, size_t cnt)
	299	{
	300	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
	301	struct timestamp_event_queue *queue = &ptp->tsevq;
c7ec0bad	302	struct ptp_extts_event *event;
d94ba80e RC	303	unsigned long flags;
d94ba80e RC	304	size_t qcnt, i;
c7ec0bad	305	int result;
d94ba80e RC	306
	307	if (cnt % sizeof(struct ptp_extts_event) != 0)
	308	return -EINVAL;
	309
c7ec0bad RC	310	if (cnt > EXTTS_BUFSIZE)
c7ec0bad RC	311	cnt = EXTTS_BUFSIZE;
d94ba80e RC	312
	313	cnt = cnt / sizeof(struct ptp_extts_event);
	314
	315	if (mutex_lock_interruptible(&ptp->tsevq_mux))
	316	return -ERESTARTSYS;
	317
	318	if (wait_event_interruptible(ptp->tsev_wq,
	319	ptp->defunct \|\| queue_cnt(queue))) {
	320	mutex_unlock(&ptp->tsevq_mux);
	321	return -ERESTARTSYS;
	322	}
	323
fb5a18cf DC	324	if (ptp->defunct) {
fb5a18cf DC	325	mutex_unlock(&ptp->tsevq_mux);
d94ba80e	326	return -ENODEV;
fb5a18cf	327	}
d94ba80e	328
c7ec0bad RC	329	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
	330	if (!event) {
	331	mutex_unlock(&ptp->tsevq_mux);
	332	return -ENOMEM;
	333	}
	334
d94ba80e RC	335	spin_lock_irqsave(&queue->lock, flags);
	336
	337	qcnt = queue_cnt(queue);
	338
	339	if (cnt > qcnt)
	340	cnt = qcnt;
	341
	342	for (i = 0; i < cnt; i++) {
	343	event[i] = queue->buf[queue->head];
	344	queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
	345	}
	346
	347	spin_unlock_irqrestore(&queue->lock, flags);
	348
	349	cnt = cnt * sizeof(struct ptp_extts_event);
	350
	351	mutex_unlock(&ptp->tsevq_mux);
	352
c7ec0bad	353	result = cnt;
fb5a18cf	354	if (copy_to_user(buf, event, cnt))
c7ec0bad	355	result = -EFAULT;
d94ba80e	356
c7ec0bad RC	357	kfree(event);
c7ec0bad RC	358	return result;
d94ba80e	359	}