// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * PTP 1588 clock support - character device implementation.
   *
   * Copyright (C) 2010 OMICRON electronics GmbH

   */
  #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
  ", 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 *ptp = container_of(pc, struct ptp_clock, clock);

  	struct ptp_sys_offset_extended *extoff = NULL;

  	struct ptp_sys_offset_precise precise_offset;
  	struct system_device_crosststamp xtstamp;

  	struct ptp_clock_info *ops = ptp->info;

  	struct ptp_sys_offset *sysoff = NULL;

  	struct ptp_system_timestamp sts;

  	struct ptp_clock_request req;
  	struct ptp_clock_caps caps;

  	struct ptp_clock_time *pct;

  	unsigned int i, pin_index;
  	struct ptp_pin_desc pd;

  	struct timespec64 ts;

  	int enable, err = 0;
  
  	switch (cmd) {
  
  	case PTP_CLOCK_GETCAPS:

  	case PTP_CLOCK_GETCAPS2:

  		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;

  		caps.adjust_phase = ptp->info->adjphase != NULL;

  		if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
  			err = -EFAULT;

  		break;
  
  	case PTP_EXTTS_REQUEST:

  	case PTP_EXTTS_REQUEST2:
  		memset(&req, 0, sizeof(req));

  		if (copy_from_user(&req.extts, (void __user *)arg,
  				   sizeof(req.extts))) {
  			err = -EFAULT;
  			break;
  		}

  		if (cmd == PTP_EXTTS_REQUEST2) {

  			/* Tell the drivers to check the flags carefully. */
  			req.extts.flags |= PTP_STRICT_FLAGS;

  			/* Make sure no reserved bit is set. */
  			if ((req.extts.flags & ~PTP_EXTTS_VALID_FLAGS) ||
  			    req.extts.rsv[0] || req.extts.rsv[1]) {
  				err = -EINVAL;
  				break;
  			}
  			/* Ensure one of the rising/falling edge bits is set. */
  			if ((req.extts.flags & PTP_ENABLE_FEATURE) &&
  			    (req.extts.flags & PTP_EXTTS_EDGES) == 0) {
  				err = -EINVAL;
  				break;
  			}

  		} else if (cmd == PTP_EXTTS_REQUEST) {

  			req.extts.flags &= PTP_EXTTS_V1_VALID_FLAGS;

  			req.extts.rsv[0] = 0;
  			req.extts.rsv[1] = 0;
  		}

  		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;

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

  		err = ops->enable(ops, &req, enable);

  		mutex_unlock(&ptp->pincfg_mux);

  		break;
  
  	case PTP_PEROUT_REQUEST:

  	case PTP_PEROUT_REQUEST2:
  		memset(&req, 0, sizeof(req));

  		if (copy_from_user(&req.perout, (void __user *)arg,
  				   sizeof(req.perout))) {
  			err = -EFAULT;
  			break;
  		}

  		if (cmd == PTP_PEROUT_REQUEST2) {
  			struct ptp_perout_request *perout = &req.perout;
  
  			if (perout->flags & ~PTP_PEROUT_VALID_FLAGS) {
  				err = -EINVAL;
  				break;
  			}
  			/*
  			 * The "on" field has undefined meaning if
  			 * PTP_PEROUT_DUTY_CYCLE isn't set, we must still treat
  			 * it as reserved, which must be set to zero.
  			 */
  			if (!(perout->flags & PTP_PEROUT_DUTY_CYCLE) &&
  			    (perout->rsv[0] || perout->rsv[1] ||
  			     perout->rsv[2] || perout->rsv[3])) {
  				err = -EINVAL;
  				break;
  			}
  			if (perout->flags & PTP_PEROUT_DUTY_CYCLE) {
  				/* The duty cycle must be subunitary. */
  				if (perout->on.sec > perout->period.sec ||
  				    (perout->on.sec == perout->period.sec &&
  				     perout->on.nsec > perout->period.nsec)) {
  					err = -ERANGE;
  					break;
  				}
  			}

  			if (perout->flags & PTP_PEROUT_PHASE) {
  				/*
  				 * The phase should be specified modulo the
  				 * period, therefore anything equal or larger
  				 * than 1 period is invalid.
  				 */
  				if (perout->phase.sec > perout->period.sec ||
  				    (perout->phase.sec == perout->period.sec &&
  				     perout->phase.nsec >= perout->period.nsec)) {
  					err = -ERANGE;
  					break;
  				}
  			}

  		} else if (cmd == PTP_PEROUT_REQUEST) {

  			req.perout.flags &= PTP_PEROUT_V1_VALID_FLAGS;

  			req.perout.rsv[0] = 0;
  			req.perout.rsv[1] = 0;
  			req.perout.rsv[2] = 0;
  			req.perout.rsv[3] = 0;
  		}

  		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;

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

  		err = ops->enable(ops, &req, enable);

  		mutex_unlock(&ptp->pincfg_mux);

  		break;
  
  	case PTP_ENABLE_PPS:

  	case PTP_ENABLE_PPS2:
  		memset(&req, 0, sizeof(req));

  		if (!capable(CAP_SYS_TIME))
  			return -EPERM;
  		req.type = PTP_CLK_REQ_PPS;
  		enable = arg ? 1 : 0;

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

  		err = ops->enable(ops, &req, enable);

  		mutex_unlock(&ptp->pincfg_mux);

  		break;

  	case PTP_SYS_OFFSET_PRECISE:

  	case PTP_SYS_OFFSET_PRECISE2:

  		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_EXTENDED:

  	case PTP_SYS_OFFSET_EXTENDED2:

  		if (!ptp->info->gettimex64) {
  			err = -EOPNOTSUPP;
  			break;
  		}
  		extoff = memdup_user((void __user *)arg, sizeof(*extoff));
  		if (IS_ERR(extoff)) {
  			err = PTR_ERR(extoff);
  			extoff = NULL;
  			break;
  		}

  		if (extoff->n_samples > PTP_MAX_SAMPLES
  		    || extoff->rsv[0] || extoff->rsv[1] || extoff->rsv[2]) {

  			err = -EINVAL;
  			break;
  		}
  		for (i = 0; i < extoff->n_samples; i++) {
  			err = ptp->info->gettimex64(ptp->info, &ts, &sts);
  			if (err)
  				goto out;
  			extoff->ts[i][0].sec = sts.pre_ts.tv_sec;
  			extoff->ts[i][0].nsec = sts.pre_ts.tv_nsec;
  			extoff->ts[i][1].sec = ts.tv_sec;
  			extoff->ts[i][1].nsec = ts.tv_nsec;
  			extoff->ts[i][2].sec = sts.post_ts.tv_sec;
  			extoff->ts[i][2].nsec = sts.post_ts.tv_nsec;
  		}
  		if (copy_to_user((void __user *)arg, extoff, sizeof(*extoff)))
  			err = -EFAULT;
  		break;

  	case PTP_SYS_OFFSET:

  	case PTP_SYS_OFFSET2:

  		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++;

  			if (ops->gettimex64)
  				err = ops->gettimex64(ops, &ts, NULL);
  			else
  				err = ops->gettime64(ops, &ts);

  			if (err)
  				goto out;

  			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:

  	case PTP_PIN_GETFUNC2:

  		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
  			err = -EFAULT;
  			break;
  		}

  		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
  				|| pd.rsv[3] || pd.rsv[4])
  			&& cmd == PTP_PIN_GETFUNC2) {
  			err = -EINVAL;
  			break;
  		} else if (cmd == PTP_PIN_GETFUNC) {
  			pd.rsv[0] = 0;
  			pd.rsv[1] = 0;
  			pd.rsv[2] = 0;
  			pd.rsv[3] = 0;
  			pd.rsv[4] = 0;
  		}

  		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:

  	case PTP_PIN_SETFUNC2:

  		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
  			err = -EFAULT;
  			break;
  		}

  		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
  				|| pd.rsv[3] || pd.rsv[4])
  			&& cmd == PTP_PIN_SETFUNC2) {
  			err = -EINVAL;
  			break;
  		} else if (cmd == PTP_PIN_SETFUNC) {
  			pd.rsv[0] = 0;
  			pd.rsv[1] = 0;
  			pd.rsv[2] = 0;
  			pd.rsv[3] = 0;
  			pd.rsv[4] = 0;
  		}

  		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;
  	}

  out:

  	kfree(extoff);

  	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;

  }