[deliverable/linux.git] / drivers / ptp / ptp_clock.c

/*
 * PTP 1588 clock support
 *
 * 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/idr.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/posix-clock.h>
#include <linux/pps_kernel.h>
#include <linux/slab.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>

#include "ptp_private.h"

#define PTP_MAX_ALARMS 4
#define PTP_PPS_DEFAULTS (PPS_CAPTUREASSERT | PPS_OFFSETASSERT)
#define PTP_PPS_EVENT PPS_CAPTUREASSERT
#define PTP_PPS_MODE (PTP_PPS_DEFAULTS | PPS_CANWAIT | PPS_TSFMT_TSPEC)

/* private globals */

static dev_t ptp_devt;
static struct class *ptp_class;

static DEFINE_IDA(ptp_clocks_map);

/* time stamp event queue operations */

static inline int queue_free(struct timestamp_event_queue *q)
{
	return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
}

static void enqueue_external_timestamp(struct timestamp_event_queue *queue,
				       struct ptp_clock_event *src)
{
	struct ptp_extts_event *dst;
	unsigned long flags;
	s64 seconds;
	u32 remainder;

	seconds = div_u64_rem(src->timestamp, 1000000000, &remainder);

	spin_lock_irqsave(&queue->lock, flags);

	dst = &queue->buf[queue->tail];
	dst->index = src->index;
	dst->t.sec = seconds;
	dst->t.nsec = remainder;

	if (!queue_free(queue))
		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;

	queue->tail = (queue->tail + 1) % PTP_MAX_TIMESTAMPS;

	spin_unlock_irqrestore(&queue->lock, flags);
}

static s32 scaled_ppm_to_ppb(long ppm)
{
	/*
	 * The 'freq' field in the 'struct timex' is in parts per
	 * million, but with a 16 bit binary fractional field.
	 *
	 * We want to calculate
	 *
	 *    ppb = scaled_ppm * 1000 / 2^16
	 *
	 * which simplifies to
	 *
	 *    ppb = scaled_ppm * 125 / 2^13
	 */
	s64 ppb = 1 + ppm;
	ppb *= 125;
	ppb >>= 13;
	return (s32) ppb;
}

/* posix clock implementation */

static int ptp_clock_getres(struct posix_clock *pc, struct timespec *tp)
{
	tp->tv_sec = 0;
	tp->tv_nsec = 1;
	return 0;
}

static int ptp_clock_settime(struct posix_clock *pc, const struct timespec *tp)
{
	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
	struct timespec64 ts = timespec_to_timespec64(*tp);

	return  ptp->info->settime64(ptp->info, &ts);
}

static int ptp_clock_gettime(struct posix_clock *pc, struct timespec *tp)
{
	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
	struct timespec64 ts;
	int err;

	err = ptp->info->gettime64(ptp->info, &ts);
	if (!err)
		*tp = timespec64_to_timespec(ts);
	return err;
}

static int ptp_clock_adjtime(struct posix_clock *pc, struct timex *tx)
{
	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
	struct ptp_clock_info *ops;
	int err = -EOPNOTSUPP;

	ops = ptp->info;

	if (tx->modes & ADJ_SETOFFSET) {
		struct timespec ts;
		ktime_t kt;
		s64 delta;

		ts.tv_sec  = tx->time.tv_sec;
		ts.tv_nsec = tx->time.tv_usec;

		if (!(tx->modes & ADJ_NANO))
			ts.tv_nsec *= 1000;

		if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC)
			return -EINVAL;

		kt = timespec_to_ktime(ts);
		delta = ktime_to_ns(kt);
		err = ops->adjtime(ops, delta);
	} else if (tx->modes & ADJ_FREQUENCY) {
		s32 ppb = scaled_ppm_to_ppb(tx->freq);
		if (ppb > ops->max_adj || ppb < -ops->max_adj)
			return -ERANGE;
		err = ops->adjfreq(ops, ppb);
		ptp->dialed_frequency = tx->freq;
	} else if (tx->modes == 0) {
		tx->freq = ptp->dialed_frequency;
		err = 0;
	}

	return err;
}

static struct posix_clock_operations ptp_clock_ops = {
	.owner		= THIS_MODULE,
	.clock_adjtime	= ptp_clock_adjtime,
	.clock_gettime	= ptp_clock_gettime,
	.clock_getres	= ptp_clock_getres,
	.clock_settime	= ptp_clock_settime,
	.ioctl		= ptp_ioctl,
	.open		= ptp_open,
	.poll		= ptp_poll,
	.read		= ptp_read,
};

static void delete_ptp_clock(struct posix_clock *pc)
{
	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);

	mutex_destroy(&ptp->tsevq_mux);
	mutex_destroy(&ptp->pincfg_mux);
	ida_simple_remove(&ptp_clocks_map, ptp->index);
	kfree(ptp);
}

/* public interface */

struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
				     struct device *parent)
{
	struct ptp_clock *ptp;
	int err = 0, index, major = MAJOR(ptp_devt);

	if (info->n_alarm > PTP_MAX_ALARMS)
		return ERR_PTR(-EINVAL);

	/* Initialize a clock structure. */
	err = -ENOMEM;
	ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
	if (ptp == NULL)
		goto no_memory;

	index = ida_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, GFP_KERNEL);
	if (index < 0) {
		err = index;
		goto no_slot;
	}

	ptp->clock.ops = ptp_clock_ops;
	ptp->clock.release = delete_ptp_clock;
	ptp->info = info;
	ptp->devid = MKDEV(major, index);
	ptp->index = index;
	spin_lock_init(&ptp->tsevq.lock);
	mutex_init(&ptp->tsevq_mux);
	mutex_init(&ptp->pincfg_mux);
	init_waitqueue_head(&ptp->tsev_wq);

	/* Create a new device in our class. */
	ptp->dev = device_create(ptp_class, parent, ptp->devid, ptp,
				 "ptp%d", ptp->index);
	if (IS_ERR(ptp->dev))
		goto no_device;

	dev_set_drvdata(ptp->dev, ptp);

	err = ptp_populate_sysfs(ptp);
	if (err)
		goto no_sysfs;

	/* Register a new PPS source. */
	if (info->pps) {
		struct pps_source_info pps;
		memset(&pps, 0, sizeof(pps));
		snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
		pps.mode = PTP_PPS_MODE;
		pps.owner = info->owner;
		ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
		if (!ptp->pps_source) {
			pr_err("failed to register pps source\n");
			goto no_pps;
		}
	}

	/* Create a posix clock. */
	err = posix_clock_register(&ptp->clock, ptp->devid);
	if (err) {
		pr_err("failed to create posix clock\n");
		goto no_clock;
	}

	return ptp;

no_clock:
	if (ptp->pps_source)
		pps_unregister_source(ptp->pps_source);
no_pps:
	ptp_cleanup_sysfs(ptp);
no_sysfs:
	device_destroy(ptp_class, ptp->devid);
no_device:
	mutex_destroy(&ptp->tsevq_mux);
	mutex_destroy(&ptp->pincfg_mux);
no_slot:
	kfree(ptp);
no_memory:
	return ERR_PTR(err);
}
EXPORT_SYMBOL(ptp_clock_register);

int ptp_clock_unregister(struct ptp_clock *ptp)
{
	ptp->defunct = 1;
	wake_up_interruptible(&ptp->tsev_wq);

	/* Release the clock's resources. */
	if (ptp->pps_source)
		pps_unregister_source(ptp->pps_source);
	ptp_cleanup_sysfs(ptp);
	device_destroy(ptp_class, ptp->devid);

	posix_clock_unregister(&ptp->clock);
	return 0;
}
EXPORT_SYMBOL(ptp_clock_unregister);

void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
{
	struct pps_event_time evt;

	switch (event->type) {

	case PTP_CLOCK_ALARM:
		break;

	case PTP_CLOCK_EXTTS:
		enqueue_external_timestamp(&ptp->tsevq, event);
		wake_up_interruptible(&ptp->tsev_wq);
		break;

	case PTP_CLOCK_PPS:
		pps_get_ts(&evt);
		pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
		break;

	case PTP_CLOCK_PPSUSR:
		pps_event(ptp->pps_source, &event->pps_times,
			  PTP_PPS_EVENT, NULL);
		break;
	}
}
EXPORT_SYMBOL(ptp_clock_event);

int ptp_clock_index(struct ptp_clock *ptp)
{
	return ptp->index;
}
EXPORT_SYMBOL(ptp_clock_index);

int ptp_find_pin(struct ptp_clock *ptp,
		 enum ptp_pin_function func, unsigned int chan)
{
	struct ptp_pin_desc *pin = NULL;
	int i;

	mutex_lock(&ptp->pincfg_mux);
	for (i = 0; i < ptp->info->n_pins; i++) {
		if (ptp->info->pin_config[i].func == func &&
		    ptp->info->pin_config[i].chan == chan) {
			pin = &ptp->info->pin_config[i];
			break;
		}
	}
	mutex_unlock(&ptp->pincfg_mux);

	return pin ? i : -1;
}
EXPORT_SYMBOL(ptp_find_pin);

/* module operations */

static void __exit ptp_exit(void)
{
	class_destroy(ptp_class);
	unregister_chrdev_region(ptp_devt, MINORMASK + 1);
	ida_destroy(&ptp_clocks_map);
}

static int __init ptp_init(void)
{
	int err;

	ptp_class = class_create(THIS_MODULE, "ptp");
	if (IS_ERR(ptp_class)) {
		pr_err("ptp: failed to allocate class\n");
		return PTR_ERR(ptp_class);
	}

	err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
	if (err < 0) {
		pr_err("ptp: failed to allocate device region\n");
		goto no_region;
	}

	ptp_class->dev_groups = ptp_groups;
	pr_info("PTP clock support registered\n");
	return 0;

no_region:
	class_destroy(ptp_class);
	return err;
}

subsys_initcall(ptp_init);
module_exit(ptp_exit);

MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
MODULE_DESCRIPTION("PTP clocks support");
MODULE_LICENSE("GPL");
Commit	Line	Data
d94ba80e RC	1	/*
	2	* PTP 1588 clock support
	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	*/
7356a764	20	#include <linux/idr.h>
d94ba80e RC	21	#include <linux/device.h>
	22	#include <linux/err.h>
	23	#include <linux/init.h>
	24	#include <linux/kernel.h>
	25	#include <linux/module.h>
	26	#include <linux/posix-clock.h>
	27	#include <linux/pps_kernel.h>
	28	#include <linux/slab.h>
	29	#include <linux/syscalls.h>
	30	#include <linux/uaccess.h>
	31
	32	#include "ptp_private.h"
	33
	34	#define PTP_MAX_ALARMS 4
d94ba80e RC	35	#define PTP_PPS_DEFAULTS (PPS_CAPTUREASSERT \| PPS_OFFSETASSERT)
	36	#define PTP_PPS_EVENT PPS_CAPTUREASSERT
	37	#define PTP_PPS_MODE (PTP_PPS_DEFAULTS \| PPS_CANWAIT \| PPS_TSFMT_TSPEC)
	38
	39	/* private globals */
	40
	41	static dev_t ptp_devt;
	42	static struct class *ptp_class;
	43
7356a764	44	static DEFINE_IDA(ptp_clocks_map);
d94ba80e RC	45
	46	/* time stamp event queue operations */
	47
	48	static inline int queue_free(struct timestamp_event_queue *q)
	49	{
	50	return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
	51	}
	52
	53	static void enqueue_external_timestamp(struct timestamp_event_queue *queue,
	54	struct ptp_clock_event *src)
	55	{
	56	struct ptp_extts_event *dst;
	57	unsigned long flags;
	58	s64 seconds;
	59	u32 remainder;
	60
	61	seconds = div_u64_rem(src->timestamp, 1000000000, &remainder);
	62
	63	spin_lock_irqsave(&queue->lock, flags);
	64
	65	dst = &queue->buf[queue->tail];
	66	dst->index = src->index;
	67	dst->t.sec = seconds;
	68	dst->t.nsec = remainder;
	69
	70	if (!queue_free(queue))
	71	queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
	72
	73	queue->tail = (queue->tail + 1) % PTP_MAX_TIMESTAMPS;
	74
	75	spin_unlock_irqrestore(&queue->lock, flags);
	76	}
	77
	78	static s32 scaled_ppm_to_ppb(long ppm)
	79	{
	80	/*
	81	* The 'freq' field in the 'struct timex' is in parts per
	82	* million, but with a 16 bit binary fractional field.
	83	*
	84	* We want to calculate
	85	*
	86	* ppb = scaled_ppm * 1000 / 2^16
	87	*
	88	* which simplifies to
	89	*
	90	* ppb = scaled_ppm * 125 / 2^13
	91	*/
	92	s64 ppb = 1 + ppm;
	93	ppb *= 125;
	94	ppb >>= 13;
	95	return (s32) ppb;
	96	}
	97
	98	/* posix clock implementation */
	99
	100	static int ptp_clock_getres(struct posix_clock pc, struct timespec tp)
	101	{
d68fb11c TG	102	tp->tv_sec = 0;
	103	tp->tv_nsec = 1;
	104	return 0;
d94ba80e RC	105	}
	106
	107	static int ptp_clock_settime(struct posix_clock pc, const struct timespec tp)
	108	{
	109	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
d7d38f5b RC	110	struct timespec64 ts = timespec_to_timespec64(*tp);
d7d38f5b RC	111
ed7c6317	112	return ptp->info->settime64(ptp->info, &ts);
d94ba80e RC	113	}
	114
	115	static int ptp_clock_gettime(struct posix_clock pc, struct timespec tp)
	116	{
	117	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
d7d38f5b RC	118	struct timespec64 ts;
	119	int err;
	120
ed7c6317 RC	121	err = ptp->info->gettime64(ptp->info, &ts);
	122	if (!err)
	123	*tp = timespec64_to_timespec(ts);
d7d38f5b	124	return err;
d94ba80e RC	125	}
	126
	127	static int ptp_clock_adjtime(struct posix_clock pc, struct timex tx)
	128	{
	129	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
	130	struct ptp_clock_info *ops;
	131	int err = -EOPNOTSUPP;
	132
	133	ops = ptp->info;
	134
	135	if (tx->modes & ADJ_SETOFFSET) {
	136	struct timespec ts;
	137	ktime_t kt;
	138	s64 delta;
	139
	140	ts.tv_sec = tx->time.tv_sec;
	141	ts.tv_nsec = tx->time.tv_usec;
	142
	143	if (!(tx->modes & ADJ_NANO))
	144	ts.tv_nsec *= 1000;
	145
	146	if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC)
	147	return -EINVAL;
	148
	149	kt = timespec_to_ktime(ts);
	150	delta = ktime_to_ns(kt);
	151	err = ops->adjtime(ops, delta);
d94ba80e	152	} else if (tx->modes & ADJ_FREQUENCY) {
d39a7435 RC	153	s32 ppb = scaled_ppm_to_ppb(tx->freq);
	154	if (ppb > ops->max_adj \|\| ppb < -ops->max_adj)
	155	return -ERANGE;
	156	err = ops->adjfreq(ops, ppb);
39a8cbd9	157	ptp->dialed_frequency = tx->freq;
5c35bad5 RC	158	} else if (tx->modes == 0) {
	159	tx->freq = ptp->dialed_frequency;
	160	err = 0;
d94ba80e RC	161	}
	162
	163	return err;
	164	}
	165
	166	static struct posix_clock_operations ptp_clock_ops = {
	167	.owner = THIS_MODULE,
	168	.clock_adjtime = ptp_clock_adjtime,
	169	.clock_gettime = ptp_clock_gettime,
	170	.clock_getres = ptp_clock_getres,
	171	.clock_settime = ptp_clock_settime,
	172	.ioctl = ptp_ioctl,
	173	.open = ptp_open,
	174	.poll = ptp_poll,
	175	.read = ptp_read,
	176	};
	177
	178	static void delete_ptp_clock(struct posix_clock *pc)
	179	{
	180	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
	181
	182	mutex_destroy(&ptp->tsevq_mux);
6092315d	183	mutex_destroy(&ptp->pincfg_mux);
7356a764	184	ida_simple_remove(&ptp_clocks_map, ptp->index);
d94ba80e RC	185	kfree(ptp);
	186	}
	187
	188	/* public interface */
	189
1ef76158 RC	190	struct ptp_clock ptp_clock_register(struct ptp_clock_info info,
1ef76158 RC	191	struct device *parent)
d94ba80e RC	192	{
	193	struct ptp_clock *ptp;
	194	int err = 0, index, major = MAJOR(ptp_devt);
	195
	196	if (info->n_alarm > PTP_MAX_ALARMS)
	197	return ERR_PTR(-EINVAL);
	198
d94ba80e RC	199	/* Initialize a clock structure. */
	200	err = -ENOMEM;
	201	ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
	202	if (ptp == NULL)
	203	goto no_memory;
	204
7356a764 JB	205	index = ida_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, GFP_KERNEL);
	206	if (index < 0) {
	207	err = index;
	208	goto no_slot;
	209	}
	210
d94ba80e RC	211	ptp->clock.ops = ptp_clock_ops;
	212	ptp->clock.release = delete_ptp_clock;
	213	ptp->info = info;
	214	ptp->devid = MKDEV(major, index);
	215	ptp->index = index;
	216	spin_lock_init(&ptp->tsevq.lock);
	217	mutex_init(&ptp->tsevq_mux);
6092315d	218	mutex_init(&ptp->pincfg_mux);
d94ba80e RC	219	init_waitqueue_head(&ptp->tsev_wq);
	220
	221	/* Create a new device in our class. */
1ef76158	222	ptp->dev = device_create(ptp_class, parent, ptp->devid, ptp,
d94ba80e RC	223	"ptp%d", ptp->index);
	224	if (IS_ERR(ptp->dev))
	225	goto no_device;
	226
	227	dev_set_drvdata(ptp->dev, ptp);
	228
	229	err = ptp_populate_sysfs(ptp);
	230	if (err)
	231	goto no_sysfs;
	232
	233	/* Register a new PPS source. */
	234	if (info->pps) {
	235	struct pps_source_info pps;
	236	memset(&pps, 0, sizeof(pps));
	237	snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
	238	pps.mode = PTP_PPS_MODE;
	239	pps.owner = info->owner;
	240	ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
	241	if (!ptp->pps_source) {
	242	pr_err("failed to register pps source\n");
	243	goto no_pps;
	244	}
	245	}
	246
	247	/* Create a posix clock. */
	248	err = posix_clock_register(&ptp->clock, ptp->devid);
	249	if (err) {
	250	pr_err("failed to create posix clock\n");
	251	goto no_clock;
	252	}
	253
d94ba80e RC	254	return ptp;
	255
	256	no_clock:
	257	if (ptp->pps_source)
	258	pps_unregister_source(ptp->pps_source);
	259	no_pps:
	260	ptp_cleanup_sysfs(ptp);
	261	no_sysfs:
	262	device_destroy(ptp_class, ptp->devid);
	263	no_device:
	264	mutex_destroy(&ptp->tsevq_mux);
6092315d	265	mutex_destroy(&ptp->pincfg_mux);
7356a764	266	no_slot:
d94ba80e RC	267	kfree(ptp);
d94ba80e RC	268	no_memory:
d94ba80e RC	269	return ERR_PTR(err);
	270	}
	271	EXPORT_SYMBOL(ptp_clock_register);
	272
	273	int ptp_clock_unregister(struct ptp_clock *ptp)
	274	{
	275	ptp->defunct = 1;
	276	wake_up_interruptible(&ptp->tsev_wq);
	277
	278	/* Release the clock's resources. */
	279	if (ptp->pps_source)
	280	pps_unregister_source(ptp->pps_source);
	281	ptp_cleanup_sysfs(ptp);
	282	device_destroy(ptp_class, ptp->devid);
	283
	284	posix_clock_unregister(&ptp->clock);
	285	return 0;
	286	}
	287	EXPORT_SYMBOL(ptp_clock_unregister);
	288
	289	void ptp_clock_event(struct ptp_clock ptp, struct ptp_clock_event event)
	290	{
	291	struct pps_event_time evt;
	292
	293	switch (event->type) {
	294
	295	case PTP_CLOCK_ALARM:
	296	break;
	297
	298	case PTP_CLOCK_EXTTS:
	299	enqueue_external_timestamp(&ptp->tsevq, event);
	300	wake_up_interruptible(&ptp->tsev_wq);
	301	break;
	302
	303	case PTP_CLOCK_PPS:
	304	pps_get_ts(&evt);
	305	pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
	306	break;
220a60a4 BH	307
	308	case PTP_CLOCK_PPSUSR:
	309	pps_event(ptp->pps_source, &event->pps_times,
	310	PTP_PPS_EVENT, NULL);
	311	break;
d94ba80e RC	312	}
	313	}
	314	EXPORT_SYMBOL(ptp_clock_event);
	315
995a9090 RC	316	int ptp_clock_index(struct ptp_clock *ptp)
	317	{
	318	return ptp->index;
	319	}
	320	EXPORT_SYMBOL(ptp_clock_index);
	321
6092315d RC	322	int ptp_find_pin(struct ptp_clock *ptp,
	323	enum ptp_pin_function func, unsigned int chan)
	324	{
	325	struct ptp_pin_desc *pin = NULL;
	326	int i;
	327
	328	mutex_lock(&ptp->pincfg_mux);
	329	for (i = 0; i < ptp->info->n_pins; i++) {
	330	if (ptp->info->pin_config[i].func == func &&
	331	ptp->info->pin_config[i].chan == chan) {
	332	pin = &ptp->info->pin_config[i];
	333	break;
	334	}
	335	}
	336	mutex_unlock(&ptp->pincfg_mux);
	337
	338	return pin ? i : -1;
	339	}
	340	EXPORT_SYMBOL(ptp_find_pin);
	341
d94ba80e RC	342	/* module operations */
	343
	344	static void __exit ptp_exit(void)
	345	{
	346	class_destroy(ptp_class);
7356a764 JB	347	unregister_chrdev_region(ptp_devt, MINORMASK + 1);
7356a764 JB	348	ida_destroy(&ptp_clocks_map);
d94ba80e RC	349	}
	350
	351	static int __init ptp_init(void)
	352	{
	353	int err;
	354
	355	ptp_class = class_create(THIS_MODULE, "ptp");
	356	if (IS_ERR(ptp_class)) {
	357	pr_err("ptp: failed to allocate class\n");
	358	return PTR_ERR(ptp_class);
	359	}
	360
7356a764	361	err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
d94ba80e RC	362	if (err < 0) {
	363	pr_err("ptp: failed to allocate device region\n");
	364	goto no_region;
	365	}
	366
3499116b	367	ptp_class->dev_groups = ptp_groups;
d94ba80e RC	368	pr_info("PTP clock support registered\n");
	369	return 0;
	370
	371	no_region:
	372	class_destroy(ptp_class);
	373	return err;
	374	}
	375
	376	subsys_initcall(ptp_init);
	377	module_exit(ptp_exit);
	378
c2ec3ff6	379	MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
d94ba80e RC	380	MODULE_DESCRIPTION("PTP clocks support");
d94ba80e RC	381	MODULE_LICENSE("GPL");