drivers/ptp/ptp_chardev.c - linux - Git at Google

 /*
  * 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 <linux/nospec.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;
 		}
 		pin_index = array_index_nospec(pin_index, ops->n_pins);
 		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;
 		}
 		pin_index = array_index_nospec(pin_index, ops->n_pins);
 		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;
 }
	/*
	* 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 <linux/nospec.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;
	}
	pin_index = array_index_nospec(pin_index, ops->n_pins);
	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;
	}
	pin_index = array_index_nospec(pin_index, ops->n_pins);
	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;
	}