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
ptp_open(struct posix_clock * pc,fmode_t fmode)27 int ptp_open(struct posix_clock *pc, fmode_t fmode)
28 {
29 return 0;
30 }
31
ptp_ioctl(struct posix_clock * pc,unsigned int cmd,unsigned long arg)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
ptp_poll(struct posix_clock * pc,struct file * fp,poll_table * wait)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
ptp_read(struct posix_clock * pc,uint rdflags,char __user * buf,size_t cnt)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