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> 24 25 #include "ptp_private.h" 26 27 int ptp_open(struct posix_clock *pc, fmode_t fmode) 28 { 29 return 0; 30 } 31 32 long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) 33 { 34 struct ptp_clock_caps caps; 35 struct ptp_clock_request req; 36 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); 37 struct ptp_clock_info *ops = ptp->info; 38 int enable, err = 0; 39 40 switch (cmd) { 41 42 case PTP_CLOCK_GETCAPS: 43 memset(&caps, 0, sizeof(caps)); 44 caps.max_adj = ptp->info->max_adj; 45 caps.n_alarm = ptp->info->n_alarm; 46 caps.n_ext_ts = ptp->info->n_ext_ts; 47 caps.n_per_out = ptp->info->n_per_out; 48 caps.pps = ptp->info->pps; 49 if (copy_to_user((void __user *)arg, &caps, sizeof(caps))) 50 err = -EFAULT; 51 break; 52 53 case PTP_EXTTS_REQUEST: 54 if (copy_from_user(&req.extts, (void __user *)arg, 55 sizeof(req.extts))) { 56 err = -EFAULT; 57 break; 58 } 59 if (req.extts.index >= ops->n_ext_ts) { 60 err = -EINVAL; 61 break; 62 } 63 req.type = PTP_CLK_REQ_EXTTS; 64 enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0; 65 err = ops->enable(ops, &req, enable); 66 break; 67 68 case PTP_PEROUT_REQUEST: 69 if (copy_from_user(&req.perout, (void __user *)arg, 70 sizeof(req.perout))) { 71 err = -EFAULT; 72 break; 73 } 74 if (req.perout.index >= ops->n_per_out) { 75 err = -EINVAL; 76 break; 77 } 78 req.type = PTP_CLK_REQ_PEROUT; 79 enable = req.perout.period.sec || req.perout.period.nsec; 80 err = ops->enable(ops, &req, enable); 81 break; 82 83 case PTP_ENABLE_PPS: 84 if (!capable(CAP_SYS_TIME)) 85 return -EPERM; 86 req.type = PTP_CLK_REQ_PPS; 87 enable = arg ? 1 : 0; 88 err = ops->enable(ops, &req, enable); 89 break; 90 91 default: 92 err = -ENOTTY; 93 break; 94 } 95 return err; 96 } 97 98 unsigned int ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait) 99 { 100 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); 101 102 poll_wait(fp, &ptp->tsev_wq, wait); 103 104 return queue_cnt(&ptp->tsevq) ? POLLIN : 0; 105 } 106 107 ssize_t ptp_read(struct posix_clock *pc, 108 uint rdflags, char __user *buf, size_t cnt) 109 { 110 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); 111 struct timestamp_event_queue *queue = &ptp->tsevq; 112 struct ptp_extts_event event[PTP_BUF_TIMESTAMPS]; 113 unsigned long flags; 114 size_t qcnt, i; 115 116 if (cnt % sizeof(struct ptp_extts_event) != 0) 117 return -EINVAL; 118 119 if (cnt > sizeof(event)) 120 cnt = sizeof(event); 121 122 cnt = cnt / sizeof(struct ptp_extts_event); 123 124 if (mutex_lock_interruptible(&ptp->tsevq_mux)) 125 return -ERESTARTSYS; 126 127 if (wait_event_interruptible(ptp->tsev_wq, 128 ptp->defunct || queue_cnt(queue))) { 129 mutex_unlock(&ptp->tsevq_mux); 130 return -ERESTARTSYS; 131 } 132 133 if (ptp->defunct) { 134 mutex_unlock(&ptp->tsevq_mux); 135 return -ENODEV; 136 } 137 138 spin_lock_irqsave(&queue->lock, flags); 139 140 qcnt = queue_cnt(queue); 141 142 if (cnt > qcnt) 143 cnt = qcnt; 144 145 for (i = 0; i < cnt; i++) { 146 event[i] = queue->buf[queue->head]; 147 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS; 148 } 149 150 spin_unlock_irqrestore(&queue->lock, flags); 151 152 cnt = cnt * sizeof(struct ptp_extts_event); 153 154 mutex_unlock(&ptp->tsevq_mux); 155 156 if (copy_to_user(buf, event, cnt)) 157 return -EFAULT; 158 159 return cnt; 160 } 161